Sample records for male reproductive fitness
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Strauss, S Y; Conner, J K; Lehtilä, K P
2001-11-01
Generally, effects of herbivory on plant fitness have been measured in terms of female reproductive success (seed production). However, male plant fitness, defined as the number of seeds sired by pollen, contributes half of the genes to the next generation and is therefore crucial to the evolution of natural plant populations. This is the first study to examine effects of insect herbivory on both male and female plant reproductive success. Through controlled field and greenhouse experiments and genetic paternity analysis, we found that foliar damage by insects caused a range of responses by plants. In one environment, damaged plants had greater success as male parents than undamaged plants. Neither effects on pollen competitive ability nor pollinator visitation patterns could explain the greater siring success of these damaged plants. Success of damaged plants as male parents appeared to be due primarily to changes in allocation to flowers versus seeds after damage. Damaged plants produced more flowers early in the season, but not more seeds, than undamaged plants. Based on total seed production, male fitness measures from the first third of the season, and flower production, we estimated that damaged and undamaged plants had equal total reproductive success at the end of the season in this environment. In a second, richer environment, damaged and undamaged plants had equal male and female plant fitness, and no traits differed significantly between the treatments. Equal total reproductive success may not be ecologically or evolutionarily equivalent if it is achieved differentially through male versus female fitness. Genes from damaged plants dispersed through pollen may escape attack from herbivores, if such attack is correlated spatially from year to year.
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No intra-locus sexual conflict over reproductive fitness or ageing in field crickets.
Directory of Open Access Journals (Sweden)
Felix Zajitschek
2007-01-01
Full Text Available Differences in the ways in which males and females maximize evolutionary fitness can lead to intra-locus sexual conflict in which genes delivering fitness benefits to one sex are costly when expressed in the other. Trade-offs between current reproductive effort and future reproduction and survival are fundamental to the evolutionary biology of ageing. This leads to the prediction that sex differences in the optimization of age-dependent reproductive effort may generate intra-locus sexual conflict over ageing rates. Here we test for intra-locus sexual conflict over age-dependent reproductive effort and longevity in the black field cricket, Teleogryllus commodus. Using a half-sib breeding design, we show that the most important components of male and female reproductive effort (male calling effort and the number of eggs laid by females were positively genetically correlated, especially in early adulthood. However, the genetic relationships between longevity and reproductive effort were different for males and females, leading to low genetic covariation between male and female longevity. The apparent absence of intra-locus sexual conflict over ageing suggests that male and female longevity can evolve largely independently of one another.
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Canine tooth size and fitness in male mandrills (Mandrillus sphinx).
Leigh, Steven R; Setchell, Joanna M; Charpentier, Marie; Knapp, Leslie A; Wickings, E Jean
2008-07-01
Sexual selection theory explains the evolution of exaggerated male morphologies and weaponry, but the fitness consequences of developmental and age-related changes in these features remain poorly understood. This long-term study of mandrill monkeys (Mandrillus sphinx) demonstrates how age-related changes in canine tooth weaponry and adult canine size correlate closely with male lifetime reproductive success. Combining long-term demographic and morphometric data reveals that male fitness covaries simply and directly with canine ontogeny, adult maximum size, and wear. However, fitness is largely independent of other somatometrics. Male mandrills sire offspring almost exclusively when their canines exceed approximately 30 mm, or two-thirds of average adult value (45 mm). Moreover, sires have larger canines than nonsires. The tooth diminishes through wear as animals age, corresponding with, and perhaps influencing, reproductive senescence. These factors combine to constrain male reproductive opportunities to a brief timespan, defined by the period of maximum canine length. Sexually-selected weaponry, especially when it is nonrenewable like the primate canine tooth, is intimately tied to the male life course. Our analyses of this extremely dimorphic species indicate that sexual selection is closely intertwined with growth, development, and aging, pointing to new directions for sexual selection theory. Moreover, the primate canine tooth has potential as a simple mammalian system for testing genetically-based models of aging. Finally, the tooth may record details of life histories in fossil primates, especially when sexual selection has played a role in the evolution of dimorphism.
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Patterns of interventions and the effect of coalitions and sociality on male fitness.
Kulik, Lars; Muniz, Laura; Mundry, Roger; Widdig, Anja
2012-02-01
In group living animals, especially among primates, there is consistent evidence that high-ranking males gain a higher reproductive output than low-ranking males. Primate studies have shown that male coalitions and sociality can impact male fitness; however, it remains unclear whether males could potentially increase their fitness by preferentially supporting and socializing with females. Here we investigate patterns of male interventions and the effect of coalitions and sociality on male fitness in rhesus macaques (Macaca mulatta) with particular focus on male-female interactions. We combined behavioural observations collected on Cayo Santiago with genetic data analysed for male reproductive output and relatedness. Our results revealed that the ten top-ranking males provided the majority of all male support observed. In contrast to other primates, male rhesus macaques mainly formed all-down coalitions suggesting that coalitions are less likely used to enhance male dominance. Males supporting females during and before their likely conception were not more likely to fertilize those females. We also found no evidence that males preferably support their offspring or other close kin. Interestingly, the most important predictor of male support was sociality, since opponents sharing a higher sociality index with a given male were more likely to be supported. Furthermore, a high sociality index of a given male-female dyad resulted in a higher probability of paternity. Overall, our results strengthen the evidence that sociality affects fitness in male primates, but also suggest that in species in which males queue for dominance, it is less likely that males derive fitness benefits from coalitions. © 2011 Blackwell Publishing Ltd.
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Male Reproductive Toxicology: Environmental Exposures vs Reproductive Competence
Like the lecture this chapter begins with an overview of male reproductive biology and transitions into male reproductive toxicology. It ends with a brief discussion of the strengths and weaknesses in male reproductive toxicology and epidemiology today. This chapter is highly il...
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Kelly, N B; Alonzo, S H
2010-11-01
Recent theory predicted that male advertisement will reliably signal investment in paternal care in species where offspring survival requires paternal care and males allocate resources between advertisement and care. However, the predicted relationship between care and advertisement depended on the marginal gains from investment in current reproductive traits. Life history theory suggests that these fitness gains are also subject to a trade-off between current and future reproduction. Here, we investigate whether male signalling remains a reliable indicator of parental care when males allocate resources between current advertisement, paternal care and survival to future reproduction. We find that advertisement is predicted to remain a reliable signal of male care but that advertisement may cease to reliably indicate male quality because low-quality males are predicted to invest in current reproduction, whereas higher-quality males are able to invest in both current reproduction and survival to future reproduction. © 2010 The Authors. Journal Compilation © 2010 European Society For Evolutionary Biology.
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Solomon-Lane, Tessa K.; Pradhan, Devaleena S.; Willis, Madelyne C.; Grober, Matthew S.
2015-01-01
While individual variation in social behaviour is ubiquitous and causes social groups to differ in structure, how these structural differences affect fitness remains largely unknown. We used social network analysis of replicate bluebanded goby (Lythrypnus dalli) harems to identify the reproductive correlates of social network structure. In stable groups, we quantified agonistic behaviour, reproduction and steroid hormones, which can both affect and respond to social/reproductive cues. We identified distinct, optimal social structures associated with different reproductive measures. Male hatching success (HS) was negatively associated with agonistic reciprocity, a network structure that describes whether subordinates ‘reciprocated’ agonism received from dominants. Egg laying was associated with the individual network positions of the male and dominant female. Thus, males face a trade-off between promoting structures that facilitate egg laying versus HS. Whether this reproductive conflict is avoidable remains to be determined. We also identified different social and/or reproductive roles for 11-ketotestosterone, 17β-oestradiol and cortisol, suggesting that specific neuroendocrine mechanisms may underlie connections between network structure and fitness. This is one of the first investigations of the reproductive and neuroendocrine correlates of social behaviour and network structure in replicate, naturalistic social groups and supports network structure as an important target for natural selection. PMID:26156769
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... With the Male Reproductive System Print en español Sistema reproductor masculino Reproduction All living things reproduce. Reproduction — ... of Use Notice of Nondiscrimination Visit the Nemours Web site. Note: All information on KidsHealth® is for ...
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Differential fitness costs of reproduction between the sexes
Penn, Dustin J.; Smith, Ken R.
2006-01-01
Natural selection does not necessarily favor maximal reproduction because reproduction imposes fitness costs, reducing parental survival, and offspring quality. Here, we show that parents in a preindustrial population in North America incurred fitness costs from reproduction, and women incurred greater costs than men. We examined the survivorship and reproductive success (Darwinian fitness) of 21,684 couples married between 1860 and 1895 identified in the Utah Population Database. We found th...
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Walzer, Andreas; Schausberger, Peter
2014-04-01
The adaptive canalization hypothesis predicts that highly fitness-relevant traits are canalized via past selection, resulting in low phenotypic plasticity and high robustness to environmental stress. Accordingly, we hypothesized that the level of phenotypic plasticity of male body size of the predatory mites Phytoseiulus persimilis (low plasticity) and Neoseiulus californicus (high plasticity) reflects the effects of body size variation on fitness, especially male lifetime reproductive success (LRS). We first generated small and standard-sized males of P. persimilis and N. californicus by rearing them to adulthood under limited and ample prey supply, respectively. Then, adult small and standard-sized males were provided with surplus virgin females throughout life to assess their mating and reproductive traits. Small male body size did not affect male longevity or the number of fertilized females but reduced male LRS of P. persimilis but not N. californicus . Proximately, the lower LRS of small than standard-sized P. persimilis males correlated with shorter mating durations, probably decreasing the amount of transferred sperm. Ultimately, we suggest that male body size is more strongly canalized in P. persimilis than N. californicus because deviation from standard body size has larger detrimental fitness effects in P. persimilis than N. californicus .
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Hauber, Mark E; Lacey, Eileen A
2005-11-01
The sex-specific slopes of Bateman's gradients have important implications for understanding animal mating systems, including patterns of sexual selection and reproductive competition. Intersexual differences in the fitness benefits derived from mating with multiple partners are expected to yield distinct patterns of reproductive success for males and females, with variance in direct fitness predicted to be greater among males. These analyses assume that typically all adults are reproductive and that failure to produce offspring is non-adaptive. Among some species of cooperatively breeding birds and mammals, however, non-breeding adult alloparents are common and may comprise the majority of individuals in social groups. The presence of a large number of non-breeding adults, particularly when coupled with greater social suppression of reproduction among females, may alter the relative variance in direct fitness between the sexes, thereby generating an apparent contradiction to Bateman's Paradigm. To explore quantitatively the effects of non-breeding alloparents on variance in reproductive success, we used genetic estimates of parentage and reproductive success drawn from the literature to calculate the relative variability in direct fitness for females and males in alloparental and "other" societies of birds and mammals. Our analyses indicate that in mammals and, to a lesser extent, in birds, variability in direct fitness is greater among females in species characterized by the presence of non-breeding alloparents. These data suggest that social interactions, including social suppression of reproduction, are powerful determinants of individual direct fitness that may modify sex-specific patterns of reproductive variance from those described by Bateman.
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Directory of Open Access Journals (Sweden)
Anand Kumar
2014-01-01
Full Text Available Male reproduction is governed by the classical hypothalamo-hypophyseal testicular axis: Hypothalamic gonadotropin releasing hormone (GnRH, pituitary luteinizing hormone (LH and follicle stimulating hormone (FSH and the gonadal steroid, principally, testosterone. Thyroid hormones have been shown to exert a modulatory influence on this axis and consequently the sexual and spermatogenic function of man. This review will examine the modulatory influence of thyroid hormones on male reproduction.
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Variation in male reproductive longevity across traditional societies.
Directory of Open Access Journals (Sweden)
Lucio Vinicius
Full Text Available Most accounts of human life history propose that women have short reproductive spans relative to their adult lifespans, while men not only remain fertile but carry on reproducing until late life. Here we argue that studies have overlooked evidence for variation in male reproductive ageing across human populations. We apply a Bayesian approach to census data from Agta hunter-gatherers and Gambian farmers to show that long post-reproductive lifespans characterise not only women but also males in some traditional human populations. We calculate three indices of reproductive ageing in men (oldest age at reproduction, male late-life reproduction, and post-reproductive representation and identify a continuum of male reproductive longevity across eight traditional societies ranging from !Kung, Hadza and Agta hunter-gatherers exhibiting low levels of polygyny, early age at last reproduction and long post-reproductive lifespans, to male Gambian agriculturalists and Turkana pastoralists showing higher levels of polygyny, late-life reproduction and shorter post-reproductive lifespans. We conclude that the uniquely human detachment between rates of somatic senescence and reproductive decline, and the existence of post-reproductive lifespans, are features of both male and female life histories, and therefore not exclusive consequences of menopause.
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Directory of Open Access Journals (Sweden)
A. I. A. Pereira
Full Text Available Abstract Sexual choice by male stink bugs is important because females that experience food shortages lay fewer eggs with lower viability compared with well-fed females. In this study, we investigated whether Podisus nigrispinus (Dallas (Heteroptera: Pentatomidae males fed with a low-quality diet during its nymphal stage show selectivity for sexual partners resulting in high-quality progeny. Lightweight males and females were obtained from nymphs fed weekly with Tenebrio molitor L. (Coleoptera: Tenebrionidae pupae. By contrast, heavyweight males and females were fed three times a week and received an extra nutritional source: cotton leaves, Gossypium hirsutum L. (Malvaceae. Lightweight males preferred to mate with heavy females (77.78 ± 14.69%, whereas heavyweight males did not discriminated between light or heavyweight females. Females mated with lightweight males showed similar levels of reproduction to those mated with heavyweight males. The results provide an indication of the importance of male and female body weight for sexual selection in Asopinae stink bugs.
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Gene-environment interaction and male reproductive function
DEFF Research Database (Denmark)
Axelsson, Jonatan; Bonde, Jens Peter; Giwercman, Yvonne L
2010-01-01
As genetic factors can hardly explain the changes taking place during short time spans, environmental and lifestyle-related factors have been suggested as the causes of time-related deterioration of male reproductive function. However, considering the strong heterogeneity of male fecundity between...... that specific genotypes may confer a larger risk of male reproductive disorders following certain exposures. This paper presents a critical review of animal and human evidence on how genes may modify environmental effects on male reproductive function. Some examples have been found that support this mechanism...... of reproduction, namely environmental and lifestyle factors as the cause of sperm DNA damage. It remains to be investigated to what extent such genetic changes, by natural conception or through the use of assisted reproductive techniques, are transmitted to the next generation, thereby causing increased morbidity...
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Male reproductive health and environmental xenoestrogens
DEFF Research Database (Denmark)
Toppari, J; Larsen, J C; Christiansen, Peter
1996-01-01
that the adverse changes may be inter-related and have a common origin in fetal life or childhood. Exposure of the male fetus to supranormal levels of estrogens, such as diethlylstilbestrol, can result in the above-mentioned reproductive defects. The growing number of reports demonstrating that common......Male reproductive health has deteriorated in many countries during the last few decades. In the 1990s, declining semen quality has been reported from Belgium, Denmark, France, and Great Britain. The incidence of testicular cancer has increased during the same time incidences of hypospadias...... and cryptorchidism also appear to be increasing. Similar reproductive problems occur in many wildlife species. There are marked geographic differences in the prevalence of male reproductive disorders. While the reasons for these differences are currently unknown, both clinical and laboratory research suggest...
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Male reproductive health and environmental xenoestrogens
DEFF Research Database (Denmark)
Toppari, J; Larsen, J C; Christiansen, Peter
1996-01-01
Male reproductive health has deteriorated in many countries during the last few decades. In the 1990s, declining semen quality has been reported from Belgium, Denmark, France, and Great Britain. The incidence of testicular cancer has increased during the same time incidences of hypospadias...... and cryptorchidism also appear to be increasing. Similar reproductive problems occur in many wildlife species. There are marked geographic differences in the prevalence of male reproductive disorders. While the reasons for these differences are currently unknown, both clinical and laboratory research suggest...... that the adverse changes may be inter-related and have a common origin in fetal life or childhood. Exposure of the male fetus to supranormal levels of estrogens, such as diethlylstilbestrol, can result in the above-mentioned reproductive defects. The growing number of reports demonstrating that common...
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[The function of ERα in male reproductive system].
Dong, Yu-Hang; Wei, Jin-Hua; Li, Zhen
2014-12-01
Estrogen receptors (ERs), including two sub-types ERα and ERβ, belong to the steroid hormone superfamily of nuclear receptors. ERα distributes in the male reproductive system and plays a crucial role in the regulation of male reproduction through estrogen-dependent and -independent ways. In this article, we mainly reviewed the molecular structure, mode of action and location of ERα in the male reproductive system, and explored the mechanism of ERα in regulating the male reproductive system by analyzing different animal models of disrupted ERα.
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[Male sexual and reproductive rights].
Diaz, A M
1998-06-01
In late 1997, PROFAMILIA began a study of the role of male sexual and reproductive rights as part of the construction of new masculine identities. The work was approached from the disciplines of law and sociology. Patriarchy, as a system of domination, permeated most cultures, giving men a position of power in relation to women and leading to a series of violent and self-destructive male behaviors. The patriarchal system imposed aggressive, promiscuous, risky, and irresponsible behaviors on men, which created a climate for sexual abuse, unwanted pregnancy, propagation of sexually transmitted diseases, and violence against women. Changes in female roles have created the need for changes in male roles. The most visible sexual and reproductive needs of men were studied through literature reviews and semistructured questionnaires with PROFAMILIA clients. Among the needs identified were a new type of male participation in family and domestic life, a new content for male sexual freedom, greater participation of men in reproductive decisions and in raising their children, and new ways of relating to others and sharing feelings and emotions. The need to avoid behaviors that put health at risk was also identified. A review of the evolution of existing sexual and reproductive rights and of the documents that constitute their ethical and juridical framework led to the conclusion that the construction of new rights specifically for men is not necessary, or juridically possible, in the current historical context.
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Gene-environment interaction and male reproductive function
Axelsson, Jonatan; Bonde, Jens Peter; Giwercman, Yvonne L.; Rylander, Lars; Giwercman, Aleksander
2010-01-01
As genetic factors can hardly explain the changes taking place during short time spans, environmental and lifestyle-related factors have been suggested as the causes of time-related deterioration of male reproductive function. However, considering the strong heterogeneity of male fecundity between and within populations, genetic variants might be important determinants of the individual susceptibility to the adverse effects of environment or lifestyle. Although the possible mechanisms of such interplay in relation to the reproductive system are largely unknown, some recent studies have indicated that specific genotypes may confer a larger risk of male reproductive disorders following certain exposures. This paper presents a critical review of animal and human evidence on how genes may modify environmental effects on male reproductive function. Some examples have been found that support this mechanism, but the number of studies is still limited. This type of interaction studies may improve our understanding of normal physiology and help us to identify the risk factors to male reproductive malfunction. We also shortly discuss other aspects of gene-environment interaction specifically associated with the issue of reproduction, namely environmental and lifestyle factors as the cause of sperm DNA damage. It remains to be investigated to what extent such genetic changes, by natural conception or through the use of assisted reproductive techniques, are transmitted to the next generation, thereby causing increased morbidity in the offspring. PMID:20348940
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Male Reproductive Cancers and Infertility: A Mutual Relationship
Directory of Open Access Journals (Sweden)
Eva Tvrda
2015-03-01
Full Text Available Reproductive dysfunction and malignancies related to the male gender represent a serious health concern, whose incidence has significantly risen over the past years. Prior to treatment, testicular or prostate cancer patients often display poor semen characteristics similar to subfertile or infertile patients. This fact is underscored by cases where the malignancy is often diagnosed in males who undergo a general fertility screening. This review aims to examine the associations between male infertility and reproductive cancers focusing on common etiologies and biological mechanisms underlining these pathologies. Furthermore, we discuss compelling epidemiological data hypothesizing that male reproductive failure may act as a precursor of future andrological malignancies, including testicular or prostate cancer, thus providing a stimulus for a more specific research in male reproductive health and emphasizing the importance of this relation for physicians taking care of male patients with a reproductive disease.
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Gene-environment interaction and male reproductive function
DEFF Research Database (Denmark)
Axelsson, Jonatan; Bonde, Jens Peter; Giwercman, Yvonne L
2010-01-01
As genetic factors can hardly explain the changes taking place during short time spans, environmental and lifestyle-related factors have been suggested as the causes of time-related deterioration of male reproductive function. However, considering the strong heterogeneity of male fecundity between...... and within populations, genetic variants might be important determinants of the individual susceptibility to the adverse effects of environment or lifestyle. Although the possible mechanisms of such interplay in relation to the reproductive system are largely unknown, some recent studies have indicated...... that specific genotypes may confer a larger risk of male reproductive disorders following certain exposures. This paper presents a critical review of animal and human evidence on how genes may modify environmental effects on male reproductive function. Some examples have been found that support this mechanism...
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Male Reproductive System (For Teens)
... Affecting the Male Reproductive System Print en español Sistema reproductor masculino All living things reproduce. Reproduction — the ... of Use Notice of Nondiscrimination Visit the Nemours Web site. Note: All information on TeensHealth® is for ...
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Aging changes in the male reproductive system
... ency/article/004017.htm Aging changes in the male reproductive system To use the sharing features on this page, please enable JavaScript. Aging changes in the male reproductive system may include changes in testicular tissue, sperm production, ...
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Hurd, Hilary; Ardin, Richard
2003-01-01
During copulation, male insects pass accessory gland components to the female with the spermatophore. These gifts can affect female reproductive behaviour, ovulation and oviposition. Here, we show that female mealworm beetles, Tenebrio molitor, mated with males infected with metacestodes of the rat tapeworm, Hymenolepis diminuta, produced significantly more offspring than those mated with uninfected males. There is a significant positive relationship between parasite intensity in the male and reproductive output in the female. Infection results in a significant increase in bean-shaped accessory gland (BAG) size. We suggest that infected males pass superior nuptial gifts to females and discuss the confounding effects of infection in male and female beetles upon overall fitness costs of infection for the host and the likelihood that the parasite is manipulating host investment in reproduction. PMID:14667373
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Cross-Generational Reproductive Fitness Enforced by Microchimeric Maternal Cells.
Kinder, Jeremy M; Jiang, Tony T; Ertelt, James M; Xin, Lijun; Strong, Beverly S; Shaaban, Aimen F; Way, Sing Sing
2015-07-30
Exposure to maternal tissue during in utero development imprints tolerance to immunologically foreign non-inherited maternal antigens (NIMA) that persists into adulthood. The biological advantage of this tolerance, conserved across mammalian species, remains unclear. Here, we show maternal cells that establish microchimerism in female offspring during development promote systemic accumulation of immune suppressive regulatory T cells (Tregs) with NIMA specificity. NIMA-specific Tregs expand during pregnancies sired by males expressing alloantigens with overlapping NIMA specificity, thereby averting fetal wastage triggered by prenatal infection and non-infectious disruptions of fetal tolerance. Therefore, exposure to NIMA selectively enhances reproductive success in second-generation females carrying embryos with overlapping paternally inherited antigens. These findings demonstrate that genetic fitness, canonically thought to be restricted to Mendelian inheritance, is enhanced in female placental mammals through vertically transferred maternal cells that promote conservation of NIMA and enforce cross-generational reproductive benefits. Copyright © 2015 Elsevier Inc. All rights reserved.
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Zika Virus in the Male Reproductive Tract
Directory of Open Access Journals (Sweden)
Liesel Stassen
2018-04-01
Full Text Available Arthropod-borne viruses (arboviruses are resurging across the globe. Zika virus (ZIKV has caused significant concern in recent years because it can lead to congenital malformations in babies and Guillain-Barré syndrome in adults. Unlike other arboviruses, ZIKV can be sexually transmitted and may persist in the male reproductive tract. There is limited information regarding the impact of ZIKV on male reproductive health and fertility. Understanding the mechanisms that underlie persistent ZIKV infections in men is critical to developing effective vaccines and therapies. Mouse and macaque models have begun to unravel the pathogenesis of ZIKV infection in the male reproductive tract, with the testes and prostate gland implicated as potential reservoirs for persistent ZIKV infection. Here, we summarize current knowledge regarding the pathogenesis of ZIKV in the male reproductive tract, the development of animal models to study ZIKV infection at this site, and prospects for vaccines and therapeutics against persistent ZIKV infection.
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Wenseleers, Tom; Helanterä, Heikki; Alves, Denise A.; Dueñez-Guzmán, Edgar; Pamilo, Pekka
2013-01-01
The conflicts over sex allocation and male production in insect societies have long served as an important test bed for Hamilton's theory of inclusive fitness, but have for the most part been considered separately. Here, we develop new coevolutionary models to examine the interaction between these two conflicts and demonstrate that sex ratio and colony productivity costs of worker reproduction can lead to vastly different outcomes even in species that show no variation in their relatedness structure. Empirical data on worker-produced males in eight species of Melipona bees support the predictions from a model that takes into account the demographic details of colony growth and reproduction. Overall, these models contribute significantly to explaining behavioural variation that previous theories could not account for. PMID:24132088
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Seasonal variation in male alternative reproductive tactics.
Monroe, M J; Amundsen, T; Utne-Palm, A C; Mobley, K B
2016-12-01
Genetic parentage analyses reveal considerable diversity in alternative reproductive behaviours (e.g. sneaking) in many taxa. However, little is known about whether these behaviours vary seasonally and between populations. Here, we investigate seasonal variation in male reproductive behaviours in a population of two-spotted gobies (Gobiusculus flavescens) in Norway. Male two-spotted gobies guard nests, attract females and care for fertilized eggs. We collected clutches and nest-guarding males early and late in the breeding season in artificial nests and used microsatellite markers to reconstruct parentage from a subset of offspring from each nest. We hypothesized that mating, reproductive success and sneaking should be more prevalent early in the breeding season when competition for mates among males is predicted to be higher. However, parentage analyses revealed similar values of mating, reproductive success and high frequencies of successful sneaking early (30% of nests) and late (27% of nests) in the season. We also found that multiple females with eggs in the same nest were fertilized by one or more sneaker males, indicating that some males in this population engage in a satellite strategy. We contrast our results to previous work that demonstrates low levels of cuckoldry in a population in Sweden. Our results demonstrate marked stability in both the genetic mating system and male alternative reproductive tactics over the breeding season. However, sneaking rates may vary geographically within a species, likely due to local selection influencing ecological factors encountered at different locations. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.
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Effects of dietary vitamin E on male reproductive system
Directory of Open Access Journals (Sweden)
Muhammad Zubair
2017-01-01
Full Text Available Vitamin E is known as important antioxidant to protect the reproductive system. The free radicals are continuously produced in last few years due to metabolic and nutritional deficiencies. These free radicals are responsible for the production of oxidative stress in animal bodies. This production of extensive amount of oxidative stress caused the detrimental effects on the sperm and various other male parameters. This imbalance between the antioxidants and oxidative stress, leads to the condition of infertility in male. Antioxidants play an important role for eliminating of these free radicals. Vitamin E is one of the best antioxidants for the removal of oxidative stress in male reproductive system. Its use increases the reproductive functions and efficiency of male reproductive system. The deficiency of this vitamin leads to degeneration of germinal epithelium and Leydig cells in seminiferous tubules. The use of selenium and vitamin E has the synergistic effects on the male reproductive system. The objective of this review was to collect the beneficial roles of this vitamin along selenium on reproductive system of birds and different animals. This review will also collect the different doses along the beneficial roles on different parameters of male reproductive system.
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Systems Toxicology of Male Reproductive Development ...
Adverse trends in male reproductive health have been reported for increased rates of testicular germ cell tumor, low semen quality, cryptorchidism, and hypospadias. An association with prenatal environmental exposure has been inferred from human and animal studies underlying male reproductive developmental defects. The present study established the links between environmental chemicals, molecular targets, and adverse outcomes using U.S. EPA animal study (ToxRefDB) and high-throughput screening (ToxCast) databases. This systems-based approach revealed a phenotypic hierarchy across 63 chemicals and a pleiotropic in vitro bioactivity profile. Although estrogenic and anti-androgenic activities have been extensively studied in male reproductive developmental toxicity, the present study showed these receptor targets to be only a subset of the potential landscape of molecular targets. A variety of chemical (e.g. phthalates, conazoles, carbamates, and phenol compounds) and bioactivity (e.g. nuclear receptors, vascular remodeling proteins, and cytochrome-P450 reductases) clusters further suggested multiple pathways leading to the adverse outcomes. This points to the need for multi-scale systems models to predict whether the occurrence of one adverse outcome may predict the risk of another. Imbalances in androgen and estrogen signaling have been a general focus in male reproductive toxicology research. While a number of recent studies have demonstrated that both hormonal
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Mating with stressed males increases the fitness of ant queens.
Directory of Open Access Journals (Sweden)
Alexandra Schrempf
Full Text Available BACKGROUND: According to sexual conflict theory, males can increase their own fitness by transferring substances during copulation that increase the short-term fecundity of their mating partners at the cost of the future life expectancy and re-mating capability of the latter. In contrast, sexual cooperation is expected in social insects. Mating indeed positively affects life span and fecundity of young queens of the male-polymorphic ant Cardiocondyla obscurior, even though males neither provide nuptial gifts nor any other care but leave their mates immediately after copulation and die shortly thereafter. PRINCIPAL FINDINGS: Here, we show that mating with winged disperser males has a significantly stronger impact on life span and reproductive success of young queens of C. obscurior than mating with wingless fighter males. CONCLUSIONS: Winged males are reared mostly under stressful environmental conditions, which force young queens to disperse and found their own societies independently. In contrast, queens that mate with wingless males under favourable conditions usually start reproducing in the safety of the established maternal nest. Our study suggests that males of C. obscurior have evolved mechanisms to posthumously assist young queens during colony founding under adverse ecological conditions.
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Briscoe Runquist, Ryan D; Geber, Monica A; Pickett-Leonard, Michael; Moeller, David A
2017-05-01
Selection on floral traits in hermaphroditic plants is determined by both male and female reproductive success. However, predictions regarding floral trait and mating system evolution are often based solely on female fitness. Selection via male fitness has the potential to affect the outcomes of floral evolution. In this study, we used paternity analysis to assess individual selfing rates and selection on floral traits via male and female fitness in an experimental population of Clarkia xantiana where pollen limitation of seed set was strong. We detected selection through both female and male fitness with reinforcing or noninterfering patterns of selection through the two sex functions. For female fitness, selection favored reduced herkogamy and protandry, traits that promote increased autonomous selfing. For male fitness, selection on petal area was disruptive, with higher trait values conferring greater pollinator attraction and outcross siring success and smaller trait values leading to higher selfed siring success. Combining both female and male fitness, selection on petal area and protandry was disruptive because intermediate phenotypes were less successful as both males and females. Finally, functional relationships among male and female fertility components indicated that selfing resulted in seed discounting and pollen discounting. Under these functional relationships, the evolutionarily stable selfing rate can be intermediate or predominantly selfing or outcrossing, depending on the segregating load of deleterious mutations.
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Persistent organic pollutants and male reproductive health
DEFF Research Database (Denmark)
Vested, Anne; Giwercman, Aleksander; Bonde, Jens Peter
2014-01-01
development. An extensive number of epidemiological studies have addressed the possible effects of exposure to POPs on male reproductive health, but the results are conflicting. Thus far, most studies have focused on investigating exposure and the different reproductive health outcomes during adulthood. Some...... suggested adverse effects of exposure to these compounds on human reproductive health, which, according to the endocrine disrupter hypothesis, are ascribed to the compounds' potential to interfere with endocrine signaling, especially when exposure occurs during certain phases of fetal and childhood...... studies have addressed the potential harmful effects of fetal exposure with respect to malformations at birth and/or reproductive development, whereas only a few studies have been able to evaluate whether intrauterine exposure to POPs has long-term consequences for male reproductive health with measurable...
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[Mechanisms of electromagnetic radiation damaging male reproduction].
Xue, Lei; Chen, Hao-Yu; Wang, Shui-Ming
2012-08-01
More and more evidence from over 50 years of researches on the effects of electromagnetic radiation on male reproduction show that a certain dose of electromagnetic radiation obviously damages male reproduction, particularly the structure and function of spermatogenic cells. The mechanisms of the injury may be associated with energy dysmetabolism, lipid peroxidation, abnormal expressions of apoptosis-related genes and proteins, and DNA damage.
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Love, Oliver P.
2007-01-01
Managing reproductive investment within the scope of an individual’s energetic condition is required to maximize fitness. To be successful, individuals must make the correct decisions about when to reproduce, when to abandon an attempt, how many resources to invest in current and future attempts and where those resources should be allocated. These reproductive decisions therefore involve complex life-history trade-offs between an individual’s condition and current reproduction, future reprodu...
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Huang, Hong Lan; Zhang, Lu; Jia, Li Ming; Liang, Yue-Long; Cai, Jun Huo
2018-04-01
To examine the reproduction fitness coefficients and individual-level fitness of Toona ciliata var. pubescens, their sexual reproduction and natural regeneration were investigated during 2006-2016, with four natural populations in Jiulianshan National Reserve as test objects. The results showed that there were only 2-10 trees for the natural populations of T. ciliata var. pubescens with a small initial number of fruiting plants (3-9 trees), which were from the initial fruiting plants or their first/second generation. The sexual reproduction of these isolated populations were significantly different, and their seed production capacities tended to decline over time. With the maturing of communities, soil seed banks and seed germinations were extremely poor, and the number of trees that could be growing to mature stage was nearly zero. The optimum maturity age of T. ciliata var. pubescens was about 40 a, and the fitness coefficients (2.0-2.8) rapidly increased in early development stage, but then was sharply reduced (0.3-0.5), and then gradually dropped to almost 0. There were significant differences in the fitness at individual level (0-14 tree·cm -2 ) among different populations, but their values were low (close to zero). Based on the existing reproduction rate, the actual values of sexual reproduction and regeneration fitness were much lower than the predicted ones. Due to the low level of genetic fitness, the sexual reproductive ability of different populations all showed decreasing trends. The natural sexual regeneration ability tended to decline, while the fitness of T. ciliata var. pubescens further decreased. All those factors suggested higher investment risks. Therefore, the systems of sexual reproduction became unbalanced and deteriorating. We proposed that more studies, including breeding mating, pollination, seed setting, and genetic diversity evaluation, are needed. Moreover, we should provide suitable forest environment through cleaning up litter in the
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Alternative reproductive tactics and the propensity of hybridization.
Tynkkynen, K; Raatikainen, K J; Häkkilä, M; Haukilehto, E; Kotiaho, J S
2009-12-01
One explanation for hybridization between species is the fitness benefits it occasionally confers to the hybridizing individuals. This explanation is possible in species that have evolved alternative male reproductive tactics: individuals with inferior tactics might be more prone to hybridization provided it increases their reproductive success and fitness. Here we experimentally tested whether the propensity of hybridization in the wild depends on male reproductive tactic in Calopteryx splendens damselflies. Counter to our expectation, it was males adopting the superior reproductive tactic (territoriality) that had greatest propensity to hybridize than males adopting the inferior tactics (sneakers and floaters). Moreover, among the territorial males, the most ornamented males had greatest propensity to hybridize whereas the pattern was reversed in the sneaker males. Our results suggest that there is fluctuating selection on male mate discrimination against heterospecific females depending on both ornament size and the male's reproductive tactic.
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Endocrine control of epigenetic mechanisms in male reproduction.
Ankolkar, Mandar; Balasinor, N H
2016-01-01
Endocrine control of reproduction is very well known and has been echoed by many research groups. However, recent developments point to the ability of toxic endocrine disrupting chemicals (EDC) to alter epigenetic information of the gametes which gets transferred to the developing embryo and affects the immediate reproductive outcome or even persists transgenerationally. These epigenetic aberrations contribute to the ensuing pathophysiology of reproductive disorders. Investigations of the female in cases of poor reproductive outcome have been the main strategy towards diagnosis. However, despite the male partner contributing half of his genome to the progeny, thorough investigations in the male have been ignored. Environmental pollutants are all pervading and are encountered in our day-to-day life. Many of these pollutants have potential to disrupt the endocrine system. Here, we discuss how the male gametes (spermatozoa) are susceptible to a myriad of epigenetic insults inflicted by exposure to endocrine disruptors and how important is the contribution of the epigenetic marks of the spermatozoa in healthy reproduction. We advocate that sperm epigenetics should be considered as a significant contributor to reproductive health and should be researched further and be subsequently included in routine diagnostic workup in cases of poor reproductive outcome.
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Reproductive strategies in males of the world's southernmost lizards.
Fernández, Jimena B; Medina, Marlin; Kubisch, Erika L; Scolaro, José A; Ibargüengoytía, Nora R
2017-03-01
Reproductive and life history patterns in reptiles are tightly related to the environmental conditions, so male reproductive cycles have been historically characterized as continuous, for tropical lizards, or seasonal, for temperate lizards. However, males of Liolaemus and Phymaturus lizards (Liolaemidae), from cold temperate climates of high altitudes or latitudes in Argentina and Chile, have developed a variety of reproductive cycles to coordinate with the short female reproductive season and to deal with the low frequency of reproductive females in the population. Using gonadal histology and morphological analysis, we describe the male reproductive biology, fat storage and sexual dimorphism of the viviparous lizards Liolaemus sarmientoi and Liolaemus magellanicus that inhabit an austral grass steppe at 51°S, in the southern limit of the American continent. Males of L. sarmientoi and L. magellanicus are reproductively available during the entire activity season of approximately 5 months. In addition, males of both species exhibit greater body sizes than females in morphological variables relevant in sexual selection. Meanwhile, females of both species exhibit larger inter-limb length than conspecific males, which suggests fecundity selection to increase space for a larger litter size. The continuous sperm production throughout the activity season allows these liolaemids to mate at any time when females ovulate, representing a selective advantage to deal with the short activity season and the adversities of the cold environment they inhabit. © 2016 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.
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An Alien in the Group: Eusocial Male Bees Sharing Nonspecific Reproductive Aggregations
dos Santos, C. F.; Ferreira-Caliman, M. J.; Nascimento, F. S.
2015-01-01
Sexual selection predicts that individuals competing for access to sexual partners should maximize their chances of mating by looking for sites where the chances of finding partners are more likely to occur. However, males of stingless bees have been observed sharing nonspecific reproductive aggregations. This uncommon behavior appears to confer no obvious increase of individual fitness. It has been suggested that this reproductive strategy is due to the similarity between male odors common to different stingless bee species. Cuticular hydrocarbons (CHCs) are candidate odors of interest because their nonvolatile pheromone nature allows them to play an important role in sexual behavior and species recognition. Here, we review the literature to evaluate whether any phylogenetic patterns exist among male stingless bees that aggregate with closely or distantly related species. We also compared the CHC profiles of males of Neotropical stingless bee species (Plebeia sp. Schwarz, Trigona spinipes (F.), Tetragona clavipes (F.), Nannotrigona testaceicornis (Lepeletier), Scaptotrigona aff. depilis (Moure), Tetragonisca angustula (Latreille), and Melipona subnitida (Ducke) to reveal any chemical similarities among their male odors. We found males of 21 stingless bee species involved in interspecific interactions mainly from Neotropical and Indo-Malayan/Australasian regions. Alien males did not necessarily visit host aggregations of closely related species. Furthermore, the CHC profiles of different studied species were very distinct from each other and do not overlapped at all. It is unclear yet why this apparently nonadaptive behavior carried out by some stingless bee males. PMID:26518220
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Male reproductive competition in spawning aggregations of cod ( Gadus morhua , L.)
DEFF Research Database (Denmark)
Bekkevold, Dorte; Hansen, Michael Møller; Loeschcke, V.
2002-01-01
Reproductive competition may lead to a large skew in reproductive success among individuals. Very few studies have analysed the paternity contribution of individual males in spawning aggregations of fish species with huge census population sizes. We quantified the variance in male reproductive...... success in spawning aggregations of cod under experimental conditions over an entire spawning season. Male reproductive success was estimated by microsatellite-based parentage analysis of offspring produced in six separate groups of spawning cod. In total, 1340 offspring and 102 spawnings distributed...... across a spawning season were analysed. Our results show that multiple males contributed sperm to most spawnings but that paternity frequencies were highly skewed among males, with larger males on average siring higher proportions of offspring. It was further indicated that male reproductive success...
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Male reproductive health and yoga
Directory of Open Access Journals (Sweden)
Pallav Sengupta
2013-01-01
Full Text Available Now-a-days reproductive health problems along with infertility in male is very often observed. Various Assisted Reproductive Technologies have been introduced to solve the problem, but common people cannot afford the cost of such procedures. Various ayurvedic and other alternative medicines, along with regular yoga practice are proven to be not only effective to enhance the reproductive health in men to produce a successful pregnancy, but also to regulate sexual desire in men who practice celibacy. Yoga is reported to reduce stress and anxiety, improve autonomic functions by triggering neurohormonal mechanisms by the suppression of sympathetic activity, and even, today, several reports suggested regular yoga practice from childhood is beneficial for reproductive health. In this regard the present review is aimed to provide all the necessary information regarding the effectiveness of yoga practice to have a better reproductive health and to prevent infertility.
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Directory of Open Access Journals (Sweden)
Anuradhi Jayaweera
Full Text Available Strategic ejaculation is a behavioural strategy shown by many animals as a response to sperm competition and/or as a potential mechanism of cryptic male choice. Males invest more mating resources when the risk of sperm competition increases or they invest more in high quality females to maximize their reproductive output. We tested this hypothesis in the false garden mantid Pseudomantis albofimbriata, where females are capable of multiply mating and body condition is an indicator of potential reproductive fitness. We predicted male mantids would ejaculate strategically by allocating more sperm to high quality females. To determine if and how males alter their ejaculate in response to mate quality, we manipulated female food quantity so that females were either in good condition with many eggs (i.e. high quality or poor condition with few eggs (i.e. low quality. Half of the females from each treatment were used in mating trials in which transferred sperm was counted before fertilisation occurred and the other half of females were used in mating trials where fertilisation occurred and ootheca mass and total eggs in the ootheca were recorded. Opposed to our predictions, the total number of sperm and the proportion of viable sperm transferred did not vary significantly between female treatments. Male reproductive success was entirely dependent on female quality/fecundity, rather than on the number of sperm transferred. These results suggest that female quality is not a major factor influencing postcopulatory male mating strategies in P. albofimbriata, and that sperm number has little effect on male reproductive success in a single mating scenario.
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Reproductive toxicity: Male and female reproductive systems as targets for chemical injury
Energy Technology Data Exchange (ETDEWEB)
Mattison, D.R.; Plowchalk, D.R.; Meadows, M.J.; Al-Juburi, A.Z.; Gandy, J.; Malek, A. (Univ. of Arkansas for Medical Sciences, Little Rock (USA))
1990-03-01
On the basis of current knowledge of reproductive biology and toxicology, it is apparent that chemicals affecting reproduction may elicit their effects at a number of sites in both the male and the female reproductive system. This multiplicity of targets is attributable to the dynamic nature of the reproductive system, in which the hypothalamic-pituitary-gonadal axis is controlled by precise positive and negative feedback mechanisms among its components. Interference by a xenobiotic at any level in either the male or the female reproductive system may ultimately impair hypothalamic or pituitary function. Normal gonadal processes such as spermatogenesis or oogenesis, ejaculation or ovulation, hormone production by Leydig or granulosa cells, and the structure or function of the accessory reproductive structures (e.g., epididymis, fallopian tube) also appear vulnerable to xenobiotics. The reproductive system is a complex one that requires local and circulating hormones for control. This brief review illustrates a system for characterizing the mechanism of action of reproductive toxicants, as well as for defining the sites available for disruption of reproduction. Unfortunately, at present, data addressing the actual vulnerability of reproduction are sorely lacking. However, when experiments have been conducted and combined with epidemiologic data or clinical observation, it has been possible to demonstrate impairment of reproductive processes by xenobiotics. The role of environmental exposure to xenobiotics in the increase in infertility that has been observed remains to be defined. 87 references.
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Nugent, B M; Stiver, K A; Alonzo, S H; Hofmann, H A
2016-10-01
The molecular mechanisms underlying phenotypic plasticity are not well understood. Identifying mechanisms underlying alternative reproductive tactics (ARTs) in species for which the behavioural and fitness consequences of this variation are well characterized provides an opportunity to integrate evolutionary and mechanistic understanding of the maintenance of variation within populations. In the ocellated wrasse Symphodus ocellatus, the behavioural phenotypes of three distinct male morphs (sneakers, satellites and nesting males), which arise from a single genome, have been thoroughly characterized. To determine the neuroendocrine and genomic mechanisms associated with discrete phenotypic variation and ARTs in S. ocellatus in their natural environment, we constructed a whole-brain de novo transcriptome and compared global patterns of gene expression between sexes and male morphs. Next, we quantified circulating cortisol and 11-ketotestosterone (11-kt), mediators of male reproductive behaviours, as well as stress and gonadal steroid hormone receptor expression in the preoptic area, ventral subpallial division of the telencephalon and dorsolateral telencephalon, critical brain regions for social and reproductive behaviours. We found higher levels of 11-kt in nesting males and higher levels of cortisol in sneaker males relative to other male morphs and females. We also identified distinct patterns of brain region-specific hormone receptor expression between males such that most hormone receptors are more highly expressed in satellites and nesting males relative to sneakers and females. Our results establish the neuroendocrine and molecular mechanisms that underlie ARTs in the wild and provide a foundation for experimentally testing hypotheses about the relationship between neuromolecular processes and reproductive success. © 2016 John Wiley & Sons Ltd.
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Persistent organic pollutants and male reproductive health
Directory of Open Access Journals (Sweden)
Anne Vested
2014-02-01
Full Text Available Environmental contaminants such as persistent organic pollutants (POPs are man-made bioaccumulative compounds with long half-lives that are found throughout the world as a result of heavy use in a variety of consumer products during the twentieth century. Wildlife and animal studies have long suggested adverse effects of exposure to these compounds on human reproductive health, which, according to the endocrine disrupter hypothesis, are ascribed to the compounds' potential to interfere with endocrine signaling, especially when exposure occurs during certain phases of fetal and childhood development. An extensive number of epidemiological studies have addressed the possible effects of exposure to POPs on male reproductive health, but the results are conflicting. Thus far, most studies have focused on investigating exposure and the different reproductive health outcomes during adulthood. Some studies have addressed the potential harmful effects of fetal exposure with respect to malformations at birth and/or reproductive development, whereas only a few studies have been able to evaluate whether intrauterine exposure to POPs has long-term consequences for male reproductive health with measurable effects on semen quality markers and reproductive hormone levels in adulthood. Humans are not exposed to a single compound at a time, but rather, to a variety of different substances with potential divergent hormonal effects. Hence, how to best analyze epidemiological data on combined exposures remains a significant challenge. This review on POPs will focus on current knowledge regarding the potential effects of exposure to POPs during fetal and childhood life and during adulthood on male reproductive health, including a critical revision of the endocrine disruption hypothesis, a comment on pubertal development as part of reproductive development and a comment on how to account for combined exposures in epidemiological research.
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Hernandez-Jimenez, Armando; Rios-Cardenas, Oscar
2017-12-06
There is extensive morphological variation of male genitalia across animals with internal fertilization, even among closely related species. Most studies attempting to explain this extraordinary diversity have focused on processes that occur post-copula (e.g. sperm competition, cryptic female choice). Only a few studies have focused on the pre-copula process of female preference. In addition, the extent to which this variation could be associated with the use of different reproductive tactics has yet to be explored. Here, we show that female preference for male genitalia length in two livebearing fishes depends on the type of reproductive tactic of the males being evaluated as well as the body condition of the female. In a species where all males coax females to acquire matings (courters), females preferred males with short genitalia. In a species with genetically influenced alternative reproductive tactics (courter males that only court and produce courter sons, sneaker males that use the coercive tactic of sneak chase and produce sneaker sons), female preference depended on an interaction between male tactic and female condition: females in good condition preferred courter males with short genitalia, and sneaker males with long genitalia. Our results suggest that female preference for male traits favourable to their sons may be an important factor contributing to the diversification of male genitalia. Despite the contrasting selection for genitalia length that our female preference tests suggest, we found no significant differences in genitalia length between coaxing (courters) and coercive (sneakers) males. Our study represents a starting point to more clearly understand the role of alternative reproductive tactics and variation in female mate preference in the evolution of male genitalia. © 2017 The Author(s).
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Zhang, He; Rebke, Maren; Becker, Peter H; Bouwhuis, Sandra
2015-01-01
Reproductive value is an integrated measure of survival and reproduction fundamental to understanding life-history evolution and population dynamics, but little is known about intraspecific variation in reproductive value and factors explaining such variation, if any. By applying generalized additive mixed models to longitudinal individual-based data of the common tern Sterna hirundo, we estimated age-specific annual survival probability, breeding probability and reproductive performance, based on which we calculated age-specific reproductive values. We investigated effects of sex and recruitment age (RA) on each trait. We found age effects on all traits, with survival and breeding probability declining with age, while reproductive performance first improved with age before levelling off. We only found a very small, marginally significant, sex effect on survival probability, but evidence for decreasing age-specific breeding probability and reproductive performance with RA. As a result, males had slightly lower age-specific reproductive values than females, while birds of both sexes that recruited at the earliest ages of 2 and 3 years (i.e. 54% of the tern population) had somewhat higher fitness prospects than birds recruiting at later ages. While the RA effects on breeding probability and reproductive performance were statistically significant, these effects were not large enough to translate to significant effects on reproductive value. Age-specific reproductive values provided evidence for senescence, which came with fitness costs in a range of 17-21% for the sex-RA groups. Our study suggests that intraspecific variation in reproductive value may exist, but that, in the common tern, the differences are small. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.
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The male reproductive system - An overview of common problems.
Wijesinha, Sanjiva; Piterman, Leon; Kirby, Catherine N
2013-05-01
Many male reproductive system problems could be perceived as being embarrassing, which may be one of the reasons that they are often not identified in general practice. This article provides an overview of some common problems affecting the male reproductive system, and outlines current treatment options. Erectile dysfunction, premature ejaculation, loss of libido, testicular cancer and prostate disease may cause embarrassment to the patient and, occasionally, the general practitioner. We describe how patients affected by these conditions may present to general practice, and discuss the reasons why they may not present. We also discuss how GPs can overcome difficulties in identifying and dealing with their male patients suffering from male reproductive system issues.
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Energy Technology Data Exchange (ETDEWEB)
Schroeder, J.H.; Peters, K.
1988-09-01
Differential courtship activity of guppy males competing for the same females was used as a bioindicator for low concentrations of water-borne pollutants in a previous study. Patterns of male sexual activity were chosen because they determine reproductive success. The mean difference between courtship activities of two male competitors determines the relative fitness of the male in question. Accordingly, the decrease in mean differential courtship after exposure to aquatic contaminants was predicted to cause a corresponding change in the relative reproductive success. The present study completed the previous one by repeating the experiment with a 10% addition of wastewater drawn from the last clearing basin of a Munich purification plant this time using virgin (non-inseminated) females which were receptive to male courtship. The females subsequently were allowed to produce as many offspring as possible. The number of young guppies sired by individual male competitors could easily be traced by the use of sex-linked phenotypic color patterns as markers. The purpose of these two studies was to show that the quantification of sexual activities of male guppies is useful for monitoring environmental alterations which affect fitness characters.
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Bouwhuis, Sandra; Choquet, Remi; Sheldon, Ben C.; Verhulst, Simon
Longitudinal studies of senescence accumulate rapidly from natural populations. However, it is largely unknown whether different fitness components senesce in parallel, how reproductive and survival senescence contribute to declines in reproductive value, and how large the fitness cost of senescence
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Reproductive health of male radiographers
International Nuclear Information System (INIS)
Shakhatreh, Farouk M.
2001-01-01
To compare certain reproductive health problems reported in 2 groups of males, one of which was exposed to x-ray radiation (radiographers) and the other group that was not exposed to x-ray radiation. The reproductive health problems were miscarriage, congenital anomalies, still births and infertility. Two groups of men were selected (90 in each group). The first group consisted of radiographers and the other groups consisted of men not exposed to x-ray radiation. The 2 groups were matched for age and source. Relative risk, attributable risk percentage and level of significance were calculated. Incidence rate of reproductive health problems was increasing with the increase in duration of exposure to x-ray radiation ranging between 17% (for those exposed for 1-5 years) to 91% (for those exposed for more than 15 years). There were significant associations between exposure to radiation and miscarriage (relative risk = 1.67, attributable risk percentage = 40%), congenital anomalies (relative risk = 10, attributable risk percentage 90%), still birth (relative risk = 7, attributable risk percentage = 86%), and infertility (relative risk = 4.5, attributable risk = 78%). The incidence rates of reproductive health problems reported by male radiographers were significantly higher than that reported by the non exposed group and higher than the incidence rates reported in community-based studies in Jordan. The incidence rates of fetal death (miscarriage and stillbirth together) and infertility reported by our radiographers were higher than had been reported by the British radiographers. An immediate plan of action is needed to protect our radiographers. Further studies are needed in this field taking into account all extraneous variables that may affect the reproductive health of radiographers. (author)
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Antidiabetic therapies and male reproductive function: where do we stand?
Tavares, R S; Escada-Rebelo, S; Silva, A F; Sousa, M I; Ramalho-Santos, J; Amaral, S
2018-01-01
Diabetes mellitus has been increasing at alarming rates in recent years, thus jeopardizing human health worldwide. Several antidiabetic drugs have been introduced in the market to manage glycemic levels, and proven effective in avoiding, minimizing or preventing the appearance or development of diabetes mellitus-related complications. However, and despite the established association between such pathology and male reproductive dysfunction, the influence of these therapeutic interventions on such topics have been scarcely explored. Importantly, this pathology may contribute toward the global decline in male fertility, giving the increasing preponderance of diabetes mellitus in young men at their reproductive age. Therefore, it is mandatory that the reproductive health of diabetic individuals is maintained during the antidiabetic treatment. With this in mind, we have gathered the available information and made a critical analysis regarding the effects of several antidiabetic drugs on male reproductive function. Unlike insulin, which has a clear and fundamental role on male reproductive function, the other antidiabetic therapies' effects at this level seem incoherent. In fact, studies are highly controversial possibly due to the different experimental study approaches, which, in our opinion, suggests caution when it comes to prescribing such drugs to young diabetic patients. Overall, much is still to be determined and further studies are needed to clarify the safety of these antidiabetic strategies on male reproductive system. Aspects such as the effects of insulin levels variations, consequent of insulin therapy, as well as what will be the impact of the side effect hypoglycemia, common to several therapeutic strategies discussed, on the male reproductive system are still to be addressed. © 2018 Society for Reproduction and Fertility.
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Melatonin and male reproductive health: relevance of darkness and antioxidant properties.
Rocha, C S; Rato, L; Martins, A D; Alves, M G; Oliveira, P F
2015-01-01
The pineal hormone melatonin controls several physiological functions that reach far beyond the regulation of the circadian rhythm. Moreover, it can be produced in extra-pineal organs such as reproductive organs. The role of melatonin in the mammalian seasonal and circadian rhythm is well known. Nevertheless, its overall effect in male reproductive physiology remains largely unknown. Melatonin is a very powerful endogenous antioxidant that can also be exogenously taken safely. Interestingly, its antioxidant properties have been consistently reported to improve the male reproductive dysfunctions associated with pathological conditions and also with the exposure to toxicants. Nevertheless, the exact molecular mechanisms by which melatonin exerts its action in the male reproductive system remain a matter of debate. Herein, we propose to present an up-to-date overview of the melatonin effects in the male reproductive health and debate future directions to disclose possible sites of melatonin action in male reproductive system. We will discuss not only the role of melatonin during darkness and sleep but also the importance of the antioxidant properties of this hormone to male fertility. Since melatonin readily crosses the physiological barriers, such as the blood-testis barrier, and has a very low toxicity, it appears as an excellent candidate in the prevention and/or treatment of the multiple male reproductive dysfunctions associated with various pathologies.
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Effects of Ascorbic Acid on Reproductive Functions of Male Wistar ...
African Journals Online (AJOL)
Effects of Ascorbic Acid on Reproductive Functions of Male Wistar Rats Exposed to Nicotine. ... smoke, and its effects on male reproductive system and fertility are well documented. ... The drugs were orally administered for thirty-five days.
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Reproductive physiology of the male camelid.
Bravo, P W; Johnson, L W
1994-07-01
The physiology of reproduction with emphasis on endocrinology of llamas and alpacas is addressed. Information regarding male anatomy, puberty, testicular function, semen description, and sexual behavior is also included.
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Duplouy, Anne; Woestmann, Luisa; Gallego Zamorano, Juan; Saastamoinen, Marjo
2018-04-01
In butterflies, male reproductive success is highly related to the quality and the size of the spermatophore transferred to the female. The spermatophore is a capsule produced by the male during copulation, which in many species contains sperm in addition to a nuptial gift, and which is digested by the female after copulation. The nuptial gift may contribute to egg production and offspring quality, and in some cases also to female body maintenance. The production of the spermatophore, however, represents a cost for the male and, in polyandrous species, ejaculates are sometimes allocated adaptively across matings. Nonetheless, although the ecological factors affecting the reproductive success of female butterflies have been the topic of numerous studies, little information exists on the factors affecting males' contribution to reproduction, and the indirect impacts on female fecundity and fitness. We used the Glanville fritillary butterfly, Melitaea cinxia (Linnaeus, 1758) (Nymphalidae), in order to assess variation in male allocation to matings. In this species, smaller males produce smaller spermatophores, but variation in spermatophore size is not correlated with female reproductive success. We show that spermatophore size increases with male age at first mating, decreases with mating frequency and adult food-deprivation, and is not influenced by developmental food-limitation. The length of copulation period does not influence the spermatophore size nor influences the polyandrous mating behavior in this species. Male contribution to his spermatophore size is clearly influenced by his condition and adult-resource at the time of mating. Despite this variation, spermatophore size does not seem to have a direct impact on female reproductive output or mating behavior. © 2016 The Authors Insect Science published by Wiley Publishing Asia Pty Ltd on behalf of Institute of Zoology, Chinese Academy of Sciences.
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Johnson, N A; Wu, C I
1993-08-01
At least six regions of the X chromosome can cause male sterility when introgressed from Drosophila mauritiana into Drosophila simulans. In this article, we present the results of the other fitness effects caused by two X-linked regions that contain hybrid male sterility factors. In both regions, females that are heterozygous for an introgression with such a sterility factor produce substantially-fewer offspring than females heterozygous for an introgression that lacks the sterility factor. Thus, the hybrid male sterility factors, or other genes nearby, have substantial effects on female productivity. In contrast, hybrid male sterility factors have little or no effect on the relative viabilities of either sex. The evolutionary implications of these findings are discussed.
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Social regulation of male reproductive plasticity in an African cichlid fish.
Maruska, Karen P; Fernald, Russell D
2013-12-01
Social interactions with the outcome of a position in a dominance hierarchy can have profound effects on reproductive behavior and physiology, requiring animals to integrate environmental information with their internal physiological state; but how is salient information from the animal's dynamic social environment transformed into adaptive behavioral, physiological, and molecular-level changes? The African cichlid fish, Astatotilapia burtoni, is ideally suited to understand socially controlled reproductive plasticity because activity of the male reproductive (brain-pituitary-gonad) axis is tightly linked to social status. Males form hierarchies in which a small percentage of brightly colored dominant individuals have an active reproductive axis, defend territories, and spawn with females, while the remaining males are subordinate, drably colored, do not hold a territory, and have a suppressed reproductive system with minimal opportunities for spawning. These social phenotypes are plastic and quickly reversible, meaning that individual males may switch between dominant and subordinate status multiple times within a lifetime. Here, we review the rapid and remarkable plasticity that occurs along the entire reproductive axis when males rise in social rank, a transition that has important implications for the operational sex ratio of the population. When males rise in rank, transformations occur in the brain, pituitary, circulation, and testes over short time-scales (minutes to days). Changes are evident in overt behavior, as well as modifications at the physiological, cellular, and molecular levels that regulate reproductive capacity. Widespread changes triggered by a switch in rank highlight the significance of external social information in shaping internal physiology and reproductive competence.
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Paternal social experience affects male reproductive behaviour in ...
Indian Academy of Sciences (India)
[Dasgupta P., Halder S. and Nandy B. 2016 Paternal social experience affects male reproductive behaviour in Drosophila .... allowed to the competitor male to interact with the female. Following ... conditions including maternal environment.
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The transcriptome of Lutzomyia longipalpis (Diptera: Psychodidae) male reproductive organs.
Azevedo, Renata V D M; Dias, Denise B S; Bretãs, Jorge A C; Mazzoni, Camila J; Souza, Nataly A; Albano, Rodolpho M; Wagner, Glauber; Davila, Alberto M R; Peixoto, Alexandre A
2012-01-01
It has been suggested that genes involved in the reproductive biology of insect disease vectors are potential targets for future alternative methods of control. Little is known about the molecular biology of reproduction in phlebotomine sand flies and there is no information available concerning genes that are expressed in male reproductive organs of Lutzomyia longipalpis, the main vector of American visceral leishmaniasis and a species complex. We generated 2678 high quality ESTs ("Expressed Sequence Tags") of L. longipalpis male reproductive organs that were grouped in 1391 non-redundant sequences (1136 singlets and 255 clusters). BLAST analysis revealed that only 57% of these sequences share similarity with a L. longipalpis female EST database. Although no more than 36% of the non-redundant sequences showed similarity to protein sequences deposited in databases, more than half of them presented the best-match hits with mosquito genes. Gene ontology analysis identified subsets of genes involved in biological processes such as protein biosynthesis and DNA replication, which are probably associated with spermatogenesis. A number of non-redundant sequences were also identified as putative male reproductive gland proteins (mRGPs), also known as male accessory gland protein genes (Acps). The transcriptome analysis of L. longipalpis male reproductive organs is one step further in the study of the molecular basis of the reproductive biology of this important species complex. It has allowed the identification of genes potentially involved in spermatogenesis as well as putative mRGPs sequences, which have been studied in many insect species because of their effects on female post-mating behavior and physiology and their potential role in sexual selection and speciation. These data open a number of new avenues for further research in the molecular and evolutionary reproductive biology of sand flies.
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Male reproductive organs are at risk from environmental hazards
DEFF Research Database (Denmark)
Bonde, Jens Peter
2010-01-01
Male reproductive disorders that are of interest from an environmental point of view include sexual dysfunction, infertility, cryptorchidism, hypospadias and testicular cancer. Several reports suggest declining sperm counts and increase of these reproductive disorders in some areas during some time...... are the best documented risk factors for impaired male reproductive function and include physical exposures (radiant heat, ionizing radiation, high frequency electromagnetic radiation), chemical exposures (some solvents as carbon disulfide and ethylene glycol ethers, some pesticides as dibromochloropropane...... reproductive toxicants. New data show that environmental low-level exposure to biopersistent pollutants in the diet may pose a risk to people in all parts of the world. For other toxicants the evidence is only suggestive and further evaluation is needed before conclusions can be drawn. Whether compounds...
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Toxoplasma gondii decreases the reproductive fitness in mice
Czech Academy of Sciences Publication Activity Database
Dvořáková-Hortová, K.; Šídlová, A.; Děd, Lukáš; Hladovcová, D.; Vieweg, M.; Weidner, W.; Steger, K.; Stopka, P.; Paradowska-Dogan, A.
2014-01-01
Roč. 9, č. 6 (2014), s. 1-11 E-ISSN 1932-6203 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:86652036 Keywords : Toxoplasma gondii * reproductive fitness * DNA methylation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.234, year: 2014
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Neethling, Lourelle Alicia Martins; Avenant-Oldewage, Annemariè
2015-02-01
The morphology of the male reproductive system as well as sperm transfer in Branchiura has been described for Dolops ranarum and Argulus japonicus. In this study, the reproductive system and accessory structures are described for male Chonopeltis australis using histology, light microscopy, and scanning electron microscopy. For the first time, we describe sperm transfer by means of a spermatophore in this genus. The internal and external morphology and mechanism of sperm transfer is compared with other Branchiura, where it has been described. The morphology of the reproductive system of C. australis is similar to that of D. ranarum while the accessory structures and the spermatophore produced are similar to that of A. japonicus. A revision of the definition of Branchiura with respect to reproduction is provided. © 2014 Wiley Periodicals, Inc.
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Characterization of male reproductive anatomy of the endangered Arabian oryx (Oryx leucoryx).
Eljarah, A; Al-Zghoul, M B; Jawasreh, K; Ababneh, M; Alsumadi, M; Alhalah, A; Ismail, Z Bani
2012-07-01
Reproductive tracts of four male Arabian oryx (Oryx leucoryx) from Shaumari Nature Reserve in Jordan were examined to characterize their reproductive anatomy. Animals were allocated into two groups based on their age: Group 1 (n = 2, males were 12 and 14 mo old) and Group 2 (n = 2, males were 7 and 9 yrs old). Observations regarding the morphology, position and orientation of different reproductive organs were made. The external and internal genital organs of male oryx were similar to other domestic ruminant species with minor differences. Copyright © 2012 Elsevier Inc. All rights reserved.
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Male reproductive health and environmental xenoestrogens
DEFF Research Database (Denmark)
Toppari, J.; Larsen, John Christian; Christiansen, Pia
1996-01-01
environmental contaminants and natural factors possess estrogenic activity presents the working hypothesis that the adverse trends in male reproductive health may be, at least in part, associated with exposure to estrogenic or other hormonally active (e.g., antiandrogenic) environmental chemicals during fetal...
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A curvilinear effect of height on reproductive success in human males
Stulp, G.; Pollet, T.V.; Verhulst, S.; Buunk, A.P.
2012-01-01
Human male height is associated with mate choice and intra-sexual competition, and therefore potentially with reproductive success. A literature review (n = 18) on the relationship between male height and reproductive success revealed a variety of relationships ranging from negative to curvilinear
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A curvilinear effect of height on reproductive success in human males
Stulp, Gert; Pollet, Thomas V.; Verhulst, Simon; Buunk, Abraham P.
Human male height is associated with mate choice and intra-sexual competition, and therefore potentially with reproductive success. A literature review (n = 18) on the relationship between male height and reproductive success revealed a variety of relationships ranging from negative to curvilinear
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Prevalence of reproductive morbidity amongst males in an urban slum of north India
Directory of Open Access Journals (Sweden)
Uppal Y
2007-01-01
Full Text Available Background: Studies assessing the prevalence of reproductive morbidity among males in India have chiefly focused on prevalence of Reproductive Tract Infections/Sexually Transmitted Infections (RTIs/STIs among males attending Sexually Transmitted Disease clinics, blood donors and other selected population groups, with only few focused on the magnitude and the type of reproductive morbidity amongst Indian males at community level. Objective: To estimate prevalence of reproductive morbidity including (RTIs/STIs among males in the age group of 20-50 years residing in an urban slum of Delhi. Methods: Out of 268 males in the targeted age group, selected by systematic random sampling, residing in an urban sum of Delhi, 260 males were subjected to clinical examination and laboratory investigations for diagnosis of reproductive morbidity. Laboratory investigations were done for diagnosis of Hepatitis B and C, Syphilis, Gonorrhoea, Non gonococcal urethritis and urinary tract infection. Results: A total of 90 (33.6% of 268 study subjects reported one or more perceived symptoms of reproductive tract / sexual morbidity in last six months. Overall reproductive morbidity based on clinical and laboratory diagnosis was present in 76 (29.2% study subjects and of this sexually acquired morbidity accounted for 21.2% cases. Hepatitis B was most common (10.3% reproductive morbidity followed by Urinary Tract Infection (5.0%, scabies (3.5% and congenital anomalies (3.5%. Conclusion: High prevalence of reproductive morbidity (29.2% amongst males in an urban slum highlights the need for more studies in different settings. There is a need for developing interventions in terms of early diagnosis and treatment and prevention.
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Heat stress affects male reproduction in a parasitoid wasp.
Nguyen, Thanh Manh; Bressac, Christophe; Chevrier, Claude
2013-03-01
In insects, reproductive success and survival are affected by temperature. Reproduction is more sensitive than other physiological traits. While the effects of heat stress on females are well known, the effects on males are less clear. Hymenopteran parasitoids are valuable for studying the consequences of heat stress on male reproduction. In these species, through arrhenotoquous parthenogenesis, the sex ratio of the offspring is directly dependent on the sperm stock acquired by females during copulation. In the lab, heat temperature treatments (32-44°C) were applied for 3 days in the pupal stage of Anisopteromalus calandrae males, and development was completed at 30°C. Three different effects were observed depending on the temperature: mortality above 42°C, sterility of emerging males at 40°C, and sub-fertility at 38°C. This sub-fertility is characterized by a dramatic decrease in male sperm supplies, of up to 7% compared to control males. In the course of ageing, the sperm stock of sub-fertile males increases but never reaches the level of control males. Survival was significantly higher in control (30°C) males than those treated at 38°C. Male mating ability was similar whatever the treatment (control and 38°C), but females mated with 38°C-treated males stored 100 times less sperm on average than those mated with control males. The offspring sex ratio of females mated with 38°C-treated males was strongly male biased. The physiological mechanisms are as yet unknown. The relationship between temperature, sperm stock and sex ratio should be taken into account in the management of parasitoids for integrated pest management. Copyright © 2012 Elsevier Ltd. All rights reserved.
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REPRODUCTIVE SEASONALITY OF THE MALE FLORIDA GAR, LEPISOSTEUS PLATYRHINCUS.
The objective of this study was to characterize the reproductive seasonality of a wild population of male Florida gar, Lepisosteus platyrhincus. We measured the gonadosomatic index, reproductive stage of the testes, seminiferous tubule area, and plasma concentrations of testoster...
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Male rank affects reproductive success and offspring performance in bank voles.
Kruczek, Małgorzata; Zatorska, Magdalena
2008-07-05
Laboratory studies reveal that in several rodent species the females prefer dominant males as mating partners. Here we investigate the correlation between males' social rank and their reproductive success. Similar numbers of females mating with relatively more dominant or relatively more subordinate males produced a litter, and parturition took place 19-21 days after mating. Relatively more dominant males tended to sire more pups than did relatively more subordinates, but the mean number of offspring per litter did not differ significantly between the two groups. Significantly more pups fathered by relatively more dominant males survived to weaning than those sired by relatively more subordinate fathers. Dominance had a long-term effect on the reproductive activity of the offspring: their rate of sexual maturation was increased. In pups sired by a relatively more dominant father, the uteruses of females, and the testes and accessory sex glands of males, were significantly heavier than those of offspring born to relatively more subordinate males. Our results suggest that social rank is an important determinant of the reproductive success of bank vole males.
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Male reproductive health and environmental xenoestrogens
DEFF Research Database (Denmark)
Toppari, J; Larsen, J C; Christiansen, Peter
1996-01-01
Male reproductive health has deteriorated in many countries during the last few decades. In the 1990s, declining semen quality has been reported from Belgium, Denmark, France, and Great Britain. The incidence of testicular cancer has increased during the same time incidences of hypospadias and cr...
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Genetic variation of male reproductive success in a laboratory population of Anopheles gambiae
Directory of Open Access Journals (Sweden)
Voordouw Maarten J
2007-07-01
Full Text Available Abstract Background For Anopheline mosquitoes, the vectors of human malaria, genetic variation in male reproductive success can have important consequences for any control strategy based on the release of transgenic or sterile males. Methods A quantitative genetics approach was used to test whether there was a genetic component to variation in male reproductive success in a laboratory population of Anopheles gambiae. Swarms of full sibling brothers were mated with a fixed number of females and their reproductive success was measured as (1 proportion of ovipositing females, (2 proportion of ovipositing females that produced larvae, (3 proportion of females that produced larvae, (4 number of eggs laid per female, (5 number of larvae per ovipositing female and (6 number of larvae per female. Results The proportion of ovipositing females (trait 1 and the proportion of ovipositing females that produced larvae (trait 2 differed among full sib families, suggesting a genetic basis of mating success. In contrast, the other measures of male reproductive success showed little variation due to the full sib families, as their variation are probably mostly due to differences among females. While age at emergence and wing length of the males were also heritable, they were not associated with reproductive success. Larger females produced more eggs, but males did not prefer such partners. Conclusion The first study to quantify genetic variation for male reproductive success in A. gambiae found that while the initial stages of male reproduction (i.e. the proportion of ovipositing females and the proportion of ovipositing females that produced larvae had a genetic basis, the overall reproductive success (i.e. the mean number of larvae per female did not.
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Loehr, John; O'Hara, Robert B
2013-08-23
We investigated fitness, military rank and survival of facial phenotypes in large-scale warfare using 795 Finnish soldiers who fought in the Winter War (1939-1940). We measured facial width-to-height ratio-a trait known to predict aggressive behaviour in males-and assessed whether facial morphology could predict survival, lifetime reproductive success (LRS) and social status. We found no difference in survival along the phenotypic gradient, however, wider-faced individuals had greater LRS, but achieved a lower military rank.
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Relaxin family peptides in the male reproductive system--a critical appraisal.
Ivell, Richard; Kotula-Balak, Malgorzata; Glynn, Danielle; Heng, Kee; Anand-Ivell, Ravinder
2011-02-01
The human genome project has identified, besides ovarian relaxin (RLN), six other relaxin-like molecules (RLN3, H1-RLN, INSL3-6), most of which appear to be expressed in the testis and/or male reproductive system, together with four different G-protein-coupled receptors responsive to one or other of these peptides. Earlier work on relaxin in the male assumed the simplistic hypothesis of only a single relaxin-like entity. This review systematically examines the expression and physiology of relaxin-like molecules in the male reproductive system in order to reappraise the importance of this hormone system for male reproductive function. Although there are important species differences, only INSL3 and INSL6 appear to be generally expressed at a moderately high level within the testis, whereas ovarian RLN is consistently a major secretory product of the prostate epithelium. However, all members of this relaxin-like family appear to be expressed also at a low level in different organs of the male reproductive system, suggesting possible autocrine/paracrine effects. The four receptors (RXFP1-4) for these peptides are also expressed to differing levels in both somatic and seminiferous compartments of the testis and in the prostate, supporting relevant functions for most members of this interesting peptide family. Recent studies of relaxin family peptides in prostate pathology highlight their functional importance in the clinical context as potential causative, diagnostic and therapeutic agents and warrant more specific and detailed studies of their roles also in regard to male fertility and other aspects of male reproductive function.
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No effects of MRI scan on male reproduction hormones.
Møllerløkken, Ole J; Moen, Bente E; Baste, Valborg; Magerøy, Nils; Oftedal, Gunnhild; Neto, Emanuel; Ersland, Lars; Bjørge, Line; Torjesen, Peter A; Mild, Kjell Hansson
2012-08-01
Magnetic resonance imaging (MRI) is increasing around the world and the possible adverse effects on reproductive health of electromagnetic fields (EMFs) in MRI are not previously studied. A prospective randomized balanced cross-over study using a head scan in real MRI with whole-body transmitting coil and sham MRI among 24 healthy male volunteers was conducted. Serum-blood samples of inhibin B, testosterone, prolactine, thyreotropine, luteinizing hormone, follicle stimulating hormone, sex-hormone binding globuline and estradiol were taken before and after the different scans. Neither immediately after, nor after 11 days were there seen any differences in the hormone levels comparing real and sham MRI. The lack of effects of EMF on male reproductive hormones should be reassuring to the public and especially for men examined in MRI. Adverse effects on other endpoints than male reproduction or possible chronic effect of multiple MRI scans have not been investigated in this study. Copyright © 2012 Elsevier Inc. All rights reserved.
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Infanticide in tree squirrels - a male reproductive strategy?
African Journals Online (AJOL)
1986-07-25
Jul 25, 1986 ... ... of such behaviour. The interpretation of infant killing as a sexually selected male reproductive ... stones of the sexual selection hypothesis of infanticide. The ... of genetically based strain differences in the occurrence of infanticide in ... Aggression plays a prominent role in social behaviour, with both males.
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Gerald, Melissa S; Higley, Sue; Lussier, I sabelle D; Westergaard, Greg C; Suomi, Stephen J; Higley, J Dee
2002-01-01
In rhesus macaque males, lower than average cerebrospinal fluid (CSF) concentrations of the principle metabolite of serotonin, 5-hydroxyindoleacetic acid (5-HIAA), have been linked to impulsivity, involvement in escalated aggression, failure to elicit consort relationships, production of fewer sperm plugs, and a relatively early age of mortality. Given these potential fitness costs, we performed two studies aimed at elucidating the effects of CSF 5-HIAA on reproduction. Study 1 retrospectively evaluated over a four-year period, the relative reproductive outcome for pairs of adult male rhesus macaques (n = 15) who lived in social groups and who differed in concentrations of CSF 5-HIAA. Study 2 examined the relationship between CSF 5-HIAA and sperm motility and density (n = 12), as a potential mechanism for maintaining variability in CSF 5-HIAA. For Study 1, an average measure from two CSF 5-HIAA samples was calculated for the two males who were present during the time when conception most likely took place (offspring birth date -165 +/- 14 days). Within-pair comparisons of CSF 5-HIAA concentrations between the sire and the non-successful male were drawn for each of the 72 offspring in the study. We found that while sires were typically the male with relatively higher CSF 5-HIAA within the pair, there were no absolute differences in CSF 5-HIAA between males who sired at least one offspring (sires) and those who failed to reproduce (non-sires). Furthermore, while absolute age was not predictive of reproductive outcome, sires with relatively high CSF 5-HIAA also tended to be also relatively older than their competitors. By contrast, for the males with relatively low CSF 5-HIAA who reproduced, sires were relatively younger than the non-sires. These differences in reproductive outcome for males differing in CSF 5-HIAA could not be explained by variability in sperm quantity or quality as we did not find evidence of a relationship between CSF 5-HIAA and either sperm
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DEFF Research Database (Denmark)
Bekkevold, Dorte
2006-01-01
Estimates of Atlantic cod Gadus morhua reproductive success, determined using experimental spawning groups and genetic paternity assignment of offspring, showed that within-group variance in male size correlated positively with the degree of male mating skew, predicting a decrease in male reprodu...
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Fitness Consequences of Boldness in Juvenile and Adult Largemouth Bass.
Ballew, Nicholas G; Mittelbach, Gary G; Scribner, Kim T
2017-04-01
To date, most studies investigating the relationship between personality traits and fitness have focused on a single measure of fitness (such as survival) at a specific life stage. However, many personality traits likely have multiple effects on fitness, potentially operating across different functional contexts and stages of development. Here, we address the fitness consequences of boldness, under seminatural conditions, across life stages and functional contexts in largemouth bass (Micropterus salmoides). Specifically, we report the effect of boldness on (1) juvenile survivorship in an outdoor pond containing natural prey and predators and (2) adult reproductive success in three outdoor ponds across three reproductive seasons (years). Juvenile survival was negatively affected by boldness, with bolder juveniles having a lower probability of survival than shyer juveniles. In contrast, bolder adult male bass had greater reproductive success than their shyer male counterparts. Female reproductive success was not affected by boldness. These findings demonstrate that boldness can affect fitness differently across life stages. Further, boldness was highly consistent across years and significantly heritable, which suggests that boldness has a genetic component. Thus, our results support theory suggesting that fitness trade-offs across life stages may contribute to the maintenance of personality variation within populations.
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Characterization of a male reproductive transcriptome for Peromyscus eremicus (Cactus mouse
Directory of Open Access Journals (Sweden)
Lauren L. Kordonowy
2016-10-01
Full Text Available Rodents of the genus Peromyscus have become increasingly utilized models for investigations into adaptive biology. This genus is particularly powerful for research linking genetics with adaptive physiology or behaviors, and recent research has capitalized on the unique opportunities afforded by the ecological diversity of these rodents. Well characterized genomic and transcriptomic data is intrinsic to explorations of the genetic architecture responsible for ecological adaptations. Therefore, this study characterizes the transcriptome of three male reproductive tissues (testes, epididymis and vas deferens of Peromyscus eremicus (Cactus mouse, a desert specialist. The transcriptome assembly process was optimized in order to produce a high quality and substantially complete annotated transcriptome. This composite transcriptome was generated to characterize the expressed transcripts in the male reproductive tract of P. eremicus, which will serve as a crucial resource for future research investigating our hypothesis that the male Cactus mouse possesses an adaptive reproductive phenotype to mitigate water-loss from ejaculate. This study reports genes under positive selection in the male Cactus mouse reproductive transcriptome relative to transcriptomes from Peromyscus maniculatus (deer mouse and Mus musculus. Thus, this study expands upon existing genetic research in this species, and we provide a high quality transcriptome to enable further explorations of our proposed hypothesis for male Cactus mouse reproductive adaptations to minimize seminal fluid loss.
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A link between hypothyroidism, obesity and male reproduction.
Aiceles, Veronica; da Fonte Ramos, Cristiane
2016-01-01
Hypothyroidism is a condition in which the serum levels of thyroid hormones are below that necessary to carry out physiological functions in the body. Hypothyroidism is related to obesity as an increase in body weight gain is seen in hypothyroid patients. Moreover, an inverse correlation between free thyroxine values and body mass index has been reported. Leptin, a polypeptide hormone produced by adipocytes, was originally thought to be an antiobesity hormone due its anorexic effects on hypothalamic appetite regulation. However, nowadays it is known that leptin conveys information about the nutritional status to the brain being considered a crucial endocrine factor for regulating several physiological processes including reproduction. Since the identification of thyroid hormone and leptin receptors on the testes, these hormones are being recognized as having important roles in male reproductive functions. A clear link exists among thyroid hormones, leptin and reproduction. Both hormones can negatively affect spermatogenesis and consequently may cause male infertility. The World Health Organization (WHO) estimates the overall prevalence of primary infertility ranging from 8 to 15%. The fact that 30% of couples' inability to conceive is related to a male factor and that the longer hypothyroidism persisted, the greater the damage to the testes, strongly suggest that more studies attempting to clarify both hormones actions directly in the testes need to be conducted specially in cases of congenital hypothyroidism. Therefore, the goal of this review is to highlight the relationship of such hormones in the reproductive system.
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The impact of male overweight on semen quality and outcome of assisted reproduction
DEFF Research Database (Denmark)
Thomsen, Lise; Humaidan, Peter; Bungum, Leif
2014-01-01
It is well-documented that male overweight and obesity causes endocrine disorders that might diminish the male reproductive capacity; however, reports have been conflicting regarding the influence of male body mass index (BMI) on semen quality and the outcome of assisted reproductive technology...... (ART). The aim of this study was to investigate whether increased male BMI affects sperm quality and the outcome of assisted reproduction in couples with an overweight or obese man and a non-obese partner. Data was prospectively collected from 612 infertile couples undergoing ART at a Danish fertility...
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Factors that Influence Male Involvement in Sexual and Reproductive ...
African Journals Online (AJOL)
Erah
discuss matters of sexuality with his female children. This cultural belief not only protects men from discussing issues of reproductive health; it contributes to the general lack of male involvement in reproductive health. Although the majority of participants mentioned that most married men. (especially the older generation) ...
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Integrative data analysis of male reproductive disorders
DEFF Research Database (Denmark)
Edsgard, Stefan Daniel
of such data in conjunction with data from publicly available repositories. This thesis presents an introduction to disease genetics and molecular systems biology, followed by four studies that each provide detailed clues to the etiology of male reproductive disorders. Finally, a fifth study illustrates......-wide association data with respect to copy number variation and show that the aggregated effect of rare variants can influence the risk for testicular cancer. Paper V provides an example of the application of RNA-Seq for expression analysis of a species with an unsequenced genome. We analysed the plant...... of this thesis is the identification of the molecular basis of male reproductive disorders, with a special focus on testicular cancer. To this end, clinical samples were characterized by microarraybased transcription and genomic variation assays and molecular entities were identified by computational analysis...
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Directory of Open Access Journals (Sweden)
Luke T Barrett
Full Text Available Males pay considerable reproductive costs in acquiring mates (precopulatory sexual selection and in producing ejaculates that are effective at fertilising eggs in the presence of competing ejaculates (postcopulatory sexual selection. Given these costs, males must balance their reproductive investment in a given mating to optimise their future reproductive potential. Males are therefore expected to invest in reproduction prudently according to the likelihood of obtaining future matings. In this study we tested this prediction by determining whether male reproductive investment varies with expected future mating opportunities, which were experimentally manipulated by visually exposing male guppies (Poecilia reticulata to high or low numbers of females in the absence of competing males. Our experiment did not reveal consistent effects of perceived future mating opportunity on either precopulatory (male mate choice and mating behaviour or postcopulatory (sperm quality and quantity investment. However, we did find that male size and female availability interacted to influence mating behaviour; large males visually deprived of females during the treatment phase became more choosy and showed greater interest in their preferred female than those given continuous visual access to females. Overall, our results suggest males tailor pre- rather than postcopulatory traits according to local female availability, but critically, these effects depend on male size.
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Hybrid male sterility and genome-wide misexpression of male reproductive proteases.
Gomes, Suzanne; Civetta, Alberto
2015-07-06
Hybrid male sterility is a common barrier to gene flow between species. Previous studies have posited a link between misregulation of spermatogenesis genes in interspecies hybrids and sterility. However, in the absence of fully fertile control hybrids, it is impossible to differentiate between misregulation associated with sterility vs. fast male gene regulatory evolution. Here, we differentiate between these two possibilities using a D. pseudoobscura species pair that experiences unidirectional hybrid sterility. We identify genes uniquely misexpressed in sterile hybrid male reproductive tracts via RNA-seq. The sterile male hybrids had more misregulated and more over or under expressed genes relative to parental species than the fertile male hybrids. Proteases were the only gene ontology class overrepresented among uniquely misexpressed genes, with four located within a previously identified hybrid male sterility locus. This result highlights the potential role of a previously unexplored class of genes in interspecific hybrid male sterility and speciation.
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Multigeneration reproduction and male developmental toxicity studies on atrazine in rats.
DeSesso, John M; Scialli, Anthony R; White, Tacey E K; Breckenridge, Charles B
2014-06-01
Reproductive toxicity of Atrazine (ATR) was evaluated in two rat multigenerational studies. Development of male reproductive parameters was evaluated in separate studies after prenatal or postnatal exposure. In multigenerational studies, rats received dietary concentrations of 0, 10, 50, 100 or 500 ppm ATR. In separate studies in female rats, ATR was administered by gavage at 0, 1, 5, 25 or 125 mg/kg/day during pregnancy (GD6-21) or lactation (LD2-21). Plasma testosterone concentration, testicular and epididymal weights, and sperm counts were measured in male offspring on PND70 and 170. In the multigenerational studies, parental systemic toxicity occurred at 500 ppm (38.7 mg/kg/day), but reproductive endpoints were unaffected. In the prenatal study, maternal toxicity and embryo-fetal mortality occurred at 125 mg/kg/day. In male offspring, testosterone levels and sperm counts were unaffected, although the percentage of abnormal sperm increased at 125 mg/kg/day (PND 70) and 25 mg/kg/day (PND170). In the postnatal study, maternal toxicity and reduced body weights of male offspring occurred at 125 mg/kg/day. Additionally, reduced testicular (PND70, PND170) and epididymal (PND70) weights and increased numbers of abnormal sperm (PND70, PND170) were seen, but no changes in plasma testosterone or sperm counts. Dietary administration of ATR did not affect rat reproduction up to a parentally toxic dose of 38.7 mg/kg/day. Some effects on male reproductive system development occurred after high dose, bolus administration to dams, but doses were much higher than expected under normal use conditions. Thus, oral RfDs for ATR would be protective for reproductive effects. © 2014 Wiley Periodicals, Inc.
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Subtotal obstruction of the male reproductive tract
Pierik, F.H.; Dohle, G.R.; Roijen, J.H. van; Vreeburg, J.T.M.; Weber, R.F.A.
2003-01-01
Bilateral obstruction of the male reproductive tract is suspected in men with azoospermia, normal testicular volume and normal FSH. A testicular biopsy is required to differentiate between an obstruction and a testicular insufficiency. Unilateral or subtotal bilateral obstructions and epididymal
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Factors associated with male involvement in reproductive care in Bangladesh
Directory of Open Access Journals (Sweden)
Ghose Bishwajit
2017-01-01
Full Text Available Abstract Background Men’s active involvement in reproductive healthcare has shown to be positively associated with maternal and child health outcomes. Bangladesh has made appreciable progress in its pursuance of maternal mortality related goals in the framework of the MDGs. However, there remains a lot to be accomplished to realise the long-term goals for which active participation of male counterparts in reproductive care is crucial. Therefore, the objective of the present study was to investigate factors associated with male involvement in reproductive health among Bangladeshi men. Methods We used data from Bangladesh Demographic and Health Survey (BDHS conducted in 2011. Study participants were 1196 married men, aged between 15 and 69 years and living in both urban and rural households. Level of male involvement (outcome variable was measured based on the responses on knowledge, awareness and practice regarding reproductive health. Chi-square tests and multivariable logistic regression models were performed for data analysis. Results Out of 1196 participants, only 40% were found to be active about partners’ reproductive healthcare. Chi-square test showed significant association between active involvement and ever hearing about family planning (FP in television, learning about FP through community health events, community health workers and poster/billboard. Results from logistic regression analysis revealed that type of residency [p = 0.004, AOR = 0.666, 95% CI = 0.504–0.879], literacy [secondary/higher education- p = 0.006. AOR = 0.579, 95% CI = 0.165–0.509], learning about family planning from Newspaper [p < 0.001. AOR = 1.952, 95% CI = 1.429–2.664], and television [p = 0.017. AOR = 1.514 95% CI = 1.298–1.886], and having been communicated about family planning by community health workers [p = 0.017. AOR = 1.946, 95% CI = 1.129–3.356] were significantly associated
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Novel roles of Pkd2 in male reproductive system development
Nie, Xuguang; Arend, Lois J
2014-01-01
Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common inherited genetic diseases, caused by mutations in PKD1 and/ or PKD2. Infertility and reproductive tract abnormalities in male ADPKD patients are very common and have higher incidence than in the general population. In this work, we reveal novel roles of Pkd2 for male reproductive system development. Disruption of Pkd2 caused dilation of mesonephric tubules/efferent ducts, failure of epididymal coiling, and defecti...
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Rock Sparrow Song Reflects Male Age and Reproductive Success
DEFF Research Database (Denmark)
Nemeth, Erwin; Kempenaers, Bart; Matessi, Giuliano
2012-01-01
The evolution of mating signals is closely linked to sexual selection. Acoustic ornaments are often used as secondary sexual traits that signal the quality of the signaller. Here we show that song performance reflects age and reproductive success in the rock sparrow (Petronia petronia...... nests. Older males could be distinguished from yearlings by singing at lower rate and higher amplitudes. Our findings suggest that song rate may be used as a signal of age and together with song pitch as a signal of reproductive success in this species. Alternatively, younger and less successful males...... success. Males with higher breeding success sang at a lower rate and with a higher maximum frequency. We found also that older males gained more extra-pair young and had a higher overall breeding success, although they also differed almost significantly by having a higher loss of paternity in their own...
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Deterioration of male reproductive functions in hyperprolactinaemia
A. Kooy (Adriaan)
1990-01-01
textabstractSince the early seventies, chronic hyperPRLaemia due to hypothalamic-pituitary disorders, drug abuse, hypothyroidism or other causes, has been recognized as a cause of reproductive dysfunctions in both women and men. Possible mechanisms by which PRL exerts its effects on male
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Imaging the male reproductive tract: current trends and future directions.
Futterer, J.J.; Heijmink, S.W.T.P.J.; Spermon, J.R.
2008-01-01
The male reproductive system encompasses several organs: the testes, ejaculatory ducts, seminal vesicles, prostate, and penis. The function of this system is to accomplish reproduction. Diagnostic imaging modalities, such as ultrasound, CT, MR imaging, and positron emission tomography (PET), are
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Effects of aging on the male reproductive system.
Gunes, Sezgin; Hekim, Gulgez Neslihan Taskurt; Arslan, Mehmet Alper; Asci, Ramazan
2016-04-01
The study aims to discuss the effects of aging on the male reproductive system. A systematic review was performed using PubMed from 1980 to 2014. Aging is a natural process comprising of irreversible changes due to a myriad of endogenous and environmental factors at the level of all organs and systems. In modern life, as more couples choose to postpone having a child due to various socioeconomic reasons, research for understanding the effects of aging on the reproductive system has gained an increased importance. Paternal aging also causes genetic and epigenetic changes in spermatozoa, which impair male reproductive functions through their adverse effects on sperm quality and count as, well as, on sexual organs and the hypothalamic-pituitary-gonadal axis. Hormone production, spermatogenesis, and testes undergo changes as a man ages. These small changes lead to decrease in both the quality and quantity of spermatozoa. The offspring of older fathers show high prevalence of genetic abnormalities, childhood cancers, and several neuropsychiatric disorders. In addition, the latest advances in assisted reproductive techniques give older men a chance to have a child even with poor semen parameters. Further studies should investigate the onset of gonadal senesce and its effects on aging men.
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Chandramouli, Kondethimmanahalli; Reish, Donald; Zhang, Huoming; Qian, Pei-Yuan; Ravasi, Timothy
2015-01-01
The polychaetous annelid Neanthes acuminata complex has a widespread distribution, with the California population referred to as N. arenaceodentata. The reproductive pattern in this complex is unique, in that the female reproduces once and then dies, whereas the male can reproduce up to nine times. The male incubates the embryos until the larvae leave the male’s tube 21–28 days later and commences feeding. Reproductive success and protein expression patterns were measured over the nine reproductive periods. The percent success of the male in producing juveniles increased during the first three reproductive periods and then decreased, but the number of juveniles produced was similar through all nine periods. iTRAQ based quantitative proteomics were used to analyze the dynamics of protein expression patterns. The expression patterns of several proteins were found to be altered. The abundant expression of muscular and contractile proteins may have affected body weight and reproductive success. Sperm have never been observed; fertilization occurs within the parent’s tube. Proteins associated with sperm maturation and fertilization were identified, including ATPase, clathrin, peroxiredoxins and enolase, which may provide clues to the molecular mechanisms enabling males to reproduce multiple times.
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Chandramouli, Kondethimmanahalli
2015-09-04
The polychaetous annelid Neanthes acuminata complex has a widespread distribution, with the California population referred to as N. arenaceodentata. The reproductive pattern in this complex is unique, in that the female reproduces once and then dies, whereas the male can reproduce up to nine times. The male incubates the embryos until the larvae leave the male’s tube 21–28 days later and commences feeding. Reproductive success and protein expression patterns were measured over the nine reproductive periods. The percent success of the male in producing juveniles increased during the first three reproductive periods and then decreased, but the number of juveniles produced was similar through all nine periods. iTRAQ based quantitative proteomics were used to analyze the dynamics of protein expression patterns. The expression patterns of several proteins were found to be altered. The abundant expression of muscular and contractile proteins may have affected body weight and reproductive success. Sperm have never been observed; fertilization occurs within the parent’s tube. Proteins associated with sperm maturation and fertilization were identified, including ATPase, clathrin, peroxiredoxins and enolase, which may provide clues to the molecular mechanisms enabling males to reproduce multiple times.
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Sex recombination, and reproductive fitness: an experimental study using Paramecium
Energy Technology Data Exchange (ETDEWEB)
Nyberg, D.
1982-08-01
The effect of sex and recombination on reproductive fitness are measured using five wild stocks of Paramecium primaurelia. Among the wild stocks there were highly significant differences in growth rates. No hybrid had as low a fitness as the least fit parental stock. Recombination produced genotypes of higher fitness than those of either parent only in the cross between the two stocks of lowest fitness. The increase in variance of fitness as a result of recombination was almost exclusively attributable to the generation lines with low fitness. The fitness consequences of sexuality and mate choice were stock specific; some individuals leaving the most descendants by inbreeding, others by outcrossing. For most crosses the short-term advantage of sex, if any, accrue from the fusion of different gametes (hybrid vigor) and not from recombination. Since the homozygous genotype with the highest fitnes left the most progeny by inbreeding (no recombination), the persistence of conjugation in P. primaurelia is paradoxical. (JMT)
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Group management influences reproductive function of the male cheetah (Acinonyx jubatus).
Koester, Diana C; Freeman, Elizabeth W; Wildt, David E; Terrell, Kimberly A; Franklin, Ashley D; Meeks, Karen; Crosier, Adrienne E
2017-03-01
Although the free-ranging cheetah is generally socially solitary, as many as 60% of males live in same-sex (usually sibling) coalitions. Under ex situ conditions, the cheetah experiences low reproductive success with only ~18% of males having ever produced young. Most male cheetahs (85%) are managed in captivity in coalitions, but with no data on the influence of social grouping on reproductive parameters. We examined the influence of singleton versus coalition management on various male cheetah physiological traits, including ejaculate quality and gonadal and adrenal hormone metabolite concentrations. We also assessed behaviour within coalitions for evidence of social hierarchy through initiation of interactions with group mates and relatedness to physiological traits. Ejaculate quality (including total motile and structurally normal spermatozoa per ejaculate) and androgen concentration profiles were higher (Pcheetah, specifically related to the development of normal, motile spermatozoa and androgen production, is influenced by management with same-sex conspecifics. The findings have implications for ex situ conservation breeding programs by suggesting that reproductive quality can be enhanced through group maintenance of cheetah males.
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Lavania, Umesh C; Basu, Surochita; Kushwaha, Jyotsana Singh; Lavania, Seshu
2014-09-01
Environmental stress in plants impacts many biological processes, including male gametogenesis, and affects several cytological mechanisms that are strongly interrelated. To understand the likely impact of rising temperature on reproductive fitness in the climate change regime, a study of tapetal mitosis and its accompanying meiosis over seasons was made to elucidate the influence of temperature change on the cytological events occurring during microsporogenesis. For this we used two species of an environmentally sensitive plant system, i.e., genus Cymbopogon Sprengel (Poaceae), namely Cymbopogon nardus (L.) Rendle var. confertiflorus (Steud.) Bor (2n = 20) and Cymbopogon jwaruncusha (Jones) Schult. (2n = 20). Both species flower profusely during extreme summer (48 °C) and mild winter (15 °C) but support low and high seed fertility, respectively, in the two seasons. We have shown that tapetal mitotic patterns over seasons entail differential behavior for tapetal mitosis. During the process of tapetum development there are episodes of endomitosis that form either (i) an endopolyploid genomically imbalanced uninucleate and multinucleate tapetum, and (or) (ii) an acytokinetic multinucleate genomically balanced tapetum, with the progression of meiosis in the accompanying sporogenous tissue. The relative frequency of occurrence of the two types of tapetum mitosis patterns is significantly different in the two seasons, and it is found to be correlated with the temperature conditions. Whereas, the former (genomically imbalanced tapetum) are prevalent during the hot summer, the latter (genomically balanced tapetum) are frequent under optimal conditions. Such a differential behaviour in tapetal mitosis vis-à-vis temperature change is also correspondingly accompanied by substantial disturbances or regularity in meiotic anaphase disjunction. Both species show similar patterns. The study underpins that tapetal mitotic behaviour per se could be a reasonable indicator to
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Directory of Open Access Journals (Sweden)
Guillaume J M Laugier
Full Text Available Reproductive strategy affects population dynamics and genetic parameters that can, in turn, affect evolutionary processes during the course of biological invasion. Life-history traits associated with reproductive strategy are therefore potentially good candidates for rapid evolutionary shifts during invasions. In a series of mating trials, we examined mixed groups of four males from invasive and native populations of the harlequin ladybird Harmonia axyridis mating freely during 48 hours with one female of either type. We recorded the identity of the first male to copulate and after the 48 h-period, we examined female fecundity and share of paternity, using molecular markers. We found that invasive populations have a different profile of male and female reproductive output. Males from invasive populations are more likely to mate first and gain a higher proportion of offspring with both invasive and native females. Females from invasive populations reproduce sooner, lay more eggs, and have offspring sired by a larger number of fathers than females from native populations. We found no evidence of direct inbreeding avoidance behaviour in both invasive and native females. This study highlights the importance of investigating evolutionary changes in reproductive strategy and associated traits during biological invasions.
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Thyroid hormone actions on male reproductive system of teleost fish.
Tovo-Neto, Aldo; da Silva Rodrigues, Maira; Habibi, Hamid R; Nóbrega, Rafael Henrique
2018-04-17
Thyroid hormones (THs) play important roles in the regulation of many biological processes of vertebrates, such as growth, metabolism, morphogenesis and reproduction. An increasing number of studies have been focused on the involvement of THs in the male reproductive system of vertebrates, in particular of fish. Therefore, this mini-review aims to summarize the main findings on THs role in male reproductive system of fish, focusing on sex differentiation, testicular development and spermatogenesis. The existing data in the literature have demonstrated that THs exert their roles at the different levels of the hypothalamic-pituitary-gonadal (HPG) axis. In general a positive correlation has been shown between THs and fish reproductive status; where THs are associated with testicular development, growth and maturation. Recently, the molecular mechanisms underlying the role of THs in spermatogenesis have been unraveled in zebrafish testis. THs promote germ cell proliferation and differentiation by increasing a stimulatory growth factor of spermatogenesis produced by Sertoli cells. In addition, THs enhanced the gonadotropin-induced androgen release in zebrafish testis. Next to their functions in the adult testis, THs are involved in the gonadal sex differentiation through modulating sex-related gene expression, and testicular development via regulation of Sertoli cell proliferation. In conclusion, this mini-review showed that THs modulate the male reproductive system during the different life stages of fish. The physiological and molecular mechanisms showed a link between the thyroid and reproduction, suggesting a possibly co-evolution and interdependence of these two systems. Copyright © 2018 Elsevier Inc. All rights reserved.
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Bunning, Harriet; Bassett, Lee; Clowser, Christina; Rapkin, James; Jensen, Kim; House, Clarissa M; Archer, Catharine R; Hunt, John
2016-07-01
Sexual selection may cause dietary requirements for reproduction to diverge across the sexes and promote the evolution of different foraging strategies in males and females. However, our understanding of how the sexes regulate their nutrition and the effects that this has on sex-specific fitness is limited. We quantified how protein (P) and carbohydrate (C) intakes affect reproductive traits in male (pheromone expression) and female (clutch size and gestation time) cockroaches (Nauphoeta cinerea). We then determined how the sexes regulate their intake of nutrients when restricted to a single diet and when given dietary choice and how this affected expression of these important reproductive traits. Pheromone levels that improve male attractiveness, female clutch size and gestation time all peaked at a high daily intake of P:C in a 1:8 ratio. This is surprising because female insects typically require more P than males to maximize reproduction. The relatively low P requirement of females may reflect the action of cockroach endosymbionts that help recycle stored nitrogen for protein synthesis. When constrained to a single diet, both sexes prioritized regulating their daily intake of P over C, although this prioritization was stronger in females than males. When given the choice between diets, both sexes actively regulated their intake of nutrients at a 1:4.8 P:C ratio. The P:C ratio did not overlap exactly with the intake of nutrients that optimized reproductive trait expression. Despite this, cockroaches of both sexes that were given dietary choice generally improved the mean and reduced the variance in all reproductive traits we measured relative to animals fed a single diet from the diet choice pair. This pattern was not as strong when compared to the single best diet in our geometric array, suggesting that the relationship between nutrient balancing and reproduction is complex in this species.
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Lebigre, Christophe; Arcese, Peter; Reid, Jane M
2013-07-01
Age-specific variances and covariances in reproductive success shape the total variance in lifetime reproductive success (LRS), age-specific opportunities for selection, and population demographic variance and effective size. Age-specific (co)variances in reproductive success achieved through different reproductive routes must therefore be quantified to predict population, phenotypic and evolutionary dynamics in age-structured populations. While numerous studies have quantified age-specific variation in mean reproductive success, age-specific variances and covariances in reproductive success, and the contributions of different reproductive routes to these (co)variances, have not been comprehensively quantified in natural populations. We applied 'additive' and 'independent' methods of variance decomposition to complete data describing apparent (social) and realised (genetic) age-specific reproductive success across 11 cohorts of socially monogamous but genetically polygynandrous song sparrows (Melospiza melodia). We thereby quantified age-specific (co)variances in male within-pair and extra-pair reproductive success (WPRS and EPRS) and the contributions of these (co)variances to the total variances in age-specific reproductive success and LRS. 'Additive' decomposition showed that within-age and among-age (co)variances in WPRS across males aged 2-4 years contributed most to the total variance in LRS. Age-specific (co)variances in EPRS contributed relatively little. However, extra-pair reproduction altered age-specific variances in reproductive success relative to the social mating system, and hence altered the relative contributions of age-specific reproductive success to the total variance in LRS. 'Independent' decomposition showed that the (co)variances in age-specific WPRS, EPRS and total reproductive success, and the resulting opportunities for selection, varied substantially across males that survived to each age. Furthermore, extra-pair reproduction increased
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Peixoto, Alexandre A.; Vigoder, Felipe M.; Bruno, Rafaela V.; Soares, Maurilio J.
2013-01-01
Background The male reproductive system of insects can have several tissues responsible for the secretion of seminal fluid proteins (SFPs), such as testes, accessory glands, seminal vesicles, ejaculatory duct and ejaculatory bulb. The SFPs are transferred during mating and can induce several physiological and behavioral changes in females, such as increase in oviposition and decrease in sexual receptivity after copulation. The phlebotomine Lutzomyia longipalpis is the main vector of visceral leishmaniasis. Despite its medical importance, little is known about its reproductive biology. Here we present morphological aspects of the male L. longipalpis reproductive system by light, scanning and transmission electron microscopy, and compare the mating frequency of both virgin and previously mated females. Results The male L. longipalpis reproductive system is comprised by a pair of oval-shaped testes linked to a seminal vesicle by vasa deferentia. It follows an ejaculatory duct with an ejaculatory pump (a large bulb enveloped by muscles and associated to tracheas). The terminal endings of the vasa deferentia are inserted into the seminal vesicle by invaginations of the seminal vesicle wall, which is composed by a single layer of gland cells, with well-developed endoplasmic reticulum profiles and secretion granules. Our data suggest that the seminal vesicle acts both as a spermatozoa reservoir and as an accessory gland. Mating experiments support this hypothesis, revealing a decrease in mating frequency after copulation that indicates the effect of putative SFPs. Conclusion Ultrastructural features of the L. longipalpis male seminal vesicle indicated its possible role as an accessory gland. Behavioral observations revealed a reduction in mating frequency of copulated females. Together with transcriptome analyses from male sandfly reproductive organs identifying ESTs encoding orthologs of SFPs, these data indicate the presence of putative L. longipalpis SFPs reducing
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Spiegel, Carolina N; Bretas, Jorge A C; Peixoto, Alexandre A; Vigoder, Felipe M; Bruno, Rafaela V; Soares, Maurilio J
2013-01-01
The male reproductive system of insects can have several tissues responsible for the secretion of seminal fluid proteins (SFPs), such as testes, accessory glands, seminal vesicles, ejaculatory duct and ejaculatory bulb. The SFPs are transferred during mating and can induce several physiological and behavioral changes in females, such as increase in oviposition and decrease in sexual receptivity after copulation. The phlebotomine Lutzomyia longipalpis is the main vector of visceral leishmaniasis. Despite its medical importance, little is known about its reproductive biology. Here we present morphological aspects of the male L. longipalpis reproductive system by light, scanning and transmission electron microscopy, and compare the mating frequency of both virgin and previously mated females. The male L. longipalpis reproductive system is comprised by a pair of oval-shaped testes linked to a seminal vesicle by vasa deferentia. It follows an ejaculatory duct with an ejaculatory pump (a large bulb enveloped by muscles and associated to tracheas). The terminal endings of the vasa deferentia are inserted into the seminal vesicle by invaginations of the seminal vesicle wall, which is composed by a single layer of gland cells, with well-developed endoplasmic reticulum profiles and secretion granules. Our data suggest that the seminal vesicle acts both as a spermatozoa reservoir and as an accessory gland. Mating experiments support this hypothesis, revealing a decrease in mating frequency after copulation that indicates the effect of putative SFPs. Ultrastructural features of the L. longipalpis male seminal vesicle indicated its possible role as an accessory gland. Behavioral observations revealed a reduction in mating frequency of copulated females. Together with transcriptome analyses from male sandfly reproductive organs identifying ESTs encoding orthologs of SFPs, these data indicate the presence of putative L. longipalpis SFPs reducing sexual mating frequency of
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Morimoto, Juliano; Wigby, Stuart
2016-01-01
Male fitness depends on the expression of costly traits involved in obtaining mates (pre-copulatory) and fertilization (post-copulatory). However, very little is known about the nutrient requirements for these traits and whether males compromise their diet to maximize one trait at the expense of another. Here we used Nutritional Geometry to investigate macronutrient requirements for pre- and post-copulatory traits in Drosophila, when males were the first or second to mate with females. We found no significant effects of male diet on sperm competitiveness. However, although males self-regulate their macronutrient intake at a protein-to-carbohydrate ratio (“P:C ratio”) of 1:1.5, this ratio does not coincide with their optima for several key reproductive traits: both the short-term (~24 hr) rate of offspring production after a female’s first mating, as well as the total offspring number sired when males were second to mate were maximized at a P:C ratio of 1:9, whereas male attractiveness (latency to mate), were maximised at a P:C ratio of 1:1. These results suggest a compromised optimum diet, and no single diet that simultaneously maximizes all male reproductive traits. The protein intake of first males also negatively affected female offspring production following remating, suggesting a long-term intersexual effect of male nutrition. PMID:27270223
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Comparative phylogenetic analysis of male alternative reproductive tactics in ray-finned fishes.
Mank, Judith E; Avise, John C
2006-06-01
Using comparative phylogenetic analysis, we analyzed the evolution of male alternative reproductive tactics (MARTs) in ray-finned fishes (Actinopterygii). Numerous independent origins for each type of MART (involving sneaker males, female mimics, pirates, and satellite males) indicate that these behaviors have been highly labile across actinopterygiian evolution, consistent with a previous notion that convergent selection in fishes can readily mold the underlying suites of reproductive hormones into similar behaviors. The evolutionary appearance of MARTs was significantly correlated with the presence of sexually selected traits in bourgeois males (P = 0.001) but not with the presence of male parental care. This suggests that MARTs often arise from selection on some males to circumvent bourgeois male investment in mate monopolization, rather than to avoid male brood care per se. We found parsimony evidence for an evolutionary progression of MARTs wherein sneaking is usually the evolutionary precursor to the presumably more complex MARTs of female mimicry and cooperative satellite behavior. Nest piracy appears not to be part of this evolutionary progression, possibly because its late onset in the life cycle of most ray-finned fishes reduces the effects of selection on this reproductive tactic.
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Variation in the post-mating fitness landscape in fruit flies.
Fricke, C; Chapman, T
2017-07-01
Sperm competition is pervasive and fundamental to determining a male's overall fitness. Sperm traits and seminal fluid proteins (Sfps) are key factors. However, studies of sperm competition may often exclude females that fail to remate during a defined period. Hence, the resulting data sets contain fewer data from the potentially fittest males that have most success in preventing female remating. It is also important to consider a male's reproductive success before entering sperm competition, which is a major contributor to fitness. The exclusion of these data can both hinder our understanding of the complete fitness landscapes of competing males and lessen our ability to assess the contribution of different determinants of reproductive success to male fitness. We addressed this here, using the Drosophila melanogaster model system, by (i) capturing a comprehensive range of intermating intervals that define the fitness of interacting wild-type males and (ii) analysing outcomes of sperm competition using selection analyses. We conducted additional tests using males lacking the sex peptide (SP) ejaculate component vs. genetically matched (SP + ) controls. This allowed us to assess the comprehensive fitness effects of this important Sfp on sperm competition. The results showed a signature of positive, linear selection in wild-type and SP + control males on the length of the intermating interval and on male sperm competition defence. However, the fitness surface for males lacking SP was distinct, with local fitness peaks depending on contrasting combinations of remating intervals and offspring numbers. The results suggest that there are alternative routes to success in sperm competition and provide an explanation for the maintenance of variation in sperm competition traits. © 2017 The Authors. Journal of Evolutionary Biology published by John Wiley & Sons Ltd on behalf of European Society for Evolutionary Biology.
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Size Dependent Male Reproductive Tactic in the Two-Spotted Goby (Gobiusculus flavescens).
Utne-Palm, A C; Eduard, K; Jensen, K H; Mayer, I; Jakobsen, P J
2015-01-01
Male investment in testes and sperm duct gland in the polygamous nest breeding two-spotted goby Gobiusculus flavescens (Fabricius) was investigated in relation to time in reproductive season and individual physical parameters. This small teleost fish is most likely the most abundant species found along the rocky shores of the North East Atlantic. The two-spotted goby has a single reproductive season, during which nest-caring males can raise several clutches of offspring. According to the literature the males are on average larger than the females. Here we report for the first time a population showing a reversal of this trend, with males on average being smaller than females, a difference likely caused by a large proportion of small males. Early in the breeding season these small males have typical sneaker characters, with relatively large testes and small seminal duct glands compared to the larger dominant territorial males. The presence of these two alternative male reproductive tactics is confirmed by histological studies, which shows the presence of sperm in the sperm duct glands (SDG) of smaller males, but not in the SDG of intermediate and larger males. To our knowledge, males with typical sneaker characters have not been reported in earlier studied populations of two-spotted goby. Interestingly we found that testes investment declined significantly over the course of the breeding season, and that this reduction was significantly more pronounced in small compared to the large males. Further, a significant increase in seminal duct gland (SDG) mass was observed for the smaller males over the breeding season. We propose that this indicates a possible shift in mating tactic by smaller males from a parasitic to a nest-holding tactic over the course of the breeding season. Thus, the observed size dependent plasticity in investment in SDG over time suggests that the reproductive tactic of G. flavescens is conditional, and possibly influenced by mate availability and
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Size Dependent Male Reproductive Tactic in the Two-Spotted Goby (Gobiusculus flavescens.
Directory of Open Access Journals (Sweden)
A C Utne-Palm
Full Text Available Male investment in testes and sperm duct gland in the polygamous nest breeding two-spotted goby Gobiusculus flavescens (Fabricius was investigated in relation to time in reproductive season and individual physical parameters. This small teleost fish is most likely the most abundant species found along the rocky shores of the North East Atlantic. The two-spotted goby has a single reproductive season, during which nest-caring males can raise several clutches of offspring. According to the literature the males are on average larger than the females. Here we report for the first time a population showing a reversal of this trend, with males on average being smaller than females, a difference likely caused by a large proportion of small males. Early in the breeding season these small males have typical sneaker characters, with relatively large testes and small seminal duct glands compared to the larger dominant territorial males. The presence of these two alternative male reproductive tactics is confirmed by histological studies, which shows the presence of sperm in the sperm duct glands (SDG of smaller males, but not in the SDG of intermediate and larger males. To our knowledge, males with typical sneaker characters have not been reported in earlier studied populations of two-spotted goby. Interestingly we found that testes investment declined significantly over the course of the breeding season, and that this reduction was significantly more pronounced in small compared to the large males. Further, a significant increase in seminal duct gland (SDG mass was observed for the smaller males over the breeding season. We propose that this indicates a possible shift in mating tactic by smaller males from a parasitic to a nest-holding tactic over the course of the breeding season. Thus, the observed size dependent plasticity in investment in SDG over time suggests that the reproductive tactic of G. flavescens is conditional, and possibly influenced by mate
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Male Reproductive Complications of Diabetes Mellitus and Possible
African Journals Online (AJOL)
USER
Objective: Male reproductive dysfunction and subsequent infertility are major complications that are becoming .... pancreatic â-islet cells, while NIDDM is usually as a result of a ... the endocrine control of spermatogenesis, it was concluded that ...
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Mangold, Alexandra; Trenkwalder, Katharina; Ringler, Max; Hödl, Walter; Ringler, Eva
2015-09-03
Reproductive skew, the uneven distribution of reproductive success among individuals, is a common feature of many animal populations. Several scenarios have been proposed to favour either high or low levels of reproductive skew. Particularly a male-biased operational sex ratio and the asynchronous arrival of females is expected to cause high variation in reproductive success among males. Recently it has been suggested that the type of benefits provided by males (fixed vs. dilutable) could also strongly impact individual mating patterns, and thereby affecting reproductive skew. We tested this hypothesis in Hyalinobatrachium valerioi, a Neotropical glass frog with prolonged breeding and paternal care. We monitored and genetically sampled a natural population in southwestern Costa Rica during the breeding season in 2012 and performed parentage analysis of adult frogs and tadpoles to investigate individual mating frequencies, possible mating preferences, and estimate reproductive skew in males and females. We identified a polygamous mating system, where high proportions of males (69 %) and females (94 %) reproduced successfully. The variance in male mating success could largely be attributed to differences in time spent calling at the reproductive site, but not to body size or relatedness. Female H. valerioi were not choosy and mated indiscriminately with available males. Our findings support the hypothesis that dilutable male benefits - such as parental care - can favour female polyandry and maintain low levels of reproductive skew among males within a population, even in the presence of direct male-male competition and a highly male-biased operational sex ratio. We hypothesize that low male reproductive skew might be a general characteristic in prolonged breeders with paternal care.
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Tales of healthy men: male reproductive bodies in biomedicine from 'Lebensborn' to sperm banks.
Kampf, Antje
2013-01-01
Using the example of 'sperm tales', borne out of the biomedical technologies that went hand in hand with the establishment of the 'science of man' (andrology), the article engages with the epistemic evolution of interrelated biomedical theories and concepts of what constitutes a 'healthy' reproductive male body. The article asks: how has the normative ideal male body been either perpetuated or interrogated through these tales of male reproduction at the interface between scientific and medical technologies? And how were changes to the normalization of male bodies central to clinical practices and cultural understandings of health and illness? With many aspects of the medical history of male reproduction in the 20th century still unexplored, this article will focus on the growing intervention of biomedicine to 'treat' male infertility by way of the classification, standardization and normalization of male corporeality, focusing in particular on the representation and construction of men and the male body, as reflected in medical science and practice from the second half of the 20th century onwards in Germany. The article analyses the rise in importance of sperm in biomedical investigation, including a consideration of the construction of infertility as the defining force behind concepts of 'healthy men', and examines the related conceptualization of male reproductive bodies at the crossroad between 'healthy' and 'normal'. It is argued that the ideal of male reproduction as being inherently healthy has lost ground. By the late 20th century, male bodies have become vulnerable, at least as represented in medical science and technology.
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Koppik, Mareike; Fricke, Claudia
2017-12-01
Senescence is accompanied by loss of reproductive functions. Here, we studied reproductive ageing in Drosophila melanogaster males and asked whether the expected decline in male reproductive success is due to diminished functionality of the male accessory gland (AG). The male AG produces the majority of seminal fluid proteins (SFPs) transferred to the female at mating. SFPs induce female postmating changes and are key to male reproductive success. We measured age-dependent gene expression changes for five representative SFP genes in males from four different age groups ranging from 1 to 6 weeks after eclosion. Simultaneously, we also measured male reproductive success in postmating traits mediated by transfer of these five SFPs. We found a decreased in male SFP gene expression with advancing age and an accompanying decline in male postmating success. Hence, male reproductive senescence is associated with a decline in functionality of the male AG. While overall individual SFP genes decreased in expression, our results point towards the idea that the composition of an ejaculate might change with male age as the rate of change was variable for those five genes. © 2017 John Wiley & Sons Ltd.
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Reproductive Toxicity of Triptolide in Male House Rat, Rattus rattus
Directory of Open Access Journals (Sweden)
Neena Singla
2014-01-01
Full Text Available The aim of study was to investigate the toxic effect of triptolide fed in bait on reproduction of male house rat, Rattus rattus. Feeding of cereal based bait containing 0.2% triptolide to male R. rattus for 5 days in no-choice feeding test, leading to mean daily ingestion of 20.45 mg/kg bw of triptolide, was found effective in significantly (P≤0.05 reducing sperm motility and viability in cauda epididymal fluid by 80.65 and 75.14%, respectively, from that of untreated rats. Pregnancy rates were decreased by 100% in untreated cyclic female rats paired with male rats treated with 0.2% triptolide. Present studies suggest the potential of 0.2% triptolide bait in regulating reproductive output of R. rattus.
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Prenatal testosterone exposure worsen the reproductive performance of male rat at adulthood.
Ramezani Tehrani, Fahimeh; Noroozzadeh, Mahsa; Zahediasl, Saleh; Ghasemi, Asghar; Piryaei, Abbas; Azizi, Fereidoun
2013-01-01
The reproductive system is extremely susceptible to environmental insults, for example exogenous steroids during gestational development and differentiation. Experimental induction of androgen excess during prenatal life in female animal models reprograms their reproductive physiology, however the fetal programming of the male reproductive system by androgen excess has not been well studied. We aimed to determine the effect of prenatal exposure of two different doses of testosterone on different gestational days, on the male reproductive system using a rat model. Sixteen pregnant rats were randomly divided into two experimental groups and two control groups. Experimental group І were subcutaneously injected with 3 mg free testosterone on gestational days 16-19 and its controls received solvent for that time; experimental group П were subcutaneously injected with 20 mg free testosterone on day 20 of gestational period and its controls received solvent at the same time. The reproductive system morphology and function of 32 male offspring of these study groups were compared at days 6-30-60 of age and after puberty. The anogenital distance of the male offspring of both experimental groups had no significant differences on the different days of measurement, compared with controls. In the offspring of experimental group І, the testes weight, number of Sertoli, Spermatocyte and Spermatid cells, sperm count and motility and the serum concentration of testosterone after puberty were significantly decreased; except for reduction of sperm motility (pmale rat fetuses to excess testosterone disrupted reproductive function, an effect highly dependent on the time, duration and level of exposure. It seems that the reproductive system in individuals exposed to high levels of androgens during fetal life should be evaluated at puberty and likely to be treated.
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Ultrasonographic assessment of the male koala (Phascolarctos cinereus) reproductive tract.
Larkin, Rebecca; Palmieri, Chiara; Oishi, Motoharu; Hulse, Lyndal; Johnston, Stephen D
2018-04-01
Studies documenting the application of ultrasonography to depict normal and pathological changes in koalas (Phascolarctos cinereus), especially in the male, are scarce. Sixty-two wild koalas were used in this study to define ultrasonographic protocols and features for the assessment of the male koala reproductive tract. Testis, epididymis and spermatic cord were examined using a hockey stick transducer. The normal koala testis showed a homogeneous echogenicity and an obvious hyper-echoic band corresponding to the tunica albuginea. The cauda epididymis was characterised by hypo- and hyper-echoic regions and was most effectively imaged in sagittal section. The koala prostate was assessed using a micro-curved transducer positioned midline, caudal to the bladder. On transverse section, it showed distinct margins and a well-defined internal structure, although the prostatic urethra was not apparent on most scans. To image the bulbourethral glands (BGs), the hockey stick transducer was placed lateral to the cloaca. BGIII was located just below the skin, while BGII was located deeper than BGIII. BGI was too small and not sufficiently echogenic to be detected. The ultrasonographic appearance of the BGs was similar to that of the testes but with more obvious hypo-echoic stippling. This comprehensive review of the ultrasonographic appearance of normal male koala reproductive tract can be used by veterinarians and others, in zoos or those working with wild koalas, during assessment of the reproductive tract of male koalas in relation to seasonal changes in accessory gland function or for the pathological investigation of reproductive lesions and infertility problems. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Garnier, Alexandre; Gaillard, Jean-Michel; Gauthier, Dominique; Besnard, Aurélien
2016-01-01
The fitness costs of reproduction can be masked by individual differences, and may only become apparent during adverse environmental conditions. Individual differences, however, are usually assessed by reproductive success, so how fitness costs are influenced by the interplay between the environmental context and overall individual differences requires further investigation. Here, we evaluated fitness costs of reproduction based on 15 yr of monitoring of individual Alpine ibex (Capra ibex) during a period when the population was affected by a severe disease outbreak (pneumonia). We quantified fitness costs using a novel multi-event capture-mark-recapture (CMR) modeling approach that accounted for uncertainty in reproductive status to estimate the survival and reproductive success of female ibex while also accounting for overall individual heterogeneity using mixture models. Our results show that the ability of females to reproduce was highly heterogeneous. In particular, one group including 76% of females had a much higher probability of giving birth annually (between 0.66 and 0.77, depending on the previous reproductive status) than females of the second group (24% of females, between 0 and 0.05 probability of giving birth annually). Low reproductive costs in terms of future reproduction occurred and were independent of the pneumonia outbreak. There was no survival cost of reproduction either before or after the epizootic, but the cost was high during the epizootic. Our findings indicate that adverse environmental conditions, such as disease outbreaks, may lead to survival costs of reproduction in long-lived species and select against females that have a high reproductive effort. Thereby, the occurrence of adverse conditions increases the diversity of reproductive tactics within a population.
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Anthropometric and physical fitness characteristics of young male soccer players
Directory of Open Access Journals (Sweden)
Leslie Andrews Portes
2010-06-01
Full Text Available The objective of this study was to determine anthropometric and physical fitnesscharacteristics of Brazilian male children and adolescents at the beginning of soccer training. Inthis study, 282 male soccer players ranging in age from 10 to 13 years were evaluated. The athletesparticipated in a formal soccer training program 3 times per week, with each training lasting 3hours. Anthropometric and physical fitness parameters were obtained. The boys were divided intoage classes and prevalence data were analyzed using Pearson’s chi-square test. Parametric datawere compared by one-way ANOVA or the Kruskal-Wallis test, when necessary. The resultsare expressed as the mean ± standard deviation and a p value <0.05 was considered to be significant.Growth, development, body adiposity and physical fitness characteristics were adequateand proportional to age among the boys studied (p<0.05. It was concluded that anthropometricand physical fitness characteristics of young male elite soccer players improve with and areproportional to age. Children and adolescents greatly benefit from regular physical activity. Thepresent results show that young male soccer players present adequate anthropometric conditionsand physical fitness prior to the initiation of formal training at soccer clubs.
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Are attractive male crickets better able to pay the costs of an immune challenge?
Telemeco, Melissa S.C.; Bartholomay, Lyric C.
2015-01-01
Reproduction and immunity are fitness-related traits that trade-off with each other. Parasite-mediated theories of sexual selection suggest, however, that higher-quality males should suffer smaller costs to reproduction-related traits and behaviours (e.g., sexual display) from an immune challenge because these males possess more resources with which to deal with the challenge. We used Gryllus texensis field crickets to test the prediction that attractive males should better maintain the performance of fitness-related traits (e.g., calling effort) in the face of an immune challenge compared with unattractive males. We found no support for our original predictions. However, that immune activation causes attractive males to significantly increase their calling effort compared with unattractive males suggests that these males might terminally invest in order to compensate for decreased future reproduction. PMID:26713249
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Role of Oxidative Stress in Male Reproductive Dysfunctions with Reference to Phthalate Compounds.
Sedha, Sapna; Kumar, Sunil; Shukla, Shruti
2015-11-14
A wide variety of environmental chemicals/xenobiotics including phthalates have been shown to cause oxidative stress targeting the endocrine system and cause reproductive anomalies. The present review describes various issues by oxidative stress causing male reproductive dysfunctions. Here in this review, the importance and role of phthalate compounds in male reproductive dysfunction has been well documented. One class of environmental endocrine disruptors is phthalates. Phthalate compounds are mostly used as plasticizers, which increase the flexibility, durability, longevity, and etc. of the plastics. Large-scale use of plastic products in our daily life as well as thousands of workers engaged in the manufacture of plastic and plastic products and recycling plastic industry are potentially exposed to these chemicals. Further, general population as well as vulnerable groups i.e. children and pregnant women are also exposed to these chemicals. Phthalates are among wide variety of environmental toxicants capable of compromising male fertility by inducing a state of oxidative stress in the testes. They may also generate reactive oxygen species (ROS) that may affect various physiological and reproductive functions. The available data points out that phthalate compounds may also induce oxidative stress in the male reproductive organs mainly testis and epididymis. They impair spermatogenic process by inducing oxidative stress and apoptosis in germ cells or target sertoli cells and thereby hamper spermatogenesis. They also impair the Leydig cell function by inducing ROS, thereby decreasing the levels of steroidogenic enzymes. Thus in utero and postnatal exposure to phthalate compounds might lead to decreased sperm count and various other reproductive anomalies in the young male.
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Environmental Hexachlorobenzene exposure and human male reproductive function
DEFF Research Database (Denmark)
Specht, Ina Olmer; Bonde, Jens Peter Ellekilde; Toft, Gunnar
2015-01-01
Hexachlorobenzene (HCB) is a persistent environmental fungicide that may disrupt androgen regulation. The aim of this study was to investigate associations between HCB levels and biomarkers of male reproductive function. 589 Spouses of pregnant women from Greenland, Poland and Ukraine were enroll...
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Genetic analysis of male reproductive success in relation to density in the zebrafish, Danio rerio
Directory of Open Access Journals (Sweden)
Jordan William C
2006-04-01
Full Text Available Abstract Background We used behavioural and genetic data to investigate the effects of density on male reproductive success in the zebrafish, Danio rerio. Based on previous measurements of aggression and courtship behaviour by territorial males, we predicted that they would sire more offspring than non-territorial males. Results Microsatellite analysis of paternity showed that at low densities territorial males had higher reproductive success than non-territorial males. However, at high density territorial males were no more successful than non-territorials and the sex difference in the opportunity for sexual selection, based on the parameter Imates, was low. Conclusion Male zebrafish exhibit two distinct mating tactics; territoriality and active pursuit of females. Male reproductive success is density dependent and the opportunity for sexual selection appears to be weak in this species.
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Human Leukocyte Antigen-G Within the Male Reproductive System: Implications for Reproduction.
Hviid, Thomas Vauvert F
2015-01-01
In sexual reproduction in humans, a man has a clear interest in ensuring that the immune system of his female partner accepts the semi-allogenic fetus. Increasing attention has been given to soluble immunomodulatory molecules in the seminal fluid as one mechanism of ensuring this, possibly by "priming" the woman's immune system before conception and at conception. Recent studies have demonstrated the presence of the immunoregulatory and tolerance-inducible human leukocyte antigen (HLA)-G in the male reproductive organs. The expression of HLA-G in the blastocyst and by extravillous trophoblast cells in the placenta during pregnancy has been well described. Highly variable amounts of soluble HLA-G (sHLA-G) in seminal plasma from different men have been reported, and the concentration of sHLA-G is associated with HLA-G genotype. A first pilot study indicates that the level of sHLA-G in seminal plasma may even be associated with the chance of pregnancy in couples, where the male partner has reduced semen quality. More studies are needed to verify these preliminary findings.
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Human leukocyte antigen-G within the male reproductive system
DEFF Research Database (Denmark)
Hviid, Thomas Vauvert F
2015-01-01
by “priming” the woman’s immune system before conception and at conception. Recent studies have demonstrated the presence of the immunoregulatory and tolerance-inducible human leukocyte antigen (HLA)-G in the male reproductive organs. The expression of HLA-G in the blastocyst and by extravillous trophoblast......In sexual reproduction in humans, a man has a clear interest in ensuring that the immune system of his female partner accepts the semi-allogenic fetus. Increasing attention has been given to soluble immunomodulatory molecules in the seminal fluid as one mechanism of ensuring this, possibly...... plasma may even be associated with the chance of pregnancy in couples, where the male partner has reduced semen quality. More studies are needed to verify these preliminary findings....
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Arterbery, Adam S; Deitcher, David L; Bass, Andrew H
2010-01-01
Corticosteroid signaling mechanisms mediate a wide range of adaptive physiological responses, including those essential to reproduction. Here, we investigated the presence and relative abundance of corticosteroid receptors during the breeding season in the plainfin midshipman fish (Porichthys notatus), a species that has two male reproductive morphs. Only type I "singing" males acoustically court females and aggressively defend a nest site, whereas type II "sneaker" males steal fertilizations from nesting type I males. Cloning and sequencing first identified glucocorticoid (GR) and mineralocorticoid (MR) receptors in midshipman that exhibited high sequence identity with other vertebrate GRs and MRs. Absolute-quantitative real-time PCR then revealed higher levels of GR in the central nervous system (CNS) of type II males than type I males and females, while GR levels in the sound-producing, vocal muscle and the liver were higher in type I males than type II males and females. MR expression was also greater in the CNS of type II males than type I males or females, but the differences were more modest in magnitude. Lastly, plasma levels of cortisol, the main glucocorticoid in teleosts, were 2- to 3-fold greater in type II males compared to type I males. Together, the results suggest a link between corticosteroid regulation and physiological and behavioral variation in a teleost fish that displays male alternative reproductive tactics.
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Diabetes-induced hyperglycemia impairs male reproductive function: a systematic review.
Maresch, Constanze C; Stute, Dina C; Alves, Marco G; Oliveira, Pedro F; de Kretser, David M; Linn, Thomas
2018-01-01
Hyperglycemia can result from a loss of pancreatic beta-cells or a decline in their function leading to decreased insulin secretion or may arise from insulin resistance and variable degrees of inadequate insulin secretion resulting in diabetes and related comorbidities. To date several reviews have addressed the issue of diabetes-related male infertility but most have focused on how metabolic syndrome causes the decline in male fertility. However, a comprehensive overview as to how diabetes-induced hyperglycemia impairs male fertility is missing. Impaired regulation of glucose and the resultant hyperglycemia are major threats to the health of individuals in modern societies especially given the rapidly rising prevalence affecting an increasing number of men in their reproductive years. Consequently, diabetes-induced hyperglycemia is likely to contribute to a decline in global birth rates especially in those societies with a high diabetic prevalence. This systematic review addresses and summarizes the impact of hyperglycemia on male reproductive health with a particular emphasis on the molecular mechanisms that influence the testis and other parts of the male reproductive tract. A systematic search of the literature published in the MEDLINE-Pubmed database (http://www.ncbi.nlm.nih.gov/pubmed) and Cochrane Library (http://www.cochranelibrary.com) was performed, as well as hand searching reference lists, from the earliest available online indexing year until May 2017, using diabetes- and male fertility-related keywords in combination with other search phrases relevant to the topic of hyperglycemia. Inclusion criteria were: clinical studies on type 1 diabetic (T1D) men and studies on T1D animal models with a focus on reproductive parameters. Case reports/series, observational studies and clinical trials were included. Studies on patients with type 2 diabetes (T2D) or animal models of T2D were excluded to distinguish hyperglycemia from other metabolic effects. A total
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Recreational fishing selectively captures individuals with the highest fitness potential.
Sutter, David A H; Suski, Cory D; Philipp, David P; Klefoth, Thomas; Wahl, David H; Kersten, Petra; Cooke, Steven J; Arlinghaus, Robert
2012-12-18
Fisheries-induced evolution and its impact on the productivity of exploited fish stocks remains a highly contested research topic in applied fish evolution and fisheries science. Although many quantitative models assume that larger, more fecund fish are preferentially removed by fishing, there is no empirical evidence describing the relationship between vulnerability to capture and individual reproductive fitness in the wild. Using males from two lines of largemouth bass (Micropterus salmoides) selectively bred over three generations for either high (HV) or low (LV) vulnerability to angling as a model system, we show that the trait "vulnerability to angling" positively correlates with aggression, intensity of parental care, and reproductive fitness. The difference in reproductive fitness between HV and LV fish was particularly evident among larger males, which are also the preferred mating partners of females. Our study constitutes experimental evidence that recreational angling selectively captures individuals with the highest potential for reproductive fitness. Our study further suggests that selective removal of the fittest individuals likely occurs in many fisheries that target species engaged in parental care. As a result, depending on the ecological context, angling-induced selection may have negative consequences for recruitment within wild populations of largemouth bass and possibly other exploited species in which behavioral patterns that determine fitness, such as aggression or parental care, also affect their vulnerability to fishing gear.
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Xun, Erna; Zhang, Yanwen; Zhao, Jimin; Guo, Jixun
2017-11-01
Metals and metalloids in soil could be transferred into reproductive organs and floral rewards of hyperaccumulator plants and influence their reproductive success, yet little is known whether non-hyperaccumulator plants can translocate heavy metals from soil into their floral organs and rewards (i.e., nectar and pollen) and, if so, whether plant reproduction will be affected. In our studies, summer squash (Cucurbita pepo L. cv. Golden Apple) was exposed to heavy-metal treatments during bud stage to investigate the translocation of soil-supplemented zinc, copper, nickel and lead into its floral organs (pistil, anther and nectary) and rewards (nectar and pollen) as well as floral metal accumulation effects on its reproduction. The results showed that metals taken up by squash did translocate into its floral organs and rewards, although metal accumulation varied depending on different metal types and concentrations as well as floral organ/reward types. Mean foraging time of honey bees to each male and female flower of squash grown in metal-supplemented soils was shorter relative to that of plants grown in control soils, although the visitation rate of honeybees to both male and female flowers was not affected by metal treatments. Pollen viability, pollen removal and deposition as well as mean mass per seed produced by metal-treated squash that received pollen from plants grown in control soils decreased with elevated soil-supplemented metal concentrations. The fact that squash could translocate soil-supplemented heavy metals into floral organs and rewards indicated possible reproductive consequences caused either directly (i.e., decreasing pollen viability or seed mass) or indirectly (i.e., affecting pollinators' visitation behavior to flowers) to plant fitness. Copyright © 2017 Elsevier Inc. All rights reserved.
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Environmental endocrine disruptors: Effects on the human male reproductive system.
Sweeney, M F; Hasan, N; Soto, A M; Sonnenschein, C
2015-12-01
Incidences of altered development and neoplasia of male reproductive organs have increased during the last 50 years, as shown by epidemiological data. These data are associated with the increased presence of environmental chemicals, specifically "endocrine disruptors," that interfere with normal hormonal action. Much research has gone into testing the effects of specific endocrine disrupting chemicals (EDCs) on the development of male reproductive organs and endocrine-related cancers in both in vitro and in vivo models. Efforts have been made to bridge the accruing laboratory findings with the epidemiological data to draw conclusions regarding the relationship between EDCs, altered development and carcinogenesis. The ability of EDCs to predispose target fetal and adult tissues to neoplastic transformation is best explained under the framework of the tissue organization field theory of carcinogenesis (TOFT), which posits that carcinogenesis is development gone awry. Here, we focus on the available evidence, from both empirical and epidemiological studies, regarding the effects of EDCs on male reproductive development and carcinogenesis of endocrine target tissues. We also critique current research methodology utilized in the investigation of EDCs effects and outline what could possibly be done to address these obstacles moving forward.
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Assisted reproduction in a cohort of same-sex male couples and single men.
Grover, Stephanie A; Shmorgun, Ziva; Moskovtsev, Sergey I; Baratz, Ari; Librach, Clifford L
2013-08-01
To date, there is limited published data on same-sex male couples and single men using assisted reproduction treatment to build their families. The objective of this retrospective study was to better understand treatment considerations and outcomes for this population when using assisted reproduction treatment. A total of 37 same-sex male couples and eight single men (seven homosexual and one heterosexual) who attended the CReATe Fertility Centre for assisted reproduction services were studied. There was a 21-fold increase in the number of same-sex male couples and single men undergoing assisted reproduction treatment since 2003. The mean age was 46years (24-58). Twenty-eight couples (76%) chose to use spermatozoa from both partners to fertilize their donated oocytes. Most men (32 same-sex male couples and seven single men; 87%) obtained oocytes from an anonymous donor, whereas five couples and one single man (13%) had a known donor. Anonymous donors who were open to be contacted by the child after the age of 18 were selected by 67% of patients. Of all 25 deliveries, eight (32%) were sets of twins. All of the twins were half genetic siblings. Copyright © 2013 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.
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Why Are Males Bad for Females? Models for the Evolution of Damaging Male Mating Behavior
Lessells, C.M.
2005-01-01
One explanation for the cost to mating for females caused by damaging male mating behavior is that this causes the females to adaptively modify their subsequent life histories in a way that also increases male fitness. This might occur because the reduction in residual reproductive value of the
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Are attractive male crickets better able to pay the costs of an immune challenge?
Directory of Open Access Journals (Sweden)
Clint D. Kelly
2015-12-01
Full Text Available Reproduction and immunity are fitness-related traits that trade-off with each other. Parasite-mediated theories of sexual selection suggest, however, that higher-quality males should suffer smaller costs to reproduction-related traits and behaviours (e.g., sexual display from an immune challenge because these males possess more resources with which to deal with the challenge. We used Gryllus texensis field crickets to test the prediction that attractive males should better maintain the performance of fitness-related traits (e.g., calling effort in the face of an immune challenge compared with unattractive males. We found no support for our original predictions. However, that immune activation causes attractive males to significantly increase their calling effort compared with unattractive males suggests that these males might terminally invest in order to compensate for decreased future reproduction.
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ANATOMY OF THE MALE REPRODUCTIVE ORGANS OF THE ...
African Journals Online (AJOL)
2014-12-10
Dec 10, 2014 ... was the urethral groove. The male reproductive anatomy of the African sideneck turtle is similar to those earlier reported in sea and freshwater turtles. Key Words: Testis, Epididymis, Morphology, Turtles. INTRODUCTION. Freshwater turtles are under increasing threats around the world. The African side.
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Effect of Nifedipine on Reproductive Functions in Male Rats ...
African Journals Online (AJOL)
Effect of Nifedipine on Reproductive Functions in Male Rats. ... Background: After life itself, fertility is probably the most highly prized human possession. ... Animals in Group 3 were allowed another 30 days after drug withdrawal for recovery.
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International Nuclear Information System (INIS)
Wibe, Asa Espmark; Rosenqvist, Gunilla; Jenssen, Bjoern Munro
2002-01-01
In past years we have witnessed decreased reproductive capacity in many wildlife species due to exposure to chemicals with endocrine-disrupting properties. In this laboratory experiment male three spine sticklebacks asterosteus aculeatus exposed to 17β-estradiol (2.0 μg/g) dispersed in peanut oil, on days 1, 7, 14, and 21, showed impaired paternal care compared to control fish that were exposed to peanut oil only. There were no differences between the two groups in number of males that built nests or in courtship displays. However, exposed males started nest building significantly later than control males. This study suggests that some but not all essential traits of male reproductive behavior may be altered as a result of exposure to 17β-estradiol. To reveal harmful effects of chemicals with suggested reproductive-disrupting properties it is thus important to take a wide variety of variables related to reproductive behavior into consideration
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Effects of nectar robbing on male and female reproductive success of a pollinator-dependent plant.
Rojas-Nossa, Sandra V; Sánchez, José María; Navarro, Luis
2016-02-01
Nectar robbers affect host fitness in different ways and by different magnitudes, both directly and indirectly, and potentially constitute an important part of pollination interactions. The aim of this study was to assess the effect of nectar robbing on several variables that characterize the reproductive success of Lonicera etrusca, a pollinator-dependent plant with long, tubular flowers that produce abundant nectar. Using fluorescent powder dye as a proxy for pollen, the distance of pollen dispersal was compared for robbed and non-robbed flowers. Artificial nectar robbing treatments were applied to test its effects on four additional measures of reproductive success, namely the quantity of pollen exported, fruit set, seed/ovule ratio and seed weight. Nectar robbing was not found to have any significant negative consequences on female and male components of reproductive success as determined through the five variables that were measured. Although L. etrusca exhibits high levels of nectar robbing and nectar robbers are common floral visitors, no evidence was found of detrimental changes in the components of reproductive success. A combination of morphological and ecological mechanisms is proposed to explain how plants may compensate for the energetic loss caused by the nectar robbers. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
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Vitousek, Maren N; Rubenstein, Dustin R; Nelson, Karin N; Wikelski, Martin
2008-07-01
Polygynous lek-mating systems are characterized by high reproductive skew, with a small number of males gaining a disproportionate share of copulations. In lekking species, where female choice drives male mating success and patterns of reproductive skew, female preferences for 'good genes' should lead to preferred males having high reproductive success in all years. Here we investigate whether these 'hotshot' males have steroid hormone patterns that are consistent over time (between two mating seasons), and whether hormone levels consistently predict display behavior. We test these questions in the Galápagos marine iguana (Amblyrhynchus cristatus), a lekking vertebrate with high male reproductive skew. We found that male mating success and testosterone levels were not consistent across years. The most successful males showed an inverse relationship in copulation success between years. Similarly, territorial males that had high testosterone in one year had low levels in the next. Across years, testosterone was strongly associated with head-bob display, suggesting that this steroid plays a key role in mate attraction. These results suggest that female marine iguanas are not choosing the same 'hotshot' males in every year, but instead base their reproductive decisions on male behavioral traits that are hormonally mediated and variable across years. By using testosterone to regulate their costly display behaviors male marine iguanas appear to have a mechanism that allows them to adjust their reproductive effort depending on extrinsic and/or intrinsic factors.
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Vitamin D metabolism, sex hormones, and male reproductive function.
Blomberg Jensen, Martin
2012-08-01
The spectrum of vitamin D (VD)-mediated effects has expanded in recent years, and VD is now recognized as a versatile signaling molecule rather than being solely a regulator of bone health and calcium homeostasis. One of the recently identified target areas of VD is male reproductive function. The VD receptor (VDR) and the VD metabolizing enzyme expression studies documented the presence of this system in the testes, mature spermatozoa, and ejaculatory tract, suggesting that both systemic and local VD metabolism may influence male reproductive function. However, it is still debated which cell is the main VD target in the testis and to what extent VD is important for sex hormone production and function of spermatozoa. This review summarizes descriptive studies on testicular VD metabolism and spatial distribution of VDR and the VD metabolizing enzymes in the mammalian testes and discusses mechanistic and association studies conducted in animals and humans. The reviewed evidence suggests some effects of VD on estrogen and testosterone biosynthesis and implicates involvement of both systemic and local VD metabolism in the regulation of male fertility potential.
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effects of electromagnetic radiations on the male reproductive system
African Journals Online (AJOL)
2018-02-28
Feb 28, 2018 ... growth, differentiation, proliferation and stress .... heat up the water if is of sufficient power, by way .... stress in male reproductive physiology. .... W., Kas, G 1998 Conspicuous behavioural abnormalities in a dairy cow herd near.
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[Effect of tail-suspension on the reproduction of adult male rats].
Zhou, Dang-xia; Qiu, Shu-dong; Wang, Zhi-yong; Zhang, Jie
2006-04-01
To study the effects on the male reproduction in adult male rats and its mechanisms through simulated weightlessness using tail-suspension, in order to do a basic works of exploring the effects on human being's reproduction in outer space. Forty Spraque-Dawley adult male rats were randomly divided into four groups, two experimental groups and two control groups. Rats in the two experimental groups were tail-suspended for 14 d and 28 d respectively, then we examined the weight and morphology of testis, the quality and amount of sperm, also tested the serum hormone by radioimmunoassay and analyzed apoptosis rate of testicular cells by TUNEL in the experimental rats and control rats. After tail-suspension, the weight of testis, the sperm count and sperm motility significantly decreased (P 0.05). These changes were not significant between two experimental groups (P > 0.05). In addition, the seminiferous tubules became atrophy with the reduction of the layers of seminiferous epithelium, and sperm amount in lumens of seminiferous tubules decreased in experimental groups. The above were more remarkable in the 28 d experimental group. Simulating weightlessness has a harmful effect on reproduction of adult male rats. These may be caused by inducing apoptosis. The blocking apoptosis of testicular cells may be useful in improving the harmful effect.
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Effects of Zingiber Officinale on Reproductive Functions in the Male ...
African Journals Online (AJOL)
To investigate the effects of Zingiber Officinale on male reproductive functions and study the mechanisms underlying these effects, aqueous extract of Zingiber Officinale were administered orally to two groups of male rats at 500mg/kg b.w. and 1000mg/kg b.w. A third group served as control and received the treatment ...
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Hybridization rapidly reduces fitness of a native trout in the wild
Muhlfeld, C.C.; Kalinowski, S.T.; McMahon, T.E.; Taper, M.L.; Painter, S.; Leary, R.F.; Allendorf, F.W.
2009-01-01
Human-mediated hybridization is a leading cause of biodiversity loss worldwide. How hybridization affects fitness and what level of hybridization is permissible pose difficult conservation questions with little empirical information to guide policy and management decisions. This is particularly true for salmonids, where widespread introgression among non-native and native taxa has often created hybrid swarms over extensive geographical areas resulting in genomic extinction. Here, we used parentage analysis with multilocus microsatellite markers to measure how varying levels of genetic introgression with non-native rainbow trout (Oncorhynchus mykiss) affect reproductive success (number of offspring per adult) of native westslope cutthroat trout (Oncorhynchus clarkii lewisi) in the wild. Small amounts of hybridization markedly reduced fitness of male and female trout, with reproductive success sharply declining by approximately 50 per cent, with only 20 per cent admixture. Despite apparent fitness costs, our data suggest that hybridization may spread due to relatively high reproductive success of first-generation hybrids and high reproductive success of a few males with high levels of admixture. This outbreeding depression suggests that even low levels of admixture may have negative effects on fitness in the wild and that policies protecting hybridized populations may need reconsideration. ?? 2009 The Royal Society.
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Environmental & lifestyle factors in deterioration of male reproductive health
Directory of Open Access Journals (Sweden)
Sunil Kumar
2014-01-01
Full Text Available Background & objectives: Male reproductive function in the general population has been receiving attention in recent years due to reports of various reproductive and developmental defects, which might be associated with various lifestyle and environmental factors. This study was carried out to determine the role of various lifestyle and environmental factors in male reproduction and their possible association with declining semen quality, increased oxidative stress as well as sperm DNA damage. Methods: Semen samples were obtained from 240 male partners of the couples consulting for infertility problem. Semen analysis was carried out using WHO criteria and subjects were categorized on the basis of self reported history of lifestyle as well as environmental exposure. The oxidative and antioxidant markers; lipid peroxidation (LPO, superoxide dismutase (SOD and catalase (CAT as well as DNA damage by acridine orange test (AO were determined. Results: The presence of abnormal semen parameters was significantly higher among the lifestyle and/or environmental exposed subjects as compared to the non-exposed population. Further, the levels of antioxidants were reduced and sperm DNA damage was more among the lifestyle and/or environmental exposed subjects, though the changes were not significant. Interpretation & conclusions: These findings indicated that various lifestyle factors such as tobacco smoking, chewing and alcohol use as well as exposure to toxic agents might be attributed to the risk of declining semen quality and increase in oxidative stress and sperm DNA damage.
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Reproductive effects of lipid soluble components of Syzygium aromaticum flower bud in male mice
Directory of Open Access Journals (Sweden)
Raghav Kumar Mishra
2013-01-01
Full Text Available Background: The flower buds of Syzygium aromaticum (clove have been used in indigenous medicines for the treatment of male sexual disorders in Indian subcontinent. Objective: To evaluate the effect of Syzygium aromaticum flower bud on male reproduction, using Parkes (P strain mice as animal model. Materials and Methods: Mice were orally administered lipid soluble components of Syzygium aromaticum flower bud in doses of 15, 30, and 60 mg/kg body weight for 35 days, and several male reproductive endpoints were evaluated. Results: Treatment with lower dose (15 mg of Syzygium increased the motility of sperm and stimulated the secretory activities of epididymis and seminal vesicle, while higher doses (30 and 60 mg had adverse effects on sperm dynamics of cauda epididymidis and on the secretory activities of epididymis and seminal vesicle. Libido was not affected in treated males; however, a significant decrease in litter in females sired by males treated with higher doses of Syzygium was recorded. Conclusion: Treatment with Syzygium aromaticum flower bud causes dose-dependent biphasic effect on male reproductive indices in P mice; lower dose of Syzygium appears stimulatory, while the higher doses have adverse effect on male reproduction. The results suggest that the lower dose of Syzygium may have androgenic effect, but further studies are needed to support this contention.
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Effect of Soybean on Male Reproductive Physiology in Male Mice
Directory of Open Access Journals (Sweden)
M Modaresi
2011-01-01
Full Text Available Introduction & Objective: Soybean (Soja hispida Moench is a member of Fabaceae family. It is a species of legume native to East Asia. Soy contains significant amount of all the essential amino acids for humans therefore, is a good source of protein .Soy has an important role in the improvement and treatment of some cancers such as colon, prostate, and breast. The aim of this study was to investigate the effect of soybeans on reproductive system in male mice. Materials & Methods: This experimental study was conducted at Isfahan Payam e Noor University in 2009. In this research, 32 male mice were randomly grouped into four experimental groups. The control group was fed with soy-free basic diet. The experimental groups 1, 2, and 3 were fed with a diet containing 20%, 30% and 50% soy diet respectively.At the end of 9 weeks of treatment, blood samples were collected and serum levels of testosterone, LH and FSH were measured. The collected data was analyzed with SPSS software using one way ANOVA with Dunnett's post test and Duncan test. Results : In the experimental group which received 20% soy diet, the level of testosterone had a meaningful decrease in comparison with the control group (P<0.05, but in the experimental group which received a 50% soy diet, the level of testosterone had a meaningful increase (P<0.05 .The LH level in 30% and 50% groups had a meaningful increase but no significant differences were observed in FSH level & weight of testicles (P<0.05.The number of sperms in all of the treatment regimes had a meaningful decrease (P0.05 Conclusion: Results of this research indicated that the 20, 30, and 50 percent soy diet had a negative effect on the male reproductive system in mice.
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Endocrine-disrupting chemicals and male reproductive health: a review
Directory of Open Access Journals (Sweden)
Damjan Balabanič
2018-03-01
Full Text Available Balanced functioning of the endocrine system is essential for preservation of human species by providing normal growth and development, reproduction, and normal functioning of all other organ systems. In the last decades, emerging area of interest is the impact of environmental exposures to human health. Important environmental pollutants are endocrine-disrupting che- micals (EDCs, which can have adverse e ects on the living organism due to their interference with the endocrine system. The group of known EDCs embraces ubiquitous synthetic substan- ces used as industrial lubricants and solvents, with their by-products, incomplete combustion remains, pharmaceuticals and personal care products, pesticides and plasticizers. Natural com- pounds such as genistein, a phytoestrogen, and heavy metals can also have endocrine e ects. Endocrine disruption is a serious public health problem. EDCs among other health problems ge- nerate reproductive disorders in males, such as decreases in sperm count and quality, increases in testicular germ cell numbers, prostate and breast cancers, cryptorchidism and hypospadias, impaired fertility, and infertility. This paper critically reviews the current knowledge of the impa- ct of EDCs on reproductive disorders in human males.
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Effects of diuron on male rat reproductive organs: a developmental and postnatal study.
Fernandes, Glaura S A; Favareto, Ana Paula A; Fernandez, Carla D B; Bellentani, Fernanda F; Arena, Arielle C; Grassi, Tony F; Kempinas, Wilma G; Barbisan, Luís F
2012-01-01
This study was performed to determine whether developmental exposure (perinatal and juvenile) to the herbicide diuron exerted adverse effects on adult rat male reproductive system. Pregnant Sprague-Dawley rats received basal diet or diet containing diuron at 500 or 750 ppm from gestational day 12 (GD 12) until the end of lactation period (postnatal day 21, PND 21). After weaning male offspring received basal diet or diet containing diuron until PND 42 (peripubertal age). At PND 90, adult male rats from each experimental group were anesthetized and euthanized for evaluation of body and reproductive organ weights, sperm parameters, plasma testosterone levels, and testicular and epididymal histopathology. Male offspring exposed to diuron at 750 ppm displayed reduced body weight at PND 10, 21, 42, and 90 compared to controls. At PND 90, diuron treatment did not induce significant change in daily sperm production, sperm morphology and motility, and testosterone levels compared to controls. In conclusion, diuron at 750 ppm induced male offspring toxicity but these alterations were not permanent, as evidenced by absence of reproductive-system alterations in adult Sprague Dawley rats.
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Aubin-Horth, Nadia; Dodson, Julian J
2004-01-01
In the conditional strategy model, divergence in reproductive phenotypes depends on whether the individual's condition is above or below a genetically determined threshold. The relative contribution of the genetic and environmental components that lead to the expression of a reproductive tactic by an individual is not well understood. In the present field study, we determined when condition diverged between males that develop the mature parr phenotype and those that do not in Atlantic salmon (Salmo salar). We also investigated the uniformity of the threshold value in the population. We sampled mature parr and immature males at age one, of the same population at six different sites for four consecutive years. Our study provides an example of the interaction of genotype and environment on the expression of a reproductive tactic. Size was significantly greater for future mature parr than for future immature males as early as 20 days after hatching (emergence), suggesting that there may be a parental effect component in the tactic adopted, since no exogenous feeding takes place before this time. Size advantage at emergence was maintained through the next spring at age one to different degrees depending on the year, thus suggesting the presence of an environmental component of tactic expression. Our results support the contention that within the conditional strategy, the environment faced by a male and his condition at the moment of reproduction consistently predicts neither the environment faced by his offspring nor the fitness they will obtain by expressing the same tactic as their father. Furthermore, higher mean size at a site did not always translate into a higher proportion of mature parr, therefore supporting the hypothesis that thresholds vary across habitats within the same population.
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Human leukocyte antigen-G in the male reproductive system and in seminal plasma
DEFF Research Database (Denmark)
Horup Larsen, Margit; Bzorek, Michael; Pass, Malene B.
2011-01-01
-eclampsia. We have investigated whether HLA-G protein is present in human seminal plasma and in different tissue samples of the male reproductive system.Western blot technique and a soluble HLA-G (sHLA-G) assay were used to detect sHLA-G in human seminal plasma samples. Immunohistochemical staining...... was performed on paraffin-embedded tissue samples. We detected sHLA-G protein in seminal plasma, and HLA-G expression in normal testis and in epididymal tissue of the male reproductive system but not in the seminal vesicle. Furthermore, the results indicated a weak expression of HLA–G in hyperplastic prostatic...... tissue. In summary, several of the findings reported in this study suggest an immunoregulatory role of HLA-G in the male reproductive system and in seminal plasma....
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Leite, Gabriel Adan Araújo; Figueiredo, Thamiris Moreira; Guerra, Marina Trevizan; Borges, Cibele Dos Santos; Fernandes, Fábio Henrique; Anselmo-Franci, Janete Aparecida; Kempinas, Wilma De Grava
2018-05-18
Obesity during childhood and adolescence is closely related to dysfunctions on lipid profile in children. Rosuvastatin is a statin that decreases serum total cholesterol. Ascorbic acid is an important antioxidant compound for male reproduction. Pre-pubertal male rats were distributed into six experimental groups that received saline solution 0.9% (vehicle), 3 or 10 mg/kg/day of rosuvastatin, 150 mg/day of ascorbic acid, or 3 or 10 mg/kg/day of rosuvastatin co-administered with 150 mg/day of ascorbic acid by gavage from post-natal day (PND)23 until PND53. Rats were maintained until adulthood and mated with nulliparous females to obtain the male offspring, whose animals were evaluated at adulthood in relation to reproductive parameters. This study is a follow up of a previous paper addressing potential effects on F0 generation only (Leite et al., 2017). Male offspring from rosuvastatin-exposed groups showed increased sperm DNA fragmentation, androgen depletion and impairment on the testicular and epididymal structure. Ascorbic acid coadministered to the fathers ameliorated the reproductive damage in the offspring. In summary, paternal exposure to rosuvastatin may affect the reproduction in the male offspring; however, paternal supplementation with ascorbic acid was able to reduce the reproductive impairment in the male offspring caused by statin treatment to the fathers. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Genetic diversity and reproductive success in mandrills (Mandrillus sphinx).
Charpentier, M; Setchell, J M; Prugnolle, F; Knapp, L A; Wickings, E J; Peignot, P; Hossaert-McKey, M
2005-11-15
Recent studies of wild animal populations have shown that estimators of neutral genetic diversity, such as mean heterozygosity, are often correlated with various fitness traits, such as survival, disease susceptibility, or reproductive success. We used two estimators of genetic diversity to explore the relationship between heterozygosity and reproductive success in male and female mandrills (Mandrillus sphinx) living in a semifree ranging setting in Gabon. Because social rank is known to influence reproductive success in both sexes, we also examined the correlation between genetic diversity and social rank in females, and acquisition of alpha status in males, as well as length of alpha male tenure. We found that heterozygous individuals showed greater reproductive success, with both females and males producing more offspring. However, heterozygosity influenced reproductive success only in dominant males, not in subordinates. Neither the acquisition of alpha status in males, nor social rank in females, was significantly correlated with heterozygosity, although more heterozygous alpha males showed longer tenure than homozygous ones. We also tested whether the benefits of greater genetic diversity were due mainly to a genome-wide effect of inbreeding depression or to heterosis at one or a few loci. Multilocus effects best explained the correlation between heterozygosity and reproductive success and tenure, indicating the occurrence of inbreeding depression in this mandrill colony.
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Saha, Kalyan B; Singh, Neeru; Chatterjee Saha, Uma; Roy, Jyotirmoy
2007-01-01
Indian tribal men's lack of participation in reproductive health not only damages their own health, but also contributes to the reproductive ill health of their female partners and children. In India the involvement of men in such matters is a new concept. There is a paucity of data particularly on Scheduled tribesmen's knowledge and the extent of their participation in reproductive health. This inhibits planning. The present study aims to understand the involvement of Scheduled tribesmen in reproductive health and the barriers to their involvement by generating a database from the Khairwar tribe of Central India. A door-to-door survey on knowledge, attitude and practice relating to aspects of reproductive health was conducted by canvassing a pre-designed interview schedule among 15-40 year old, currently married Khairwar males in the Sidhi district of Madhya Pradesh, India. As far as reproductive morbidity is concerned, only 17% of the respondents had heard of HIV/AIDS, and most had no proper knowledge of its transmission. Although 74% of the respondents had heard about reproductive tract infections, the majority of them were unaware of the mechanism of transmission and seriousness of the problem. The duel role of condoms, both as a method of family planning and a protective measure against sexually transmitted infections, was also unknown to them. Approximately 59% of the males were aware of family planning but only 13% were using any method (mostly female sterilization) at the time of survey. Their view on the ideal number of children (3.56) exceeded the actual number of children born and living. High infant and child mortality influenced their preference for higher fertility. Very few among them (29%) had knowledge of antenatal care. They expressed faulty knowledge, myths and unhelpful attitudes towards sexual health matters. The study revealed the male Scheduled tribe population's lack of knowledge and misinformation regarding male sexual health issues, the
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Age-dependent trade-offs between immunity and male, but not female, reproduction.
McNamara, Kathryn B; van Lieshout, Emile; Jones, Therésa M; Simmons, Leigh W
2013-01-01
Immune function is costly and must be traded off against other life-history traits, such as gamete production. Studies of immune trade-offs typically focus on adult individuals, yet the juvenile stage can be a highly protracted period when reproductive resources are acquired and immune challenges are ubiquitous. Trade-offs during development are likely to be important, yet no studies have considered changes in adult responses to immune challenges imposed at different stages of juvenile development. By manipulating the timing of a bacterial immune challenge to the larvae of the cotton bollworm moth, we examined potential trade-offs between investment into immunity at different stages of juvenile development (early or late) and subsequent adult reproductive investment into sperm or egg production. Our data reveal an age-dependent trade-off between juvenile immune function and adult male reproductive investment. Activation of the immune response during late development resulted in a reduced allocation of resources to eupyrene (fertilizing) sperm production. Immune activation from the injection procedure itself (irrespective of whether individuals were injected with an immune elicitor or a control solution) also caused reproductive trade-offs; males injected early in development produced fewer apyrene (nonfertilizing) sperm. Contrary to many other studies, our study demonstrates these immune trade-offs under ad libitum nutritional conditions. No trade-offs were observed between female immune activation and adult reproductive investment. We suggest the differences in trade-offs observed between male sperm types and the absence of reproductive trade-offs in females may be the result of ontogenetic differences in gamete production in this species. Our data reveal developmental windows when trade-offs between immune function and gametic investment are made, and highlight the importance of considering multiple developmental periods when making inferences regarding the
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Multiscale Systems Modeling of Male Reproductive Tract ...
The reproductive tract is a complex, integrated organ system with diverse embryology and unique sensitivity to prenatal environmental exposures that disrupt morphoregulatory processes and endocrine signaling. U.S. EPA’s in vitro high-throughput screening (HTS) database (ToxCastDB) was used to profile the bioactivity of 54 chemicals with male developmental consequences across ~800 molecular and cellular features [Leung et al., accepted manuscript]. The in vitro bioactivity on molecular targets could be condensed into 156 gene annotations in a bipartite network. These results highlighted the role of estrogen and androgen signaling pathways in male reproductive tract development, and importantly, broadened the list of molecular targets to include GPCRs, cytochrome-P450s, vascular remodeling proteins, and retinoic acid signaling. A multicellular agent-based model was used to simulate the complex interactions between morphoregulatory, endocrine, and environmental influences during genital tubercle (GT) development. Spatially dynamic signals (e.g., SHH, FGF10, and androgen) were implemented in the model to address differential adhesion, cell motility, proliferation, and apoptosis. Urethral tube closure was an emergent feature of the model that was linked to gender-specific rates of ventral mesenchymal proliferation and urethral plate endodermal apoptosis, both under control of androgen signaling [Leung et al., manuscript in preparation]. A systemic parameter sweep w
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Changes in male reproductive health and effects of endocrine disruptors in Scandinavian countries
Directory of Open Access Journals (Sweden)
Toppari Jorma
2002-01-01
Full Text Available Male reproductive health has deteriorated in many ways during the last decades. The incidence of testicular cancer has rapidly increased in Europe and European-derived populations. Sperm concentrations have declined and sperm motility and morphology have worsened in many areas. Both adverse trends have been shown to be associated with year of birth. Older birth cohorts have better reproductive health than the younger generations. Incidences of cryptorchidism and hypospadias have also increased according to several studies. The reasons for secular trends are unknown, but the rapid pace of the change points to environmental causes. Endocrine disrupting chemicals have been hypothesized to influence male reproductive health.
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Effects of Male on Reproductive Behavior of Markhoz Female Goats in Breeding Season
Directory of Open Access Journals (Sweden)
H. Daghigh Kia
2012-09-01
Full Text Available In order to study the effect of male on reproductive behavior of female goats, 88 Markhoz breed goats with initial body weight of 42±2kg, 3.5 year old, and 10 male goats were used for 6 weeks. This study was conducted in two phases. In the first experiment 48 female goats were allocated in three groups, each group included eight animals with 2 replicate on both sides of male goats, respectively, at intervals of 0-5, 10-15 and 25-30 meters. In the second experiment, 24 female goats having CIDR were used in an order similar to that of first group. However, the goats were located only in one side of the males. The third group was the control group which was treated in a separate saloon in two groups, each of them having eight animals in it. Results showed a significant effect of male animal in estrus synchronization, the earlier beginning of the reproductive cycle and fertility in the early reproductive season. The first group showed better results in creation and synchronization of estrus in comparison to CIDR received animals (respectively 116.7 vs. 91.6%.
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Haron, M N; Mohamed, M
2016-06-01
Exposure to prenatal stress is associated with impaired reproductive function in male rat offspring. Honey is traditionally used by the Malays for enhancement of fertility. The aim of this study was to determine the effect of honey on reproductive system of male rat offspring exposed to prenatal restraint stress. Dams were divided into four groups (n = 10/group): control, honey, stress and honey + stress groups. Dams from honey and honey + stress groups received oral honey (1.2 g kg(-1) body weight) daily from day 1 of pregnancy, meanwhile dams from stress and honey + stress groups were subjected to restraint stress (three times per day) from day 11 of pregnancy until delivery. At 10 weeks old, each male rat offspring was mated with a regular oestrus cycle female. Male sexual behaviour and reproductive performance were evaluated. Then, male rats were euthanised for assessment on reproductive parameters. Honey supplementation during prenatal restraint stress significantly increased testis and epididymis weights as well as improved the percentages of abnormal spermatozoa and sperm motility in male rat offspring. In conclusion, this study might suggest that supplementation of honey during pregnancy seems to reduce the adverse effects of restraint stress on reproductive organs weight and sperm parameters in male rat offspring. © 2015 Blackwell Verlag GmbH.
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Rubinstein, C Dustin; Wolfner, Mariana F
2014-01-01
Seminal proteins are critical for reproductive success in all animals that have been studied. Although seminal proteins have been identified in many taxa, and female reproductive responses to receipt of these proteins have been documented in several, little is understood about the mechanisms by which seminal proteins affect female reproductive physiology. To explore this topic, we investigated how a Drosophila seminal protein, ovulin, increases ovulation rate in mated females. Ovulation is a relatively simple physiological process, with known female regulators: previous studies have shown that ovulation rate is promoted by the neuromodulator octopamine (OA) in D. melanogaster and other insects. We found that ovulin stimulates ovulation by increasing OA signaling in the female. This finding supports a model in which a male seminal protein acts through "hacking" a well-conserved, regulatory system females use to adjust reproductive output, rather than acting downstream of female mechanisms of control or in parallel pathways altogether. We also discuss similarities between 2 forms of intersexual control of behavior through chemical communication: seminal proteins and pheromones.
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Testosterone and reproductive effort in male primates.
Muller, Martin N
2017-05-01
Considerable evidence suggests that the steroid hormone testosterone mediates major life-history trade-offs in vertebrates, promoting mating effort at the expense of parenting effort or survival. Observations from a range of wild primates support the "Challenge Hypothesis," which posits that variation in male testosterone is more closely associated with aggressive mating competition than with reproductive physiology. In both seasonally and non-seasonally breeding species, males increase testosterone production primarily when competing for fecund females. In species where males compete to maintain long-term access to females, testosterone increases when males are threatened with losing access to females, rather than during mating periods. And when male status is linked to mating success, and dependent on aggression, high-ranking males normally maintain higher testosterone levels than subordinates, particularly when dominance hierarchies are unstable. Trade-offs between parenting effort and mating effort appear to be weak in most primates, because direct investment in the form of infant transport and provisioning is rare. Instead, infant protection is the primary form of paternal investment in the order. Testosterone does not inhibit this form of investment, which relies on male aggression. Testosterone has a wide range of effects in primates that plausibly function to support male competitive behavior. These include psychological effects related to dominance striving, analgesic effects, and effects on the development and maintenance of the armaments and adornments that males employ in mating competition. Copyright © 2016 Elsevier Inc. All rights reserved.
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Survival rates and lifetime reproduction of breeding male Cooper’s Hawks in Wisconsin, 1980-2005
Rosenfield, Robert N.; Bielefeldt, John; Rosenfield, Laura J.; Booms, Travis L.; Bozek, Michael A.
2009-01-01
There are few published data on annual survival and no reports of lifetime reproduction for breeding Cooper's Hawks (Accipiter cooperii). Breeding males (n = 105) in central and southeastern Wisconsin had an annual mortality rate of 19%, or a survival rate of 81% for birds ≤10 years of age. We did not detect significant differences in mortality rates between urban and rural habitats, nor between the earlier 13 years and later 13 years of this study. Male Cooper's Hawks produced from zero to 32 nestlings during their lifetimes. Body mass or size appeared unrelated to annual survivorship and lifetime reproduction, although lifetime reproduction was correlated strongly with longevity of breeding males. Fifteen of 66 males (23%) produced most (53%) of the nestlings. Our studies occurred in an area where breeding populations may be increasing with some of the highest reported productivity indices and nesting densities for this species. Habitat used for nesting on our Wisconsin study areas may be less important for survivorship and lifetime reproduction than acquisition of a nesting area in which a male will breed throughout his life.
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Male and female alcohol consumption and live birth after assisted reproductive technology treatment
DEFF Research Database (Denmark)
Vittrup, Ida; Petersen, Gitte Lindved; Kamper-Jørgensen, Mads
2017-01-01
The objective was to assess the potential association between female and male alcohol consumption and probability of achieving a live birth after assisted reproductive treatment. From a nationwide Danish register-based cohort information on alcohol consumption at assisted reproductive treatment i...
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Low birth weight and male reproductive function
DEFF Research Database (Denmark)
Main, K M; Jensen, R B; Asklund, C
2006-01-01
Scientific interest in morbidity in children born small for gestational age (SGA) has increased considerably over the last few decades. The elevated risk of cardiovascular and metabolic diseases in adulthood in individuals born SGA has been well documented, whereas data on gonadal development are...... of individual study results, the combined evidence from all data leaves little doubt that fetal growth restriction is associated with increased risk of male reproductive health problems, including hypospadias, cryptorchidism and testicular cancer....
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Gross and Morphometric Anatomy of the Male Reproductive System of Bats (Eidolon helvum
Directory of Open Access Journals (Sweden)
A. Danmaigoro
2014-01-01
Full Text Available The present study aimed at examining the gross and morphometry of the reproductive tract of the male bats (Eidolon helvum. Thirty male bats (adults n=17 and juveniles n=13 were captured using net, weighed, aged using relative ossification of the wing bone, and dissected for gross examination. Morphologically, the mean body weight and forearm length in both adults and juveniles were 235.31±6.30 g, 12.14±0.19 cm and 69.54±7.68 g, 7.77±0.29 cm, respectively. The testicles were completely descended in adults with the penis projected cranially. The epididymides were found at the median border of the testis and continues as vas deferens. No significant differences (P>0.05 were observed between right and left testicular weights in both adults and juveniles and also in lengths of different parts of the reproductive segments in both age groups assessed, respectively. This work has documented the gross anatomy of the male reproductive tract in bats. Ultrastructure and histochemistry are recommended for further insight into the reproductive biology.
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Expression of GAT1 in male reproductive system and its effects on reproduction in mice.
Zhang, JinFu; Gui, YaPing; Yuan, Tao; Bian, CuiDong; Guo, LiHe
2009-12-01
The present study was carried out to identify GABA (gamma-aminobutyric acid) transport protein I (GAT1) in male reproductive organs and to study the effect of GAT1 overexpression on the male reproductive system in GAT1 transgenic mice (TG). Expression and location of GAT1 in testes, epididymis, and sperm of wild-type (WT) mice were identified by immunohistochemistry and western-blot. Histological changes of testes, epididymis, and sperm of transgenic mice overexpressing GAT1 were detected by immunofluorenscent staining and haematoxylin and eosin (HE) staining. GAT1 expression was detected in the testes, epididymis, and sperm of non-transgenic mice. Vacuolization and deformity of spermatogenic cells were observed in the transgenic mice, but the epididymis was unremarkable. Immunofluorenscent staining showed that the number of diastrophic and decapitated sperm increased significantly in transgenic mice to 46.9% from 7.3% in nontransgenic mice. These results suggest that abnormal expression of GAT1 could result in spermiogenesis function injury, sperm paramorphia and dysgenesis.
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Effects of Ascorbic Acid on Reproductive Functions of Male Wistar ...
African Journals Online (AJOL)
In conclusion, ascorbic acid supplement may suppress nicotine toxic effects on reproductive functions in male rats. ... et al., 2007). Nicotine is rapidly absorbed by the brain .... difference (LSD) test. p<0.05 was considered significant. Statistical ...
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Freyth, Katharina; Janowitz, Tim; Nunes, Frank; Voss, Melanie; Heinick, Alexander; Bertaux, Joanne; Scheu, Stefan; Paul, Rüdiger J
2010-10-01
Laboratory breeding conditions of the model organism C. elegans do not correspond with the conditions in its natural soil habitat. To assess the consequences of the differences in environmental conditions, the effects of air composition, medium and bacterial food on reproductive fitness and/or dietary-choice behavior of C. elegans were investigated. The reproductive fitness of C. elegans was maximal under oxygen deficiency and not influenced by a high fractional share of carbon dioxide. In media approximating natural soil structure, reproductive fitness was much lower than in standard laboratory media. In seminatural media, the reproductive fitness of C. elegans was low with the standard laboratory food bacterium E. coli (γ-Proteobacteria), but significantly higher with C. arvensicola (Bacteroidetes) and B. tropica (β-Proteobacteria) as food. Dietary-choice experiments in semi-natural media revealed a low preference of C. elegans for E. coli but significantly higher preferences for C. arvensicola and B. tropica (among other bacteria). Dietary-choice experiments under quasi-natural conditions, which were feasible by fluorescence in situ hybridization (FISH) of bacteria, showed a high preference of C. elegans for Cytophaga-Flexibacter-Bacteroides, Firmicutes, and β-Proteobacteria, but a low preference for γ-Proteobacteria. The results show that data on C. elegans under standard laboratory conditions have to be carefully interpreted with respect to their biological significance.
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Effect of Sleep Deprivation on the Male Reproductive System in Rats.
Choi, Ji Ho; Lee, Seung Hoon; Bae, Jae Hyun; Shim, Ji Sung; Park, Hong Seok; Kim, Young Sik; Shin, Chol
2016-10-01
There has been no study reporting on the influence of sleep deprivation on the male reproductive system including sperm quality. In this study, we hypothesized that sleep deprivation could lead to adverse effect on the male reproductive system. The rats were divided into three groups: 1) control (home-cage, n = 10); 2) SD4 (sleep deprivation for 4 days, n = 10); and 3) SD7 (sleep deprivation for 7 days, n = 10). Sleep deprivation was performed by a modified multiple platform method. Sperm quality (sperm motion parameters and counts), hormone levels (corticosterone and testosterone), and the histopathology of testis were evaluated and compared between the three groups. A statistically significant reduction (P = 0.018) was observed in sperm motility in the SD7 group compared to those of the control group. However, there were no significant differences in other sperm motion parameters, or in sperm counts of the testis and cauda epididymis between three groups. Compared with the control group, the SD4 (P = 0.033) and SD7 (P = 0.002) groups exhibited significant increases of corticosterone levels, but significant decreases of testosterone levels were found in the SD4 (P = 0.001) and SD7 (P Sleep deprivation may have an adverse effect on the male reproductive system in rats.
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Effect of diet on male reproductive tract of Podisus nigrispinus (Dallas (Heteroptera: Pentatomidae
Directory of Open Access Journals (Sweden)
W. P Lemos
Full Text Available The morphology and histology of the reproductive tract of males of the predator Podisus nigrispinus (Dallas fed on different diets were studied. P. nigrispinus was fed on diets of: larvae of Alabama argillacea (Hübner, Tenebrio molitor L., Musca domestica L., and an artificial diet. The male reproductive tract, independent of diet, showed testes with intense red coloration in a compact, circular, or slightly oval structure. The vasa deferentia were similar in color to the testes and formed long filaments, which joined with the yellow-cream colored ejaculatory duct. The morphological characteristics of the male reproductive tract were similar under all diets, except for the artificial one. The histological studies demonstrated that independent of the diet the testes of P. nigrispinus were composed of four to six follicles. The testes with six follicles generally had four developed and two atrophied follicles. The morphological and histological differences of the testes of P. nigrispinus when fed with different prey are presented and discussed.
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Possible influence of vitamin D on male reproduction
DEFF Research Database (Denmark)
Boisen, Ida Marie; Hansen, Lasse Bøllehuus; Mortensen, Li Juel
2017-01-01
Vitamin D is a versatile signaling molecule with an established role in the regulation of calcium homeostasis and bone health. In recent years the spectrum of vitamin D target organs has expanded and a reproductive role is supported by the presence of the vitamin D receptor (VDR) and the vitamin D...... studies have supported the notion of a positive association between serum 25-hydroxyvitamin D (25-OHD) level and semen quality in both fertile and infertile men. However, it remains to be determined whether this association reflects a causal effect. The VDR is ubiquitously expressed and activated vitamin...... steroid production in infertile men. In this review known and possible future implications of vitamin D in human male reproduction function will be discussed....
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Kelly, Natasha B; Alonzo, Suzanne H
2009-09-07
Existing theory predicts that male signalling can be an unreliable indicator of paternal care, but assumes that males with high levels of mating success can have high current reproductive success, without providing any parental care. As a result, this theory does not hold for the many species where offspring survival depends on male parental care. We modelled male allocation of resources between advertisement and care for species with male care where males vary in quality, and the effect of care and advertisement on male fitness is multiplicative rather than additive. Our model predicts that males will allocate proportionally more of their resources to whichever trait (advertisement or paternal care) is more fitness limiting. In contrast to previous theory, we find that male advertisement is always a reliable indicator of paternal care and male phenotypic quality (e.g. males with higher levels of advertisement never allocate less to care than males with lower levels of advertisement). Our model shows that the predicted pattern of male allocation and the reliability of male signalling depend very strongly on whether paternal care is assumed to be necessary for offspring survival and how male care affects offspring survival and male fitness.
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Energy Technology Data Exchange (ETDEWEB)
Tian, Hua; Li, Yun; Wang, Wei; Wu, Peng; Ru, Shaoguo, E-mail: rusg@ouc.edu.cn
2012-09-01
Monocrotophos is a highly toxic organophosphorus pesticide that has been confirmed to be an endocrine‐disrupting chemical. To evaluate the influence of this pollutant on the reproductive system of male fish, we studied the sex steroid levels, reproductive traits, sex ratio, and reproductive success in male guppies (Poecilia reticulata) exposed to 40% monocrotophos pesticide at the nominal concentrations of 0.01, 0.10, and 1.00 mg/L for 90 days from birth to adulthood in a semi‐static exposure system. Radioimmunoassay and western blot analyses demonstrated that the long‐term exposure to monocrotophos pesticide during the sexual development of male guppies caused a significant increase in 17β‐estradiol levels and consequently induced vitellogenin synthesis, suggesting the feminization of the males. Monocrotophos pesticide also caused a significant decrease in testosterone levels, which consequently inhibited testis growth and reduced the sperm count and the area and intensity of their sexually attractive orange spots, which collectively indicated the significant demasculinization of the male sexual characteristics. Furthermore, these changes in the sexual characteristics at the cellular and organ levels translated into ecologically important effects on the reproductive success at the individual level, as measured by a decrease in offspring production and survival rate. The present study provides the first evidence that monocrotophos pesticide can cause severe reproductive abnormalities in fish due to its endocrine‐disrupting action. -- Highlights: ► Monocrotophos pesticide caused an increase in 17β‐estradiol levels of male guppies. ► Monocrotophos pesticide induced vitellogenin synthesis of male guppies. ► Monocrotophos pesticide caused a decrease in testosterone levels of male guppies. ► Monocrotophos pesticide caused demasculinization of male sexual characteristics. ► Monocrotophos pesticide caused a reduction in reproductive success of male
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International Nuclear Information System (INIS)
Tian, Hua; Li, Yun; Wang, Wei; Wu, Peng; Ru, Shaoguo
2012-01-01
Monocrotophos is a highly toxic organophosphorus pesticide that has been confirmed to be an endocrine‐disrupting chemical. To evaluate the influence of this pollutant on the reproductive system of male fish, we studied the sex steroid levels, reproductive traits, sex ratio, and reproductive success in male guppies (Poecilia reticulata) exposed to 40% monocrotophos pesticide at the nominal concentrations of 0.01, 0.10, and 1.00 mg/L for 90 days from birth to adulthood in a semi‐static exposure system. Radioimmunoassay and western blot analyses demonstrated that the long‐term exposure to monocrotophos pesticide during the sexual development of male guppies caused a significant increase in 17β‐estradiol levels and consequently induced vitellogenin synthesis, suggesting the feminization of the males. Monocrotophos pesticide also caused a significant decrease in testosterone levels, which consequently inhibited testis growth and reduced the sperm count and the area and intensity of their sexually attractive orange spots, which collectively indicated the significant demasculinization of the male sexual characteristics. Furthermore, these changes in the sexual characteristics at the cellular and organ levels translated into ecologically important effects on the reproductive success at the individual level, as measured by a decrease in offspring production and survival rate. The present study provides the first evidence that monocrotophos pesticide can cause severe reproductive abnormalities in fish due to its endocrine‐disrupting action. -- Highlights: ► Monocrotophos pesticide caused an increase in 17β‐estradiol levels of male guppies. ► Monocrotophos pesticide induced vitellogenin synthesis of male guppies. ► Monocrotophos pesticide caused a decrease in testosterone levels of male guppies. ► Monocrotophos pesticide caused demasculinization of male sexual characteristics. ► Monocrotophos pesticide caused a reduction in reproductive success of male
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Muniz, Laura; Perry, Susan; Manson, Joseph H; Gilkenson, Hannah; Gros-Louis, Julie; Vigilant, Linda
2010-12-01
Theory and a growing body of empirical evidence suggest that higher ranking males experience reproductive advantages in group-living mammals. White-faced capuchins (Cebus capucinus) exhibit an interesting social system for investigating the relationship between dominance and reproductive success (RS) because they live in multimale multifemale social groups, in which the alpha males can have extraordinarily long tenures (i.e. they coreside with daughters of reproductive age). Genetic paternity was determined from fecal samples for 120 infants born into three social groups of wild C. capucinus at Lomas Barbudal Biological Reserve, Costa Rica. Alpha males produced far more offspring than expected by chance, and significantly high Nonac's B indices (a measure of deviation from a random distribution of RS among potentially breeding individuals) were a feature of six out of eight male tenures. The likelihood of the alpha male siring a particular offspring was predicted by the kin relationship between the mother and the alpha male, as well as the total number of males and females in the group. The almost complete lack of father-daughter inbreeding [Muniz et al., 2006] constitutes an impediment to alpha male reproductive monopolization in this population, particularly toward the end of long alpha male tenures. © 2010 Wiley-Liss, Inc.
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Male reproduction and environmental and occupational exposures: a review of epidemiologic methods
Directory of Open Access Journals (Sweden)
Golden Anne L.
1999-01-01
Full Text Available Concerns that chemical exposures in the environment have been detrimental to male sexual development and fertility have been heightened by reports of declining sperm counts over the past 50 years. Marked geographic variation has been found in semen quality and in the incidence of testicular cancer and certain urogenital defects. Debate continues over the existence, magnitude and significance of these trends, and how best to evaluate the hypothesis that in utero and childhood exposures to estrogenic compounds may be to blame. Epidemiologic methods for assessing the impact of hazardous substances on male reproductive health have been developed mainly in the area of occupational medicine, and this paper will review the currently recommended methods. These include questionnaires to determine reproductive history and sexual function; reproductive hormone profiles; and semen analyses such as sperm concentration, motility, and morphology. New research tools that show significant promise from the fields of clinical reproductive medicine and reproductive toxicology are discussed as possible additions to epidemiologic studies, including assays of sperm function and genetic integrity, and biomarkers of DNA damage. For population-based studies involving occupational groups or communities with environmental exposures, issues related to the cost, validity, precision and utility of these methods must be carefully considered.
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Sodium arsenite-induced reproductive toxicities in male Wistar rats ...
African Journals Online (AJOL)
Sodium arsenite-induced reproductive toxicities in male Wistar rats: role of Tridax procumbens leaf extract. ... Bulletin of Animal Health and Production in Africa ... In the present study, the effects of ethanol leaf extract of Tridax procumbens ... in Groups B to D as compared to Group A was significantly reduced (p<0.05).
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International Nuclear Information System (INIS)
Shin, Takeshi; Tanaka, Takashi; Nishio, Koujiro; Arai, Manabu; Okada, Horoshi; Nozaki, Miwako; Kaji, Yasushi
2017-01-01
This paper reviewed the current situation and problems of cancer - reproductive therapy from the standpoint of male reproductive therapy. Common causes for male infertility include spermatogenic dysfunction, seminal duct dysfunction, and sexual dysfunction. Causes of male infertility in cancer patients include the presence of cancer itself, as well as pathological conditions due to surgery, radiation therapy, or chemotherapy for cancer, namely spermatogenic dysfunction, seminal duct dysfunction, and sexual dysfunction. The American Society of Clinical Oncology (ASCO) presents the risk classification of infertility due to anti-cancer drugs or radiotherapy. Cancer treating physicians evaluate infertility risk associated with treatment according to this risk classification and provide patients with information. If a patient wishes to preserve fertility, it is recommended in ASCO's fertility preservation guidelines to introduce the facilities that can store frozen sperm. Questionnaire surveys on sperm cryopreservation to blood physician show that the description of sperm cryopreservation is made at only about two-thirds of facilities and there is a problem that the systemization of cryopreservation has not progressed. The only way to acquire a baby in a patient who has undergone cancer treatment without cryopreservation and became permanent azoospermia is microscopic testis sperm collection and microinsemination. (A.O.)
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Development of a male reproductive toxicity assay for evaluating the success of bioremediation
International Nuclear Information System (INIS)
Schrock, E.J.; Bantle, J.A.
1995-01-01
The Eglin Air Force Base was contaminated with JP-4 over 10 years ago. The project goal was to develop and evaluate male reproductive toxicity testing procedures and endpoints using the gametes of the South African clawed frog Xenopus laevis with particular emphasis on assessing the toxicity of contaminated soil from Eglin Air Force Base in Florida. Reproductive toxicity tests were done to evaluate several different locations within the original spill area. Specific sites were selected based on their location to the spill site. The site was evaluated before and after remediation. Before remediation, the males were exposed to the JP-4 orally for 73 days, with the contaminant injected into the food source. After remediation, the males were directly exposed to the contaminated soil samples for 60 days. The endpoints measured in both studies were: change in body weight, organ to body weight ratios, sperm counts, number of malformed sperm, and sperm motility. In both the pre and post remediation studies, there were no significant effects on body weight or organ weight data at the p ≤ 0.05 level. However, there were effects seen in sperm count and morphology. The male reproductive toxicity assay under development has given useful information in initially determining the reproductive toxicity of JP-4. Significant effects were seen in both the pre and post remediation direct exposure tests, indicating that the direct exposure route may be the most promising for future testing
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Cardoso, Sara D.; Faustino, Ana Isabel Soares; Costa, Silvia S.; Valério, Fábio; Gonçalves, David; Oliveira, Rui Filipe
2016-01-01
Material suplementar está disponível online em doi: 10.1007/s10211-016-0249-9, disponibilizado a todos os utilizadores autorizados. Alternative reproductive tactics (ARTs) evolve when there is strong intra-sexual competition between conspecifics for access to mates. Typically, larger Bbourgeois^ males reproduce by securing the access to reproductive resources while smaller Bparasitic^ males reproduce by stealing fertilizations from larger males. A number of factors can influ...
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Kappeler, Peter M.; Port, Markus
2008-01-01
The social organization of gregarious lemurs significantly deviates from predictions of the socioecological model, as they form small groups in which the number of males approximately equals the number of females. This study uses models of reproductive skew theory as a new approach to explain this unusual group composition, in particular the high number of males, in a representative of these lemurs, the redfronted lemur (Eulemur fulvus rufus). We tested two central predictions of “concession”...
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Directory of Open Access Journals (Sweden)
Chapman Tracey
2008-08-01
Full Text Available Abstract Background Exaggerated male ornaments and displays often evolve in species where males only provide females with ejaculates during reproduction. Although "good genes" arguments are typically invoked to explain this phenomenon, a simpler alternative is possible if variation in male reproductive quality (e.g. sperm number, ejaculate content, mating rate is an important determinant of female reproductive success. The "phenotype-linked fertility hypothesis" states that female preference for male ornaments or displays has been selected to ensure higher levels of fertility and has driven the evolution of exaggerated male traits. Females of the stalk-eyed fly Teleopsis dalmanni must mate frequently to maintain high levels of fertility and prefer to mate with males exhibiting large eyespan, a condition-dependent sexual ornament. If eyespan indicates male reproductive quality, females could directly increase their reproductive success by mating with males with large eyespan. Here we investigate whether male eyespan indicates accessory gland and testis length, and then ask whether mating with large eyespan males affects female fertility. Results Male eyespan was a better predictor of two key male reproductive traits – accessory gland and testis length – than was body size alone. This positive relationship held true over three levels of increasing environmental stress during the maturation of the adult accessory glands and testes. Furthermore, females housed with a large eyespan male exhibited higher levels of fertility than those with small eyespan males. Conclusion Male eyespan in stalk-eyed flies is subject to strong directional mate preference and is a reliable indicator of male reproductive quality – both because males with larger eyespan have bigger accessory glands and testes, and also as they confer higher fertility on females. Fertility enhancement may have arisen because males with larger eyespan mated more often and/or because
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Directory of Open Access Journals (Sweden)
Severin Dushimirimana
2012-02-01
The sterile insect technique (SIT is increasingly used to control pest insect populations. The success of SIT control programs depends on the ability to release sterile males and on the capacity of sterile males to compete with wild males to inseminate wild females. In this study, we evaluated the mating performance of Schistocerca gregaria (Försk. males irradiated with 4 Gray. We compared reproductive traits, such as duration of precopulation time, mating duration, quantity of sperm stored by females after copulation, number of females mated successively and postmating competition of irradiated males with non-irradiated males. Irradiated males were able to mate but the resulting number of offspring was dramatically reduced compared to the average number of offspring observed during a regular mating. During a single copulation, irradiated males transferred fewer sperm than regular males but, theoretically, this quantity is enough to fertilize all the eggs produced by a female during its reproductive life. Irradiated males also had the ability to remove sperm from a previous mating with unirraditated males. This new information on the mating strategies helps explain the post-copulation guarding behaviour of S. gregaria.
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Cuccu, Danila; Mereu, Marco; Agus, Blondine; Cau, Angelo; Culurgioni, Jacopo; Sabatini, Andrea; Jereb, Patrizia
2014-09-01
Coleoid cephalopods go through a single breeding period in their life cycle, i.e., they are semelparous, although a great flexibility has been observed in their reproductive strategies, which range from simultaneous terminal spawning over a short period at the end of the animal's life to continuous spawning over a long period of the animal's life. So far, the information available on deep-sea species reproductive strategies is still poor and most of our knowledge about squid reproduction relates to females. In particular, not much is known on what strategy male squids have evolved to store sperm into spermatophores and adapt to semelparity. In this study an investigation of male reproductive strategy of the deep-sea umbrella squid Histioteuthis bonnellii (Férussac, 1835) is presented. The reproductive system was examined in 119 males caught in the Sardinian waters (Central Western Mediterranean) and is described for the first time. Results indicate that this species produces and stores spermatophores over a considerable period of time. The total number of spermatophores found in the reproductive system ranged between 12 and 3097 and the size of spermatophores stored by a single individual varied greatly, up to over 300%. Spermatophore length (SpL) gradually decreased towards the distal end of the reproductive system, so that spermatophores found in the proximal part of Needham's Sac were larger than those found in the terminal organ. Body size and SpL of spermatophores from the proximal part of Needham's Sac were positively correlated. Both indices of the sperm mass and of the ejaculatory apparatus decreased with the increase of SpL, while the cement body index increased, indicating that larger spermatophores contain less sperm and are equipped with larger cement bodies. Up to 64 spermatangia were found, exclusively in the terminal organ. The large size range of mature males (ML: 60.0-198.0 mm; TW: 113.50-2409.00 g) and the variation in spermatophore number and
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State of reproductive system glands in males participated in the Chernobyl accident response
International Nuclear Information System (INIS)
Evdokimov, V.V.; Erasova, V.I.; Demin, A.I.; Dubinina, E.B.; Lyubchenko, P.N.
1993-01-01
State of reproductive system glands in males participated in the Chernobyl accident response and exposed to external irradiation at the dose up to 25 cGy was studied. 164 men at the age of 22-50 y.o. were examinated. Percentages of the various reproductive disorders were presented
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Adverse Effects of Common Sports and Recreational Activities on Male Reproduction.
Panara, Kush; Masterson, John M; Savio, Luis F; Ramasamy, Ranjith
2018-05-03
Male factor infertility plays a significant role in infertility. Many factors have been associated with male infertility; however, the link between many sports and recreational factors and male reproduction remains poorly characterized. To evaluate the current literature regarding the impact of many common sports and recreational factors on male reproduction. A comprehensive PubMed and Embase search for relevant articles published between 1970 and 2017 was performed by combining the following search terms: male, sports (including individual sports), traumatic brain injury, sauna, hot tub, fertility, erectile dysfunction, varicocele, environment, cell phone, and laptop computer. Hypogonadism and erectile dysfunction can be associated with sports with high rates of head injuries, such as American football. Although early reports linked other sports, such as bicycling, to erectile dysfunction, subsequent studies isolated these associations to sports cycling rather than recreational cycling. Certain sports (football, basketball, handball, and volleyball) were linked to increasing prevalence and severity of varicocele, offering a potential link to male infertility. In addition, recreational activities such as sauna, hot tubs, Jacuzzis, heated car seats, and laptop use were associated with high testicular temperature, which can impair spermatogenesis. Radio frequency electromagnetic waves from cell phones and laptops have also been shown to have deleterious effects on sperm viability and motility. Many common sports and daily activities represent potential sources of male infertility. Clinicians should be aware of these associations in explaining idiopathic infertility in males. Male infertility is an often overlooked component of a couple's inability to conceive. We outline many common and often overlooked sports and recreational exposures that have been associated with male infertility. Copyright © 2018 European Association of Urology. Published by Elsevier B.V. All
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Silk amino acids improve physical stamina and male reproductive function of mice.
Shin, Sunhee; Yeon, Seongho; Park, Dongsun; Oh, Jiyoung; Kang, Hyomin; Kim, Sunghyun; Joo, Seong Soo; Lim, Woo-Taek; Lee, Jeong-Yong; Choi, Kyung-Chul; Kim, Ki Yon; Kim, Seung Up; Kim, Jong-Choon; Kim, Yun-Bae
2010-01-01
The effects of a silk amino acid (SAA) preparation on the physical stamina and male reproductive function of mice were investigated. Eight-week-old male ICR mice (29-31 g) were orally administered SAA (50, 160 or 500 mg/kg) for 44 d during 30-min daily swimming exercise. The mice were subjected to a weight-loaded (5% of body weight) forced swimming on the 14th, 28th and 42nd day to determine maximum swimming time, and after a 2-d recovery period (treated with SAA without swimming exercise), parameters related to fatigue and reproductive function were analyzed from blood, muscles and reproductive organs. Repeated swimming exercise increased the maximum swimming time to some extent, in spite of a marked reduction in body weight gain, and SAA further enhanced the stamina in a dose-dependent manner. Forced swimming exercises increased blood parameters of tissue injury, but depleted blood glucose and tissue glycogen, which were substantially prevented by SAA treatment. In addition, SAA significantly reduced the muscular thiobarbituric acid-reactive substances and blood corticosterone content increased by forced swimming. Swimming exercise decreased the blood testosterone level, which was recovered by SAA, leading to enhanced sperm counts. These combined results indicate that SAA not only enhances physical stamina by minimizing damage to tissues, including muscles, as well as preventing energy depletion caused by swimming stress, but also improves male reproductive function by increasing testosterone and sperm counts.
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Partridge, Charlyn G; MacManes, Matthew D; Knapp, Rosemary; Neff, Bryan D
2016-01-01
Bluegill sunfish (Lepomis macrochirus) are one of the classic systems for studying male alternative reproductive tactics (ARTs) in teleost fishes. In this species, there are two distinct life histories: parental and cuckolder, encompassing three reproductive tactics, parental, satellite, and sneaker. The parental life history is fixed, whereas individuals who enter the cuckolder life history transition from sneaker to satellite tactic as they grow. For this study, we used RNAseq to characterize the brain transcriptome of the three male tactics and females during spawning to identify gene ontology (GO) categories and potential candidate genes associated with each tactic. We found that sneaker males had higher levels of gene expression differentiation compared to the other two male tactics. Sneaker males also had higher expression in ionotropic glutamate receptor genes, specifically AMPA receptors, compared to other males, which may be important for increased spatial working memory while attempting to cuckold parental males at their nests. Larger differences in gene expression also occurred among male tactics than between males and females. We found significant expression differences in several candidate genes that were previously identified in other species with ARTs and suggest a previously undescribed role for cAMP-responsive element modulator (crem) in influencing parental male behaviors during spawning.
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Human leukocyte antigen-G in the male reproductive system and in seminal plasma.
Larsen, Margit Hørup; Bzorek, Michael; Pass, Malene B; Larsen, Lise Grupe; Nielsen, Mette Weidinger; Svendsen, Signe Goul; Lindhard, Anette; Hviid, Thomas Vauvert F
2011-12-01
One of the non-classical human leukocyte antigen (HLA) class Ib proteins, HLA-G, is believed to exert important immunoregulatory functions, especially during pregnancy. The presence of HLA protein in paternal seminal fluid has been suggested to have an influence on the risk of developing pre-eclampsia. We have investigated whether HLA-G protein is present in human seminal plasma and in different tissue samples of the male reproductive system. Western blot technique and a soluble HLA-G (sHLA-G) assay were used to detect sHLA-G in human seminal plasma samples. Immunohistochemical staining was performed on paraffin-embedded tissue samples. We detected sHLA-G protein in seminal plasma, and HLA-G expression in normal testis and in epididymal tissue of the male reproductive system but not in the seminal vesicle. Furthermore, the results indicated a weak expression of HLA-G in hyperplastic prostatic tissue. In summary, several of the findings reported in this study suggest an immunoregulatory role of HLA-G in the male reproductive system and in seminal plasma.
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Progressive effects of silver nanoparticles on hormonal regulation of reproduction in male rats
International Nuclear Information System (INIS)
Dziendzikowska, K.; Krawczyńska, A.; Oczkowski, M.; Królikowski, T.; Brzóska, K.; Lankoff, A.; Dziendzikowski, M.; Stępkowski, T.; Kruszewski, M.
2016-01-01
The growing use of silver nanoparticles (AgNPs) in various applications, including consumer, agriculture and medicine products, has raised many concerns about the potential risks of nanoparticles (NPs) to human health and the environment. An increasing body of evidence suggests that AgNPs may have adverse effects of humans, thus the aim of this study was to investigate the effects of AgNPs on the male reproductive system. Silver particles (20 nm AgNPs (groups Ag I and Ag II) and 200 nm Ag sub-micron particles (SPs) (group Ag III)) were administered intravenously to male Wistar rats at a dose of 5 (groups Ag I and Ag III) or 10 (group Ag II) mg/kg of body weight. The biological material was sampled 24 h, 7 days and 28 days after injection. The obtained results revealed that the AgNPs had altered the luteinising hormone concentration in the plasma and the sex hormone concentration in the plasma and testes. Plasma and intratesticular levels of testosterone and dihydrotestosterone were significantly decreased both 7 and 28 days after treatment. No change in the prolactin and sex hormone-binding globulin concentration was observed. Exposure of the animals to AgNPs resulted in a considerable decrease in 5α-reductase type 1 and the aromatase protein level in the testis. Additionally, expression analysis of genes involved in steroidogenesis and the steroids metabolism revealed significant down-regulation of Star, Cyp11a1, Hsd3b1, Hsd17b3 and Srd5a1 mRNAs in AgNPs/AgSPs-exposed animals. The present study demonstrates the potential adverse effect on the hormonal regulation of the male reproductive function following AgNP/AgSP administration, in particular alterations of the sex steroid balance and expression of genes involved in steroidogenesis and the steroids metabolism. - Highlights: • Assessment of the toxic effects of AgNPs/AgSPs on the regulation of male reproductive function • AgNP −/AgSP-induced alterations of sex steroid status in male Wistar rats.
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Progressive effects of silver nanoparticles on hormonal regulation of reproduction in male rats
Energy Technology Data Exchange (ETDEWEB)
Dziendzikowska, K., E-mail: k.dziendzikowska@gmail.com [Division of Nutrition Physiology, Department of Dietetics, Faculty of Human Nutrition and Consumer Science, Warsaw University of Life Sciences – SGGW, Nowoursynowska 159C, 02-776 Warsaw (Poland); Krawczyńska, A. [Laboratory of Molecular Biology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Instytucka 3, 05-110 Jabłonna (Poland); Oczkowski, M.; Królikowski, T. [Division of Nutrition Physiology, Department of Dietetics, Faculty of Human Nutrition and Consumer Science, Warsaw University of Life Sciences – SGGW, Nowoursynowska 159C, 02-776 Warsaw (Poland); Brzóska, K. [Centre for Radiobiology and Biological Dosimetry, Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw (Poland); Lankoff, A. [Centre for Radiobiology and Biological Dosimetry, Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw (Poland); Department of Radiobiology and Immunology, Institute of Biology, Jan Kochanowski University, Świetokrzyska 15, 25-406 Kielce (Poland); Dziendzikowski, M. [Airworthiness Division, Air Force Institute of Technology, Ks. Boleslawa 6, 01-494 Warsaw (Poland); Stępkowski, T. [Centre for Radiobiology and Biological Dosimetry, Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw (Poland); Kruszewski, M. [Department of Medical Biology and Translational Research, Faculty of Medicine, University of Information Technology and Management, Sucharskiego 2, 35-225 Rzeszów (Poland); Department of Molecular Biology and Translational Research, Institute of Rural Health, Jaczewskiego 2, 20-090 Lublin (Poland); and others
2016-12-15
The growing use of silver nanoparticles (AgNPs) in various applications, including consumer, agriculture and medicine products, has raised many concerns about the potential risks of nanoparticles (NPs) to human health and the environment. An increasing body of evidence suggests that AgNPs may have adverse effects of humans, thus the aim of this study was to investigate the effects of AgNPs on the male reproductive system. Silver particles (20 nm AgNPs (groups Ag I and Ag II) and 200 nm Ag sub-micron particles (SPs) (group Ag III)) were administered intravenously to male Wistar rats at a dose of 5 (groups Ag I and Ag III) or 10 (group Ag II) mg/kg of body weight. The biological material was sampled 24 h, 7 days and 28 days after injection. The obtained results revealed that the AgNPs had altered the luteinising hormone concentration in the plasma and the sex hormone concentration in the plasma and testes. Plasma and intratesticular levels of testosterone and dihydrotestosterone were significantly decreased both 7 and 28 days after treatment. No change in the prolactin and sex hormone-binding globulin concentration was observed. Exposure of the animals to AgNPs resulted in a considerable decrease in 5α-reductase type 1 and the aromatase protein level in the testis. Additionally, expression analysis of genes involved in steroidogenesis and the steroids metabolism revealed significant down-regulation of Star, Cyp11a1, Hsd3b1, Hsd17b3 and Srd5a1 mRNAs in AgNPs/AgSPs-exposed animals. The present study demonstrates the potential adverse effect on the hormonal regulation of the male reproductive function following AgNP/AgSP administration, in particular alterations of the sex steroid balance and expression of genes involved in steroidogenesis and the steroids metabolism. - Highlights: • Assessment of the toxic effects of AgNPs/AgSPs on the regulation of male reproductive function • AgNP −/AgSP-induced alterations of sex steroid status in male Wistar rats.
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Ma, Qiang; Huang, Hui; Sun, Long; Zhou, Tong; Zhu, Jingyuan; Cheng, Xuemin; Duan, Lijv; Li, Zhiyuan; Cui, Liuxin; Ba, Yue
2017-12-01
The occurrence of endemic fluorosis is derived from high fluoride levels in drinking water and industrial fumes or dust. Reproductive disruption is also a major harm caused by fluoride exposure besides dental and skeletal lesions. However, few studies focus on the mechanism of fluoride exposure on male reproductive function, especially the possible interaction of fluoride exposure and gene polymorphism on male reproductive hormones. Therefore, we conducted a cross-sectional study in rural areas of Henan province in China to explore the interaction between the estrogen receptor alpha (ERα) gene and fluoride exposure on reproductive hormone levels in male farmers living in the endemic fluorosis villages. The results showed that fluoride exposure significantly increased the serum level of estradiol in the hypothalamic-pituitary-testicular (HPT) axis in male farmers. Moreover, the observations indicated that fluoride exposure and genetic markers had an interaction on serum concentration of follicle-stimulating hormone and estradiol, and the interaction among different loci of the ERα gene could impact the serum testosterone level. Findings in the present work suggest that chronic fluoride exposure in drinking water could modulate the levels of reproductive hormones in males living in endemic fluorosis areas, and the interaction between fluoride exposure and ERα polymorphisms might affect the serum levels of hormones in the HPT axis in male farmers. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Impairment of male reproductive function after sleep deprivation.
Alvarenga, Tathiana A; Hirotsu, Camila; Mazaro-Costa, Renata; Tufik, Sergio; Andersen, Monica L
2015-05-01
To evaluate the influence of sleep loss on sexual behavior, hormone levels, sperm parameters, and testis-specific gene expression in male rats. Experimental research. Animal laboratory. Male adult Wistar-Hannover rats. Sexually experienced rats were subjected to paradoxic sleep deprivation (PSD) for 96 hours or sleep restriction (SR) for 21 days or kept in their home cage as control (CTRL). Sexual behavior, hormone levels, sperm parameters and expression of stress and nitric oxide-related genes were evaluated. PSD significantly decreased sexual behavior compared with the CTRL group, whereas SR had no effect. The PSD group had significantly lower testosterone levels than the CTRL group. Both PSD and SR groups had lower sperm viabilities than the CTRL group. The decrease in the number of live sperm compared with the CTRL group was larger in the PSD group than in the SR group. Regarding testicular gene expression, both PSD and SR led to an increase of iNOS and hydroxysteroid 11β-dehydrogenase 1 expressions compared with the CTRL group. These changes were more pronounced in the PSD group. A significant increase in endothelial nitric oxide synthase expression was observed in the PSD groups compared with the CTRL group. No changes were observed in dimethylarginine dimethylaminohydrolase 1 and casein kinase 2β-polypeptide expressions. Sleep loss can promote marked changes in the male reproductive system of rats, particularly affecting spermatic function in part by interfering in the testicular nitric oxide pathway. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.
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Oliveira, R F; Canario, A V; Grober, M S
2001-09-01
In species in which intense intermale competition for the access to females is present males of lower competitive ability may adopt alternative reproductive tactics (ART) to get access to mates. These ART translate in many cases into male sexual polymorphism, with individuals following distinctly different tactics. Usually two alternative male morphs can be recognized in species with ART: (1) bourgeois males that compete for access to mates invest in typically male behaviors, such as building elaborated nests or displaying ornaments; and (2) parasitic males that take advantage of the success of the bourgeois males in attracting females and attempt "sneaker" fertilizations (e.g., sneaker and satellite males). In combtooth blennies (Blenniidae) the co-occurrence of ART and male sexual polymorphism has been described for two temperate species: the peacock blenny, Salaria pavo, and the Azorean rock-pool blenny, Parablennius sanguinolentus parvicornis. Interestingly, while in the peacock blenny the alternative male morph adopts a sneaker tactic, in the rock-pool blenny parasitic males act as satellites to nest-holder males. Thus, this variation in the ART expressed in these two closely related species allows for a comparative study of the proximate and ultimate factors affecting the expression of the two ART. In this article we summarize the available information on androgen levels in bourgeois and parasitic males of natural populations of the two species and of recent studies on the effect of exogenous administration of androgens on tactic switching in parasitic males of the two species. The information is discussed within the frame of the relative plasticity hypothesis, which predicts that plastic alternative morphs should show differences in hormone levels and that the administration of sex steroids should be effective in promoting the switch from the parasitic to bourgeois tactic. The evidence is only partly consistent with this hypothesis. Alternatively, a social
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Inhibin activity in male rat reproductive organs during treatment with dihydrotestosterone
International Nuclear Information System (INIS)
Gladkova, A.I.
1986-01-01
The effect of dihydrotestosterone (DHT) on the inhibin level in the male reproductive system is studied. Hormones were determined in the peripheral blood of the donor rats by radioimmunoassay. Inhibin activity in the male rats is shown. DHT caused a very small increase in inhibin activity in the testis. Further study of relations between androgens and inhibin at peripheral and central levels will facilitate fertility control
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Reproductive potential of male catfish treated with gel extract of Aloe ...
African Journals Online (AJOL)
The reproductive potential of male catfish treated with gel extract of Aloe vera plant was studied using twelve male fish weighing 500-560g.The fish were divided into 3 groups; A, B and C with four fish in each group. Group A was treated with 2% Aloe vera gel while group B was treated with 3% and Group C the control was ...
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Oxytocin--its role in male reproduction and new potential therapeutic uses.
Thackare, Hemlata; Nicholson, Helen D; Whittington, Kate
2006-01-01
Oxytocin (OT) is traditionally thought of as a "female" neurohypophysis hormone due to its role in parturition and milk ejection. However, OT is recognized as having endocrine and paracrine roles in male reproduction. At ejaculation, a burst of OT is released from the neurohypophysis into the systemic circulation and stimulates contractions of the reproductive tract aiding sperm release. There is conclusive evidence that OT is synthesized within the mammalian testis, epididymis and prostate and the presence of OT receptors (OTRs) through the reproductive tract supports a local action for this peptide. OT has a paracrine role in stimulating contractility of the seminiferous tubules, epididymis and the prostate gland. Interestingly, OT has also been shown to modulate androgen levels in these tissues via stimulation of the conversion of testosterone to dihydrotestostone (DHT) by 5alpha-reductase. The elucidation of OT's role in male reproduction has suggested a number of potential therapeutic uses for this hormone. Exogenous administration of OT has, in some cases, been shown to increase the numbers of ejaculated sperm, possibly by stimulating contractions of the reproductive tract and thus aiding sperm passage. Within the prostate, OT has been shown to affect gland growth both directly and via its interaction with androgen metabolism. Prostate pathologies due to unregulated cell proliferation/growth, such as benign prostatic hyperplasia and cancer, are unfortunately very common and few effective treatments are available. Greater understanding of paracrine growth mediators, such as OT, is likely to provide new mechanisms for treating such pathologies.
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REPRODUCTIVE HORMONES AND CORTISOL RESPONSES TO PLYOMETRIC TRAINING IN MALES
Serife Vatansever Ozen
2012-01-01
Plyometric training activities are commonly used by a wide range of athletes to increase jump performance and improve explosive power and muscular activation patterns. The purpose of the study was to evaluate the effects of plyometric training on male reproductive hormones. Nineteen recreationally active males volunteered to participate in this study and were randomly assigned to plyometrically trained (n=10, 21.2 ±2.3 years) and control groups (n=9, 21.4± 2.1). The plyometric training group ...
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Determining the pattern of cementum annuli and relationship to reproduction in male sea otters
Proper, Josh; von Biela, Vanessa R.; Burns, Jennifer M.
2007-01-01
Since the early 1990s, the southwestern Alaskan sea otter (Enhydra lutris) population has declined dramatically and the cause has yet to be determined. Population trajectories of large mammals are determined by three factors: survival rate, reproduction rate, and age of first reproduction (AFR). Of these three, AFR should respond first to environmental change. Life history theory predicts that AFR will be older with bottom-up causes (ie, food limitation) and younger when the cause of the decline is top-down (ie, predation), as there is usually abundant resources in this scenario. Traditionally, determining AFR required lethal sampling, which may not always be possible. Work on many mammalian species suggests that the width of annual cementum layers in teeth may decline when breeding begins. If so, examining teeth annuli may provide a nonlethal alternative for determining AFR. Ongoing research has shown this relationship in female sea otters, but male sea otters have not been tested. Sea otter testes and premolar teeth slides were collected by subsistence hunters working with the US Fish and Wildlife Service and the Alaska Sea Otter and Steller Sea Lion Commission from Alaska (1994– 2005). We determined the pattern in cementum annuli thickness for male sea otters across age by measuring annuli at three sites on each of the two slide sections available. We found that cementum annuli layers decreased with age, but found no correlation between cementum annuli and sexual maturity in male sea otters. This lack of correlation may be due to sampling error or different energy expenditures during reproduction for each sex. Since females expend large amounts of energy through gestation and lactation, we hypothesize that the width of female cementum annuli decreases at a much sharper rate when they reach AFR.The southwest Alaskan sea otter population has plummeted up to 90% since the early 1990s and the reason is unknown.1 Declines may be due to a bottom-up source caused by
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Vitamin D and male reproductive system.
Costanzo, Pablo R; Knoblovits, Pablo
2016-12-01
Vitamin D deficiency is a highly prevalent worldwide condition and affects people of all ages. The most important role of vitamin D is the regulation of intestinal calcium absorption and metabolism of calcium and phosphorus to maintain muscle and bone homeostasis. Furthermore, in recent years it has been discovered that the vitamin D receptor (VDR) is widely distributed in many organs and tissues where vitamin D can perform other actions that include the modulation of the immune response, insulin secretion, anti-proliferative effect on cells of vascular smooth muscle, modulation of the renin-angiotensin-aldosterone system and regulates cell growth in several organs. The VDR is widely distributed in the male reproductive system. Vitamin D induces changes in the spermatozoa's calcium and cholesterol content and in protein phosphorylation to tyrosine/threonine residues. These changes could be involved in sperm capacitation. Vitamin D seems to regulate aromatase expression in different tissues. Studies analyzing seasonal variations of sex steroids in male populations yield conflicting results. This is probably due to the wide heterogeneity of the populations included according to age, systemic diseases and obesity.
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Vitamin E modulates reproductive toxicity of pyrethroid lambda-cyhalothrin in male rabbits.
Yousef, Mokhtar I
2010-05-01
The objective of the current study was to analyze the reproductive toxicity caused by lambda-cyhalothrin (LCT) in male rabbits, and to evaluate the possible protective effect of vitamin E (Vit. E) as antioxidant. Animals were orally administered their respective doses of LCT every other day and given drinking water supplemented with vitamin E for 16 weeks. Results showed that semen quality was deteriorated following treatment with LCT. Also, testosterone levels, body weight (BW), feed intake (FI), and relative testes (RTW) and epididymis (REW) weights were significantly decreased. Concentrations of thiobarbituric acid-reactive substances (TBARS) were significantly increased in seminal plasma of rabbits treated with LCT compared with control. While, activities of glutathione S-transferase (GST), transaminases and acid phosphatase (AcP) were significantly decreased. Vitamin E alone significantly increased testosterone levels, BW, FI, RTW, REW, semen characteristics and seminal plasma enzymes, and decreased the levels of TBARS. Also, the present study showed that vitamin E might be effective against LCT-induced reproductive toxicity. It was suggested that LCT exerted a significant adverse effect on reproductive performance of male rabbits. Furthermore, vitamin E antagonized the toxic effects of LCT and improved semen quality of male rabbit. Copyright (c) 2010 Elsevier Ltd. All rights reserved.
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Beani, L; Marchini, D; Cappa, F; Petrocelli, I; Gottardo, M; Manfredini, F; Giusti, F; Dallai, R
2017-08-01
Parasitic castration is an adaptive strategy where parasites usurp the hosts' reproductive physiology to complete their life cycle. The alterations in the host traits vary in their magnitude, from subtle changes in the host morpho-physiology and behaviour to the production of complex aberrant phenotypes, which often depend on the host gender. The strepsipteran macroparasite Xenos vesparum induces dramatic behavioural and physiological changes in its female host, the paper wasp Polistes dominula, while its effect on the male phenotype is largely unknown. In this study we investigated how a single X. vesparum parasite influences the functional morphology of P. dominula male reproductive apparatus. We performed morphometry and ultrastructure characterization of corpora allata, testes, seminal vesicles and accessory glands in parasitized and unparasitized males, and also in young and old males to control for the effect of age on the natural deterioration of these organs. Our results show that age significantly affects the development of male reproductive apparatus. A low parasite load - one parasite per host is the common prevalence in the field - has only a marginal impact on the reproductive morphology of P. dominula males, affecting quantitatively but not qualitatively the protein content of male accessory glands. Thus, in male P. dominula wasps, X. vesparum appears to behave as a true "parasite", in clear opposition to the role of "parasitoid" that it takes in female hosts where castration causes the reproductive death. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Kilcoyne, Karen R; Mitchell, Rod T
2017-12-01
Human male reproductive disorders (cryptorchidism, hypospadias, testicular cancer and low sperm counts) are common and some may be increasing in incidence worldwide. These associated disorders can arise from subnormal testosterone production during fetal life. This has resulted in a focus on in-utero environmental influences that may result in reproductive effects on the offspring in later life. Over recent years, there has been a dramatic increase in the scientific literature describing associations between in-utero environmental exposures (eg, industrial chemicals and pharmaceuticals) and subsequent reproductive outcomes in male offspring. This includes studies investigating a potential role for in-utero analgesic exposure(s) on the fetal testis; however, providing definitive evidence of such effects presents numerous challenges. In this review, we describe an approach to assessing the potential clinical relevance of in-utero (and postnatal) environmental exposures on subsequent male reproductive function using exposure to the analgesic paracetamol as an example. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
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Yan, Juan; Wang, Gang; Sui, Yi; Wang, Menglin; Zhang, Ling
2016-04-13
Floral colour change is visual signals for pollinators to avoid old flowers and increase pollination efficiency. Quisqualis indica flowers change colour from white to pink to red may be associated with a shift from moth to butterfly pollination. To test this hypothesis, we investigated Q. indica populations in Southwest China. Flowers secreted nectar continuously from the evening of anthesis until the following morning, then decreased gradually with floral colour change. The scent compounds in the three floral colour stages were similar; however, the scent composition was different, and the scent emission rate decreased from the white to red stage. Dichogamy in Q. indica prevents self-pollination and interference of male and female functions. Controlled pollinations demonstrated that this species is self-incompatible and needs pollinators for seed production. Different pollinators were attracted in each floral colour stage; mainly moths at night and bees and butterflies during the day. Observations of open-pollinated inflorescences showed that white flowers had a higher fruit set than pink or red flowers, indicating the high contribution of moths to reproductive success. We concluded that the nectar and scent secretion are related to floral colour change in Q. indica, in order to attract different pollinators and promote reproductive fitness.
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The male reproductive system of Hippolyte inermis Leach 1815 (Decapoda, Caridea)
Cobos, Vanesa; Díaz, Vanessa; Raso, Jose Enrique García; Manjón-Cabeza, M. E.
2011-03-01
The present work completes a series of studies on the biology of the shrimp Hippolyte inermis Leach 1815, where we suggested the species to be gonochoristic. The morphology of the male reproductive system (testes, vasa deferentia, gonopores) and the different stages of male germ cell development are described for the first time in the genus Hippolyte, using TEM, SEM, and histological methods. All males from 1.70 to 3.42 mm in carapace length had active testes and well-developed vasa deferentia. No case of sex reversal could be found.
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Effects of exposure to clothianidin on the reproductive system of male quails.
Tokumoto, Junko; Danjo, Megumi; Kobayashi, Yoshihiro; Kinoshita, Kyoko; Omotehara, Takuya; Tatsumi, Atsutoshi; Hashiguchi, Mineo; Sekijima, Tsuneo; Kamisoyama, Hiroshi; Yokoyama, Toshifumi; Kitagawa, Hiroshi; Hoshi, Nobuhiko
2013-01-01
Clothianidin (CTD) is a neonicotinoid developed in the 1990s as an insecticide having selective toxicity, but it was later found to cause reproductive abnormalities in rats through oxidative stress. There is an attempt to preserve endangered animals, including the Japanese crested ibis, in Japan. However, there is a concern that neonicotinoid affects the reproduction of this bird, since it is used in its habitat. CTD toxicity in the birds is poorly understood, so we investigated whether or not the daily oral administration of CTD has any deleterious effects on the reproductive functions of mature male quails as experimental animals. The animals were randomly divided into four groups of 6 or 7 quails each, treated orally with 0, 0.02, 1 or 50 mg CTD/kg body weight (Control, CTD0.02, CTD1 and CTD50). After that the males bred with untreated females to estimate the egg weights, and rates of fertilization and normal development, the testes, liver and spleen were examined histologically. Vacuolization and the number of germ cells having fragmented DNA in seminiferous tubules, and the number and size of vacuoles in hepatocytes increased dose-dependently. There were no significant differences in egg weights and fertilization rates between the groups, but some eggs of the CTD1 and CTD50 groups failed to develop, and embryonic length decreased dose-dependently. Thus, it was found that CTD affected the reproduction of the male quail through the fragmentation of germ cells and the inhibition or delay of embryonic development.
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York, Raymond G; Kennedy, Gerald L; Olsen, Geary W; Butenhoff, John L
2010-04-30
Ammonium perfluorooctanoate (ammonium PFOA) is an industrial surfactant that has been used primarily as a processing aid in the manufacture of fluoropolymers. The environmental and metabolic stability of PFOA together with its presence in human blood and long elimination half-life have led to extensive toxicological studies in laboratory animals. Two recent publications based on observations from the Danish general population have reported: (1) a negative association between serum concentrations of PFOA in young adult males and their sperm counts and (2) a positive association among women with time to pregnancy. A two-generation reproduction study in rats was previously published (2004) in which no effects on functional reproduction were observed at doses up to 30mg ammonium PFOA/kg body weight. The article contained the simple statement: "In males, fertility was normal as were all sperm parameters". In order to place the recent human epidemiological data in perspective, herein we provide the detailed male reproductive parameters from that study, including sperm quality and testicular histopathology. Sperm parameters in rats from the two-generation study in all ammonium PFOA treatment groups were unaffected by treatment with ammonium PFOA. These observations reflected the normal fertility observations in these males. No evidence of altered testicular and sperm structure and function was observed in ammonium PFOA-treated rats whose mean group serum PFOA concentrations ranged up to approximately 50,000ng/mL. Given that median serum PFOA in the Danish cohorts was approximately 5ng/mL, it seems unlikely that concentrations observed in the general population, including those recently reported in Danish general population, could be associated causally with a real decrement in sperm number and quality.
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K Chandra, Amar; Sengupta, Pallav; Goswami, Haimanti; Sarkar, Mahitosh
2012-05-01
Calcium is essential for functioning of different systems including male reproduction. However, it has also been reported as chemo-castrative agent. The study has been undertaken to elucidate the effect of excessive dietary calcium on male reproductive system in animals with possible action. Adult male healthy rats fed CaCl(2) at different doses (0.5, 1.0 and 1.5 g%) in diet for 13 and 26 days to investigate reproductive parameters as well as the markers of oxidative stress. Significant alteration was found (P male reproduction.
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Horsley, Kimberly; Stark, Lloyd R; McLetchie, D Nicholas
2011-05-01
Expected life history trade-offs associated with sex differences in reproductive investment are often undetected in seed plants, with the difficulty arising from logistical issues of conducting controlled experiments. By controlling genotype, age and resource status of individuals, a bryophyte was assessed for sex-specific and location-specific patterns of vegetative, asexual and sexual growth/reproduction across a regional scale. Twelve genotypes (six male, six female) of the dioecious bryophyte Bryum argenteum were subcultured to remove environmental effects, regenerated asexually to replicate each genotype 16 times, and grown over a period of 92 d. Plants were assessed for growth rates, asexual and sexual reproductive traits, and allocation to above- and below-ground regenerative biomass. The degree of sexual versus asexual reproductive investment appears to be under genetic control, with three distinct ecotypes found in this study. Protonemal growth rate was positively correlated with asexual reproduction and sexual reproduction, whereas asexual reproduction was negatively correlated (appeared to trade-off) with vegetative growth (shoot production). No sex-specific trade-offs were detected. Female sex-expressing shoots were longer than males, but the sexes did not differ in growth traits, asexual traits, sexual induction times, or above- and below-ground biomass. Males, however, had much higher rates of inflorescence production than females, which translated into a significantly higher (24x) prezygotic investment for males relative to females. Evidence for three distinct ecotypes is presented for a bryophyte based on regeneration traits. Prior to zygote production, the sexes of this bryophyte did not differ in vegetative growth traits but significantly differed in reproductive investment, with the latter differences potentially implicated in the strongly biased female sex ratio. The disparity between males and females for prezygotic reproductive investment is
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Aubret, Fabien; Bonnet, Xavier; Shine, Richard; Lourdais, Olivier
2002-09-01
Reproduction is energetically expensive for both sexes, but the magnitude of expenditure and its relationship to reproductive success differ fundamentally between males and females. Males allocate relatively little to gamete production and, thus, can reproduce successfully with only minor energy investment. In contrast, females of many species experience high fecundity-independent costs of reproduction (such as migration to nesting sites), so they need to amass substantial energy reserves before initiating reproductive activity. Thus, we expect that the relationship between energy reserves and the intensity of reproductive behavior involves a threshold effect in females, but a gradual (or no) effect in males. We tested this prediction using captive vipers (Vipera aspis), dividing both males and females into groups of high versus low body condition. Snakes from each group were placed together and observed for reproductive behavior; sex-steroid levels were also measured. As predicted, females in below-average body condition had very low estradiol levels and did not show sexual receptivity, whereas males of all body condition indices had significant testosterone levels and displayed active courtship. Testosterone levels and courtship intensity increased gradually (i.e., no step function) with body condition in males, but high estradiol levels and sexual receptivity were seen only in females with body reserves above a critical threshold. Copyright 2002 Elsevier Science (USA)
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A potential mate influences reproductive development in female, but not male, pine siskins.
Watts, Heather E; Edley, Bruce; Hahn, Thomas P
2016-04-01
The role of photoperiod in avian reproductive timing has been well studied, and we are increasingly recognizing the roles of other environmental cues such as social cues. However, few studies have evaluated the extent to which males and females of the same species respond similarly to the same type of cue. Moreover, previous studies have rarely examined how variation in the quality or nature of a given social cue might modulate its effect. Here, we examine the sensitivity of male and female pine siskins (Spinus pinus) to a potential mate as a stimulatory cue for gonadal recrudescence, and we investigate whether variation in the relationship between a bird and its potential mate modulates the effect of that potential mate. Birds were initially housed without opposite sex birds on a 12L:12D photoperiod with ad libitum food. After gonadal recrudescence had begun males and females were randomly paired with an opposite sex bird or housed alone. An additional group of males was paired with estradiol-implanted females. In males, these social treatments had no effect on testis length, cloacal protuberance length, luteinizing hormone (LH) levels, or testosterone levels. In females, presence of a potential mate had a significant and positive effect on ovary score, defeathering of the brood patch, and LH levels. Among paired birds, the degree of affiliation within a pair corresponded to the extent of reproductive development in females, but not males. Thus, reproductive timing in females appears to be sensitive to both the presence of a potential mate and her relationship with him. Copyright © 2016 Elsevier Inc. All rights reserved.
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Macleod, D J; Sharpe, R M; Welsh, M; Fisken, M; Scott, H M; Hutchison, G R; Drake, A J; van den Driesche, S
2010-04-01
We have shown previously that deficient androgen action within a masculinization programming window (MPW; e15.5-e18.5 in rats) is important in the origin of male reproductive disorders and in programming male reproductive organ size, but that androgen action postnatally may be important to achieve this size. To further investigate importance of the MPW, we used two rat models, in which foetal androgen production or action was impaired during the MPW by exposing in utero to either di(n-butyl) phthalate (DBP) or to flutamide. Reduced anogenital distance (AGD) was used as a monitor of androgen production/action during the MPW. Offspring were evaluated in early puberty (Pnd25) to establish if reproductive organ size was altered. The testes, penis, ventral prostate (VP) and seminal vesicles (SV) were weighed and penis length measured. Both DBP and flutamide exposure in the MPW significantly reduced penis, VP and SV size along with AGD at Pnd25; AGD and organ size were highly correlated. In DBP-, but not flutamide-, exposed animals, testis weight was also reduced and correlated with AGD. Intratesticular testosterone was also measured in control and DBP-exposed males during (e17.5) or after (e21.5) the MPW and related to AGD at e21.5. To evaluate the importance of postnatal androgen action in reproductive organ growth, the effect of combinations of prenatal and postnatal maternal treatments on AGD and penis size at Pnd25 was evaluated. In prenatally DBP-exposed animals, further postnatal exposure to either DBP or flutamide significantly reduced AGD and penis size in comparison with prenatal DBP exposure alone. In comparison, rats exposed postnatally to testosterone propionate after prenatal vehicle-exposure showed considerable increase in these parameters vs. controls. In conclusion, we show that the size of all male reproductive organs is programmed by androgen exposure in the MPW, but that growth towards this size is dependent on androgen action postnatally.
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Is there any effect of insulin resistance on male reproductive system?
Directory of Open Access Journals (Sweden)
Ayhan Verit
2014-03-01
Full Text Available Objectives: To investigate the possible effect of insulin resistance (IR on male reproductive system via evaluation of semen analysis, male sex hormones and serum lipid profiles, and testicular volumes. Methods: After the exclusions, a total of 80 male patients were enrolled in this prospective study. Body Mass Index (BMI, Testicular volume, semen samples, serum hormone/lipid profiles, high sensitive C-Reactive Protein (hsCRP were obtained from all the subjects. Results: The patients were divided into two groups as study and control according to the presence of IR. There were no statistical differences in terms of age, marriage period, testicular volume, serum levels of hormone and lipid profiles and BMI between the groups. There were no relationship between homeostasis model assessment of insulin resistance (HOMA-IR and semen volume (r = -0.10, p = 0.37, total sperm count (r = -0.09, p = 0.39, motility (r = -0.15, p = 0.16 and morphology (r = -0.14, p = 0.19. However, HOMA-IR was closely associated with hsCRP levels (r = 0.94, p < 0.0001. Conclusions: Despite of the documented strong inverse relationships between Diabetes Mellitus (DM and male/female fertility, and also between IR and female infertility via ovarian functions as in polycystic ovary syndrome, to our knowledge, there is no report about any influence of IR on male fertility. DM and metabolic syndrome (MetS have negative influence on fertility. Thus, IR may be accused of causing detrimental effect on male infertility due to hyperinsulinemic state and being one of the components for MetS. Interestingly, due to our preliminary results, we do not found any inverse correlation between IR and male reproductive functions.
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Gañán, Natalia; Sestelo, Adrián; Garde, J Julián; Martínez, Fernando; Vargas, Astrid; Sánchez, Iñigo; Pérez-Aspa, María José; López-Bao, José Vicente; Palomares, Francisco; Gomendio, Montserrat; Roldan, Eduardo R S
2010-01-01
The Iberian lynx (Lynx pardinus) is the most endangered felid in the world. Adequate genetic management of in situ and ex situ populations, and linkage between both, require knowledge on male reproductive biology and factors influencing it. We examined the influence of age, free-ranging versus captive conditions and seasonality on phenotypic, endocrine and semen traits, and links between reproductive traits and male fertility. Males had relatively small testes, produced low sperm numbers, a low proportion of normal sperm, and a high proportion of motile sperm. Young (2-year-old) males had lower testosterone levels, fewer sperm, and a lower proportion of motile and normal sperm than > or =4-year-old males. No major differences were found in semen traits before and after the mating season or between free-ranging and captive males, although the latter had better sperm motility. Males with larger relative testes weight and more sperm copulated more frequently, whereas males that produced more sperm with higher motility produced more cubs per female. In conclusion, small relative testes size and low sperm quality could indicate either low levels of sperm competition or high levels of inbreeding. Young males are probably subfertile; there is a slight trend for males in the captive breeding programme to have better semen quality than wild males, and males with higher sperm production are sexually more active and more fertile. These findings have major implications for decisions regarding which males should breed, provide samples for the genetic resource bank, or participate in programmes involving the use of assisted reproductive techniques.
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Reproductive status in adult male long-term survivors of childhood cancer
Tromp, K.; Claessens, J. J. M.; Knijnenburg, S. L.; van der Pal, H. J. H.; van Leeuwen, F. E.; Caron, H. N.; Beerendonk, C. C. M.; Kremer, L. C. M.
2011-01-01
This study assessed the long-term effects of cancer therapies on reproductive status in adult male childhood cancer survivors, evaluated the treatment-related risk factors for hypergonadotropic hypogonadism and assessed the association between the FSH levels and the later need for assisted
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EXPOSURE TO HAZARDOUS SUBSTANCES AND MALE REPRODUCTIVE HEALTH: A RESEARCH FRAMEWORK
The discovery in the mid-1970s that occupational exposures to pesticides could diminish or destroy the fertility of workers sparked concern about the effects of hazardous substances on male reproductive health. More recently, there is evidence that sperm quantity and quality may ...
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Reproductive status in adult male long-term survivors of childhood cancer
Tromp, K.; Claessens, J.J.M.; Knijnenburg, S.L.; Pal, H.J. van der; Leeuwen, F.E. van; Caron, H.N.; Beerendonk, C.C.M.; Kremer, L.C.
2011-01-01
BACKGROUND: This study assessed the long-term effects of cancer therapies on reproductive status in adult male childhood cancer survivors, evaluated the treatment-related risk factors for hypergonadotropic hypogonadism and assessed the association between the FSH levels and the later need for
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Schradin, Carsten; Eder, Susanne; Müller, Karin
2012-05-01
Males that follow alternative reproductive tactics might differ in their investment into testis development and sperm production. The resource-allocation hypothesis predicts that males following a sneaker tactic should invest more into sperm production than dominant territorial males which should invest more into mate guarding. This hypothesis is supported by studies in species where individual males cannot switch between tactics (fixed tactics). Here we present the first data for a species where males can switch between tactics (plastic tactics). We studied African striped mice (Rhabdomys pumilio) in captivity, mimicking three tactics observed in the field: philopatric group-living males, singly-housed males representing roaming males, and group-living breeding males. We measured quantitative and qualitative reproductive traits, as well as serum and testis hormone concentrations. We found no support for the resource-allocation hypothesis, since breeding and singly-housed males invested similarly in testes and sperm. However, philopatric males had significantly smaller testes and epididymides, lower sperm counts, lower testosterone and higher corticosterone levels than males of the two other tactics. Philopatric males did not reach a larger body mass than singly-housed males with well developed reproductive traits, indicating that they did not trade investment in sperm production against growth. Interestingly, testis testosterone concentrations of philopatric males did not differ from those of other males. Our data suggest that philopatric males are reproductively suppressed by the breeding male, but might be ready to increase their serum testosterone levels when social and environmental conditions allow for this physiological switch accompanying the behavioral switch between tactics. Copyright © 2012 Elsevier Inc. All rights reserved.
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International Nuclear Information System (INIS)
Abdel-Kawy, F.K.; El-Naggar, S.E.
2000-01-01
Changes in the male reproductive ability of Trogoderma Granarium Everts as regards to sterilization and structural changes in the accessory glands due to gamma radiation were studied. The reproductive ability of males irradiated as full grown pupae and mated with normal females was dose-dependent. A dose 100 Gy increased sterility of males to about 61.1%, while 200 Gy dose sterilized males completely. The number of eggs per mated female was significantly different from the control. The number of eggs decreased from 51.1 at 50 Gy to 5.9 at 200 Gy. Eclosion and deformity of males irradiated from 50 to 200 Gy seemed to be less affected as compared to the reproductive ability. When full grown male pupae were irradiated with the sterilizing dose, a considerable effect on the structure of accessory glands was observed. The dose 200 Gy caused lysis and damage of all type of secretory cells. The secretory epithelial cells showed abnormal appearance and became separated from each other. The cytoplasm was often shrunk, leaving spaces. The muscular sheaths surrounding the gland and lining its lumen were shrunk and damaged in some parts. The mitochondria and golgi bodies were completely lost. The multi microvilli lining the lumen of the gland disappeared. The basement membrane became loose and acquired irregular appearance in most parts. Intercellular microtubules disappeared completely. The gland generally was greatly damaged and lost its normal structure
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Environmental and Life Style Factors in Relation to Male Reproductive Disorders
DEFF Research Database (Denmark)
Krysiak-Baltyn, Konrad
on the environmental aspects of TDS, generating further support for the hypothesis that environmental factors may play a critical role in the observed trends. This thesis is divided into four parts. In the first part I introduce male reproductive disorders and the current state of affairs. In the second part, I focus......During the past four decades, the incidence rates of testicular cancer and other male reproductive disorders have been increasing at a rapid rate, predominantly in developed and industrialized countries. This increase is considered too great to be explained by genetic factors alone, and thus...... environmental factors have strongly been suspected to play a major role. There is a large amount of clinical research which has tried to pinpoint the mechanism of action for this trend. Although the exact mechanism of action has not been elucidated, a number of genetic factors as well as environmental chemicals...
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Wu, Yi-Fei; Wei, Lu-Sha; Anthony Torres, Mark; Zhang, Xu; Wu, Shao-Ping; Chen, Hui
2017-01-01
Studying the reproductive attributes of pests is central to understanding their life cycle history and in crafting management strategies to regulate, if not bring down, their population below threshold levels. In this article, the morphology of the male reproductive tract, topology of the spermatozoa, and salient features of spermiogenesis in the Chinese white pine beetle, Dendroctonus armandi Tsai and Li was studied to provide baseline information for further pest management studies. Results showed that male reproductive tract of this species differs from those documented in other Coleopterans by having 20 testicular tubules in each testis and the presence of two types of accessory glands. The spermatozoon is seen having peculiar characteristics such as an "h"-shaped acrosomal vesicle with a "puff"-like expansion, one centriole, one large spongy body, and two accessory bodies. Despite with some morphological differences of the male reproductive organ, spermatogenesis in this organism is similar to other Coleopterans. Overall, detailed studies regarding the components of the primary male reproductive organ of this beetle species would expand the knowledge on the less-understood biology of Coleopteran pests and would help in designing regulatory measures to conserve endemic and indigenous pine trees in China. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.
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Jiao Zhang, Jiao; Luong Huynh, Do; Chandimali, Nisansala; Kang, Tae Yoon; Kim, Nameun; Mok, Young Sun; Kwon, Taeho; Jeong, Dong Kee
2018-05-01
This study investigated whether plasma treatment of fertilized eggs before hatching could affect the growth and reproduction of chickens. Three point five-day-incubated fertilized eggs exposed to non-thermal dielectric barrier discharge plasma at 2.81 W of power for 2 min resulted in the highest growth in chickens. Plasma growth-promoting effect was regulated by the reactive oxygen species homeostasis and the improvement of energy metabolism via increasing serum hormones and adenosine triphosphate levels which were resulted from the regulation of genes involved in antioxidant defense, hormone biosynthesis and energetic metabolism. Interestingly, plasma-treated male chickens conspicuously grew faster than females. Further, aspects of male reproductive system (testosterone level and sperm quality) were improved by the plasma treatment but female reproduction (estradiol and progesterone levels, egg-laying rate and egg weight) had no significant changes. Unfortunately, offspring whose parents were the optimal plasma-treated chickens did not show any difference on growth characteristics and failed to inherit excellent growth features from their parents. Our results suggest a new method to improve the growth rate and male reproductive capacity in poultry but it is only effective in the plasma direct-treated generation.
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Ota, Kazutaka; Kohda, Masanori; Hori, Michio; Sato, Tetsu
2011-10-01
Alternative reproductive tactics are widespread in males and may cause intraspecific differences in testes investment. Parker's sneak-guard model predicts that sneaker males, who mate under sperm competition risk, invest in testes relatively more than bourgeois conspecifics that have lower risk. Given that sneakers are much smaller than bourgeois males, sneakers may increase testes investment to overcome their limited sperm productivity because of their small body sizes. In this study, we examined the mechanism that mediates differential testes investment across tactics in the Lake Tanganyika cichlid fish Lamprologus callipterus. In the Rumonge population of Burundi, bourgeois males are small compared with those in other populations and have a body size close to sneaky dwarf males. Therefore, if differences in relative testis investment depend on sperm competition, the rank order of relative testis investment should be dwarf males > bourgeois males in Rumonge = bourgeois males in the other populations. If differences in relative testis investment depend on body size, the rank order of relative testes investment should be dwarf males > bourgeois males in Rumonge > bourgeois males in the other populations. Comparisons of relative testis investment among the three male groups supported the role of sperm competition, as predicted by the sneak-guard model. Nevertheless, the effects of absolute body size on testes investment should be considered to understand the mechanisms underlying intraspecific variation in testes investment caused by alternative reproductive tactics.
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When the seasons don't fit: speedy molt as a routine carry-over cost of reproduction.
Directory of Open Access Journals (Sweden)
Maurine W Dietz
Full Text Available The failure of animals to fit all life-cycle stages into an annual cycle could reduce the chances of successful breeding. In some cases, non-optimal strategies will be adopted in order to maintain the life-cycle within the scope of one year. We studied trade-offs made by a High Arctic migrant shorebird, the red knot Calidris canutus islandica, between reproduction and wing feather molt carried out in the non-breeding period in the Dutch Wadden Sea. We compared primary molt duration between birds undertaking the full migratory and breeding schedule with birds that forego breeding because they are young or are maintained in captivity. Molt duration was ca. 71 days in breeding adults, which was achieved by an accelerated feather replacement strategy. Second-year birds and captive adults took ca. 22% and 27% longer, respectively. Second-year birds start molt in late June, more than four weeks before captive adults, and almost seven weeks before adults that return from breeding in late July-August. Adults finish molt in October when steeply increasing thermostatic costs and reductions in food availability occur. Primary molt duration was longer in female than in male knots (all ages, which was accordance with the somewhat larger body size of females. Since fast growth leads to lower quality feathers, the speedy wing molt shown by Arctic-breeding birds may represent a time constraint that is an unavoidable and routine cost of reproduction. So far it was hypothesized that only birds over 1 kg would have difficulty fitting molt within a year. Here we show that in birds an order of magnitude smaller, temporal imperatives may impose the adoption of non-optimal life-cycle routines in the entire actively breeding population.
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When the seasons don't fit: speedy molt as a routine carry-over cost of reproduction.
Dietz, Maurine W; Rogers, Ken G; Piersma, Theunis
2013-01-01
The failure of animals to fit all life-cycle stages into an annual cycle could reduce the chances of successful breeding. In some cases, non-optimal strategies will be adopted in order to maintain the life-cycle within the scope of one year. We studied trade-offs made by a High Arctic migrant shorebird, the red knot Calidris canutus islandica, between reproduction and wing feather molt carried out in the non-breeding period in the Dutch Wadden Sea. We compared primary molt duration between birds undertaking the full migratory and breeding schedule with birds that forego breeding because they are young or are maintained in captivity. Molt duration was ca. 71 days in breeding adults, which was achieved by an accelerated feather replacement strategy. Second-year birds and captive adults took ca. 22% and 27% longer, respectively. Second-year birds start molt in late June, more than four weeks before captive adults, and almost seven weeks before adults that return from breeding in late July-August. Adults finish molt in October when steeply increasing thermostatic costs and reductions in food availability occur. Primary molt duration was longer in female than in male knots (all ages), which was accordance with the somewhat larger body size of females. Since fast growth leads to lower quality feathers, the speedy wing molt shown by Arctic-breeding birds may represent a time constraint that is an unavoidable and routine cost of reproduction. So far it was hypothesized that only birds over 1 kg would have difficulty fitting molt within a year. Here we show that in birds an order of magnitude smaller, temporal imperatives may impose the adoption of non-optimal life-cycle routines in the entire actively breeding population.
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Impacts of Elevated Atmospheric CO2 and O3 on Paper Birch (Betula papyrifera: Reproductive Fitness
Directory of Open Access Journals (Sweden)
Joseph N. T. Darbah
2007-01-01
Full Text Available Atmospheric CO2 and tropospheric O3 are rising in many regions of the world. Little is known about how these two commonly co-occurring gases will affect reproductive fitness of important forest tree species. Here, we report on the long-term effects of CO3 and O3 for paper birch seedlings exposed for nearly their entire life history at the Aspen FACE (Free Air Carbon Dioxide Enrichment site in Rhinelander, WI. Elevated CO2 increased both male and female flower production, while elevated O3 increased female flower production compared to trees in control rings. Interestingly, very little flowering has yet occurred in combined treatment. Elevated CO2 had significant positive effect on birch catkin size, weight, and germination success rate (elevated CO2 increased germination rate of birch by 110% compared to ambient CO2 concentrations, decreased seedling mortality by 73%, increased seed weight by 17%, increased root length by 59%, and root-to-shoot ratio was significantly decreased, all at 3 weeks after germination, while the opposite was true of elevated O3 (elevated O3 decreased the germination rate of birch by 62%, decreased seed weight by 25%, and increased root length by 15%. Under elevated CO2, plant dry mass increased by 9 and 78% at the end of 3 and 14 weeks, respectively. Also, the root and shoot lengths, as well as the biomass of the seedlings, were increased for seeds produced under elevated CO2, while the reverse was true for seedlings from seeds produced under the elevated O3. Similar trends in treatment differences were observed in seed characteristics, germination, and seedling development for seeds collected in both 2004 and 2005. Our results suggest that elevated CO2 and O3 can dramatically affect flowering, seed production, and seed quality of paper birch, affecting reproductive fitness of this species.
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Functional study of Cordyceps sinensis and cordycepin in male reproduction: A review
Directory of Open Access Journals (Sweden)
Yung-Chia Chen
2017-01-01
Full Text Available Cordyceps sinensis has various biological and pharmacological functions, and it has been claimed as a tonic supplement for sexual and reproductive dysfunctions for a long time in oriental society. In this article, the in vitro and in vivo effects of C. sinensis and cordycepin on mouse Leydig cell steroidogenesis are briefly described, the stimulatory mechanisms are summarized, and the recent findings related to the alternative substances regulating male reproductive functions are also discussed.
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Effects of ascorbic acid supplementation on male reproductive system during exposure to hypoxia
Havazhagan, G.; Riar, S. S.; Kain, A. K.; Bardhan, Jaya; Thomas, Pauline
1989-09-01
Two groups of male rats were exposed to simulated altitudes of 6060 m and 7576 m for 6 h/day for 7 days (intermittent exposure). In two additional groups of animals exposed to the same altitude, 100 mg of ascorbic acid (AA) was fed daily for 5 days prior to the exposure period and also during the exposure period. Rats that did not receive AA showed loss of body weight and weight of reproductive organs after exposure. Sex organs showed atrophy on histological examination and there was a deterioration in spermatozoal quality. There was an increase in alkaline and acid phosphatase, and decrease in protein, sialic acid and glyceryl phosphorylcholine content in various reproductive tissues after exposure. All the above changes in histology and biochemical composition could be partially prevented by AA supplementation. AA supplementation can therefore protect the male reproductive system from deleterious effects of hypoxia. The probable mechanism of action of AA is discussed.
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D-galactose-induced animal model of male reproductive aging
Sulistyoningrum, Evy
2017-01-01
Aging is a complex biological process involving molecular, cellular and organic changes. Aging process is not merely caused by chronological age but it can be accelerated by environmental factors contributes to oxidative stress. Aging in male reproductive system is characterized by many conditions such as terticular atrophy, decreases testicular function of spermatogenesis, decreased testicular function of testosteron production which can lead to a serious clinical condition, infertility. Man...
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Metformin and male reproduction: effects on Sertoli cell metabolism
Directory of Open Access Journals (Sweden)
2014-08-01
Full Text Available Metformin, widely used for the treatment of type 2 diabetes, is increasingly becoming the subject of research in other areas of medicine. Apart form antihyperglycemic effect of metformin has an inhibitory effect on the proliferation of various tumor cells both in vivo and in vitro. Metformin is well established in the treatment of anovulatory infertility in polycystic ovary syndrome, while its influence male reproductive function are poorly understood.
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Roles of autophagy in male reproductive development in plants
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Shigeru eHanamata
2014-09-01
Full Text Available Autophagy, a major catabolic pathway in eukaryotic cells, is essential in development, maintenance of cellular homeostasis, immunity and programmed cell death (PCD in multicellular organisms. In plant cells, autophagy plays roles in recycling of proteins and metabolites including lipids, and is involved in many physiological processes such as abiotic and biotic stress responses. However, its roles during reproductive development had remained poorly understood. Quantitative live cell imaging techniques for the autophagic flux and genetic studies in several plant species have recently revealed significant roles of autophagy in developmental processes, regulation of PCD and lipid metabolism. We here review the novel roles of autophagic fluxes in plant cells, and discuss their possible significance in PCD and metabolic regulation, with particular focus on male reproductive development during the pollen maturation.
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Voice and Handgrip Strength Predict Reproductive Success in a Group of Indigenous African Females
Sorokowska, Agnieszka; Sorokowski, Piotr; Mberira, Mara; Bartels, Astrid; Gallup, Gordon G.
2012-01-01
Evolutionary accounts of human traits are often based on proxies for genetic fitness (e.g., number of sex partners, facial attractiveness). Instead of using proxies, actual differences in reproductive success is a more direct measure of Darwinian fitness. Certain voice acoustics such as fundamental frequency and measures of health such as handgrip strength correlate with proxies of fitness, yet there are few studies showing the relation of these traits to reproduction. Here, we explore whether the fundamental frequency of the voice and handgrip strength account for differences in actual reproduction among a population of natural fertility humans. Our results show that both fundamental frequency and handgrip strength predict several measures of reproductive success among a group of indigenous Namibian females, particularly amongst the elderly, with weight also predicting reproductive outcomes among males. These findings demonstrate that both hormonally regulated and phenotypic quality markers can be used as measures of Darwinian fitness among humans living under conditions that resemble the evolutionary environment of Homo sapiens. We also argue that these findings provide support for the Grandmother Hypothesis. PMID:22870251
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[Effect of External Irradiation and Immobilization Stress on the Reproductive System of Male Rats].
Vereschako, G G; Tshueshova, N V; Gorokh, G A; Kozlov, I G; Naumov, A D
2016-01-01
We studied the state of the reproductive system of male rats after irradiation at a dose of 2.0 Gy, immobilization stress (6 hours/day for 7 days) and their combined effects. On the 30th day after the combined treatment (37 days after irradiation) a decrease in the testicular weight by almost 50% compared with the control and lesions connected with the process of spermatogenesis are observed. In the remote period--on the 60th day (67th after irradiation) the effect of irradiation and irradiation in combination with immobilization stress leads to a sharp drop in the number of epididymal sperm (up to 18% of the control), and a reduction of their viability. The reaction ofthe reproductive system to the immobilization stress is expressed in a certain increase in the mass of the testes and epididymis, moderate imbalances in the composition of spermatogenic cells in the testis tissue, and in the long term--in the increased number of epididymal sperm and the decrease in their viability. Changes of testosterone in the blood serum, especially significant for the combined effect, reflect impairments of the regulation of the reproductive system of males under these conditions. With regard to individual indicators of the reproductive system of male rats in some cases, the- combined effects of radiation and stress had a synergistic, or, on the contrary, antagonistic character.
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Affonso, Cristiano R. G.; Fernandes, Rozeverter M.; Oliveira, Jamylla M. G. de; Martins, Maria do Carmo de Carvalho e; Lima, Sidney G. de; Sousa Júnior, Gustavo R. de; Fernandes, Maria Zenaide de Lima C. Moreno; Zanini, Surama F.
2012-01-01
The essential oil of Schinus terebinthifolius (Anacardiaceae) was analyzed by GC and GC-MS. α-Fenchene, limonene, β-pinene, α-phellandrene, and β-isosylvestrene represent about 80% of the oil composition. The reproductive toxicity of the essential oil in Wistar male rats was evaluated. No changes were observed in the mass of the reproductive organs, number and morphology of spermatozoa, reproductive rates, and the body mass of offspring of male rats after treatment with the essential oil of S...
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Canine length in wild male baboons: maturation, aging and social dominance rank.
Directory of Open Access Journals (Sweden)
Jordi Galbany
Full Text Available Canines represent an essential component of the dentition for any heterodont mammal. In primates, like many other mammals, canines are frequently used as weapons. Hence, tooth size and wear may have significant implications for fighting ability, and consequently for social dominance rank, reproductive success, and fitness. We evaluated sources of variance in canine growth and length in a well-studied wild primate population because of the potential importance of canines for male reproductive success in many primates. Specifically, we measured maxillary canine length in 80 wild male baboons (aged 5.04-20.45 years from the Amboseli ecosystem in southern Kenya, and examined its relationship with maturation, age, and social dominance rank. In our analysis of maturation, we compared food-enhanced baboons (those that fed part time at a refuse pit associated with a tourist lodge with wild-feeding males, and found that food-enhanced males achieved long canines earlier than wild-feeding males. Among adult males, canine length decreased with age because of tooth wear. We found some evidence that, after controlling for age, longer canines were associated with higher adult dominance rank (accounting for 9% of the variance in rank, but only among relatively high-ranking males. This result supports the idea that social rank, and thus reproductive success and fitness, may depend in part on fighting ability mediated by canine size.
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Dai, Xin; Shi, Jia; Han, Mei; Wang, Ai Qin; Wei, Wan Hong; Yang, Sheng Mei
2017-05-15
Plant secondary metabolite 6-methoxybenzoxazolinone (6-MBOA) has been suggested to stimulate animal reproduction. 6-MBOA is detected in Leymus chinensis, a main diet of Brandt's vole (Lasiopodomys brandtii). We have previously reported a stimulatory effect of 6-MBOA on reproduction of male Brandt's voles under a short-day photoperiod. The goal of this study was to investigate the effect of 6-MBOA on reproductive physiology of male Brandt's voles under a long-day photoperiod and examine if 6-MBOA under this photoperiodic regime altered the reproductive status of male Brandt's voles differently than the short-day photoperiod. Under the long-day photoperiod, a high dose of 6-MBOA decreased KiSS-1 mRNA in the arcuate nucleus (ARC), and we also saw a decrease in circulating levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone (T). Steroidogenic acute regulatory protein (StAR) and cytochrome P450 11a1 (CYP11a1) in the testes, and relative testis weight also decreased with 6-MBOA administration. Compared to the short-day photoperiod, animals under the long-day photoperiod exhibited increased body weight as well as all other reproductive parameters. Our results showed that 6-MBOA inhibited the reproduction of male Brandt's vole under a long-day photoperiod, a stark contrast from its stimulatory effects under a short-day photoperiod. The paradoxical effects of 6-MBOA suggest it may act as a partial agonist of melatonin. These results provide insight into the complex interactions between environmental factors such as photoperiod and diet in the control of Brandt's vole reproduction. Copyright © 2017 Elsevier Inc. All rights reserved.
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Saad, Ramadan A; Mahmoud, Yomna I
2014-12-01
Ursodeoxycholic acid is the most widely used drug for treating cholestatic liver diseases. However, its effect on the male reproductive system alterations associated with cholestasis has never been studied. Thus, this study aimed to investigate the effect of ursodeoxycholic acid on cholestasis-induced alterations in the male reproductive system. Cholestasis was induced by bile duct ligation. Bile duct-ligated rats had higher cholestasis biomarkers and lower levels of testosterone, LH and FSH than did the Sham rats. They also had lower reproductive organs weights, and lower sperm motility, density and normal morphology than those of Sham rats. Histologically, these animals suffered from testicular tubular atrophy, interstitial edema, thickening of basement membranes, vacuolation, and depletion of germ cells. After ursodeoxycholic acid administration, cholestasis-induced structural and functional alterations were significantly ameliorated. In conclusion, ursodeoxycholic acid can ameliorate the reproductive complications of chronic cholestasis in male patients, which represents an additional benefit to this drug. Copyright © 2014 Elsevier Inc. All rights reserved.
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Effects of dietary vitamin E on male reproductive system
Muhammad Zubair
2017-01-01
Vitamin E is known as important antioxidant to protect the reproductive system. The free radicals are continuously produced in last few years due to metabolic and nutritional deficiencies. These free radicals are responsible for the production of oxidative stress in animal bodies. This production of extensive amount of oxidative stress caused the detrimental effects on the sperm and various other male parameters. This imbalance between the antioxidants and oxidative stress, leads to the condi...
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Bonde, J.P.; Giwercman, A.; Ernst, E.; Joffe, M.; Bisanti, L.; Hoorne M, van M.; Thonneau, P.; Zielhuis, G.; Kiss, P.; Abell, A.; Larsen, S.B.; Danscher, G.; Kolstad, H.
1996-01-01
Malfunction of the male reproductive system might be a sensitive marker of environmental hazards, the effects of which may extend beyond reproductive function. The testis is more vulnerable to heat and ionising radiation than any other organ of the body and several xenobiotics are known to disrupt
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Major reproductive health characteristics in male Gulf War Veterans. The Danish Gulf War Study
DEFF Research Database (Denmark)
Ishøy, T; Andersson, A M; Suadicani, Poul Vilhelm
2001-01-01
The male reproductive system could have been affected by various hazardous agents and exposures during and in the aftermath of the Persian Gulf War scenario. We tested the hypothesis that, compared to controls, male Danish Gulf War Veterans would have adverse sex hormone levels, decreased fertility...
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Directory of Open Access Journals (Sweden)
Fabiana Aparecida do Nascimento
Full Text Available This study describes the histology and histochemistry of the male reproductive system in Callinectes ornatus, comparing juvenile and adult developmental stages. We also analyzed changes in the gonadosomatic (GSI and hepatosomatic (HSI indices, and the weights of the testis and vas deferens during the development. The results showed that all stages, beginning with the juvenile (JUV, through developing (DEV and mature (MAT adult males of C. ornatus produce sperm and spermatophores. During development, testicular lobes showed the same characteristics of production and release of sperm into the seminiferous duct. The vas deferens showed little histological and histochemical change in the epithelium in juvenile and adult males. The differences consisted of the larger amount of secretion in MAT males compared to JUV and DEV ones. The chemical composition of the seminal fluid was similar, but MAT males produced a more homogeneous secretion. Morphological and physiological maturation are not synchronized in C. ornatus, since JUV males produced spermatophores similar to those in DEV and MAT males. However, these JUV are not yet able to reproduce, since they still have the abdomen attached to the cephalothoracic sternum. The increase of the GSI during development was significant for MAT males, and is related to the production of sufficient volume of seminal fluid to form the sperm "plug" in the female seminal receptacle. The HSI decreased from DEV to MAT adult stages, indicating that reserves from the hepatopancreas are used to develop the reproductive system after the pubertal molt.
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Institute of Scientific and Technical Information of China (English)
Eliana PINTUS; Stefania UCCHEDDU; Knut H RED; Javier Prez GONZALZ; Juan CARRANZA; Mauri NIEMINEN; ystein HOLAND
2015-01-01
Polygynous males can change their mating tactics across their lifetime, but information is scarce on the flexibility of this trait within a given season and the relative costs and benefits of using different tactics. Here, we monitored individually marked male reindeerRangifer tarandus and classified their mating tactics as harem-defense, sneaking, or mixed. The costs of the male reproductive effort were assessed using both direct (i.e. percentage of body mass lost) and indirect measures (i.e. activity patterns such as feeding, standing, and walking), while mating group size and reproductive success were recorded as mating ef-fort benefits. Our results show that reindeer males may switch between the harem-defense and sneaking tactics throughout the same breeding season, providing further support to the notion that reproductive tactics are flexible in ungulates. The costs and benefits of male mating effort vary according to the mating tactic, reaching the highest values in harem-holders and the lowest values in sneaking males. Moreover, males who switched between the sneaking tactic and the harem-defence tactic tended to achieve higher mating success than males who consistently used the least costly tactic. Indeed, all harem-holders successfully sired offspring, whereas only two out of three mixed-tactic males sired one calf, and sneaking males did not sire any calves. In conclusion, our results show that reindeer males can modulate their mating efforts during the same breeding season by switching between the most costly harem-defense tactic and the least costly sneaking tactic, suggesting individual solutions to the balance between reproductive effort and mating opportunities [Current Zoology 61 (5): 802–810, 2015].
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Occupational exposure and effects on the male reproductive system
Directory of Open Access Journals (Sweden)
Erika Kaltenecker Retto de Queiroz
Full Text Available A significant increase in the incidence of male infertility has been described in the international literature, raising questions about its causes. Part of this effect may result from synthetic toxic substances acting on the endocrine system (endocrine disruptors, many of which are routinely used in work processes. We provide a critical review of the specialized literature on work-related chemical substances capable of causing male infertility. Pesticides such as DDT, linuron, and others, heavy metals like mercury, lead, cadmium, and copper, and substances from various industrial uses and residues such as dioxins, polychlorinated biphenyls (PCBs, ethylene dibromide (EDB, phthalates, polyvinyl chloride (PVC, and ethanol are among the main endocrine disruptors that can cause male infertility. Based on the literature, gonadal dysfunction and congenital malformation are the main alterations caused by these substances in the male reproductive system. We conclude that despite the relative lack of studies on this issue, the relevance of such risk calls for further studies as well as measures to prevent workers' exposure to the various substances.
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Chirault, Marl?ne; Lucas, Christophe; Goubault, Marl?ne; Chevrier, Claude; Bressac, Christophe; L?cureuil, Charlotte
2015-01-01
In recent years, several studies have shown a decline in reproductive success in males in both humans and wildlife. Research on male fertility has largely focused on vertebrates, although invertebrates constitute the vast majority of terrestrial biodiversity. The reduction of their reproductive capacities due to environmental stresses can have strong negative ecological impacts, and also dramatic consequences on world food production if it affects the reproductive success of biological contro...
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Directory of Open Access Journals (Sweden)
Maria eDe Falco
2015-02-01
Full Text Available Endocrine disrupting chemicals (EDCs are identified for their ability to perturb the homeostasis of endocrine system and hormonal balance. The male reproductive system is under close control of hormones and each change in their concentration and time of exposition and action can induce a deregulation of its physiology. In this review we summarize the most recent studies on two main categories of EDCs with different action: the estrogenic bisphenol A and alkylphenols and the anti-androgenic phthalates. This review describes the main effects of these substances on male reproductive system.
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Effect of Maytenus macrocarpa“Chuchuhuasi” in the male system reproductive of mouse (Mus musculus
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Láyonal G. Acosta
2014-03-01
Full Text Available Maytenus macrocarpa(chuchuhuasi is native tree of the Peruvian Amazon used as traditional medicine for the treatment of many diseases, but its effect on the male reproductive system has not yet been elucidated. The aim of this study is evaluate the effect of aqueous extract of M. macrocarpa in daily doses for 7 days on reproductive parameters of male mice. We used C57BL mature male mice divided into 2 groups (n= 10, Control Group (C: 0.9% NaCl and Treatment group (T: Aqueous extract of Chuchuhuasi, both supplied daily via oral gavages. At the eight day of treatment the mice were euthanized. The weight of the body and reproductive organs: testis, epididymis and vas deferens, were registered. Concentration, motility and sperm morphology were evaluated. The results showed significantly differences (t- Student test P<0.05 in the weight of the head and body epididymis (C: 19.25±1.1 vs T: 21.26±2.0, vas deferens (C: 10.61±0.7 vs T: 11.75±0.5, progressive sperm motility (C: 42.16±5.2 vs T: 25.82±8.4 and immobile sperm (C: 36.05±4.9 vs T: 48.51±7.2. No difference in sperm count was observed. The sperm normal morphology diminished with ingest of M. macrocarpa(tStudent test p <0.05 (C: 39.72±1.3 vs T: 30.78±4.9. We conclude that the aqueous extract of chuchuhuasi, has a negative effect on the male reproductive system of mice.
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Role of the Na+/K+-ATPase ion pump in male reproduction and embryo development.
Câmara, D R; Kastelic, J P; Thundathil, J C
2017-08-01
Na + /K + -ATPase was one of the first ion pumps studied because of its importance in maintaining osmotic and ionic balances between intracellular and extracellular environments, through the exchange of three Na + ions out and two K + ions into a cell. This enzyme, which comprises two main subunits (α and β), with or without an auxiliary polypeptide (γ), can have specific biochemical properties depending on the expression of associated isoforms (α1β1 and/or α2β1) in the cell. In addition to the importance of Na + /K + -ATPase in ensuring the function of many tissues (e.g. brain, heart and kidney), in the reproductive tract this protein is essential for embryo development because of its roles in blastocoel formation and embryo hatching. In the context of male reproduction, the discovery of a very specific subunit (α4), apparently restricted to male germ cells, only expressed after puberty and able to influence sperm function (e.g. motility and capacitation), opened a remarkable field for further investigations regarding sperm biology. Therefore, the present review focuses on the importance of Na + /K + -ATPase on male reproduction and embryo development.
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Can persistence hunting signal male quality? A test considering digit ratio in endurance athletes.
Directory of Open Access Journals (Sweden)
Daniel Longman
Full Text Available Various theories have been posed to explain the fitness payoffs of hunting success among hunter-gatherers. 'Having' theories refer to the acquisition of resources, and include the direct provisioning hypothesis. In contrast, 'getting' theories concern the signalling of male resourcefulness and other desirable traits, such as athleticism and intelligence, via hunting prowess. We investigated the association between androgenisation and endurance running ability as a potential signalling mechanism, whereby running prowess, vital for persistence hunting, might be used as a reliable signal of male reproductive fitness by females. Digit ratio (2D:4D was used as a proxy for prenatal androgenisation in 439 males and 103 females, while a half marathon race (21km, representing a distance/duration comparable with that of persistence hunting, was used to assess running ability. Digit ratio was significantly and positively correlated with half-marathon time in males (right hand: r = 0.45, p<0.001; left hand: r = 0.42, p<0.001 and females (right hand: r = 0.26, p<0.01; left hand: r = 0.23, p = 0.02. Sex-interaction analysis showed that this correlation was significantly stronger in males than females, suggesting that androgenisation may have experienced stronger selective pressure from endurance running in males. As digit ratio has previously been shown to predict reproductive success, our results are consistent with the hypothesis that endurance running ability may signal reproductive potential in males, through its association with prenatal androgen exposure. However, further work is required to establish whether and how females respond to this signalling for fitness.
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Impairment of male reproduction in adult rats exposed to hydroxyprogesterone caproate in utero
Pushpalatha, T.; Ramachandra Reddy, P.; Sreenivasula Reddy, P.
Hydroxyprogesterone caproate is one of the most effective and widely used drugs for the treatment of uterine bleeding and threatened miscarriage in women. Hydroxyprogesterone caproate was administered to pregnant rats in order to assess the effect of intraperitoneal exposure to supranormal levels of hydroxyprogesterone caproate on the male reproductive potential in the first generation. The cauda epididymal sperm count and motility decreased significantly in rats exposed to hydroxyprogesterone caproate during embryonic development, when compared with control rats. The levels of serum testosterone decreased with an increase in follicle stimulating hormone and luteinizing hormone in adult rats exposed to hydroxyprogesterone caproate during the embryonic stage. It was suggested that the impairment of male reproductive performance could be mediated through the inhibition of testosterone production.
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Komdeur, J; Edelaar, P
2001-01-01
In cooperatively breeding species, helping at the nest and budding off part of the natal territory have been advanced as strategies to increase fitness in an environment that is saturated with territories. The importance of helping or territory budding as a determinant of lifetime reproductive
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Adverse trends in male reproductive health have been reported for increased rates of testicular germ cell tumor, low semen quality, cryptorchidism, and hypospadias. An association with prenatal environmental exposure has been inferred from human and animal studies underlying male...
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Czech Academy of Sciences Publication Activity Database
Lecocq, T.; Gérard, M.; Maebe, K.; Brasero, N.; Dehon, L.; Smagghe, G.; Valterová, Irena; De Meulemeester, T.; Rasmont, P.; Michez, D.
2017-01-01
Roč. 24, č. 4 (2017), s. 623-630 ISSN 1672-9609 Institutional support: RVO:61388963 Keywords : bee decline * bumblebees * conservation * diploid male s * premating recognition * reproductive traits Subject RIV: EG - Zoology OBOR OECD: Entomology Impact factor: 2.026, year: 2016
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Reproductive toxicological aspects of chromium in males
International Nuclear Information System (INIS)
Ernst, E.
1994-01-01
To expand our present understanding of the effects of chromium on male fertility a number of studies were designed to achieve this through the use of chromium intoxicated experimental animals and through investigation of sexual hormones and sperm quality in welders. Also in view of the lack of an experimental model for effects of noxious substance on the epididymal spermatozoa the main objectives of the series of studies reviewed here were: A. To establish a model for evaluation of epididymal sperm count and motility in the rat. B. To investigate and compare the effects of tri- and hexavalent chromium on epididymal spermatozoa. Further to describe the effects of low-dose long-time exposure of rats to the most toxicological interesting chromium oxidative state - hexavalent chromium. C. By the use of autoradiography and γ-countinuing to expand the present knowledge on the distribution of chromium in the body with special reference to the male reproductive organs. D. To describe the effects of exposure to hexavalent chromium in welding fume on levels of sexual hormones and semen parameters in welders. (EG)
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Male reproductive function in long-term survivors of childhood cancer
International Nuclear Information System (INIS)
Jaffe, N.; Sullivan, M.P.; Ried, H.; Boren, H.; Marshall, R.; Meistrich, M.; Maor, M.; da Cunha, M.
1988-01-01
We evaluated reproductive function in 27 male long-term survivors of childhood cancer treated during the prepubertal and pubertal period. Sperm samples were obtained from 23 patients; four who refused to provide specimens indicated that they had fathered normal healthy children. Thirteen patients were 12 years old or younger at the time of diagnosis and initiation of therapy. Chemotherapy was calculated according to the cumulative amount of drug administered and correlated with the surface area. Sterility was associated with large doses of single alkylating agents or reduced doses administered with other agents in combination regimens. It was noted in boys treated in both the prepubertal and pubertal period. Sterility was also observed in patients who received testicular radiation alone or in combination with chemotherapy. However, it was not an inevitable consequence in all patients, despite treatment with similar or identical regimens. Fertility potential could not be predicted by clinical examination (testicular size) or gonadotrophin and testosterone values. The results were compared to published reports of treatment-induced sterility in adult males. Additional investigations are required to establish more accurate correlations of dosage with reproductive potential
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Reproductive ability of pubertal male and female rats
Directory of Open Access Journals (Sweden)
T. Zemunik
2003-07-01
Full Text Available Ten Fisher rats 50 to 55 days of age made up the pubertal group, and ten rats 90 to 95 days of age served as the controls. The testicular and epididymal weights and volumes of the pubertal males were lower than those of the controls (P0.05. At the beginning of gestation, the pubertal dams weighed less than the controls (P<0.001 but following uterectomy the body weights were equal. Pubertal dams delivered fewer pups than the controls (8.1 ± 2.5 vs 10.4 ± 1.3, P<0.05. There was no difference in the body weights of their offspring or in the weights of their placentas. The results suggest that, in contrast to their female counterparts, pubertal male rats are not fully mature and have not reached complete reproductive capacity at 50-55 days of age.
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Lifespan and reproduction in brain-specific miR-29-knockdown mouse.
Takeda, Toru; Tanabe, Hiroyuki
2016-03-18
The microRNA miR-29 is widely distributed and highly expressed in adult mouse brain during the mouse's lifetime. We recently created conditional mutant mice whose miR-29 was brain-specifically knocked down through overexpression of an antisense RNA transgene against miR-29. To explore a role for brain miR-29 in maximizing organismal fitness, we assessed somatic growth, reproduction, and lifespan in the miR-29-knockdown (KD) mice and their wild-type (WT) littermates. The KD mice were developmentally indistinguishable from WT mice with respect to gross morphology and physical activity. Fertility testing revealed that KD males were subfertile, whereas KD females were hyperfertile, only in terms of reproductive success, when compared to their gender-matched WT correspondents. Another phenotypic difference between KD and WT animals appeared in their lifespan data; KD males displayed an overall increasing tendency in post-reproductive survival relative to WT males. In contrast, KD females were prone to shorter lifespans than WT females. These results clarify that brain-targeted miR-29 knockdown affects both lifespan and reproduction in a gender-dependent manner, and moreover that the reciprocal responsiveness to the miR-29 knockdown between these two phenotypes in both genders closely follow life-course models based on the classical trade-off prediction wherein elaborate early-life energetic investment in reproduction entails accelerated late-life declines in survival, and vice versa. Thus, this study identified miR-29 as the first mammalian miRNA that is directly implicated in the lifetime trade-off between the two major fitness components, lifespan and reproduction. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.
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von Kuerthy, Corinna; Ros, Albert F H; Taborsky, Michael
2016-11-15
Alternative reproductive tactics (ARTs), which can be plastic or fixed for life, may be characterized by distinct hormonal profiles. The relative plasticity hypothesis predicts flexible androgen regulation for adult males pursuing plastic tactics, but a less flexible regulation for males using a fixed tactic throughout life. Furthermore, androgen profiles may respond to changes in the social environment, as predicted by the social reciprocity models of hormone/behaviour interactions. The cichlid fish Lamprologus callipterus provides a rare opportunity to study the roles of androgens for male ARTs within a single species, because fixed and plastic ARTs coexist. We experimentally exposed males to competitors pursuing either the same or different tactics to test predictions of the relative plasticity and the social reciprocity models. Androgen profiles of different male types partly comply with predictions derived from the relative plasticity hypothesis: males of the plastic bourgeois/sneaker male trajectory showed different 11-ketotestosterone (11-KT) levels when pursuing either bourgeois or parasitic sneaker male behaviours. Surprisingly, males pursuing the fixed dwarf male tactic showed the highest free and conjugated 11-KT and testosterone (T) levels. Our experimental social challenges significantly affected the free 11-KT levels of bourgeois males, but the androgen responses did not differ between challenges involving different types of competitors. Furthermore, the free T-responses of the bourgeois males correlated with their aggressive behaviour exhibited against competitors. Our results provide new insights into the endocrine responsiveness of fixed and plastic ARTs, confirming and refuting some predictions of both the relative plasticity and the social reciprocity models. © 2016. Published by The Company of Biologists Ltd.
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Santos-del-Blanco, L; Climent, J; González-Martínez, S C; Pannell, J R
2012-11-01
The study of local adaptation in plant reproductive traits has received substantial attention in short-lived species, but studies conducted on forest trees are scarce. This lack of research on long-lived species represents an important gap in our knowledge, because inferences about selection on the reproduction and life history of short-lived species cannot necessarily be extrapolated to trees. This study considers whether the size for first reproduction is locally adapted across a broad geographical range of the Mediterranean conifer species Pinus pinaster. In particular, the study investigates whether this monoecious species varies genetically among populations in terms of whether individuals start to reproduce through their male function, their female function or both sexual functions simultaneously. Whether differences among populations could be attributed to local adaptation across a climatic gradient is then considered. Male and female reproduction and growth were measured during early stages of sexual maturity of a P. pinaster common garden comprising 23 populations sampled across the species range. Generalized linear mixed models were used to assess genetic variability of early reproductive life-history traits. Environmental correlations with reproductive life-history traits were tested after controlling for neutral genetic structure provided by 12 nuclear simple sequence repeat markers. Trees tended to reproduce first through their male function, at a size (height) that varied little among source populations. The transition to female reproduction was slower, showed higher levels of variability and was negatively correlated with vegetative growth traits. Several female reproductive traits were correlated with a gradient of growth conditions, even after accounting for neutral genetic structure, with populations from more unfavourable sites tending to commence female reproduction at a lower individual size. The study represents the first report of genetic
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Endocrine-disrupting chemicals-Mechanisms of action on male reproductive system.
Sidorkiewicz, Iwona; Zaręba, Kamil; Wołczyński, Sławomir; Czerniecki, Jan
2017-07-01
Endocrine-disrupting chemicals (EDCs) are exogenous compounds that can cause disturbances in the endocrine system and have multiple harmful effects on health by targeting different organs and systems in the human body. Mass industrial production and widespread use of EDCs have resulted in worldwide contamination. Accumulating evidence suggest that human exposure to EDCs is related to the impairment of male reproductive function and can interrupt other hormonally regulated metabolic processes, particularly if exposure occurs during early development. Investigation of studies absent in previous reviews and meta-analysis of adverse effects of EDCs on functioning of the male reproductive system is the core of this work. Four main modes of action of EDCs on male fertility have been summarized in this review. First, studies describing estrogen- pathway disturbing chemicals are investigated. Second, androgen-signaling pathway alterations and influence on androgen sensitive tissues are examined. Third, evaluation of steroidogenesis dysfunction is discussed by focusing on the steroid hormone biosynthesis pathway, which is targeted by EDCs. Last, the reportedly destructive role of reactive oxygen species (ROS) on sperm function is discussed. Spermatogenesis is a remarkably complex process, hence multiple studies point out various dysfunctions depending on the development state at which the exposure occurred. Collected data show the need to account for critical windows of exposure such as fetal, perinatal and pubertal periods as well as effects of mixtures of several compounds in future research.
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Hernández, Emilio; Liedo, Pablo; Toledo, Jorge; Montoya, Pablo; Perales, Hugo; Ruiz-Montoya, Lorena
2017-12-05
The sterile insect technique uses males that have been mass-reared in a controlled environment. The insects, once released in the field, must compete to mate. However, the mass-rearing condition supposes a loss of fitness that will be noticeable by wild females. To compare the fitness of wild males and mass-reared males, three competition settings were established. In setting 1, wild males, mass-reared males and wild females were released in field cages. In setting 2, wild females and wild males were released without competition, and in setting 3, mass-reared males and mass-reared females were also released without competition. Male fitness was based on their mating success, fecundity, weight and longevity. The fitness of the females was measured based on weight and several demographic parameters. The highest percentage of mating was between wild males and wild females between 0800 and 0900 h in the competition condition, while the mass-reared males started one hour later. The successful wild males weighed more and showed longer mating times, greater longevity and a higher number of matings than the mass-reared males. Although the mass-reared males showed the lowest percentage of matings, their fecundity when mating with wild females indicated a high fitness. Since the survival and fecundity of wild females that mated with mass-reared males decreased to become similar to those of mass-reared females that mated with mass-reared males, females seem to be influenced by the type of male (wild or mass-reared). © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
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[Age changes of immunological, morphological and biochemical indices of male reproductive system].
Boĭko, O V; Akhmineeva, A Kh; Gudinskaia, N I; Boĭko, V I; Kozak, D M
2014-01-01
The article analyzes the dependence of bactericidal activity of sperm--natural resistance factors controlling the survival of bacteria in the urogenital tract, on the age of men. These data are compared with the results of the standard (on the recommendations of the WHO) spermogram, reflecting reproductive health. Due to the fact that one of the main etiological agents of infectious disease groups in the male reproductive system in adulthood are Staphylococcus spp., we consider the level of bactericidal activity of sperm in resident and transient carriage of S. aureus and S. epidermidis.
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A MATHEMATICAL MODEL FOR THE KINETICS OF THE MALE REPRODUCTIVE ENDOCRINE SYSTEM
In this presentation a model for the hormonal regulation of the reproductive endocrine system in the adult male rat will be discussed. The model includes a description of the kinetics of the androgenic hormones testosterone and dihydrotestosterone, as well as the receptor-mediate...
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Prostasomes--their effects on human male reproduction and fertility.
Burden, H P; Holmes, C H; Persad, R; Whittington, K
2006-01-01
The prostate is a glandular male accessory sex organ vital for normal fertility. It provides the prostatic component of seminal plasma which nourishes and protects sperm following ejaculation. Prostasomes are small (40-500 nm) membrane-bound vesicles produced by epithelial cells lining the prostate acini and are a component of prostatic secretions. Although the existence of these particles has been known for many years, their full function and relevance to reproductive health are largely unknown. Proteomic studies have shown a wide range of proteins (enzymes, structural proteins and novel, unannotated proteins) present in or on the surface of prostasomes providing them with a diverse nature. Interestingly prostasomes are able to fuse with sperm, this event and the associated transfer of proteins lies at the heart of many of their proposed functions. Sperm motility is increased by the presence of prostasomes and their fusion prevents premature acrosome reactions. Prostasomes have been shown to aid protection of sperm within the female reproductive tract because of immunosuppressive, antioxidant and antibacterial properties. Clinically these functions imply a role for prostasomes in male factor infertility. However, the very functions that promote fertility may have negative connotations in later life; recent work has suggested that prostasomes are involved in prostate cancer. Clearly more work is needed to clarify the role of these novel particles and their impact on men's health.
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Bolund, Elisabeth; Lummaa, Virpi; Smith, Ken R.; Hanson, Heidi A.; Maklakov, Alexei A.
2016-01-01
The causes underlying sex differences in lifespan are strongly debated. While females commonly outlive males in humans, this is generally less pronounced in societies before the demographic transition to low mortality and fertility rates. Life-history theory suggests that reduced reproduction should benefit female lifespan when females pay higher costs of reproduction than males. Using unique longitudinal demographic records on 140,600 reproducing individuals from the Utah Population Database, we demonstrate a shift from male-biased to female-biased adult lifespans in individuals born before versus during the demographic transition. Only women paid a cost of reproduction in terms of shortened post-reproductive lifespan at high parities. Therefore, as fertility decreased over time, female lifespan increased, while male lifespan remained largely stable, supporting the theory that differential costs of reproduction in the two sexes result in the shifting patterns of sex differences in lifespan across human populations. Further, our results have important implications for demographic forecasts in human populations and advance our understanding of lifespan evolution. PMID:27087670
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[The reproductive correlates of social hierarchy in laboratory male mice].
Osadchuk, L B; Salomacheva, I N; Bragin, A V; Osadchuk, A V
2007-01-01
In laboratory male mice the effects of social hierarchy on hormonal and spermatogenic testicular function, accessory organs and testicular weights, sexual behaviour have been investigated using an experimental model of social hierarchy, which is characterised by a minimal size (two male mice) and 5 days period of social interactions. The social rank of the partners was detected by asymmetry in aggressive behaviour. Using the experimental condition, when the both partners have no preferences for exclusive use of area we demonstrated that there were no rank differences in the number of mounts and testicular testosterone content. Nevertheless a rank asymmetry in the male sniffing behaviour towards a receptive female, weights of the testes, seminal vesicles, epididymes and the number of epididymal sperm was kept up in a stable social group. Social dominance was found to affect negatively on testicular testosterone increase in response to introduction of a receptive female and sexual attractiveness of male to a receptive female in both dominant and subordinate males. The results obtained demonstrate the impact of social hierarchy on reproduction in laboratory male mice, particular in respect of spermatogenesis and the testicular testosterone in response to a receptive female.
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Animal models of physiologic markers of male reproduction: genetically defined infertile mice
Energy Technology Data Exchange (ETDEWEB)
Chubb, C.
1987-10-01
The present report focuses on novel animal models of male infertility: genetically defined mice bearing single-gene mutations that induce infertility. The primary goal of the investigations was to identify the reproductive defects in these mutant mice. The phenotypic effects of the gene mutations were deciphered by comparing the mutant mice to their normal siblings. Initially testicular steroidogenesis and spermatogenesis were investigated. The physiologic markers for testicular steroidogenesis were steroid secretion by testes perifused in vitro, seminal vesicle weight, and Leydig cell histology. Spermatogenesis was evaluated by the enumeration of homogenization-resistant sperm/spermatids in testes and by morphometric analyses of germ cells in the seminiferous epithelium. If testicular function appeared normal, the authors investigated the sexual behavior of the mice. The parameters of male sexual behavior that were quantified included mount patency, mount frequency, intromission latency, thrusts per intromission, ejaculation latency, and ejaculation duration. Females of pairs breeding under normal circumstances were monitored for the presence of vaginal plugs and pregnancies. The patency of the ejaculatory process was determined by quantifying sperm in the female reproductive tract after sexual behavior tests. Sperm function was studied by quantitatively determining sperm motility during videomicroscopic observation. Also, the ability of epididymal sperm to function within the uterine environment was analyzed by determining sperm capacity to initiate pregnancy after artificial insemination. Together, the experimental results permitted the grouping of the gene mutations into three general categories. They propose that the same biological markers used in the reported studies can be implemented in the assessment of the impact that environmental toxins may have on male reproduction.
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Current updates on laboratory techniques for the diagnosis of male reproductive failure
Directory of Open Access Journals (Sweden)
Suresh C Sikka
2016-01-01
Full Text Available The incidence of male reproductive failure leading to infertility, whether due to delayed parenthood, environmental issues, genetic factors, drugs, etc., is increasing throughout the world. The diagnosis and prognosis of male subfertility have become a challenge. While the basic semen assessment has been performed for many years, a number of studies question the value of the traditional semen characteristics. This is partly due to inadequate methods and standardization, limited knowledge of technical requirements for quality assurance, and an incomplete understanding of what clinical information a semen assessment can provide. Laboratories currently performing semen and endocrine assessment show great variability. The World Health Organization (WHO manual for the evaluation of semen has been the core of andrology and fertility evaluation that has helped in further development of this field over many years. These include the physical appearance of the ejaculate, assessments of sperm count, motility, vitality, morphology, and functional aspects of the sperm and semen sample. These tests also include male endocrine profile, biochemical evaluation of the semen, detection of antisperm antibodies in serum, the use of computer-aided sperm analysis (CASA, sperm DNA integrity, and its damage due to oxidative stress. Assisted reproductive techniques (e.g., IVF, ICSI have shown great success but are too expensive. Further development in this field with newer techniques and extensive training/instructions can improve accuracy and reduce variability, thus maintaining the quality and standards of such an evaluation. There is an urgent need to have standardized training centers and increased awareness in this area of men′s health for reproductive success.
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Abbott, Jessica K; Innocenti, Paolo; Chippindale, Adam K; Morrow, Edward H
2013-01-01
When males and females have different fitness optima for the same trait but share loci, intralocus sexual conflict is likely to occur. Epigenetic mechanisms such as genomic imprinting (in which expression is altered according to parent-of-origin) and sex-specific maternal effects have been suggested as ways by which this conflict can be resolved. However these ideas have not yet been empirically tested. We designed an experimental evolution protocol in Drosophila melanogaster that enabled us to look for epigenetic effects on the X-chromosome-a hotspot for sexually antagonistic loci. We used special compound-X females to enforce father-to-son transmission of the X-chromosome for many generations, and compared fitness and gene expression levels between Control males, males with a Control X-chromosome that had undergone one generation of father-son transmission, and males with an X-chromosome that had undergone many generations of father-son transmission. Fitness differences were dramatic, with experimentally-evolved males approximately 20% greater than controls, and with males inheriting a non-evolved X from their father about 20% lower than controls. These data are consistent with both strong intralocus sexual conflict and misimprinting of the X-chromosome under paternal inheritance. However, expression differences suggested that reduced fitness under paternal X inheritance was largely due to deleterious maternal effects. Our data confirm the sexually-antagonistic nature of Drosophila's X-chromosome and suggest that the response to male-limited X-chromosome evolution entails compensatory evolution for maternal effects, and perhaps modification of other epigenetic effects via coevolution of the sex chromosomes.
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Social Rank, Stress, Fitness, and Life Expectancy in Wild Rabbits
von Holst, Dietrich; Hutzelmeyer, Hans; Kaetzke, Paul; Khaschei, Martin; Schönheiter, Ronald
Wild rabbits of the two sexes have separate linear rank orders, which are established and maintained by intensive fights. The social rank of individuals strongly influence their fitness: males and females that gain a high social rank, at least at the outset of their second breeding season, have a much higher lifetime fitness than subordinate individuals. This is because of two separate factors: a much higher fecundity and annual reproductive success and a 50% longer reproductive life span. These results are in contrast to the view in evolutionary biology that current reproduction can be increased only at the expense of future survival and/or fecundity. These concepts entail higher physiological costs in high-ranking mammals, which is not supported by our data: In wild rabbits the physiological costs of social positions are caused predominantly by differential psychosocial stress responses that are much lower in high-ranking than in low-ranking individuals.
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Ezenwa, Vanessa O; Snider, Matthew H
2016-05-25
Parasites are ubiquitous components of the environment that contribute to behavioural and life-history variation among hosts. Although it is well known that host behaviour can affect parasite infection risk and that parasites can alter host behaviour, the potential for dynamic feedback between these processes is poorly characterized. Using Grant's gazelle (Nanger granti) as a model, we tested for reciprocal effects of behaviour on parasites and parasites on behaviour to understand whether behaviour-parasite feedback could play a role in maintaining variation in male reproductive behaviour. Adult male gazelles either defend territories to attract mates or reside in bachelor groups. Territoriality is highly variable both within- and between-individuals, suggesting that territory maintenance is costly. Using a combination of longitudinal and experimental studies, we found that individual males transition frequently between territorial and bachelor reproductive status, and that elevated parasite burdens are a cost of territoriality. Moreover, among territorial males, parasites suppress aspects of behaviour related to territory maintenance and defence. These results suggest that territorial behaviour promotes the accumulation of parasites in males, and these parasites dampen the very behaviours required for territory maintenance. Our findings suggest that reciprocal feedback between host behaviour and parasitism could be a mechanism maintaining variation in male reproductive behaviour in the system. © 2016 The Author(s).
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Mating with an allopatric male triggers immune response and decreases longevity of ant queens.
Schrempf, A; von Wyschetzki, K; Klein, A; Schrader, L; Oettler, J; Heinze, J
2015-07-01
In species with lifelong pair bonding, the reproductive interests of the mating partners are aligned, and males and females are expected to jointly maximize their reproductive success. Mating increases both longevity and fecundity of female reproductives (queens) of the ant Cardiocondyla obscurior, indicating a tight co-evolution of mating partners. Here, we show that mating with a male from their own population increases lifespan and reproductive success of queens more than mating with a male from a different population, with whom they could not co-evolve. A comparison of transcriptomes revealed an increased expression of genes involved in immunity processes in queens, which mated with males from a different population. Increased immune response might be proximately associated with decreased lifespan. Our study suggests a synergistic co-evolution between the sexes and sheds light on the proximate mechanisms underlying the decreased fitness of allopatrically mated queens. © 2015 John Wiley & Sons Ltd.
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Regional differences and temporal trends in male reproductive health disorders
DEFF Research Database (Denmark)
Nordkap, Loa; Joensen, Ulla Nordström; Blomberg Jensen, Martin
2012-01-01
of various low-dose exposures to endocrine disrupters in our environment are responsible for the adverse effects in the male reproductive system. Semen quality may be the most sensitive marker of adverse environmental exposures, and we suggest that standardized surveillance studies of semen quality...... entities share the same patho-physiological etiology caused by disturbed testicular development in early fetal life. It seems likely that the rapid rise in TDS-associated conditions can, at least partly, be explained by environmental factors. Animal studies provide strong evidence that manmade chemicals...... to endocrine disrupters also in adulthood may affect semen quality and reproductive hormones. Causal relationships are inherently difficult to establish in humans, and a clear connection between the disorders and specific toxicants has not been established. It seems likely that the cumulative effects...
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Barratt, Christopher L R; De Jonge, Christopher J; Sharpe, Richard M
2018-04-01
Approximately 1 in 20 young men today have sperm counts low enough to impair fertility, whereas this may not have been the case historically. The cause(s) of such a decline in male reproductive health is unknown, despite it being a global health issue. Concomitantly, little progress has been made in answering fundamental questions in andrology or in developing new diagnostic tools or alternative management strategies to ICSI in infertile men. We advocate formulation of a detailed roadmap for male reproductive health to facilitate development of a research agenda that highlights the present unmet needs and key unanswered questions, and seeks to deliver effective funding and investment to address them. This vision we term 'a Male Reproductive Health Ecosystem'.
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Skakkebaek, Niels E.; Rajpert-De Meyts, Ewa; Buck Louis, Germaine M.; Toppari, Jorma; Andersson, Anna-Maria; Eisenberg, Michael L.; Jensen, Tina Kold; Jørgensen, Niels; Swan, Shanna H.; Sapra, Katherine J.; Ziebe, Søren; Priskorn, Lærke; Juul, Anders
2015-01-01
It is predicted that Japan and European Union will soon experience appreciable decreases in their populations due to persistently low total fertility rates (TFR) below replacement level (2.1 child per woman). In the United States, where TFR has also declined, there are ethnic differences. Caucasians have rates below replacement, while TFRs among African-Americans and Hispanics are higher. We review possible links between TFR and trends in a range of male reproductive problems, including testicular cancer, disorders of sex development, cryptorchidism, hypospadias, low testosterone levels, poor semen quality, childlessness, changed sex ratio, and increasing demand for assisted reproductive techniques. We present evidence that several adult male reproductive problems arise in utero and are signs of testicular dysgenesis syndrome (TDS). Although TDS might result from genetic mutations, recent evidence suggests that it most often is related to environmental exposures of the fetal testis. However, environmental factors can also affect the adult endocrine system. Based on our review of genetic and environmental factors, we conclude that environmental exposures arising from modern lifestyle, rather than genetics, are the most important factors in the observed trends. These environmental factors might act either directly or via epigenetic mechanisms. In the latter case, the effects of exposures might have an impact for several generations post-exposure. In conclusion, there is an urgent need to prioritize research in reproductive physiology and pathophysiology, particularly in highly industrialized countries facing decreasing populations. We highlight a number of topics that need attention by researchers in human physiology, pathophysiology, environmental health sciences, and demography. PMID:26582516
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Directory of Open Access Journals (Sweden)
William C Ratcliff
2009-06-01
Full Text Available Stresses like dietary restriction or various toxins increase lifespan in taxa as diverse as yeast, Caenorhabditis elegans, Drosophila and rats, by triggering physiological responses that also tend to delay reproduction. Food odors can reverse the effects of dietary restriction, showing that key mechanisms respond to information, not just resources. Such environmental cues can predict population trends, not just individual prospects for survival and reproduction. When population size is increasing, each offspring produced earlier makes a larger proportional contribution to the gene pool, but the reverse is true when population size is declining.We show mathematically that natural selection can favor facultative delay in reproduction when environmental cues predict a decrease in total population size, even if lifetime fecundity decreases with delay. We also show that increased reproduction from waiting for better conditions does not increase fitness (proportional representation when the whole population benefits similarly.We conclude that the beneficial effects of stress on longevity (hormesis in diverse taxa are a side-effect of delaying reproduction in response to environmental cues that population size is likely to decrease. The reversal by food odors of the effects of dietary restriction can be explained as a response to information that population size is less likely to decrease, reducing the chance that delaying reproduction will increase fitness.
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Effect of current tobacco consumption on the male reproductive hormone profile.
Blanco-Muñoz, Julia; Lacasaña, Marina; Aguilar-Garduño, Clemente
2012-06-01
The knowledge about the effect of cigarette smoking on the male reproductive function is still limited. The objective of this study was to evaluate the association between active exposure to tobacco smoke and the male reproductive hormone profile in a group of 136 Mexican flower growers. Serum levels of FSH, LH, prolactin, total testosterone, Inhibin B and estradiol were measured using enzyme-linked immunoabsorbent assay. Weight and height were also measured and a structured questionnaire was applied to get information on sociodemographic characteristics, clinical and work history and alcohol and tobacco consumption (current smoking habit and number of cigarettes smoked per day). Based on this information tobacco consumption was divided into four categories: never-smokers, ex-smokers, current smokers under five cigarettes/day and current smokers over or equal to five cigarettes/day. Using the group of never-smokers as reference and after adjusting for potential confounders, current smokers of five or more cigarettes/day showed significantly higher levels of LH (β=0.33, p=0.01), prolactin (β=0.18, p=0.03) and testosterone (β=0.21, p=0.02). Current smokers of less than five cigarettes/day also showed higher levels of prolactin (β=0.12, p=0.03) and testosterone (β=0.18, pconsumption may act as an endocrine disruptor on the male hormone profile. Copyright © 2012 Elsevier B.V. All rights reserved.
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Long-term Effects of Dexamethasone on Reproductive Parameters in Male Mice
Directory of Open Access Journals (Sweden)
jalogoden Gouyandeh
2015-02-01
Full Text Available Background & aim: The adverse effect of chemical drugs such as dexamethasone as anti-inflammatory -steroidal drugs on different body systems and infertility and reproductive efficiency is of concern. The purpose of this study was to evaluate the long-term effects of dexamethasone on the reproductive system in male rats. Methods: In the present experimental study, fifty matured male mice were divided into five groups including control, placebo and three treatment groups. Control group had no injections, placebo group only received normal saline and treatments groups received dexamethasone (0.1, 0.5 and 1 mg/kg which was injected in peritoneum every other day for a period of twenty days. Their Testosterone was measured by ELISA and testes were dissected for histological examination. The data were analyzed using SPSS 11.5 software. Results: Significant increases were shown in FSH level in all three groups treated with dexamethasone. LH in treatment group of 0.1 mg/kg decreased, but at dose of 1 mg/kg increased significantly.Testosterone levels in a dose of 1 mg/kg significantly increased compared with the control group (p<0.05. However, testis weight, the rate of testicular germ cells, primary spermatocytes, epididymal sperm and fertility significantly increased in all three groups (p<0.05. Conclusion: Dexamethasone had a negative effect on reproduction therefore, the use of this medication at different doses and time periods considers the possible complications beforehand. Keywords: .
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O'Hanlon, James C.; Wignall, Anne E.; Herberstein, Marie E.
2018-02-01
Male reproductive performance can vary with condition, age and future reproductive opportunities. Web-building spiders are ideal models to examine the effects of senescence on fitness-related behaviours due to strong selection on male courtship to reduce pre-copulatory sexual cannibalism. Argiope keyserlingi spiders generate courtship vibrations, or `shudders', that reduce female aggression. We found that male A. keyserlingi courtship slowed with chronological age. Older males took longer to travel across the courtship thread, and overall number of shudders increased. Males retained some ability to modulate courtship quality (shudder duration and number of rocks within each shudder) in response to female quality. A change in courtship performance over time, despite strong selection for repeatability, indicates that ageing in male A. keyserlingi may have direct impacts on reproductive performance.
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Subtotal obstruction of the male reproductive tract.
Dohle, G R; van Roijen, J H; Pierik, F H; Vreeburg, J T M; Weber, R F A
2003-03-01
Bilateral obstruction of the male reproductive tract is suspected in men with azoospermia, normal testicular volume and normal FSH. A testicular biopsy is required to differentiate between an obstruction and a testicular insufficiency. Unilateral or subtotal bilateral obstructions and epididymal dysfunction may cause severe oligozoospermia in men with a normal spermatogenesis. However, information on spermatogenesis in oligozoospermic men is lacking, since testicular biopsy is not routinely performed. Men with a sperm concentration of scoring method. A testicular biopsy was performed in 78 men with severe oligozoospermia. The medical history showed male accessory gland infection in 12.8%, previous hernia repair in 14.1% and a history of cryptorchidism in 12.8%. A normal or slightly disturbed spermatogenesis (Johnsen score >8) was present in 39/78 (50%) of the men. Hernia repair occurred more often in men with normal spermatogenesis. A varicocele was predominantly seen in men with a disturbed spermatogenesis. FSH was significantly lower ( Preproductive tract is a frequent cause of severe oligozoospermia in men with a normal testicular volume and a normal FSH. In other cases, an epididymal dysfunction might explain the oligozoospermia in men with a normal testicular biopsy score.
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Poli, Federica; Locatello, Lisa; Rasotto, Maria B
2018-05-29
The most common adaptation to sperm competition in males is represented by an increase in the sperm number and/or quality released at mating, to raise their probability of egg fertilization. However, rapidly mounting evidence highlights that seminal fluid may directly influence the competitive fertilization success of a male by affecting either own and/or rival sperm performances. In the black goby, Gobius niger , an external fertilizer with guard-sneaker mating tactics and high sperm competition level, sneaker males' ejaculates contain less seminal fluid and more sperm, that are also of better quality, than those of territorial males. However, territorial males, gain a higher paternity success inside natural nests. Here, we ask whether the seminal fluid can contribute to territorial males' reproductive success by enhancing their sperm performances and/or by decreasing those of sneaker males. Using sperm and seminal fluid manipulation and in vitro fertilization tests, we found that own seminal fluid influences the velocity and fertilization ability of sperm only in territorial males, making them as faster as those of sneakers and with similar fertilization rate. Moreover, both sneaker and territorial males' sperm remain unaffected by the seminal fluid of rival males. Thus, black goby males respond to the different level of sperm competition faced by differently allocating in sperm and non-sperm components of the ejaculate, with sneakers primarily investing in sperm of intrinsic high quality and territorial males relying on the effect of seminal fluid to increase the lower intrinsic quality of their sperm. © 2018. Published by The Company of Biologists Ltd.
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Aniline Is Rapidly Converted Into Paracetamol Impairing Male Reproductive Development.
Holm, Jacob Bak; Chalmey, Clementine; Modick, Hendrik; Jensen, Lars Skovgaard; Dierkes, Georg; Weiss, Tobias; Jensen, Benjamin Anderschou Holbech; Nørregård, Mette Marie; Borkowski, Kamil; Styrishave, Bjarne; Martin Koch, Holger; Mazaud-Guittot, Severine; Jegou, Bernard; Kristiansen, Karsten; Kristensen, David Møbjerg
2015-11-01
Industrial use of aniline is increasing worldwide with production estimated to surpass 5.6 million metric tons in 2016. Exposure to aniline occurs via air, diet, and water augmenting the risk of exposing a large number of individuals. Early observations suggest that aniline is metabolized to paracetamol/acetaminophen, likely explaining the omnipresence of low concentrations of paracetamol in European populations. This is of concern as recent studies implicate paracetamol as a disrupter of reproduction. Here, we show through steroidogenic profiling that exposure to aniline led to increased levels of the Δ4 steroids, suggesting that the activity of CYP21 was decreased. By contrast, paracetamol decreased levels of androgens likely through inhibition of CYP17A1 activity. We confirm that aniline in vivo is rapidly converted to paracetamol by the liver. Intrauterine exposure to aniline and paracetamol in environmental and pharmaceutical relevant doses resulted in shortening of the anogenital distance in mice, a sensitive marker of fetal androgen levels that in humans is associated with reproductive malformations and later life reproductive disorders. In conclusion, our results provide evidence for a scenario where aniline, through its conversion into antiandrogenic paracetamol, impairs male reproductive development. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
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Bubnov, Rostyslav V; Drahulian, Maria V; Buchek, Polina V; Gulko, Tamara P
2018-03-01
Liver fibrosis (LF) is a chronic disease, associated with many collateral diseases including reproductive dysfunction. Although the normal liver has a large regenerative capacity the complications of LF could be severe and irreversible. Hormone and sex-related issues of LF development and interactions with male reproductive have not been finally studied. The aim was to study the reproductive function of male rats in experimental CCl 4 -induced liver fibrosis rat model, and the capability for restoration of both the liver and male reproduction system. Studies were conducted on 20 3-month old Wistar male rats. The experimental animals were injected with freshly prepared 50% olive oil solution of carbohydrate tetrachloride (CCl 4 ). On the 8th week after injection we noted the manifestations of liver fibrosis. The rats were left to self-healing of the liver for 8 weeks. All male rats underwent ultrasound and biopsy of the liver and testes on the 8th and 16th weeks. The male rats were mated with healthy females before CCl 4 injection, after modeling LF on the 8th week, and after self-healing of the liver. Pregnancy was monitored on ultrasound. On the 8th week of experiment we observed ultrasound manifestation of advanced liver fibrosis, including hepatosplenomegaly, portal hypertension. Ultrasound exam of the rat testes showed testicular degeneration, hydrocele, fibrosis, scarring, petrifications, size reduction, and restriction of testicular descent; testes size decreased from 1.24 ± 0.62 ml to 0.61 ± 0.13, p reproductive system and altering of fertility: the offspring of male rats with advanced LF was 4.71 ± 0.53 born alive vs 9.55 ± 0.47 born from mating with healthy males, p reproductive system.
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Morphofunctional state of reproductive system in the male-rats, which were intrauterine irradiated
International Nuclear Information System (INIS)
Fedosenko, O.L.
2008-01-01
The changes in cytogenetic studies and morphofunctional state of reproductive system in the male-rats, which were intrauterine irradiated. The alterations in relative mass organs, increase of number sperm cells and abnormal form of sperm cells in epididymis were ascertained. (authors)
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Lecocq, Thomas; Gérard, Maxence; Maebe, Kevin; Brasero, Nicolas; Dehon, Lauren; Smagghe, Guy; Valterová, Irena; De Meulemeester, Thibaut; Rasmont, Pierre; Michez, Denis
2017-08-01
The current bumblebee decline leads to inbreeding in populations that fosters a loss of allelic diversity and diploid male production. As diploid males are viable and their offspring are sterile, bumblebee populations can quickly fall in a vortex of extinction. In this article, we investigate for the first time a potential premating mechanism through a major chemical reproductive trait (male cephalic labial gland secretions) that could prevent monandrous virgin queens from mating with diploid males. We focus our study on the cephalic labial gland secretions of diploid and haploid males of Bombus terrestris (L.). Contrary to initial expectations, our results do not show any significant differentiation of cephalic labial gland secretions between diploid and haploid specimens. Queens seem therefore to be unable to avoid mating with diploid males based on their compositions of cephalic labial gland secretions. This suggests that the vortex of extinction of diploid males could not be stopped through premating avoidance based on the cephalic labial gland secretions but other mechanisms could avoid mating between diploid males and queens. © 2016 Institute of Zoology, Chinese Academy of Sciences.
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Impact of reactive oxygen species on antioxidant capacity of male reproductive system.
Riaz, Muhammad; Mahmood, Zahed; Shahid, Muhammad; Saeed, M Usman Qamar; Tahir, Imtiaz Mahmood; Shah, Sm Ali; Munir, Naveed; El-Ghorab, Ahmed
2016-09-01
The present research work was aimed to study the mutual interaction of reactive oxygen species (ROS) and basal cells antioxidant capacity in the male reproductive system and to further establish the association between selected heavy metals and stress markers. Total oxidant status (TOS) and total antioxidant status (TAS) of serum and seminal plasma were determined by automated photometric methods. The concentrations of Selenium (Se), Lead (Pb), and Cadmium (Cd) were determined by using atomic absorption spectrophotometer. The TOS was increased significantly (P male infertility. © The Author(s) 2015.
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Directory of Open Access Journals (Sweden)
V.U. Nna
2016-09-01
Conclusion: Serum prolactin concentration correlated negatively with male reproductive hormones and may play a major role in reproductive deficits associated with chronic use of PDE5 inhibitors and opioids.
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Directory of Open Access Journals (Sweden)
Marlène Chirault
Full Text Available In recent years, several studies have shown a decline in reproductive success in males in both humans and wildlife. Research on male fertility has largely focused on vertebrates, although invertebrates constitute the vast majority of terrestrial biodiversity. The reduction of their reproductive capacities due to environmental stresses can have strong negative ecological impacts, and also dramatic consequences on world food production if it affects the reproductive success of biological control agents, such as parasitic wasps used to control crop pests. Here Nasonia vitripennis, a parasitic wasp of various fly species, was studied to test the effects of 24h-heat stress applied during the first pupal stage on male fertility. Results showed that only primary spermatocytes were present at the first pupal stage in all cysts of the testes. Heat stress caused a delay in spermatogenesis during development and a significant decrease in sperm stock at emergence. Females mated with these heat-stressed males showed a reduce sperm count stored in their spermatheca. Females did not appear to distinguish heat-stressed from control males and did not remate more frequently to compensate for the lack of sperm transferred. As a result, females mated with heat-stressed males produced a suboptimal lifetime offspring sex ratio compared to those mated with control males. This could further impact the population dynamics of this species. N. vitripennis appears to be an interesting biological model to study the mechanisms of subfertility and its consequence on female reproductive strategies and provides new research perspectives in both invertebrates and vertebrates.
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Chirault, Marlène; Lucas, Christophe; Goubault, Marlène; Chevrier, Claude; Bressac, Christophe; Lécureuil, Charlotte
2015-01-01
In recent years, several studies have shown a decline in reproductive success in males in both humans and wildlife. Research on male fertility has largely focused on vertebrates, although invertebrates constitute the vast majority of terrestrial biodiversity. The reduction of their reproductive capacities due to environmental stresses can have strong negative ecological impacts, and also dramatic consequences on world food production if it affects the reproductive success of biological control agents, such as parasitic wasps used to control crop pests. Here Nasonia vitripennis, a parasitic wasp of various fly species, was studied to test the effects of 24h-heat stress applied during the first pupal stage on male fertility. Results showed that only primary spermatocytes were present at the first pupal stage in all cysts of the testes. Heat stress caused a delay in spermatogenesis during development and a significant decrease in sperm stock at emergence. Females mated with these heat-stressed males showed a reduce sperm count stored in their spermatheca. Females did not appear to distinguish heat-stressed from control males and did not remate more frequently to compensate for the lack of sperm transferred. As a result, females mated with heat-stressed males produced a suboptimal lifetime offspring sex ratio compared to those mated with control males. This could further impact the population dynamics of this species. N. vitripennis appears to be an interesting biological model to study the mechanisms of subfertility and its consequence on female reproductive strategies and provides new research perspectives in both invertebrates and vertebrates.
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Lind, Craig M; Beaupre, Steven J
2015-01-01
Life-history theory predicts that organisms will hedge current reproductive investment against potential costs in terms of survivorship and future fecundity. However, little is known regarding the endocrine mechanisms underlying bet-hedging strategies in free-ranging male vertebrates. We examined the relationships among individual energetic status, steroid hormones, mate search, and reproductive behavior in free-ranging male timber rattlesnakes. Snakes were monitored over four active seasons in order to test two hypotheses: (1) males adjust the amount of time and energy allocated toward reproduction according to the level of individual energy stores, and (2) observed condition-dependent reproductive allocation is associated with circulating concentrations of steroid hormones (testosterone and corticosterone) thought to regulate reproductive behaviors in vertebrates. A positive relationship between body condition and testosterone was observed in both the field and the laboratory. Male mate search effort was positively correlated with both body condition and testosterone. Body condition and testosterone concentrations were negatively related to time allocated toward foraging during the breeding season. A strong effect of year was observed in the analysis of testosterone and search effort, suggesting that multiple environmental factors impact hormone production and reproductive investment. Corticosterone was not related to any measured variable. Therefore, our results did not indicate a clear role of corticosterone in mediating observed relationships between energetic status and behavior. Observed relationships are consistent with the hypothesis that males allocate time and energy toward reproduction according to individual energetic status and that testosterone plays a role in mediating the trade-off between current reproductive investment and residual reproductive value.
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Nickel, Desirée; Civetta, Alberto
2009-01-01
Reproductive isolation between closely related species is expressed through uncoordinated courtship, failed fertilization, and (or) postzygotic barriers. Behavioural components of mating often form an initial barrier to hybridization between species. In many animals, females are responsible for mating discrimination in both intra- and interspecific crosses; males of Drosophila virilis group represent an exception to this trend. Using overall productivity tests, we show that a lower proportion of D. virilis males sire progeny when paired with a heterospecific female (Drosophila novamexicana or Drosophila americana texana) for 2 weeks. This suggests male mate discrimination or some other kind of asymmetrical incompatibility in courtship and mating or early zygote mortality. We used males from D. virilis-D. novamexicana and from D. virilis-D. a. texana backcross populations to map chromosome effects responsible for male reproductive isolation. Results from the analysis of both backcross male populations indicate a major X chromosome effect. Further, we conduct a male behavioural analysis to show that D. virilis males significantly fail to continue courtship after the first step of courtship, when they tap heterospecific females. The combined results of a major X chromosome effect and the observation that D. virilis males walk away from females after tapping suggest that future studies should concentrate on the identification of X-linked genes affecting the ability of males to recognize conspecific females.
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Bistodeau, T.J.; Barber, L.B.; Bartell, S.E.; Cediel, R.A.; Grove, K.J.; Klaustermeier, J.; Woodard, J.C.; Lee, K.E.; Schoenfuss, H.L.
2006-01-01
The ubiquitous presence of nonylphenolethoxylate/octylphenolethoxylate (NPE/OPE) compounds in aquatic environments adjacent to wastewater treatment plants (WWTP) warrants an assessment of the endocrine disrupting potential of these complex mixtures on aquatic vertebrates. In this study, fathead minnow larvae were exposed for 64 days to a mixture of NPE/OPE, which closely models the NPE/OPE composition of a major metropolitan WWTP effluent. Target exposure concentrations included a total NPE/OPE mixture load of 200% of the WWTP effluent concentration (148 ??g/L), 100% of the WWTP effluent concentration (74 ??g/L) and 50% of the WWTP effluent concentration (38 ??g/L). The NPE/OPE mixture contained 0.2% 4-t-octylphenol, 2.8% 4-nonylphenol, 5.1% 4-nonylphenolmonoethoxylate, 9.3% 4-nonylphenoldiethoxylate, 0.9% 4-t-octylphenolmonoethoxylate, 3.1% 4-t-octylphenoldiethoxylate, 33.8% 4-nonylphenolmonoethoxycarboxylate, and 44.8% 4-nonylphenoldiethoxycarboxylate. An additional exposure of 5 ??g/L 4-nonylphenol (nominal) was conducted. The exposure utilized a flow-through system supplied by ground water and designed to deliver consistent concentrations of applied chemicals. Following exposure, larvae were raised to maturity. Upon sexual maturation, exposed male fish were allowed to compete with control males in a competitive spawning assay. Nest holding ability of control and exposed fish was carefully monitored for 7 days. All male fish were then sacrificed and analyzed for plasma vitellogenin, developmental changes in gonadal tissues, alterations in the development of secondary sexual characters, morphometric changes, and changes to reproductive behavior. When exposed to the 200% NPE/OPE treatment most larvae died within the first 4 weeks of exposure. Both the 100% and 50% NPE/OPE exposures caused a significant decrease in reproductive behavior, as indicated by an inability of many of the previously exposed males to acquire and hold a nest site required for reproduction
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U.S. Environmental Protection Agency — Background: Trends in male reproductive health have been reported for increased rates of testicular germ cell tumors, low semen quality, cryptorchidism, and...
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The Effect of Hindlimb Suspension on the Reproductive System of Young Male Rats
Tou, Janet; Grindeland, R.; Baer, L.; Guran, G.; Fung, C.; Wade, C.; Dalton, Bonnie P. (Technical Monitor)
2001-01-01
Colonization of space requires the ability to reproduce in reduced gravity. Following spaceflight, astronauts and male rats exhibit decreased testosterone (T). This has important implications as T effects the testes and accessory sex glands. To our knowledge no studies have examined the effects of spaceflight on accessory sex glands. Due to the rarity of spaceflight opportunities, ground models have been used to simulate weightlessness. The objective of this study was to determine the effect of long-term (21 d) weightlessness on the reproductive system of male rats. Weightlessness was simulated using the Morey-Holton hindlimb suspension (HLS) model. Age 10 week old, male Sprague-Dawley rats weighing (209.0 +9.7g) were randomly assigned (n=10/group) to either HLS or ambulatory control. In HLS rats, testes mass was 33% lower (pmale rats. This discrepancy may have been due to the age of animal and timing of sampling. T levels vary dramatically during testes development as well as within normal diurnal cycles. In young HLS rats, testes weight was reduced but not plasma T. Subsequently there was no effect on accessory sex glands. However, this may not be the case in older rats. More studies using standardized methods are needed to gain a better understanding of male reproduction function and capability in weightlessness. Funding provided by NASA.
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Directory of Open Access Journals (Sweden)
Jan E Aagaard
Full Text Available Understanding the genetic basis of reproductive isolation promises insight into speciation and the origins of biological diversity. While progress has been made in identifying genes underlying barriers to reproduction that function after fertilization (post-zygotic isolation, we know much less about earlier acting pre-zygotic barriers. Of particular interest are barriers involved in mating and fertilization that can evolve extremely rapidly under sexual selection, suggesting they may play a prominent role in the initial stages of reproductive isolation. A significant challenge to the field of speciation genetics is developing new approaches for identification of candidate genes underlying these barriers, particularly among non-traditional model systems. We employ powerful proteomic and genomic strategies to study the genetic basis of conspecific pollen precedence, an important component of pre-zygotic reproductive isolation among yellow monkeyflowers (Mimulus spp. resulting from male pollen competition. We use isotopic labeling in combination with shotgun proteomics to identify more than 2,000 male function (pollen tube proteins within maternal reproductive structures (styles of M. guttatus flowers where pollen competition occurs. We then sequence array-captured pollen tube exomes from a large outcrossing population of M. guttatus, and identify those genes with evidence of selective sweeps or balancing selection consistent with their role in pollen competition. We also test for evidence of positive selection on these genes more broadly across yellow monkeyflowers, because a signal of adaptive divergence is a common feature of genes causing reproductive isolation. Together the molecular evolution studies identify 159 pollen tube proteins that are candidate genes for conspecific pollen precedence. Our work demonstrates how powerful proteomic and genomic tools can be readily adapted to non-traditional model systems, allowing for genome-wide screens
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Kordonowy, Lauren; MacManes, Matthew
2017-06-23
The understanding of genomic and physiological mechanisms related to how organisms living in extreme environments survive and reproduce is an outstanding question facing evolutionary and organismal biologists. One interesting example of adaptation is related to the survival of mammals in deserts, where extreme water limitation is common. Research on desert rodent adaptations has focused predominantly on adaptations related to surviving dehydration, while potential reproductive physiology adaptations for acute and chronic dehydration have been relatively neglected. This study aims to explore the reproductive consequences of acute dehydration by utilizing RNAseq data in the desert-specialized cactus mouse (Peromyscus eremicus). We exposed 22 male cactus mice to either acute dehydration or control (fully hydrated) treatment conditions, quasimapped testes-derived reads to a cactus mouse testes transcriptome, and then evaluated patterns of differential transcript and gene expression. Following statistical evaluation with multiple analytical pipelines, nine genes were consistently differentially expressed between the hydrated and dehydrated mice. We hypothesized that male cactus mice would exhibit minimal reproductive responses to dehydration; therefore, this low number of differentially expressed genes between treatments aligns with current perceptions of this species' extreme desert specialization. However, these differentially expressed genes include Insulin-like 3 (Insl3), a regulator of male fertility and testes descent, as well as the solute carriers Slc45a3 and Slc38a5, which are membrane transport proteins that may facilitate osmoregulation. These results suggest that in male cactus mice, acute dehydration may be linked to reproductive modulation via Insl3, but not through gene expression differences in the subset of other a priori tested reproductive hormones. Although water availability is a reproductive cue in desert-rodents exposed to chronic drought
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Effects of exposure to short-term heat stress on male reproductive fitness in a soil arthropod.
Zizzari, Z.V.; Ellers, J.
2011-01-01
Ambient temperature is a key environmental factor influencing a variety of aspects of the ecology and evolution of ectotherms. Reproductive traits have been suggested to be more sensitive to thermal stress than other life history traits. This study investigated the direct and indirect effects of
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The rock-paper-scissors game and the evolution of alternative male strategies
Sinervo, B.; Lively, C. M.
1996-03-01
MANY species exhibit colour polymorphisms associated with alternative male reproductive strategies, including territorial males and 'sneaker males' that behave and look like females1-3. The prevalence of multiple morphs is a challenge to evolutionary theory because a single strategy should prevail unless morphs have exactly equal fitness4,5 or a fitness advantage when rare6,7. We report here the application of an evolutionary stable strategy model to a three-morph mating system in the side-blotched lizard. Using parameter estimates from field data, the model predicted oscillations in morph frequency, and the frequencies of the three male morphs were found to oscillate over a six-year period in the field. The fitnesses of each morph relative to other morphs were non-transitive in that each morph could invade another morph when rare, but was itself invadable by another morph when common. Concordance between frequency-dependent selection and the among-year changes in morph fitnesses suggest that male interactions drive a dynamic 'rock-paper-scissors' game7.
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Vitamin D metabolism, sex hormones, and male reproductive function
DEFF Research Database (Denmark)
Blomberg Jensen, Martin
2012-01-01
The spectrum of vitamin D (VD)-mediated effects has expanded in recent years, and VD is now recognized as a versatile signaling molecule rather than being solely a regulator of bone health and calcium homeostasis. One of the recently identified target areas of VD is male reproductive function...... is the main VD target in the testis and to what extent VD is important for sex hormone production and function of spermatozoa. This review summarizes descriptive studies on testicular VD metabolism and spatial distribution of VDR and the VD metabolizing enzymes in the mammalian testes and discusses...
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Friesen, Christopher R; Johansson, Rasmus; Olsson, Mats
2017-08-01
Polymorphism has fascinated biologists for over a century because morphs persist within populations through evolutionary time in spite of showing disparate behavioral and physiological phenotypes; any one morph should go to fixation with the slightest fitness advantage over the others. Surely there must be trade-offs that balance selection on them. The polychromatic morphs of the Australian painted dragon lizard, Ctenophorus pictus, are one such system. The male color morphs of painted dragons have different physiological and behavioral traits including reproductive tactics, hormone levels, and the rate of body condition loss through the reproductive season. Due to their differences in physiology and reproductive tactics, we tested the hypotheses that male morphs would differ in resting metabolic rates (RMRs) and that the morphs' RMR would decline at different rates through the mating season. We found that bib-morphs (yellow gular patch) differ in RMR with bibbed (more aggressive) males having consistently higher RMR than non-bibbed males. Furthermore, we show that male dragons experience a decline in RMR as they age from reproductively active to inactive. We also found that the RMR of bibbed males has higher repeatability than non-bibbed males. Our results reinforce previous hypotheses about the morph-specific costs of bearing a gular patch in painted dragons. © 2017 Wiley Periodicals, Inc.
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Metabolomics reveals metabolic changes in male reproductive cells exposed to thirdhand smoke
Xu, Bo; Chen, Minjian; Yao, Mengmeng; Ji, Xiaoli; Mao, Zhilei; Tang, Wei; Qiao, Shanlei; Schick, Suzaynn F.; Mao, Jian-Hua; Hang, Bo; Xia, Yankai
2015-10-01
Thirdhand smoke (THS) is a new term for the toxins in cigarette smoke that linger in the environment long after the cigarettes are extinguished. The effects of THS exposure on male reproduction have not yet been studied. In this study, metabolic changes in male germ cell lines (GC-2 and TM-4) were analyzed after THS treatment for 24 h. THS-loaded chromatography paper samples were generated in a laboratory chamber system and extracted in DMEM. At a paper: DMEM ratio of 50 μg/ml, cell viability in both cell lines was normal, as measured by the MTT assay and markers of cytotoxicity, cell cycle, apoptosis and ROS production were normal as measured by quantitative immunofluorescence. Metabolomic analysis was performed on methanol extracts of GC-2 and TM-4 cells. Glutathione metabolism in GC-2 cells, and nucleic acid and ammonia metabolism in TM-4 cells, was changed significantly by THS treatment. RT-PCR analyses of mRNA for enzyme genes Gss and Ggt in GC-2 cells, and TK, SMS and Glna in TM-4 cells reinforced these findings, showing changes in the levels of enzymes involved in the relevant pathways. In conclusion, exposure to THS at very low concentrations caused distinct metabolic changes in two different types of male reproductive cell lines.
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A Brief Review of the Link between Environment and Male Reproductive Health
DEFF Research Database (Denmark)
Skakkebaek, Niels E
2016-01-01
. There is little doubt that environmental factors associated with modern lifestyles have - in a broad sense - had an adverse influence on male reproductive health. The hypothesis that exposure to endocrine-disrupting chemicals plays a fundamental role in this trend is plausible. This is based on evidence from......During the past few decades there has been a significantly increasing trend in germ cell tumours all over the world, particularly in countries with Caucasian populations. The changes in incidence have occurred so fast that only environmental factors can explain this development. This review focuses...... animal studies that demonstrate adverse reproductive effects caused by a number of endocrine-disrupting chemicals to which humans are exposed as part of our modern lifestyle....
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Antiherbivore defenses alter natural selection on plant reproductive traits.
Thompson, Ken A; Johnson, Marc T J
2016-04-01
While many studies demonstrate that herbivores alter selection on plant reproductive traits, little is known about whether antiherbivore defenses affect selection on these traits. We hypothesized that antiherbivore defenses could alter selection on reproductive traits by altering trait expression through allocation trade-offs, or by altering interactions with mutualists and/or antagonists. To test our hypothesis, we used white clover, Trifolium repens, which has a Mendelian polymorphism for the production of hydrogen cyanide-a potent antiherbivore defense. We conducted a common garden experiment with 185 clonal families of T. repens that included cyanogenic and acyanogenic genotypes. We quantified resistance to herbivores, and selection on six floral traits and phenology via male and female fitness. Cyanogenesis reduced herbivory but did not alter the expression of reproductive traits through allocation trade-offs. However, the presence of cyanogenic defenses altered natural selection on petal morphology and the number of flowers within inflorescences via female fitness. Herbivory influenced selection on flowers and phenology via female fitness independently of cyanogenesis. Our results demonstrate that both herbivory and antiherbivore defenses alter natural selection on plant reproductive traits. We discuss the significance of these results for understanding how antiherbivore defenses interact with herbivores and pollinators to shape floral evolution. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.
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Leite, Gabriel Adan Araújo; Figueiredo, Thamiris Moreira; Sanabria, Marciana; Dias, Ana Flávia Mota Gonçalves; Silva, Patrícia Villela E; Martins Junior, Airton da Cunha; Barbosa Junior, Fernando; Kempinas, Wilma De Grava
2017-10-01
Dyslipidemias are occurring earlier in the population due to the increase of obesity and bad eating habits. Rosuvastatin inhibits the enzyme HMG-CoA reductase, decreasing total cholesterol. Ascorbic acid is an important antioxidant compound for male reproductive system. This study aimed to evaluate whether ascorbic acid supplementation may prevent the reproductive damage provoked by rosuvastatin administration at prepuberty. Male pups were distributed into six experimental groups that received saline solution 0.9%, 3 or 10mg/kg/day of rosuvastatin, 150mg/day of ascorbic acid, or 150mg/day of ascorbic acid associated with 3 or 10mg/kg/day of rosuvastatin from post-natal day (PND) 23 until PND53. Rosuvastatin-treated groups showed delayed puberty installation, androgen depletion and impairment on testicular and epididymal morphology. Ascorbic acid partially prevented these reproductive damages. In conclusion, rosuvastatin exposure is a probable risk to reproductive development and ascorbic acid supplementation may be useful to prevent the reproductive impairment of rosuvastatin exposure. Copyright © 2017 Elsevier Inc. All rights reserved.
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Reproductive strategies in snakes.
Shine, Richard
2003-05-22
Snakes of both sexes display remarkable flexibility and diversity in their reproductive tactics. Many features of reproduction in female snakes (such as reproductive mode and frequency, seasonality and multiple mating) allow flexible maternal control. For example, females can manipulate not only the genotypes of their offspring (through mate choice or enhanced sperm competition) but also the phenotypes of their offspring (through allocation 'decisions', behavioural and physiological thermoregulation, and nest-site selection). Reliance on stored energy ('capital') to fuel breeding results in low frequencies of female reproduction and, in extreme cases, semelparity. A sophisticated vomeronasal system not only allows male snakes to locate reproductive females by following scent trails, but also facilitates pheromonally mediated mate choice by males. Male-male rivalry takes diverse forms, including female mimicry and mate guarding; combat bouts impose strong selection for large body size in males of some species. Intraspecific (geographical) variation and phenotypic plasticity in a wide array of reproductive traits (offspring size and number; reproductive frequency; incidence of multiple mating; male tactics such as mate guarding and combat; mate choice criteria) provide exceptional opportunities for future studies.
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Ball, Evan R; Caniglia, Mary Kay; Wilcox, Jenna L; Overton, Karla A; Burr, Marra J; Wolfe, Brady D; Sanders, Brian J; Wisniewski, Amy B; Wrenn, Craige C
2010-03-01
Endocrine disruptors, chemicals that disturb the actions of endogenous hormones, have been implicated in birth defects associated with hormone-dependent development. Phytoestrogens are a class of endocrine disruptors found in plants. In the current study we examined the effects of exposure at various perinatal time periods to genistein, a soy phytoestrogen, on reproductive development and learning in male rats. Dams were fed genistein-containing (5 mg/kg feed) food during both gestation and lactation, during gestation only, during lactation only, or during neither period. Measures of reproductive development and body mass were taken in the male offspring during postnatal development, and learning and memory performance was assessed in adulthood. Genistein exposure via the maternal diet decreased body mass in the male offspring of dams fed genistein during both gestation and lactation, during lactation only, but not during gestation only. Genistein decreased anogenital distance when exposure was during both gestation and lactation, but there was no effect when exposure was limited to one of these time periods. Similarly, spatial learning in the Morris water maze was impaired in male rats exposed to genistein during both gestation and lactation, but not in rats exposed during only one of these time periods. There was no effect of genistein on cued or contextual fear conditioning. In summary, the data indicate that exposure to genistein through the maternal diet significantly impacts growth in male offspring if exposure is during lactation. The effects of genistein on reproductive development and spatial learning required exposure throughout the pre- and postnatal periods. Copyright 2009 Elsevier Inc. All rights reserved.
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Effects of leached components from a hybrid resin composite on the reproductive system of male mice
Directory of Open Access Journals (Sweden)
Taher Akbari Saeed
2012-01-01
Full Text Available Background and Aims: There is concern that leached components from dental composites may cause adverse changes in the reproductive health. This study aimed to assess the effects of leached components from a hybrid resin composite on the reproductive system of male mice.Materials and Methods: In the present animal study, twenty adult Syrian male mice were divided into two groups of 10 mice each. In the test group, components which leached from samples made from Filtek Z250 resin composite into 75% ethanol were daily administered to the mice for 28 days. In the control group, the procedure was repeated in the same way as the test group but without placing composite samples in the solution. Then, the body weight, weights of paired testes, Gonado Somatic Index, sperm viability, sperm motility, epididymal sperm reserve and daily sperm production were recorded. Four male mice in each group were mated with untreated female mice for 10 days. After that, the number of pregnant females and number of infants were recorded. The data were analyzed using repeated measures ANOVA, Chi-square test and t-test.Results: There was a significant reduction in the sperm viability and sperm motility of male mice in the test group compared to the control group (P=0.001. There was no any significant differences in other parameters between two groups (P>0.05.Conclusion: This study showed that the leached components from resin composites cannot cause infertility but they could potentially cause some adverse effects on the reproductive system of male mice.
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Influence of chronic exposure to uranium on male reproduction in mice
International Nuclear Information System (INIS)
Llobet, J.M.; Sirvent, J.J.; Ortega, A.; Domingo, J.L.
1991-01-01
Relatively few data are available concerning the reproductive and developmental toxicity of uranium. The present study was designed to evaluate the reproductive effects of this metal in male Swiss mice. The animals were treated with uranyl acetate dihydrate at doses of 0, 10, 20, 40, and 80 mg/kg/day given in the drinking water for 64 days. To evaluate the fertility of the uranium-treated males, mice were mated with untreated females for 4 days. There was a significant but non-dose-related decrease in the pregnancy rate of these animals. Body weights were significantly depressed only in the 80 mg/kg/day group. Testicular function/spermatogenesis was not affected by uranium at any dose, as evidenced by normal testes and epididymis weights and normal spermatogenesis, whereas interstitial alterations and vacuolization of Leydig cells were seen at 80 mg/kg/day. The results of this investigation indicate that uranium does not cause any adverse effect on testicular function in mice at the concentrations usually ingested in the diet and drinking water, with a safety factor of more than 1000. However, although spermatogenesis was not affected by uranium administration, uranium produces a significant decrease in the pregnancy rate at 10, 20, 40, or 80 mg/kg/day
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Turkington, B. A.
This autoinstructional lesson deals with the study of the human body with emphasis on the life process of reproduction. It is a learning activity included in high school biology or health education classes. The behavioral objectives are listed and the equipment and materials needed to help the student gain these objectives are also included in the…
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Newlin, David B.
2002-01-01
A new theory of substance use disorders is proposed—the SPFit theory—that is based on evolutionary biology and adaptive systems. Self‐perceived survival ability and reproductive fitness (SPFit) is proposed as a human psychobiological construct that prioritizes and organizes (i.e. motivates) behavior, but is highly vulnerable to temporary, artificial activation by drugs of abuse. Autoshaping/ sign‐tracking/feature positive phenomena are proposed to underlie the development of craving and expec...
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Facultative symbiont infections affect aphid reproduction.
Directory of Open Access Journals (Sweden)
Jean-Christophe Simon
Full Text Available Some bacterial symbionts alter their hosts reproduction through various mechanisms that enhance their transmission in the host population. In addition to its obligatory symbiont Buchnera aphidicola, the pea aphid Acyrthosiphon pisum harbors several facultative symbionts influencing several aspects of host ecology. Aphids reproduce by cyclical parthenogenesis whereby clonal and sexual reproduction alternate within the annual life cycle. Many species, including the pea aphid, also show variation in their reproductive mode at the population level, with some lineages reproducing by cyclical parthenogenesis and others by permanent parthenogenesis. While the role of facultative symbionts has been well studied during the parthenogenetic phase of their aphid hosts, very little is known on their possible influence during the sexual phase. Here we investigated whether facultative symbionts modulate the capacity to produce sexual forms in various genetic backgrounds of the pea aphid with controlled symbiont composition and also in different aphid genotypes from natural populations with previously characterized infection status and reproductive mode. We found that most facultative symbionts exhibited detrimental effects on their hosts fitness under sex-inducing conditions in comparison with the reference lines. We also showed that the loss of sexual phase in permanently parthenogenetic lineages of A. pisum was not explained by facultative symbionts. Finally, we demonstrated that Spiroplasma infection annihilated the production of males in the host progeny by inducing a male-killing phenotype, an unexpected result for organisms such as aphids that reproduce primarily through clonal reproduction.
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Facultative symbiont infections affect aphid reproduction.
Simon, Jean-Christophe; Boutin, Sébastien; Tsuchida, Tsutomu; Koga, Ryuichi; Le Gallic, Jean-François; Frantz, Adrien; Outreman, Yannick; Fukatsu, Takema
2011-01-01
Some bacterial symbionts alter their hosts reproduction through various mechanisms that enhance their transmission in the host population. In addition to its obligatory symbiont Buchnera aphidicola, the pea aphid Acyrthosiphon pisum harbors several facultative symbionts influencing several aspects of host ecology. Aphids reproduce by cyclical parthenogenesis whereby clonal and sexual reproduction alternate within the annual life cycle. Many species, including the pea aphid, also show variation in their reproductive mode at the population level, with some lineages reproducing by cyclical parthenogenesis and others by permanent parthenogenesis. While the role of facultative symbionts has been well studied during the parthenogenetic phase of their aphid hosts, very little is known on their possible influence during the sexual phase. Here we investigated whether facultative symbionts modulate the capacity to produce sexual forms in various genetic backgrounds of the pea aphid with controlled symbiont composition and also in different aphid genotypes from natural populations with previously characterized infection status and reproductive mode. We found that most facultative symbionts exhibited detrimental effects on their hosts fitness under sex-inducing conditions in comparison with the reference lines. We also showed that the loss of sexual phase in permanently parthenogenetic lineages of A. pisum was not explained by facultative symbionts. Finally, we demonstrated that Spiroplasma infection annihilated the production of males in the host progeny by inducing a male-killing phenotype, an unexpected result for organisms such as aphids that reproduce primarily through clonal reproduction.
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A review of human male field studies of hormones and behavioral reproductive effort.
Gray, Peter B; McHale, Timothy S; Carré, Justin M
2017-05-01
The purpose of this paper is to review field studies of human male hormones and reproductive behavior. We first discuss life history theory and related conceptual considerations. As illustrations, distinctive features of human male life histories such as coalitional aggression, long-term partnering and paternal care are noted, along with their relevance to overall reproductive effort and developmental plasticity. We address broad questions about what constitutes a human male field study of hormones and behavior, including the kinds of hormone and behavioral measures employed in existing studies. Turning to several sections of empirical review, we present and discuss evidence for links between prenatal and juvenile androgens and sexual attraction and aggression. This includes the proposal that adrenal androgens-DHEA and androstenedione-may play functional roles during juvenility as part of a life-stage specific system. We next review studies of adult male testosterone responses to competition, with these studies emphasizing men's involvement in individual and team sports. These studies show that men's testosterone responses differ with respect to variables such as playing home/away, winning/losing, and motivation. Field studies of human male hormones and sexual behavior also focus on testosterone, showing some evidence of patterned changes in men's testosterone to sexual activity. Moreover, life stage-specific changes in male androgens may structure age-related differences in sexual behavior, including decreases in sexual behavior with senescence. We overview the considerable body of research on male testosterone, partnerships and paternal care, noting the variation in social context and refinements in research design. A few field studies provide insight into relationships between partnering and paternal behavior and prolactin, oxytocin, and vasopressin. In the third section of the review, we discuss patterns, limitations and directions for future research. This
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Offspring Size and Reproductive Allocation in Harvester Ants.
Wiernasz, Diane C; Cole, Blaine J
2018-01-01
A fundamental decision that an organism must make is how to allocate resources to offspring, with respect to both size and number. The two major theoretical approaches to this problem, optimal offspring size and optimistic brood size models, make different predictions that may be reconciled by including how offspring fitness is related to size. We extended the reasoning of Trivers and Willard (1973) to derive a general model of how parents should allocate additional resources with respect to the number of males and females produced, and among individuals of each sex, based on the fitness payoffs of each. We then predicted how harvester ant colonies should invest additional resources and tested three hypotheses derived from our model, using data from 3 years of food supplementation bracketed by 6 years without food addition. All major results were predicted by our model: food supplementation increased the number of reproductives produced. Male, but not female, size increased with food addition; the greatest increases in male size occurred in colonies that made small females. We discuss how use of a fitness landscape improves quantitative predictions about allocation decisions. When parents can invest differentially in offspring of different types, the best strategy will depend on parental state as well as the effect of investment on offspring fitness.
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Czech Academy of Sciences Publication Activity Database
Lecocq, T.; Coppée, A.; Mathy, T.; Lhomme, P.; Cammaerts-Tricot, M. C.; Urbanová, Klára; Valterová, Irena; Rasmont, P.
2015-01-01
Roč. 46, č. 5 (2015), s. 595-605 ISSN 0044-8435 R&D Projects: GA ČR(CZ) GA14-04291S Institutional support: RVO:61388963 Keywords : mate preference * reproductive traits * cephalic labial gland secretions * male marking pheromone * subspecies * olfactometer Subject RIV: CC - Organic Chemistry Impact factor: 1.655, year: 2015
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Reproductive, cytological and biochemical toxicity of Yohimbe in male Swiss albino mice.
Al-Majed, Abdulhakeem A; Al-Yahya, Abdulaziz A; Al-Bekairi, A M; Al-Shabanah, Othman A; Qureshi, Shoeb
2006-07-01
To study the effect of Corynanthe Yohimbe (Yohimbe) on germ cells in Swiss albino mice. Adult male mice were orally (gavage) treated with different doses (188, 375 and 750 mg/[kg x day]) of aqueous suspension of Yohimbe for 90 days. The following parameters were evaluated: (i) reproductive organ weight, (ii) motility and count of sperm, (iii) study on rate of pregnancy and mean implants, (iv) spermatozoa morphology, (v) cytology of the testes chromosomes, and (vi) biochemical study on estimation of proteins, RNA, DNA, malondialdehyde, nonprotein sulfhydryl (NP-SH) and hormones. The treatment caused significant increase in the weight of seminal vesicles, motility and count of spermatozoa, pre- and post-implants. Male fertility was decreased. These results are confirmed by our data on spermatozoa abnormalities and chromosomal aberrations. The data on biochemical parameters showed increase of malondialdehyde and depletion of NP-SH, proteins, RNA and DNA in the testicular cells. Our results elucidated the role of free radical species in cytological and reproductive changes, possibly, under the influence of yohimbine (principal constituent of Yohimbe) on neurotransmitters, including norephinephrine. These data warrant careful use of Yohimbe.
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La Rosa, Raffica J; Conner, Jeffrey K
2017-01-01
Central questions in plant reproductive ecology are whether the functions of floral traits in hermaphrodites create conflict between sexes that could slow evolution, and whether individual floral traits function in pollinator attraction, efficiency, or both. We studied how floral traits affect pollinator visitation and efficiency, and how they affect male and female function and female fitness within and across three Asclepias species that differ in floral morphology. Using separate multiple regressions, we regressed pollen removal, deposition, and fruit number onto six floral traits. We also used path analyses integrating these variables with pollinator visitation data for two of the species to further explore floral function and its effects on fruit production. Most traits affected male pollination success only, and these effects often differed between species. The exception was increased slit length, which increased pollinia insertion in two of the species. There were no interspecific differences in the effects of the traits on female pollination success. All traits except horn reach affected pollination efficiency in at least one species, and horn reach and two hood dimensions were the only traits to affect pollinator attraction, but in just one species. Traits tended to function in only one sex, and more traits affected function through pollinator efficiency than through attraction. There was no significant link between female pollination success and female fitness in any of the three species; this pattern is consistent with fruit production not being limited by pollen deposition. © 2017 Botanical Society of America.
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Sparkes, T C; Rush, V; Kopp, D A; Foster, S A
2013-05-01
The effects of nuptial colour, parasites and body size on reproductive success were examined in a natural population of three-spined stickleback Gasterosteus aculeatus. Reproductive males were collected, with the contents of their nests, during the embryo-guarding stage from Lynne Lake (Cook Inlet, Alaska, U.S.A.), and nuptial colour, infection status and body size were recorded. Regression analysis revealed that male body size was the only predictor, of those measured, of reproductive success in nature. © 2013 The Authors. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.
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Combined action of radiation and immobilization stress on reproductive system male rats station
International Nuclear Information System (INIS)
Vereshchako, G.G.; Chueshova, N.V.; Gorokh, G.A.; Naumov, A.D.
2015-01-01
It was studied the effect of irradiation (0.5 Gy), immobilization stress (3 hours/day for 7 days), and their combined effect on the reproductive system of male rats. The action of these factors, individually or together caused a significant imbalance quantitative composition of the spermatogenic cells in the testis tissue, marked decrease the viability of epididymal spermatozoa, and increased DNA fragmentation in them, which may result in reduced fertility of animals. Under these influences reproductive disorders save for a long time. In some cases, the effects of the combined action of irradiation and immobilization stress is significantly higher than the isolated action of each of them. (authors)
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Haddi, Khalid; Mendes, Marcos V.; Lino-Neto, José; Freitas, Hemerson L.; Guedes, Raul Narciso C.; Oliveira, Eugênio E.
2016-01-01
Environmental stress in newly-emerged adult insects can have dramatic consequences on their life traits (e.g., dispersion, survival and reproduction) as adults. For instance, insects sublethally exposed to environmental stressors (e.g., insecticides) can gain fitness benefits as a result of hormesis (i.e., benefits of low doses of compounds that would be toxic at higher doses). Here, we experimentally tested whether sublethal exposure to the insecticide imidacloprid would hormetically affect the sexual fitness of newly-emerged adults of the Neotropical brown stink bug Euschistus heros (Hemiptera: Heteroptera: Pentatomidae), which is the most abundant and prevalent insect pest in Neotropical soybean fields. We evaluated the sexual fitness of four couple combinations: unexposed couples, exposed females, exposed males, and exposed couples. Sublethal exposure to dry residues (i.e., contact) of imidacloprid (at 1% of recommended field rate) did not affect insect survival, but led to higher mating frequencies when at least one member of the couple was exposed. However, the average mating duration was shortened when only females were exposed to imidacloprid. Moreover, exposed males showed higher locomotory (walking) activity, lower respiration rates and induced higher fecundity rates when mated to unexposed females. Although the reproductive tracts of exposed males did not differ morphometrically from unexposed males, their accessory glands exhibited positive reactions for acidic and basic contents. Our findings suggest that males of the Neotropical brown stink bug hormetically increase their sexual fitness when cued by impending insecticidal stress in early adulthood. PMID:27284906
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Directory of Open Access Journals (Sweden)
Khalid Haddi
Full Text Available Environmental stress in newly-emerged adult insects can have dramatic consequences on their life traits (e.g., dispersion, survival and reproduction as adults. For instance, insects sublethally exposed to environmental stressors (e.g., insecticides can gain fitness benefits as a result of hormesis (i.e., benefits of low doses of compounds that would be toxic at higher doses. Here, we experimentally tested whether sublethal exposure to the insecticide imidacloprid would hormetically affect the sexual fitness of newly-emerged adults of the Neotropical brown stink bug Euschistus heros (Hemiptera: Heteroptera: Pentatomidae, which is the most abundant and prevalent insect pest in Neotropical soybean fields. We evaluated the sexual fitness of four couple combinations: unexposed couples, exposed females, exposed males, and exposed couples. Sublethal exposure to dry residues (i.e., contact of imidacloprid (at 1% of recommended field rate did not affect insect survival, but led to higher mating frequencies when at least one member of the couple was exposed. However, the average mating duration was shortened when only females were exposed to imidacloprid. Moreover, exposed males showed higher locomotory (walking activity, lower respiration rates and induced higher fecundity rates when mated to unexposed females. Although the reproductive tracts of exposed males did not differ morphometrically from unexposed males, their accessory glands exhibited positive reactions for acidic and basic contents. Our findings suggest that males of the Neotropical brown stink bug hormetically increase their sexual fitness when cued by impending insecticidal stress in early adulthood.
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de Arruda, Aline; Cardoso, Claudia Andrea L; Vieira, Maria do Carmo; Arena, Arielle Cristina
2016-01-01
Hibiscus sabdariffa L. (Malvaceae) is a species widely used in folk medicine for the treatment of some disorders. This study evaluated the effects of H. sabdariffa (HS) on the development of the male reproductive tract in rats following in utero exposure. Pregnant rats received 250 or 500 mg/kg of HS extract or vehicle from gestational day 12 until day 21 of lactation. Both doses of HS increased the body weight of male offspring at weaning, without compromising the puberty onset parameters. At puberty, there was a significant increase in the vas deferens absolute weight and a significant reduction in the relative weight of kidney at higher dose. These animals also presented a significant reduction in the sperm number in the caput/corpus of epididymis after exposure to both doses and a reduction in the sperm number in the cauda epididymis for the lower dose. At adulthood, the highest dose significantly reduced the sperm production in relation to controls and both doses provoked a reduction in the relative sperm number in the epididymis without affecting the sperm morphology. These findings demonstrated that maternal exposure to H. sabdariffa can adversely influence the male reproductive system in rats.
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Notes on the Diet of Reproductively Active Male Rafinesque's Big Eared Bats
International Nuclear Information System (INIS)
Menzel, M.A.; Carter, T.C.; Menzel, J.M.; Edwards, J.W.; Ford, W.M.
2002-01-01
Diet examination through the use of fecal samples, of five reproductively active male Rafinesque's big-eared bats from the Upper Coastal Plain of South Carolina during August and September 1999. Diets of these individuals in upland pine stands were similar to diets of Rafinesque's big-eared bats in bottomland and upland hardwood habitats. Although fecal samples had three insect orders, the diet consisted primarily of lepidopterans
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Directory of Open Access Journals (Sweden)
APT Medeiros
Full Text Available The red hybrid tilapia, Oreochromis niloticus (Linnaeus, 1758 x O. mossambicus (Peters, 1852 is a fertile hybrid used in the semi-intensive level of fish culture in the Northeast of Brazil. It is a territorial cichlid and is highly aggressive towards conspecifics during the breeding season. The purpose of this study was to investigate and describe the aggressive behaviour displayed by the males of this hybrid in non-reproductive and reproductive contexts. Behavioural observations revealed that aggression displayed by the reproductive males of red hybrid tilapia included threatening, undulation, parallel, lateral and frontal attacks, chasing, escape and submission. Possession of a territory influenced male aggressiveness, which was more intense in their own territory than that observed in a neutral situation. The males built nests, irrespective of female presence. All the behavioural patterns were in accordance with those previously described for one parental species, the Nile tilapia, O. niloticus.
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Expression of group III metabotropic glutamate receptors in the reproductive system of male mice.
Marciniak, Marcin; Chruścicka, Barbara; Lech, Tomasz; Burnat, Grzegorz; Pilc, Andrzej
2016-03-01
Although the presence of metabotropic glutamate (mGlu) receptors in the central nervous system is well documented, they have recently been found in peripheral and non-neuronal tissues. In the present study we investigated the expression of group III mGlu receptors in the reproductive system of male mice. Reverse transcription-polymerase chain reaction analysis revealed the presence of mGlu6, mGlu7 and mGlu8 (but not mGlu4) receptor transcripts in testes and epididymides from adult mice. In addition, expression of mGlu6 (Grm6) and mGlu8 receptor (Grm8) mRNA was detected in spermatozoa isolated from the vas deferens. The vas deferens was found to contain only mGlu7 receptor (Grm7) mRNA, which was particularly intense in 21-day-old male mice. In penile homogenates, only the mGlu7 receptor signal was detected. Genetic ablation of the mGlu7 receptor in males led to fertility disorders manifested by decreased insemination capability as well as deterioration of sperm parameters, particularly sperm motility, vitality, sperm membrane integrity and morphology, with a simultaneous increase in sperm concentration. These results indicate that constitutively expressed mGlu receptors in the male reproductive system may play an important role in ejaculation and/or erection processes, as well as in the formation and maturation of spermatozoa.
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Alcohol and male reproductive health
DEFF Research Database (Denmark)
Jensen, Tina Kold; Swan, Shanna; Jørgensen, Niels
2014-01-01
.1-32.2) higher free testosterone than men with a weekly intake between 1 and 10 units. Alcohol intake was not significantly associated with serum inhibin B, FSH or LH levels in either group of men. The study is the largest of its kind and has sufficient power to detect changes in semen quality and reproductive......STUDY QUESTION: Is there an association between alcohol intake and semen quality and serum reproductive hormones among healthy men from the USA and Europe? SUMMARY ANSWER: Moderate alcohol intake is not adversely associated with semen quality in healthy men, whereas it was associated with higher...... serum testosterone levels. WHAT IS KNOWN ALREADY: High alcohol intake has been associated with a wide range of diseases. However, few studies have examined the correlation between alcohol and reproductive function and most have been conducted in selected populations of infertile men or have a small...
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Bose, A P H; Adragna, J B; Balshine, S
2017-01-01
In this study, the morphology of sagittal otoliths of the plainfin midshipman fish Porichthys notatus was compared between populations, sexes and male alternative reproductive phenotypes (known as 'type I males or guarders' and 'type II males or sneakers'). Sagitta size increased with P. notatus size and changes in shape were also detected with increasing body size. Porichthys notatus sagittae begin as simple rounded structures, but then elongate as they grow and take on a more triangular and complex shape with several prominent notches and indentations along the dorsal and caudal edges. Moreover, the sagittae of the two geographically and genetically distinct populations of P. notatus (northern and southern) differed in shape. Porichthys notatus from the north possessed taller sagittae with deeper caudal indentations compared to P. notatus from the south. Sagitta shape also differed between females and males of the conventional guarder tactic. Furthermore, guarder males had smaller sagittae for their body size than did sneaker males or females. These differences in sagittal otolith morphology are discussed in relation to ecological and life history differences between the sexes and male tactics of this species. This is the first study to investigate teleost otolith morphology from the perspective of alternative reproductive tactics. © 2016 The Fisheries Society of the British Isles.
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Moxon, Steve
2009-07-01
Dominance is a biological concept of an asymmetric 'power' relationship between (any pair of) individuals, as a result of previous encounters with others biasing likelihood of contesting. That this requires dedicated neural structure shows that dominance is adaptive; and it is usually thought that fitness is increased through dominance (hierarchy) minimising mutually unproductive contest over resources, and/or determining access to or control over resources. But highly inconsistent data indicates that this operational definition is too wide, and given clear evidence that dominance is invariably same-sex, it would seem instead to function primarily to allocate reproduction. Dominance contest exposes individual differences in metabolic vigor especially, but also in various other, including sophisticated attributes; and by a self-organising process there is ranking of same-sex individuals in a hierarchy. But this achieves nothing in itself without an integral mechanism of corresponding individual variable self-suppression of the physiology re reproduction--and mate choice with rank as the criteria. Reproductive suppression would appear to vary along a continuum, from in some species (most 'cooperative breeders') a 100% reproductive skew with total suppression of all individuals bar the sole breeder to, in most others, a gradient down the length of the dominance hierarchy. The mechanism in most species is directly either hormonal or pheromonal, on top of an indirect consequence of the stress caused by relatively low rank. Dominance would seem to have evolved as a major instrument of the proposed 'genetic filter' function of the male, whereby in effect accumulated deleterious genetic material is 'quarantined' in the male half of the lineage from where it is purged, so as to keep this source of reproductive logjam away from females, thereby to avoid amplifying the problem of the female being necessarily the limiting factor in reproduction. The theory makes predictions
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Effect of chronic treatment with a cyclooxygenase inhibitor on reproductive parameters in male rat
International Nuclear Information System (INIS)
Saeed, S.A.; Anwar, N.; Khan, K.M.; Sarfraz, N.
2009-01-01
Indomethacin is a member of non-steroidal anti-inflammatory drugs (NSAIDs) commonly used for treatment of gout, arthritis, and other inflammatory conditions. It has been shown to inhibit ovarian prostaglandins synthesis in mammals, birds, fish and reptiles. However, the effects of its chronic administration on male reproductive functions remain largely unknown. Using rat as a model, we studied the effect of chronic treatment with indomethacin on the male reproductive system. Methods: Testosterone was measured in the serum, testicular tissue, and testicular interstitial fluid by radioimmunoassay. Moreover, we also studied the direct effect of indomethacin in vitro on luteinizing hormone stimulated testosterone secretion from the Leydig cells isolated from various treatment groups. Results: Indomethacin treatment for 50 days caused a significant but reversible decrease in prostate weight, epididymal sperm reserves and sperm motility score compared with control rats (p<0.05). In vitro stimulation of Leydig cells isolated from treated rat's testes with luteinizing hormone (250 mu IU) produced significantly reduced testosterone compared with cells from control groups (p<0.05). Furthermore, stimulatory effect of luteinizing hormone on the control Leydig cells was significantly reduced when these cells were challenged with luteinizing hormone in the presence of indomethacin, (p<0.05). Testosterone concentration in the testicular tissue and testicular interstitial fluid reduced after indomethacin treatment (p<0.05). Conclusion: Due to its significant inhibition of key reproductive hormones, indomethacin effectively inhibits reproductive functions if used on a long-term basis. In his study, we have identified potential risks in the long-term use of cyclooxygenase inhibitors. (author)
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Sifakis, Stavros; Androutsopoulos, Vasilis P; Tsatsakis, Aristeidis M; Spandidos, Demetrios A
2017-04-01
Endocrine disrupting chemicals (EDCs) comprise a group of chemical compounds that have been examined extensively due to the potential harmful effects in the health of human populations. During the past decades, particular focus has been given to the harmful effects of EDCs to the reproductive system. The estimation of human exposure to EDCs can be broadly categorized into occupational and environmental exposure, and has been a major challenge due to the structural diversity of the chemicals that are derived by many different sources at doses below the limit of detection used by conventional methodologies. Animal and in vitro studies have supported the conclusion that endocrine disrupting chemicals affect the hormone dependent pathways responsible for male and female gonadal development, either through direct interaction with hormone receptors or via epigenetic and cell-cycle regulatory modes of action. In human populations, the majority of the studies point towards an association between exposure to EDCs and male and/or female reproduction system disorders, such as infertility, endometriosis, breast cancer, testicular cancer, poor sperm quality and/or function. Despite promising discoveries, a causal relationship between the reproductive disorders and exposure to specific toxicants is yet to be established, due to the complexity of the clinical protocols used, the degree of occupational or environmental exposure, the determination of the variables measured and the sample size of the subjects examined. Future studies should focus on a uniform system of examining human populations with regard to the exposure to specific EDCs and the direct effect on the reproductive system. Copyright © 2017 Elsevier B.V. All rights reserved.
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Effect of gasoline fumes on reproductive function in male albino rats.
Owagboriaye, Folarin O; Dedeke, Gabriel A; Ashidi, Joseph S; Aladesida, Adeyinka A; Olooto, Wasiu E
2018-02-01
The increase in the frequency of exposure to gasoline fumes and the growing incidence of infertility among humans has been a major concern and subject of discussion over the years in Nigeria. We therefore present the reproductive effect of gasoline fumes on inhalation exposure in 40 male albino rats. The rats were randomized into five experimental treatments (T) with eight rats per treatment. T1 (control) was exposed to distilled water while T2, T3, T4, and T5 were exposed to gasoline fumes in exposure chambers for 1, 3, 5, and 9 h daily respectively for 12 weeks. Serum level of testosterone, follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin, oxidative stress markers in the testicular tissue, epididymal sperm health assessment, and testicular histopathology of the rats were used as a diagnostic marker of reproductive dysfunction. Significant (p percentage motility in the exposed rats were observed. Significant (p < 0.05) increased in abnormal sperm cells characterized by damaged head, bent tail, damaged tail, and without head were also observed in the exposed rats. Histopathologically, severe degenerative testicular architectural lesions characterized by alterations in all the generations of sperm cells and reduction of interstitial cells were seen in the exposed rats. Gasoline fume is thus said to interfere with spermatogenesis and impair fertility in male gonad.
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Vitamin D status predicts reproductive fitness in a wild sheep population.
Handel, Ian; Watt, Kathryn A; Pilkington, Jill G; Pemberton, Josephine M; Macrae, Alastair; Scott, Philip; McNeilly, Tom N; Berry, Jacqueline L; Clements, Dylan N; Nussey, Daniel H; Mellanby, Richard J
2016-01-13
Vitamin D deficiency has been associated with the development of many human diseases, and with poor reproductive performance in laboratory rodents. We currently have no idea how natural selection directly acts on variation in vitamin D metabolism due to a total lack of studies in wild animals. Here, we measured serum 25 hydroxyvitamin D (25(OH)D) concentrations in female Soay sheep that were part of a long-term field study on St Kilda. We found that total 25(OH)D was strongly influenced by age, and that light coloured sheep had higher 25(OH)D3 (but not 25(OH)D2) concentrations than dark sheep. The coat colour polymorphism in Soay sheep is controlled by a single locus, suggesting vitamin D status is heritable in this population. We also observed a very strong relationship between total 25(OH)D concentrations in summer and a ewe's fecundity the following spring. This resulted in a positive association between total 25(OH)D and the number of lambs produced that survived their first year of life, an important component of female reproductive fitness. Our study provides the first insight into naturally-occurring variation in vitamin D metabolites, and offers the first evidence that vitamin D status is both heritable and under natural selection in the wild.
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Directory of Open Access Journals (Sweden)
Seok-Won Jung
2015-07-01
Conclusion: The present study shows a possibility that KRGE could be applied as a useful agent to prevent or protect the male reproductive system from the adverse side effects induced by administration of anticancer agents such as busulfan.
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Androgens and the male reproductive tract: an overview of classical roles and current perspectives.
Patrão, Marilia T C C; Silva, Erick J R; Avellar, Maria Christina W
2009-11-01
Androgens are steroid hormones that play key roles in the development and maintenance of male phenotype and reproductive function. These hormones also affect the function of several non-reproductive organs, such as bone and skeletal muscle. Endogenous androgens exert most of their effects by genomic mechanisms, which involve hormone binding to the androgen receptor (AR), a ligand-activated transcription factor, resulting in the modulation of gene expression. AR-induced non-genomic mechanisms have also been reported. A large number of steroidal and non-steroidal AR-ligands have been developed for therapeutic use, including the treatment of male hypogonadism (AR agonists) and prostate diseases (AR antagonists), among other pathological conditions. Here, the AR gene and protein structure, mechanism of action and AR gene homologous regulation were reviewed. The AR expression pattern, its in vivo regulation and physiological relevance in the developing and adult testis and epididymis, which are sites of sperm production and maturation, respectively, were also presented.
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Pinto, P; Velez, Z; Sousa, C; Santos, S; Andrade, A; Alvarado, M V; Felip, A; Zanuy, S; Canário, A V M
2017-09-01
The neuropeptide galanin (Gal) is a putative factor regulating puberty onset and reproduction through its actions on the pituitary. The present study investigated the pituitary responsiveness to galanin and the patterns of galanin receptors (Galrs) expression throughout the reproductive cycle of two years old male European sea bass (Dicentrarchus labrax), an important aquaculture species. Quantitative analysis of pituitary and hypothalamus transcript expression of four galr subtypes revealed differential regulation according to the testicular developmental stage, with an overall decrease in expression from the immature stage to the mid-recrudescence stage. Incubation of pituitary cells with mammalian 1-29Gal peptide induced significant changes in cAMP concentration, with sensitivities that varied according to the testicular development stages. Furthermore 1-29Gal was able to stimulate both follicle stimulating hormone (Fsh) and luteinizing hormone (Lh) release from pituitary cell suspensions. The magnitude of the effects and effective concentrations varied according to reproductive stage, with generalized induction of Fsh and Lh release in animals sampled in January (full spermiation). The differential expression of galrs in pituitary and hypothalamus across the reproductive season, together with the differential effects of Gal on gonadotropins release in vitro strongly suggests the involvement of the galaninergic system in the regulation the hypothalamus-pituitary-gonad axis of male sea bass. This is to our knowledge the first clear evidence for the involvement of galanin in the regulation of reproduction in non-mammalian vertebrates. Copyright © 2017 Elsevier Inc. All rights reserved.
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Directory of Open Access Journals (Sweden)
Seun Funmilola Akomolafe
2015-01-01
Full Text Available Tetracarpidium conophorum (Mull. Arg. Hutch. & Dalz is one of the many medicinal plants used in folklore as male fertility enhancers. This research was aimed at evaluating the anti-peroxidative activity of the leaves of this plant by determining their capacity to reduce malondialdehyde (MDA level in reproductive organs and accessory glands of rats. Adult male rats were administered orally with the aqueous leaf extract from T. conophorum at 50, 500 and 1000 mg/kg body weight for 21 consecutive days while clomiphene citrate (1.04 mg/kg body weight, a fertility drug was used as standard. The results of the study indicated that there was increase in relative organ weight, body weight, mean total food and water consumed by the treated groups. Testicular MDA level was highly significantly different from that of the control (p<0.0001 although a tentatively decreased MDA level was observed. However, MDA levels in the reproductive accessory glands, epididymis, seminal vesicle and prostate gland were insignificantly (p<0.05 lower than those of controls. The highest percentage decrease of MDA level (66.35, 42.68, 62.50 and 63.36% was observed at the highest concentration of the extract (1000 mg/kg in the testis, epididymis, seminal vesicle and prostate gland respectively. These values were two-fold greater than the values obtained for the standard drug. Interestingly, the treatment of rats with the extract significantly increased the activities of superoxide dismutase, catalase (CAT, glutathione peroxidase (GPx, glutathione-S-transferase (GST and the levels of GSH, vitamin C and total protein. Collectively, the results suggest that the extract from T. conophorum leaves had greater capacity to reduce lipid peroxidation in reproductive organs and accessory glands and thus, this plant may be useful in the treatment/management of reproductive cellular damage involving reactive oxygen species.
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Michalik, Peter; Ramírez, Martín J
2014-07-01
The male reproductive system and spermatozoa of spiders are known for their high structural diversity. Spider spermatozoa are flagellate and males transfer them to females in a coiled and encapsulated state using their modified pedipalps. Here, we provide a detailed overview of the present state of knowledge of the primary male reproductive system, sperm morphology and the structural diversity of seminal fluids with a focus on functional and evolutionary implications. Secondly, we conceptualized characters for the male genital system, spermiogenesis and spermatozoa for the first time based on published and new data. In total, we scored 40 characters for 129 species from 56 families representing all main spider clades. We obtained synapomorphies for several taxa including Opisthothelae, Araneomorphae, Dysderoidea, Scytodoidea, Telemidae, Linyphioidea, Mimetidae, Synotaxidae and the Divided Cribellum Clade. Furthermore, we recovered synspermia as a synapomorphy for ecribellate Haplogynae and thus propose Synspermiata as new name for this clade. We hope that these data will not only contribute to future phylogenetic studies but will also stimulate much needed evolutionary studies of reproductive systems in spiders. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Potential negative effects of anti-histamines on male reproductive function.
Mondillo, Carolina; Varela, María Luisa; Abiuso, Adriana María Belén; Vázquez, Ramiro
2018-05-01
Histamine (HA) is a pleiotropic biogenic amine synthesized exclusively by histidine decarboxylase (HDC) in most mammalian tissues. The literature on the role of HA within the male gonad has expanded over the last years, attracting attention to potential unexpected side-effects of anti-histamines on testicular function. In this regard, HA receptors (HRH1, HRH2 and HRH4) have been described in Leydig cells of different species, including human. Via these receptors, HA has been reported to trigger positive or negative interactions with the LH/hCG signaling pathway depending upon its concentration, thereby contributing to the local control of testicular androgen levels. It should then be considered that anti-histamines may affect testicular homeostasis by increasing or decreasing steroid production. Additionally, HRH1 and HRH2 receptors are present in peritubular and germ cells, and HRH2 antagonists have been found to negatively affect peritubular cells and reduce sperm viability. The potential negative impact of anti-histamines on male reproduction becomes even more dramatic if we consider that HA has also been associated with human sexual behavior and penile erection. What is more, although testicular mast cells are the major source of locally produced HA, recent studies have described HDC expression in macrophages, Leydig cells and germ cells, revealing the existence of multiple sources of HA within the testis. Undoubtedly, the more we learn about the testicular histaminergic system, the more opportunities there will be for rational design of drugs aimed at treating HA-related pathologies, with minimum or nule negative impact on fertility. © 2018 Society for Reproduction and Fertility.
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Young, Samantha A M; Aitken, R John; Ikawa, Masahito
2015-01-01
Gene disruption technology has long been beneficial for the study of male reproductive biology. However, because of the time and cost involved, this technology was not a viable method except in specialist laboratories. The advent of the CRISPR/Cas9 system of gene disruption has ushered in a new era of genetic investigation. Now, it is possible to generate gene-disrupted mouse models in very little time and at very little cost. This Highlight article discusses the application of this technology to study the genetics of male fertility and looks at some of the future uses of this system that could be used to reveal the essential and nonessential genetic components of male reproductive mechanisms.
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Reproductive conflict in social insects: Male production by workers in a slave-making ant
DEFF Research Database (Denmark)
Brunner, Elizabeth; Trindl, Andreas; Falk, Karl H.
2005-01-01
by producing their own sons than workers in nonparasitic species. In this study we investigated worker reproduction in four natural colonies of the slave-making ant Polyergus rufescens, using highly variable microsatellite markers. Our results show that workers produce up to 100% of the males. This study thus...
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Long-term effects of x-ray irradiation on reproductive function in male rats
International Nuclear Information System (INIS)
Varga, S.V.; Demchenko, V.N.; Chajkovskaya, L.V.; Reznikov, A.G.
1994-01-01
Reproductive function in male rats was studied in 1, 3 and 6 months after x-ray irradiation at doses of 2 and 3 Gy. It was been established that long-term effects of irradiation at a dose of 3 Gy are manifested through decrease in spermatozoa content in the epididymis and reduction of nucleie acid and protein content in the testes. Fertility of male rats under study significantly lowered shortly after irradiation and full recovery of fecundating ability was observed 6 months later. The effect of irradiation with a dose of 2 Gy was less pronounced
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The Slavic NBN Founder Mutation: A Role for Reproductive Fitness?
Directory of Open Access Journals (Sweden)
Eva Seemanova
Full Text Available The vast majority of patients with Nijmegen Breakage Syndrome (NBS are of Slavic origin and carry a deleterious deletion (c.657del5; rs587776650 in the NBN gene on chromosome 8q21. This mutation is essentially confined to Slavic populations and may thus be considered a Slavic founder mutation. Notably, not a single parenthood of a homozygous c.657del5 carrier has been reported to date, while heterozygous carriers do reproduce but have an increased cancer risk. These observations seem to conflict with the considerable carrier frequency of c.657del5 of 0.5% to 1% as observed in different Slavic populations because deleterious mutations would be eliminated quite rapidly by purifying selection. Therefore, we propose that heterozygous c.657del5 carriers have increased reproductive success, i.e., that the mutation confers heterozygote advantage. In fact, in our cohort study of the reproductive history of 24 NBS pedigrees from the Czech Republic, we observed that female carriers gave birth to more children on average than female non-carriers, while no such reproductive differences were observed for males. We also estimate that c.657del5 likely occurred less than 300 generations ago, thus supporting the view that the original mutation predated the historic split and subsequent spread of the 'Slavic people'. We surmise that the higher fertility of female c.657del5 carriers reflects a lower miscarriage rate in these women, thereby reflecting the role of the NBN gene product, nibrin, in the repair of DNA double strand breaks and their processing in immune gene rearrangements, telomere maintenance, and meiotic recombination, akin to the previously described role of the DNA repair genes BRCA1 and BRCA2.
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Hauser, Russ; Skakkebaek, Niels E; Hass, Ulla; Toppari, Jorma; Juul, Anders; Andersson, Anna Maria; Kortenkamp, Andreas; Heindel, Jerrold J; Trasande, Leonardo
2015-04-01
Increasing evidence suggests that endocrine-disrupting chemicals (EDCs) contribute to male reproductive diseases and disorders. To estimate the incidence/prevalence of selected male reproductive disorders/diseases and associated economic costs that can be reasonably attributed to specific EDC exposures in the European Union (EU). An expert panel evaluated evidence for probability of causation using the Intergovernmental Panel on Climate Change weight-of-evidence characterization. Exposure-response relationships and reference levels were evaluated, and biomarker data were organized from carefully identified studies from the peer-reviewed literature to represent European exposure and approximate burden of disease as it occurred in 2010. The cost-of-illness estimation utilized multiple peer-reviewed sources. The expert panel identified low epidemiological and strong toxicological evidence for male infertility attributable to phthalate exposure, with a 40-69% probability of causing 618,000 additional assisted reproductive technology procedures, costing €4.71 billion annually. Low epidemiological and strong toxicological evidence was also identified for cryptorchidism due to prenatal polybrominated diphenyl ether exposure, resulting in a 40-69% probability that 4615 cases result, at a cost of €130 million (sensitivity analysis, €117-130 million). A much more modest (0-19%) probability of causation in testicular cancer by polybrominated diphenyl ethers was identified due to very low epidemiological and weak toxicological evidence, with 6830 potential cases annually and costs of €848 million annually (sensitivity analysis, €313-848 million). The panel assigned 40-69% probability of lower T concentrations in 55- to 64-year-old men due to phthalate exposure, with 24 800 associated deaths annually and lost economic productivity of €7.96 billion. EDCs may contribute substantially to male reproductive disorders and diseases, with nearly €15 billion annual
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Czech Academy of Sciences Publication Activity Database
Řežucha, Radomil; Smith, C.; Reichard, Martin
2012-01-01
Roč. 149, č. 5 (2012), s. 531-553 ISSN 0005-7959 R&D Projects: GA ČR GA206/09/1163 Institutional support: RVO:68081766 Keywords : alternative reproductive behaviour * animal personality * boldness * behavioural syndrome * mating system * sperm competition * territorial males Subject RIV: EG - Zoology Impact factor: 1.661, year: 2012
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Inhibition of the reproductive system by deslorelin in male and female pigeons (Columba livia).
Cowan, Melinda Lee; Martin, Graeme Bruce; Monks, Deborah Jane; Johnston, Stephen Douglas; Doneley, Robert James Tyson; Blackberry, Margaret Anne
2014-06-01
Veterinary practitioners frequently encounter disorders of the reproductive system in avian patients. Management of these disorders relies on manipulating reproduction by modifying the environment, diet, and social interactions, and by the use of pharmacologic agents and surgery, with varying levels of success and side effects. An alternative is to use the gonadotropin-releasing hormone (GnRH) agonist deslorelin to suppress the pituitary-gonadal axis. To determine the efficacy of deslorelin in domestic pigeons (Columba livia), male (n = 10) and female (n = 10) birds each were implanted intramuscularly with a single long-acting implant containing 4.7 mg deslorelin. Untreated males (n = 11) and females (n = 10) were used as controls. The baseline serum concentration of luteinizing hormone (LH) was assayed at 7, 28, 56, and 84 days after treatment, and egg production was recorded weekly. In females, deslorelin administration significantly reduced serum LH concentrations compared to pretreatment levels at 7, 28, 56, and 84 days (P < .05). In males, deslorelin significantly reduced LH concentrations at 7, 28, and 56 days (P < .05). Female birds treated with deslorelin laid significantly fewer eggs over the course of the study (mean = 1.46, SEM = 0.84) compared with controls (mean = 5.54, SEM = 0.88). Deslorelin treatment had no discernible effect on body weight. Deslorelin is effective for controlling egg laying in female pigeons for at least 49 days, but further research is required to determine the effects on male fertility and the duration of action in both sexes.
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Chen, Yu-Jung; Chen, Kai-Wen; Shih, Yu-Leung; Su, Fang-Ying; Lin, Yen-Po; Meng, Fan-Chun; Lin, Felicia; Yu, Yun-Shun; Han, Chih-Lu; Wang, Chih-Hung; Lin, Jia-Wei; Hsieh, Tsai-Yuan; Li, Yi-Hwei; Lin, Gen-Min
2017-07-07
To investigate the association of chronic hepatitis B and nonalcoholic steatohepatitis with physical fitness in a Taiwanese military male cohort. We made a cross-sectional examination of this association using 3669 young adult military males according to cardiorespiratory fitness and hospitalization events recorded in the Taiwan Armed Forces study. Cases of chronic hepatitis B ( n = 121) were defined by personal history and positive detection of hepatitis B surface antigen. Cases of nonalcoholic steatohepatitis ( n = 129) were defined by alanine transaminase level > 60 U/L, liver ultrasound finding of steatosis, and absence of viral hepatitis A, B or C infection. All other study participants were defined as unaffected ( n = 3419). Physical fitness was evaluated by performance in 3000-m run, 2-min sit-ups, and 2-min push-ups exercises, with all the procedures standardized by a computerized scoring system. Multiple linear regression analysis was used to determine the relationship. Chronic hepatitis B negatively correlated with 2-min push-up numbers (β = -2.49, P = 0.019) after adjusting for age, service specialty, body mass index, systolic and diastolic blood pressures, current cigarette smoking, alcohol intake status, serum hemoglobin, and average weekly exercise times. Nonalcoholic steatohepatitis was borderline positively correlated with 3000-m running time (β = 11.96, P = 0.084) and negatively correlated with 2-min sit-up numbers (β = -1.47, P = 0.040). Chronic hepatitis B viral infection and nonalcoholic steatohepatitis affects different physical performances in young adult military males, and future study should determine the underlying mechanism.
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Quantifying the life-history response to increased male exposure in female Drosophila melanogaster.
Edward, Dominic A; Fricke, Claudia; Gerrard, Dave T; Chapman, Tracey
2011-02-01
Precise estimates of costs and benefits, the fitness economics, of mating are of key importance in understanding how selection shapes the coevolution of male and female mating traits. However, fitness is difficult to define and quantify. Here, we used a novel application of an established analytical technique to calculate individual- and population-based estimates of fitness-including those sensitive to the timing of reproduction-to measure the effects on females of increased exposure to males. Drosophila melanogaster females were exposed to high and low frequencies of contact with males, and life-history traits for each individual female were recorded. We then compared different fitness estimates to determine which of them best described the changes in life histories. We predicted that rate-sensitive estimates would be more accurate, as mating influences the rate of offspring production in this species. The results supported this prediction. Increased exposure to males led to significantly decreased fitness within declining but not stable or increasing populations. There was a net benefit of increased male exposure in expanding populations, despite a significant decrease in lifespan. The study shows how a more accurate description of fitness, and new insights can be achieved by considering individual life-history strategies within the context of population growth. © 2010 The Author(s). Evolution© 2010 The Society for the Study of Evolution.
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Newlin, David B
2002-04-01
A new theory of substance use disorders is proposed-the SPFit theory-that is based on evolutionary biology and adaptive systems. Self-perceived survival ability and reproductive fitness (SPFit) is proposed as a human psychobiological construct that prioritizes and organizes (i.e. motivates) behavior, but is highly vulnerable to temporary, artificial activation by drugs of abuse. Autoshaping/sign-tracking/feature positive phenomena are proposed to underlie the development of craving and expectations about drugs as the individual learns that abused drugs will easily and reliably inflate SPFit. The cortico-mesolimbic dopamine system and its modulating interconnections are viewed as the biological substrate of SPFit; it is proposed to be a survival and reproductive motivation system rather than a reward center or reward pathway. Finally, the concept of modularity of mind is applied to the SPFit construct. Although considerable empirical data are consistent with the theory, new research is needed to test specific hypotheses derived from SPFit theory.
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Endosulfan is toxic to the reproductive health of male freshwater fish, Cyprinion watsoni
Islam, Fakhar ul; Jalali, Samina; Shafqat, Mustafa Nawaz; Shah, Syed Tahir Abbas
2017-12-01
Endosulfan is an organochlorine pesticide that is toxic to aquatic life. Endosulfan might hamper the reproductive health of indigenous fish in agricultural areas of Pakistan where this pesticide is sprayed widely. The aim of the current study is to investigate the toxic effects of endosulfan on selected reproductive parameters of male freshwater fish, Cyprinion watsoni. Two concentrations of endosulfan (0.5 and 1 ppb for 30 days exposure) were tested for their effects on body weight, body length, and testicular weight, length, and width. Testicular testosterone was assayed from tissue extracts using enzyme immunoassay (EIA). A significant increase in the mortality rate was observed in both treated groups during both spawning and quiescent seasons. The overall behavior of fish in the aquarium was normal in all control and treated groups. However, the treated fish exhibited anxiety after treatment with endosulfan. The body weight and length, and testicular weight, length and width were not significantly different to the control group. The testicular testosterone concentrations were significantly lower in both endosulfan-treated groups compared to the control. The decrease was dose-dependent, with a significant difference between the two treated groups. The histomorphological results demonstrated various testicular alterations in the treated groups. These alterations included an increase in interlobular areas and clumping patterns in spermatocytes/spermatids. Because spermatids eventually differentiate into sperms, their low count will directly result in lower sperm count. Taken together, these results suggest that endosulfan is a toxicant that at least disturbs testosterone levels (possibly others) and negatively impacts the reproductive health of male freshwater fish.
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Directory of Open Access Journals (Sweden)
Jonathan P Evans
Full Text Available In many species, mating with multiple males confers benefits to females, but these benefits may be offset by the direct and indirect costs associated with elevated mating frequency. Although mating frequency (number of mating events is often positively associated with the degree of multiple mating (actual number of males mated, most studies have experimentally separated these effects when exploring their implications for female fitness. In this paper I describe an alternative approach using the guppy Poecilia reticulata, a livebearing freshwater fish in which females benefit directly and indirectly from mating with multiple males via consensual matings but incur direct and indirect costs of mating as a consequence of male sexual harassment. In the present study, females were experimentally assigned different numbers of mates throughout their lives in order to explore how elevated mating frequency and multiple mating combine to influence lifetime reproductive success (LRS and survival (i.e. direct components of female fitness. Under this mating design, survival and LRS were not significantly affected by mating treatment, but there was a significant interaction between brood size and reproductive cycle (a correlate of female age because females assigned to the high mating treatment produced significantly fewer offspring later in life compared to their low-mating counterparts. This negative effect of mating treatment later in life may be important in these relatively long-lived fishes, and this effect may be further exacerbated by the known cross-generational fitness costs of sexual harassment in guppies.
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Directory of Open Access Journals (Sweden)
Alana de Fátima Andrade Santos
Full Text Available Abstract Ayahuasca is a psychoactive beverage used ancestrally by indigenous Amazonian tribes and, more recently, by Christian religions in Brazil and other countries. This study aimed to investigate the reproductive effects of this beverage in male Wistar rats after chronic exposure. The rats were treated by gavage every other day for 70 days at 0 (control, 1×, 2×, 4× and 8× the dose used in a religious ritual (12 animals per group, and animals euthanized on the 71st day. Compared to controls, there was a significant decrease in food consumption and body weight gain in rats from the 4× and 8× groups, and a significant increase in the brain and stomach relative weight at the 8× group. There was a significant increase in total serum testosterone, and a decrease in spermatic transit time and spermatic reserves in the epididymis caudae in the 4× group, but not in the highest dose group. No significant changes were found in the other reproductive endpoints (spermatozoid motility and morphology, total spermatozoid count and daily sperm production, and histology of testis and epididymis. This study identified a no-observed-adverse-effect-level for chronic and reproductive effects of ayahuasca in male Wistar rats at 2× the ritualistic dose, which corresponds in this study to 0.62 mg/kg bw N, N-dimethyltryptamine, 6.6 mg/kg bw harmine and 0.52 mg/kg bw harmaline. A potential toxic effect of ayahuasca in male rats was observed at the 4× dose, with a non-monotonic dose–response. Studies investigating the role of ayahuasca components in regulating testosterone levels are needed to better understand this action.
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Directory of Open Access Journals (Sweden)
O. A. Nikiforov
2015-12-01
Full Text Available The study of male reproductive health is relevant, because it is one of the leading causes of the demographic crisis and depopulation of the Ukrainian nation. The article highlights the problems of male infertility, in particular, the question regarding the reasons of the decline in men reproductive potential under the influence of adverse conditions of the industrial city. Aim. The purpose is to study the factors of male infertility in Zaporozhye and Zaporozhye region, the relationship between the area of residence and occupational status. Methods and results. The analysis of ejaculate indicators in men, living in ecologically unfavorable areas and regularities that reflect the pathogenetic mechanisms of occurrence and development of violations of gametogenesis and the functional inferiority of the sex cells have been studied. Conclusion. This shows the increasing trend of male factor infertility, which is from 40% to 60%, and the demographic losses in Ukraine.
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Effects of 90-Day Feeding of Transgenic Maize BT799 on the Reproductive System in Male Wistar Rats
Directory of Open Access Journals (Sweden)
Qian-ying Guo
2015-12-01
Full Text Available BT799 is a genetically modified (GM maize plant that expresses the Cry1Ac gene from Bacillus thuringiensis (Bt. The Cry1Ac gene was introduced into maize line Zhen58 to encode the Bt crystal protein and thus produce insect-resistant maize BT799. Expression of Bt protein in planta confers resistance to Lepidopteran pests and corn rootworms. The present study was designed to investigate any potential effects of BT799 on the reproductive system of male rats and evaluate the nutritional value of diets containing BT799 maize grain in a 90-day subchronic rodent feeding study. Male Wistar rats were fed with diets containing BT799 maize flours or made from its near isogenic control (Zhen58 at a concentration of 84.7%, nutritionally equal to the standard AIN-93G diet. Another blank control group of male rats were treated with commercial AIN-93G diet. No significant differences in body weight, hematology and serum chemistry results were observed between rats fed with the diets containing transgenic BT799, Zhen58 and the control in this 13-week feeding study. Results of serum hormone levels, sperm parameters and relative organ/body weights indicated no treatment-related side effects on the reproductive system of male rats. In addition, no diet-related changes were found in necropsy and histopathology examinations. Based on results of the current study, we did not find any differences in the parameters tested in our study of the reproductive system of male rats between BT799 and Zhen58 or the control.
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Demay, Stephanie M; Becker, Penny A; Waits, Lisette P; Johnson, Timothy R; Rachlow, Janet L
2016-04-01
Understanding reproduction and mating systems is important for managers tasked with conserving vulnerable species. Genetic tools allow biologists to investigate reproduction and mating systems with high resolution and are particularly useful for species that are otherwise difficult to study in their natural environments. We conducted parentage analyses using 19 nuclear DNA microsatellite loci to assess the influence of population density, genetic diversity, and ancestry on reproduction, and to examine the mating system of pygmy rabbits (Brachylagus idahoensis) bred in large naturalized enclosures for the reintroduction and recovery of the endangered distinct population in central Washington, USA. Reproductive output for females and males decreased as population density and individual homozygosity increased. We identified an interaction indicating that male reproductive output decreased as genetic diversity declined at high population densities, but there was no effect at low densities. Males with high amounts (> 50%) of Washington ancestry had higher reproductive output than the other ancestry groups, while reproductive output was decreased for males with high northern Utah/Wyoming ancestry and females with high Oregon/Nevada ancestry. Females and males bred with an average of 3.8 and 3.6 mates per year, respectively, and we found no evidence of positive or negative assortative mating with regards to ancestry. Multiple paternity was confirmed in 81% of litters, and we report the first documented cases of juvenile breeding by pygmy rabbits. This study demonstrates how variation in population density, genetic diversity, and ancestry impact fitness for an endangered species being bred for conservation. Our results advance understanding of basic life history characteristics for a cryptic species that is difficult to study in the wild and provide lessons for managing populations of vulnerable species in captive and free-ranging populations.
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Farahani, Farideh Khalaj Abadi; Shah, Iqbal; Cleland, John; Mohammadi, Mohammad Reza
2012-04-01
Despite cultural and religious prohibitions against premarital heterosexual relationships and intimacy, some recent evidence suggests some rise in premarital heterosexual interactions and relationships among young people. On the other hand, although HIV in Iran is a concentrated epidemic and mainly reported among high risk groups such as injecting drug users (IDUs), but there are evidences that the mode of transmission is shifting towards sexual contacts. This trend has caused concern among health policy makers in terms of prevention of STDs and HIV/AIDS particularly, among young people. This paper was prepared with the aim of highlighting how gender contributes to variation in reproductive health needs and conduct of young people in Iran. This paper is based on a secondary analysis and compares comparable reproductive beliefs and conducts of women and men based on the data of two surveys conducted in Tehran in 2002 and 2005. A survey among 1385 adolescent males and another survey among 1743 female undergraduate students in four multidisciplinary universities in Tehran. Both surveys used anonymous self-administered questionnaires. To make the two samples comparable, the data of unmarried female university undergraduate students who resided in Tehran were merged with the data of adolescent male students who intended to pursue higher education. Common variables of the two surveys were identified, homogenized, merged and analysed. Reproductive health knowledge among male adolescents was poor compared to that of their female peers. Although premarital friendships were moderately acceptable from view points of both males and females, the majority were against premarital sex, particularly among female participants. There were evidences of gender-based double standards in perceptions of premarital sexuality among both males and females; particularly, it was stronger among males than females. Male adolescents reported earlier and greater experiences of premarital
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David, Dalia; Degani, Gad
2011-04-01
This study examined the effect of temperature on reproduction and growth-related factors in blue gourami males under nonreproductive and reproductive conditions. Males that were maintained under nonreproductive conditions did not build nest and the gonado-somatic index (% GSI) was significantly higher in fish maintained at 27°C compared with fish maintained at 23°C. The relative mRNA levels of brain gonadotropin-releasing hormone 3 (GnRH3), pituitary adenylate cyclase-activating polypeptide (PACAP), insulin-like growth factor-1(IGF-1), pituitary β-luteinizing hormone (βLH), and prolactin were significantly higher when the fish were maintained at 27°C than at 23°C or 31°C. β-Follicle-stimulating hormone (βFSH) mRNA levels were significantly lower when maintained at 31°C than at the other temperatures. Nests were observed only in males under reproductive conditions. In these fish, higher mRNA levels of GnRH3, PACAP, βFSH, βLH and prolactin were detected at 27°C, and higher mRNA levels of IGF-1 were detected at 23°C, when compared with other temperature of maintenance or with fish that did not build nest. In conclusion, we propose that temperature has more effect on the transcription of genes, associated with reproduction, than on those pertaining to growth. Copyright © 2011 Wiley-Liss, Inc., A Wiley Company.
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Mazaro, Renata; Di Stasi, Luiz; De Grava Kempinas, Wilma
2002-09-01
Austroplenckia populnea (Reiss.) Lundell. was selected for this study because it has been shown that some plants from the Celastraceae family have antifertility effects. Twelve adult male rats were treated with hydromethanolic extract made from the leaves, 500 mg/kg/day, orally, for 70 days. Distilled water was administered to the control animals (n = 10). At the end of the experiment, and before killing the rats, their sexual behavior was evaluated. The number of intromissions, latencies to first mount and ejaculation, and first intromission after ejaculation were significantly reduced in the treated group, but the total number of ejaculations did not differ from the control group. The weight and histology of the reproductive organs, sperm production, spermatogenesis, prostate fructose content, cauda epidydimides duct diameter, and sperm morphology were not affected. Sperm concentration in cauda epidydimides was significantly decreased. The results showed that A. populnea has effects on male rat reproduction, affecting the sexual behavior and epididymal sperm concentration.
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Han, Xue; Cui, Zhihong; Zhou, Niya; Ma, Mingfu; Li, Lianbing; Li, Yafei; Lin, Hui; Ao, Lin; Shu, Weiqun; Liu, Jinyi; Cao, Jia
2014-03-01
This study was designed to investigate the phthalates exposure levels in general population in Chongqing City of China, and to determine the possible associations between phthalate exposure and male reproductive function parameters. We recruited 232 general men through Chongqing Family Planning Research Institute and Reproductive Center of Chongqing. In a single spot urine sample from each man, phthalate metabolites, including mono-butyl phthalate (MBP), mono-ethyl phthalate (MEP), mono-(2-ethylhexyl) phthalate (MEHP), mono-benzyl phthalate (MBzP), phthalic acid (PA), and total PA were analyzed using solid phase extraction and coupled with high-performance liquid chromatography and detection by tandem mass spectrometry. Semen parameters were dichotomized based on World Health Organization reference values. Sperm DNA damage were analyzed using the alkaline single-cell gel electrophoresis assay. Reproductive hormones were determined in serum by the radioimmunoassay kit. We observed a weak association between urinary MBP concentration and sperm concentration in Chongqing general population. MBP levels above the median were 1.97 times (95% confidence interval [CI] 0.97-4.04) more likely to have sperm concentration below the reference value. There were no other associations between phthalate metabolites and reproductive function parameters after adjusted for potential risk factors. Our study suggested that general population in Chongqing area of China exposure to the environmental level of phthalate have weak or without adverse effects on the reproduction. Copyright © 2013 Elsevier GmbH. All rights reserved.
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Sepehrimanesh, Masood; Saeb, Mehdi; Nazifi, Saeed; Kazemipour, Nasrin; Jelodar, Gholamali; Saeb, Saeedeh
2014-09-01
This work analyzes the effects of radiofrequency-electromagnetic field (RF-EMF) exposure on the reproductive system of male rats, assessed by measuring circulating levels of FSH, LH, inhibin B, activin B, prolactin, and testosterone. Twenty adult male Sprague-Dawley rats (180 ± 10 g) were exposed to 900 MHz RF-EMF in four equal separated groups. The duration of exposure was 1, 2, and 4 h/day over a period of 30 days and sham-exposed animals were kept under the same environmental conditions as the exposed group except with no RF-EMF exposure. Before the exposure, at 15 and 30 days of exposure, determination of the abovementioned hormone levels was performed using ELISA. At the end of the experiment, FSH and LH values of the long time exposure (LTE) group were significantly higher than the sham-exposed group ( p reproductive hormone levels are disturbed as a result of RF-EMF exposure and it may possibly affect reproductive functions. However, testosterone and inhibin B concentrations as a fertility marker and spermatogenesis were decreased significantly.
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Rosemary L. Pendleton
2000-01-01
Male and female reproductive output of Cucurbita foetidissima, a gynodioecious native perennial, was examined in a 2-yr greenhouse/outplanting study. Plants were divided into three treatment groups: (1) a lowphosphorus (P) soil mix control; (2) a low-P soil mix with the addition of mycorrhizal inoculum (Glomus intraradices); and (3) a high-P soil mix. Plants were...
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Thériault, Véronique; Moyer, Gregory R; Jackson, Laura S; Blouin, Michael S; Banks, Michael A
2011-05-01
Supplementation of wild salmonids with captive-bred fish is a common practice for both commercial and conservation purposes. However, evidence for lower fitness of captive-reared fish relative to wild fish has accumulated in recent years, diminishing the apparent effectiveness of supplementation as a management tool. To date, the mechanism(s) responsible for these fitness declines remain unknown. In this study, we showed with molecular parentage analysis that hatchery coho salmon (Oncorhynchus kisutch) had lower reproductive success than wild fish once they reproduced in the wild. This effect was more pronounced in males than in same-aged females. Hatchery spawned fish that were released as unfed fry (age 0), as well as hatchery fish raised for one year in the hatchery (released as smolts, age 1), both experienced lower lifetime reproductive success (RS) than wild fish. However, the subset of hatchery males that returned as 2-year olds (jacks) did not exhibit the same fitness decrease as males that returned as 3-year olds. Thus, we report three lines of evidence pointing to the absence of sexual selection in the hatchery as a contributing mechanism for fitness declines of hatchery fish in the wild: (i) hatchery fish released as unfed fry that survived to adulthood still had low RS relative to wild fish, (ii) age-3 male hatchery fish consistently showed a lower relative RS than female hatchery fish (suggesting a role for sexual selection), and (iii) age-2 jacks, which use a sneaker mating strategy, did not show the same declines as 3-year olds, which compete differently for females (again, implicating sexual selection). © 2011 Blackwell Publishing Ltd.
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Fagundes, Teresa; Simões, Mariana G; Gonçalves, David; Oliveira, Rui F
2012-10-10
Phenotypic change in response to variation in environmental cues has been widely documented in fish. Transitions in social dominance, in particular, have been shown to induce a rapid switch in reproductive phenotypes in many species. However, this effect has been mainly studied in adults and focused on behavioural transitions. The way social cues constraint the phenotypic development of juveniles remains poorly studied in fish. We tested the importance of social dominance and density in the phenotypic development of juveniles of the peacock blenny Salaria pavo. This species shows sequential male alternative reproductive tactics. In the first breeding season males can reproduce as nest-holders or as parasitic males (female-mimicking), or postpone reproduction; from the following season afterwards all males reproduce as nest-holders. Parasitic males have relatively larger testes that lack a testicular gland, present in the testes of nest-holders. The testicular gland is the main source of androgens in the testes and accordingly nest-holders have higher circulating androgen levels. In addition, exogenous androgen administration to parasitic males promotes the development of secondary sexual characters (SSC) only present in nest-holders such as a head crest and an anal gland. We raised juveniles under a high or low-density treatment and monitored social interactions for 1 month. No significant effect of density on the development of juvenile males was detected. However, within each replicate, the relative body size of juvenile males at the beginning of the experiment determined their dominance status, with dominant males developing towards the nest-holder morphotype. Dominant males engaged in more nest defence behaviour, showed larger testicular glands, had higher levels of 11-ketotestosterone (11-KT) and testosterone (T) and developed more SSC, as compared to subordinate males. However, these effects of social dominance were moderated by body condition as only
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Smith, Emma A Elliott; Newsome, Seth D; Estes, James A; Tinker, M Tim
2015-05-01
Intraspecific variation in behavior and diet can have important consequences for population and ecosystem dynamics. Here, we examine how differences in reproductive investment and spatial ecology influence individual diet specialization in male and female southern sea otters (Enhydra lutris nereis). We hypothesize that greater reproductive constraints and smaller home ranges of females lead to more pronounced intraspecific competition and increased specialization. We integrate stable carbon (δ(13)C) and nitrogen (δ(15)N) isotope analysis of sea otter vibrissae with long-term observational studies of five subpopulations in California. We define individual diet specialization as low ratios of within-individual variation (WIC) to total population niche width (TNW). We compare isotopic and observational based metrics of WIC/TNW for males and females to data on population densities, and movement patterns using both general linear and linear mixed-effects models. Consistent with our hypothesis, increasing population density is associated with increased individual diet specialization by females but not by males. Additionally, we find the amount of coastline in a sea otter's home range positively related with individual dietary variability, with increased range span resulting in weaker specialization for both males and females. We attribute our results to sex-based differences in movement, with females needing to specialize in their small ranges to maximize energy gain, and posit that the paradigm of individual prey specialization in sea otters with increased intraspecific competition may be a pattern driven largely by females. Our work highlights a potentially broader role of sex in the mechanistic pressures promoting and maintaining diet specialization.
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Reproductive health in young male adults with chronic diseases in childhood.
De Sanctis, Vincenzo; Soliman, Ashraf; Mohamed, Yassin
2013-01-01
The Centres for Disease Control and Prevention have defined a chronic diseases as an "illnesses that are prolonged, do not resolve spontaneously, and are rarely cured completely". Approximately 20% of all children have a chronic illness and 65% of them the illness is severe enough to interfere with daily activities. Failure of pubertal growth, delay or absence of sexual development, infertility and sexual dysfunction due to hypogonadism and defective spermatogenesis are well recognized disturbances among adolescents and young male adult patients with chronic diseases. The causes are multifactorial and can be due to disease itself, associated complications or drugs. Haemoglobinopathies, endocrine disorders, gastrointestinal and renal diseases are some examples that frequently cause some degree of disability. Infertility affects the future quality of life of these patients and is a predictor of stress in current and future relationships. Health care providers often neglect the reproductive health of chronically ill adolescents and young adults, although many studies indicate that they are sexually active and interested in knowing about their future fertility. This review article provides an overview of the literature concerning the impact of some chronic diseases in adolescents and young adults on reproductive health but will not address patients with cancer because it has been tackled adequately in the literature.MEDLINE database search of English-language medical journal articles published between 1975 and 2012 for papers related to reproductive health in adolescents and young adults with chronic diseases since childhood was done. Several Authors, recommend that all young adult patients with severe/prolonged chronic disease in childhood should be offered reproductive health care in a specialized center with appropriate expertise, involving a multidisciplinary team, including endocrinologists, andrologists, geneticists, psychologists, urologists and specialist
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Directory of Open Access Journals (Sweden)
Merve Baysal
Full Text Available Levetiracetam (LEV is an antiepileptic drug commonly used in the treatment of epilepsy because of its excellent safety profile in all age groups. It is remarkable that there are no studies evaluating the toxic effects of this drug on the male reproductive system, as it is commonly used in male patients of reproductive age. From this point of view, our aim was to evaluate the possible toxic effects of LEV on the male reproductive system. Therefore, LEV was administered to male rats orally at 50, 150, and 300 mg/kg for 70 consecutive days. At the end of this period, alterations to body and organ weights were calculated, and sperm concentration, motility, and morphology were investigated by a computer-assisted sperm analysis system. Sperm DNA damage was determined by comet assay and histopathological examination of the testes was carried out. Serum testosterone, follicle-stimulating hormone (FSH, and luteinizing hormone (LH levels were measured by ELISAs to determine the effects of hormonal status, while glutathione, superoxide dismutase, catalase, and malondialdehyde levels in the testes were measured by colorimetric assay kits to determine the role of oxidative status in potential toxicity. According to the results, sperm quality was decreased by LEV treatment in a dose-dependent manner. LEV induced significant DNA damage in the 150 and 300 mg/kg LEV-administered groups. Histopathology of the testes showed that LEV resulted in testicular injury in the 300 mg/kg LEV-administered group. Serum testosterone, FSH, and LH levels were significantly decreased in the 300 mg/kg LEV-administered group. Glutathione, superoxide dismutase, and catalase levels were significantly decreased in all experimental groups while malondialdehyde levels were significantly increased in 150 and 300 mg/kg LEV-administered groups. According to these results, it was determined that LEV administration decreased sperm quality and it was alleged that hormonal alteration and
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Survival and reproductive rate of mites in relation to resistance of their barn swallow hosts.
Møller, A P
2000-08-01
Parasite resistance may act via a number of different mechanisms that regulate or control the survival and the reproductive rate of parasites. Observations and experiments were used to test for effects of host resistance on parasite survival and rate of reproduction. Natural levels of infestation of barn swallow Hirundo rustica nests by the tropical fowl mite Ornithonyssus bursa were positively related to brood size, inversely related to the length of the outermost tail feathers of male nest owners (a secondary sexual character) and affected by time of reproduction by the host. A mite inoculation experiment, in which 50 adult mites were introduced into nests during the laying period of the host, was used to test for differential survival and reproduction of mites as a function of host resistance. The relationship between survival and reproduction of parasites, male tail length and host resistance was investigated. There was a negative relationship between mite numbers per nest after fledging of nestlings and male tail length. This relationship was mainly caused by a reduction in the number of mites in the first and second nymph stage with increasing tail length of male hosts, implying a reduction in rate of reproduction of mites. The proportion of mites that had recently fed was inversely related to tail length of male hosts. The proportion of nymph stages was positively related to the proportion of mites that had recently had a blood meal. Parasite resistance of barn swallows to the tropical fowl mite thus appeared to act through increased mortality rate of adult and nymph stages of mites, and through reduced reproductive rates of mites on resistant hosts. This is the first study demonstating a direct relationship between fitness components of a parasite and the expression of a secondary sexual character of a host.
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Effect of 17β-trenbolone on male and female reproduction in Japanese quail (Coturnix japonica)
Henry, Paula F.P.; Akuffo, Valorie G.; Chen, Yu; Karouna-Renier, Natalie K.; Sprague, Daniel T.; Bakst, Murray R.
2012-01-01
The anabolic steroid 17β trenbolone (17β-TB), a known endocrine disrupting chemical, may influence reproductive functions in avian wildlife. We evaluated the effects of dietary exposure to 17β-TB at 5 and 20 ppm on reproductive functional endpoints in Japanese quail during and after sexual maturation. In the male, 5 and 20 ppm treatments revealed no differences in body and testes weight, testes histology, plasma testosterone concentrations, or size and weight of the foam glands. However, the onset of foam production was significantly earlier (days of age) in the 20 ppm males. In females, dietary 17β-TB at 20 ppm caused a reduction in the number of maturing yellow yolk follicles and overall egg production. Plasma testosterone concentrations were reduced compared to controls. Histology of the oviductal sperm storage tubules was normal in all treatments. The number of sperm holes, sites on the perivitelline layer (PVL) where sperm bound and hydrolyzed a path through the PVL, was significantly greater in the 10th egg laid compared to the 1st egg laid in the 20 ppm treatment. Potential effects, albeit transient, on endpoints associated with male maturation warrant further investigation into the sensitivity of these measures in the event of embryonic and/or trans-generational exposure to 17β-TB.
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Reproductive tactics of male bearded goby (Sufflogobius bibarbatus) in anoxic and hypoxic waters
Seivåg, Maria Larsen; Salvanes, Anne Gro Vea; Utne-Palm, Anne Christine; Kjesbu, Olav Si'gurd
2016-03-01
The bearded goby (Sufflogobius bibarbatus), a key species in the northern Benguela Upwelling Ecosystem, tolerates extremely low levels of oxygen. Yet little is known about how its reproduction is affected by these harsh living conditions. The distribution patterns of alternative reproductive tactics of male bearded goby across the continental shelf off Namibia were investigated. Histology and stereology were for the first time used to validate macroscopic maturity development by estimating volume fraction of the different stages of spermatogenesis using "Delesse principle", an approach so far for teleosts barely used in studies on testes but applied in advanced oocyte estimation. The macroscopic scale appeared suitable for the purpose, and the prevalence of territorial and sneaker tactics could therefore be documented. The sneakers had relative large testes and small seminal vesicles (SV), with the opposite being the case for the territorials. A third, numerous category with intermediate sized testes and SV was also recognized with unclear underlying tactical rationale, although regression analyses indicated similar investment in testes weight in relation to somatic weight as for the territorials. Low oxygen levels were the most important factor limiting spawning activity in territorial males. Our data suggested the existence of a spawning site on the outer shelf of the central Namibian shelf where the bottom water is hypoxic (oxygen saturation of 6.2-6.7%) while the anoxic middle shelf area (oxygen saturation of 1.7-2.9%) appeared to show too low oxygen levels for spawning to take place. Hence, significant parts of this large shelf area appear unsuited for successful reproduction of the bearded goby, in particular for nest building by the territorials.
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Male reproductive organs are at risk from environmental hazards
DEFF Research Database (Denmark)
Bonde, Jens Peter
2010-01-01
are the best documented risk factors for impaired male reproductive function and include physical exposures (radiant heat, ionizing radiation, high frequency electromagnetic radiation), chemical exposures (some solvents as carbon disulfide and ethylene glycol ethers, some pesticides as dibromochloropropane......, ethylendibromide and DDT/DDE, some heavy metals as inorganic lead and mercury) and work processes such as metal welding. Improved working conditions in affluent countries have dramatically decreased known hazardous workplace exposures, but millions of workers in less affluent countries are at risk from...... as phthalates, bisphenol A and boron that are present in a large number of industrial and consumer products entails a risk remains to be established. The same applies to psychosocial stressors and use of mobile phones. Finally, there are data indicating a particular vulnerability of the fetal testis...
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Anholeto, Luís Adriano; Oliveira, Patrícia Rosa de; Rodrigues, Rodney Alexandre Ferreira; Yamane, Lais Thiemi; Castro, Karina Neoob de Carvalho; Ferreira, Allan Roberto Fernandes; Camargo-Mathias, Maria Izabel
2017-09-15
The present study evaluated through morphohistological and histochemical techniques the effects of different concentrations of crude ethanolic extract of A. oleracea (EEAO) (Jambu) on the male reproductive system of Amblyomma cajennense sensu stricto (s.s.) ticks. The toxicity of this natural chemical was stablished, signalizing the promising potential of the compound as a strategy to control ectoparasites in the near future. For the experiment, 100 males fed on host rabbits with homogeneous weight (p>0.05) were used. The ticks were divided into five groups (10 animals each): Control 1-exposed to distilled water; Control 2-exposed to ethanol 50% and DMSO 1%; Treatment 1-3-exposed to the concentrations of 6.2, 12.5 and 25mg/mL of the EEAO, respectively, diluted in ethanol 50% and DMSO 1%, with exposure by immersion. After exposure, the males were dissected for the removal of the reproductive system and subjected to routine histological analysis with HE staining and histochemical techniques (PAS for the detection of neutral polysaccharides and Bromophenol blue to detect total proteins). The exposed individuals showed alterations in the glandular complex cells; however, the testes remained intact. The secretory cells of the multilobulated accessory glands presented intense cytoplasmic vacuolation. Additionally, the synthesis and secretion were reduced in the secretion granules, mainly concerning the polysaccharides, glyco- and lipoprotein elements, substances that will constitute the seminal fluid and enable the capacitation of spermatozoa in the female genital tract and also necessary for the formation of the spermatophore, which will encapsulate the mature spermatids. The alterations were dose-dependent, i.e., more intense and severe as the concentration of the product increased. .This experiment confirmed the cytotoxic potential of A. oleracea ethanolic extract in the concentrations of 6.2, 12.5 and 25mg/mL on the reproductive system of A. cajennense s.s. male
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Karacaoğlu, Elif; Selmanoğlu, Güldeniz
2010-05-01
Furan (C(4)H(4)O) is a volatile, colorless liquid and is used in some segments of the chemical manufacturing industry. It is found in variety of foods such as coffee, jarred and canned foods that undergo heat treatment. This study was designed to investigate the effect of furan exposure on reproductive system of male rats. Three to four weeks old rats were exposed to furan at 2, 4 and 8 mg/kg/day doses by orally for 90 days. Hematology, weights, histology and morphometry of reproductive organs, serum LH and testosterone levels, sperm count and morphology and apoptosis in testis were evaluated. Slight changes were observed in hematological parameters of furan-treated rats. The weights of seminal vesicle reduced significantly whereas the weights of prostate increased significantly in the highest furan dose group. LH and testosterone levels decreased in furan-treated rats. Histological examinations have revealed that furan caused impairments in testis, epididymis and prostate gland. Furan showed no effects on sperm counts and morphology. On the other hand apoptotic cells in testis increased significantly. According to morphometrical examination, the epithelial heights and lumen diameters of the reproductive organs have changed in treatment groups. These results indicate that subchronic furan treatment induces toxicity of the male reproductive system. Copyright (c) 2010 Elsevier Ltd. All rights reserved.
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Directory of Open Access Journals (Sweden)
Jacques Auger
2014-02-01
Full Text Available In the present review, we first summarize the main benefits, limitations and pitfalls of conventional in vivo approaches to assessing male reproductive structures and functions in rodents in cases of endocrine active substance (EAS exposure from the postulate that they may provide data that can be extrapolated to humans. Then, we briefly present some integrated approaches in rodents we have recently developed at the organism level. We particularly focus on the possible effects and modes of action (MOA of these substances at low doses and in mixtures, real-life conditions and at the organ level, deciphering the precise effects and MOA on the fetal testis. It can be considered that the in vivo experimental EAS exposure of rodents remains the first choice for studies and is a necessary tool (together with the epidemiological approach for understanding the reproductive effects and MOA of EASs, provided the pitfalls and limitations of the rodent models are known and considered. We also provide some evidence that classical rodent models may be refined for studying the multiple consequences of EAS exposure, not only on the reproductive axis but also on various hormonally regulated organs and tissues, among which several are implicated in the complex process of mammalian reproduction. Such models constitute an interesting way of approaching human exposure conditions. Finally, we show that organotypic culture models are powerful complementary tools, especially when focusing on the MOA. All these approaches have contributed in a combinatorial manner to a better understanding of the impact of EAS exposure on human reproduction.
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Energy Technology Data Exchange (ETDEWEB)
Jia, Xiuying; Cai, Chenchen; Wang, Jia; Gao, Nana; Zhang, Hangjun, E-mail: zhanghangjun@gmail.com
2014-10-15
Highlights: • Low-dose MCLR (1 μg/L) elicits a potential ecological effect on amphibian populations. • MCLR can induce abnormal sperm morphologies and activities on male frogs. • MCLR can induce a decrease in serum testosterone and an increase in serum estradiol of male frogs. • MCLR can increase SF-1 protein levels and decrease P450 aromatase levels in the gonads of frogs. - Abstract: Toxic cyanobacterial blooms are potential global threats to aquatic ecosystems and human health. The World Health Organization has set a provisional guideline limit of 1 μg/L microcystin-LR (MCLR) in freshwater. However, MCLR concentrations in several water bodies have exceeded this level. Despite this recommended human safety standard, MCLR-induced endocrine-disrupting effects and reproductive toxicity on male frog (Rana nigromaculata) were demonstrated in this study. Results showed that sperm motility and sperm count were significantly and negatively correlated with exposure time and concentration. By contrast, abnormal sperm rate was positively correlated with both parameters. Ultrastructural observation results revealed abnormal sperm morphologies, vacuoles in spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli. These results indicated that MCLR could induce toxic effects on the reproductive system of frogs, significantly decrease testosterone content, and rapidly increase estradiol content. Prolonged exposure and increased concentration enhanced the relative expression levels of P450 aromatase and steroidogenic factor 1; thus, endocrine function in frogs was disrupted. This study is the first to demonstrate in vivo MCLR toxicity in the reproductive system of male R. nigromaculata. This study provided a scientific basis of the global decline in amphibian populations.
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International Nuclear Information System (INIS)
Jia, Xiuying; Cai, Chenchen; Wang, Jia; Gao, Nana; Zhang, Hangjun
2014-01-01
Highlights: • Low-dose MCLR (1 μg/L) elicits a potential ecological effect on amphibian populations. • MCLR can induce abnormal sperm morphologies and activities on male frogs. • MCLR can induce a decrease in serum testosterone and an increase in serum estradiol of male frogs. • MCLR can increase SF-1 protein levels and decrease P450 aromatase levels in the gonads of frogs. - Abstract: Toxic cyanobacterial blooms are potential global threats to aquatic ecosystems and human health. The World Health Organization has set a provisional guideline limit of 1 μg/L microcystin-LR (MCLR) in freshwater. However, MCLR concentrations in several water bodies have exceeded this level. Despite this recommended human safety standard, MCLR-induced endocrine-disrupting effects and reproductive toxicity on male frog (Rana nigromaculata) were demonstrated in this study. Results showed that sperm motility and sperm count were significantly and negatively correlated with exposure time and concentration. By contrast, abnormal sperm rate was positively correlated with both parameters. Ultrastructural observation results revealed abnormal sperm morphologies, vacuoles in spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli. These results indicated that MCLR could induce toxic effects on the reproductive system of frogs, significantly decrease testosterone content, and rapidly increase estradiol content. Prolonged exposure and increased concentration enhanced the relative expression levels of P450 aromatase and steroidogenic factor 1; thus, endocrine function in frogs was disrupted. This study is the first to demonstrate in vivo MCLR toxicity in the reproductive system of male R. nigromaculata. This study provided a scientific basis of the global decline in amphibian populations
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The Relative Age Effect and Physical Fitness Characteristics in German Male Tennis Players
Directory of Open Access Journals (Sweden)
Alexander Ulbricht, Jaime Fernandez-Fernandez, Alberto Mendez-Villanueva, Alexander Ferrauti
2015-09-01
Full Text Available The aims of the study were to test: 1 whether the relative age effect (RAE was prevalent in young (U12-U18 German male tennis players; 2 the potential influence of age and/or skill level on RAE and 3 whether maturity, anthropometric and fitness measures vary according to birth date distribution in elite youth tennis players. For the present study the following male populations were analysed: Overall German population (n = 3.216.811, all players affiliated to the German Tennis Federation (DTB (n = 120.851, players with DTB official ranking (n = 7165, regional (n = 381 and national (n = 57 squads (11-17 years old, as well as the top 50 German senior players were analyzed. RAEs were more prevalent at higher competitive levels with more players born in the first quarter of the year compared with the reference population for ranked (29.6%, regional (38.1% and national (42.1% players. No systematic differences were found in any of the maturity, anthropometric and fitness characteristics of the regional squad players born across different quarters. RAEs are present in the DTB competitive system and it was more pronounced at higher competitive levels. Compared with early born, late born players who were selected into elite squads did not differ in maturation, anthropometric and fitness characteristics.
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Tian, Hua; Wu, Peng; Wang, Wei; Ru, Shaoguo
2015-05-01
Although bioaccumulation of tributyltin (TBT) in fish has been confirmed, information on possible effects of TBT on reproductive system of fish is still relatively scarce, particularly at environmentally relevant levels. To evaluate the adverse effects and intrinsic toxicological properties of TBT in male fish, we studied aromatase gene expression in the brain, sex steroid contents, primary and secondary sexual characteristics, and reproductive behavior in male guppies (Poecilia reticulata) exposed to tributyltin chloride at the nominal concentrations of 5, 50, and 500 ng/L for 28 days in a semi-static exposure system. Radioimmunoassay demonstrated that treatment with 50 ng/L TBT caused an increase in systemic levels of testosterone of male guppies. Gonopodial index, which showed a positive correlation with testosterone levels, was elevated in the 5 ng/L and 50 ng/L TBT treated groups. Real-time PCR revealed that TBT exposure had inhibiting effects on expression of two isoforms of guppy aromatase in the brain, and these changes at the molecular levels were associated with a disturbance of reproductive behavior of the individuals, as measured by decreases in frequencies of posturing, sigmoid display, and chase activities when males were paired with females. This study provides the first evidence that TBT can cause abnormalities of secondary sexual characteristics in teleosts and that suppression of reproductive behavior in teleosts by TBT is due to its endocrine-disrupting action as an aromatase inhibitor targeting the nervous system. Copyright © 2015 Elsevier B.V. All rights reserved.
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Kusuda, Satoshi; Hashikawa, Hisashi; Takeda, Masato; Ito, Hideki; Goto, Atsushi; Oguchi, Jun; Doi, Osamu
2013-01-01
The purposes of the present study were to clarify age- and season- related androgen patterns, and to compare the reproductive physiology between Japanese captive koala populations and Australian populations. To measure fecal androgens, feces were collected from male koalas (4.2 to 13.8 years of age) kept in Japanese zoos. Fecal androgens were extracted with methanol from the lyophilized samples and determined by enzyme immunoassay using 4-androstene-3,17-dione antibody. Fecal androgen concentration in male koalas increased after sexual maturation and remained relatively high until old age. In the survey with the Japanese zoo studbook of koalas, copulation (conception) month showed a pyramid shape with a peak in March to June (60.7%) in koalas born and reared in Japanese zoos and from July to April with the highest concentration in September to January (69.7%) in Australian institutes. Japanese zoo koala populations have a characteristic physiological cycle adapted to Japan's seasonal changes. The suitable month of year for copulation or conception in Japan is diametrically opposed to that in Australia. Mean fecal androgen concentrations by month in the males born and reared in Japan indicated annual changes with the highest concentration in May and the lowest value in November. Fecal androgen analysis may be a noninvasive alternative tool to monitor circulating testosterone and may be helpful in understanding reproductive activity and physiology in male koalas.
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Directory of Open Access Journals (Sweden)
François VÉzina, Katrina G. SALVANTE
2010-12-01
Full Text Available Interest in phenotypic flexibility has increased dramatically over the last decade, but flexibility during reproduction has received relatively little attention from avian scientists, despite its possible impact on fitness. Because most avian species maintain atrophied reproductive organs when not active, reproduction in birds requires major tissue remodeling in preparation for breeding. Females undergo rapid (days recrudescence and regression of their reproductive organs at each breeding attempt, while males grow their organs ahead of time at a much slower rate (weeks and may maintain them at maximal size throughout the breeding season. Reproduction is associated with significant metabolic costs. Egg production leads to a 22–27% increase in resting metabolic rate (RMR over non-reproductive values. This is partly due to the activity of the oviduct, an organ that may allow females to adjust reproductive investment by modulating egg size and quality. In males, gonadal recrudescence may lead to a 30% increase in RMR, but the data are inconsistent and general conclusions regarding energetic costs of reproduction in males will require more research. Recent studies on captive female zebra finches describe the impacts of these costs on daily energy budgets and highlight the strategies used by birds to maintain their investment in reproduction when energy is limited. Whenever possible, birds use behavioral flexibility as a first means of saving energy. Decreasing locomotor activity saves energy during challenges such as egg production or exposure to cold temperatures and is an efficient way to buffer variation in individual daily energy budgets. However, when behavioral flexibility is not possible, birds must rely on flexibility at the physiological level to meet energy demands. In zebra finches breeding in the cold, this results in a reduced pace of laying, likely due to down-regulation of both reproductive and non-reproductive function, allowing
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Shao, Yi Ta; Tseng, Yung Che; Chang, Chia-Hao; Yan, Hong Young; Hwang, Pung Pung; Borg, Bertil
2015-02-01
In vertebrates, reproduction is regulated by the brain-pituitary-gonad (BPG) axis, where the gonadotropin-releasing hormone (GnRH) is one of the key components. However, very little is known about the possible role of GnRH in the environmental and feedback control of fish reproduction. To investigate this, full-length gnrh2 (chicken GnRH II) and gnrh3 (salmon GnRH) sequences of male three-spined sticklebacks (Gasterosteus aculeatus), which are clustered with the taxa of the same GnRH type as other Euteleostei, were cloned and annotated. gnrh1 is absent in this species. The mRNA levels of gnrh2 and gnrh3 in the sticklebacks' brain were measured under breeding and post-breeding conditions as well as in castrated and sham-operated breeding fish and castrated/sham-operated fish kept under long-day (LD 16:8) and short-day (LD 8:16) conditions. Fully breeding males had considerably higher mRNA levels of gnrh2 and gnrh3 in the thalamus (Th) and in the telencephalon and preoptic area (T+POA), respectively, than post-breeding males. Sham-operated breeding males have higher gnrh3 mRNA levels than the corresponding castrated males. Moreover, higher gnrh2 mRNA levels in the Th and higher gnrh3 mRNA levels in the T+POA and hypothalamus (HypTh) were also found in long-day sham-operated males than in sham-operated fish kept under an inhibitory short day photoperiod. Nevertheless, gnrh2 and gnrh3 mRNA levels were not up-regulated in castrated males kept under long-day photoperiod, which suggests that positive feedbacks on the brain-pituitary-gonad axis are necessary for this response. Copyright © 2014 Elsevier Inc. All rights reserved.
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The penis: a new target and source of estrogen in male reproduction.
Mowa, C N; Jesmin, S; Miyauchi, T
2006-01-01
In the past decade, interest and knowledge in the role of estrogen in male reproduction and fertility has gained significant momentum. More recently, the cellular distribution and activity of estrogen receptors (alpha and beta)(ER) and aromatase (estrogen synthesis) has been reported in the penis, making the penis the latest "frontier" in the study of estrogen in male reproduction. ER and aromatase are broadly and abundantly expressed in various penile compartments and cell types (erectile tissues, urethral epithelia, vascular and neuronal cells), suggesting the complexity and significance of the estrogen-ER system in penile events. Unraveling this complexity is important and will require utilization of the various resources that are now at our disposal including, animal models and human lacking or deficient in ER and aromatase and the use of advanced and sensitive techniques. Some of the obvious areas that require our attention include: 1) a comprehensive mapping of ER-alpha and -beta cellular expression in the different penile compartments and subpopulations of cells, 2) delineation of the specific roles of estrogen in the different subpopulations of cells, 3) establishing the relationship of the estrogen-ER system with the androgen-androgen receptor system, if any, and 4) characterizing the specific penile phenotypes in human and animals lacking or deficient in estrogen and ER. Some data generated thus far, although preliminary, appear to challenge the long held dogma that, overall, androgens have a regulatory monopoly of penile development and function.
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Piché, Jacinthe; Hutchings, Jeffrey A; Blanchard, Wade
2008-07-07
Alternative reproductive tactics may be a product of adaptive phenotypic plasticity, such that discontinuous variation in life history depends on both the genotype and the environment. Phenotypes that fall below a genetically determined threshold adopt one tactic, while those exceeding the threshold adopt the alternative tactic. We report evidence of genetic variability in maturation thresholds for male Atlantic salmon (Salmo salar) that mature either as large (more than 1 kg) anadromous males or as small (10-150 g) parr. Using a common-garden experimental protocol, we find that the growth rate at which the sneaker parr phenotype is expressed differs among pure- and mixed-population crosses. Maturation thresholds of hybrids were intermediate to those of pure crosses, consistent with the hypothesis that the life-history switch points are heritable. Our work provides evidence, for a vertebrate, that thresholds for alternative reproductive tactics differ genetically among populations and can be modelled as discontinuous reaction norms for age and size at maturity.
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Stiver, Kelly A; Alonzo, Suzanne H
2013-03-01
Although cooperating individuals may gain benefits, they risk being cheated by their allies. Therefore, to understand the persistence of cooperation by mutual benefits, it is important to document both the potential benefits of cooperation and the risks of cheating. We experimentally examined evidence of cooperation in the ocellated wrasse (Symphodus ocellatus), a fish species with males that exercise three reproductive strategies: satellite and sneaker males attempt to parasitically spawn in the nests of nesting males. Nesting males have been hypothesized to tolerate satellites as a result of satellite aid in defense against sneaker males and help in courting females. Here, we provide evidence that cooperation between reproductive competitors may arise in response to sperm competition from other males. After we experimentally removed satellites, nesting males had more sneakers at their nest and experienced a higher rate of sneaking when they spawned (increased sperm competition risk). When we experimentally distracted nesting males to prevent their acting aggressively toward satellites, satellites spawned with females and ate eggs in the nest. Our results suggest that nesting males and satellites gain fitness benefits of reduced direct reproductive and sperm competition through cooperation. However, nesting males risk losing paternity, while satellites experience increased aggression and must invest in aggression themselves (i.e., they act aggressively toward sneakers).
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Endocrine phenotype, reproductive success and survival in the great tit, Parus major.
Ouyang, J Q; Sharp, P; Quetting, M; Hau, M
2013-09-01
A central goal in evolutionary ecology is to characterize and identify selection patterns on the optimal phenotype in different environments. Physiological traits, such as hormonal responses, provide important mechanisms by which individuals can adapt to fluctuating environmental conditions. It is therefore expected that selection shapes hormonal traits, but the strength and the direction of selection on plastic hormonal signals are still under investigation. Here, we determined whether, and in which way, selection is acting on the hormones corticosterone and prolactin by characterizing endocrine phenotypes and their relationship with fitness in free-living great tits, Parus major. We quantified variation in circulating concentrations of baseline and stress-induced corticosterone and in prolactin during the prebreeding (March) and the breeding season (May) for two consecutive years, and correlated these with reproductive success (yearly fledgling number) and overwinter survival in female and male individuals. In both years, individuals with high baseline corticosterone concentrations in March had the highest yearly fledgling numbers; while in May, individuals with low baseline corticosterone had the highest yearly reproductive success. Likewise, individuals that displayed strong seasonal plasticity in baseline corticosterone concentrations (high in March and low in May) had the highest reproductive success in each year. Prolactin concentrations were not related to reproductive success, but were positively correlated to the proximity to lay. Between-year plasticity in stress-induced corticosterone concentrations of males was related to yearly variation in food abundance, but not to overall reproductive success. These findings suggest that seasonally alternating directional selection is operating on baseline corticosterone concentrations in both sexes. The observed between-year consistency in selection patterns indicates that a one-time hormone sample in a given
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Aromatase and estrogen receptors in male reproduction.
Carreau, Serge; Delalande, Christelle; Silandre, Dorothée; Bourguiba, Sonia; Lambard, Sophie
2006-02-26
Aromatase is a terminal enzyme which transforms irreversibly androgens into estrogens and it is present in the endoplasmic reticulum of numerous tissues. We have demonstrated that mature rat germ cells express a functional aromatase with a production of estrogens equivalent to that of Leydig cells. In humans in addition to Leydig cells, we have shown the presence of aromatase in ejaculated spermatozoa and in immature germ cells. In most tissues, high affinity estrogen receptors, ERalpha and/or ERbeta, mediate the role of estrogens. Indeed, in human spermatozoa, we have successfully amplified ERbeta mRNA but the protein was not detectable. Using ERalpha antibody we have detected two proteins in human immature germ cells: one at the expected size 66 kDa and another at 46 kDa likely corresponding to the ERalpha isoform lacking exon 1. In spermatozoa only the 46 kDa isoform was present, and we suggest that it may be located on the membrane. In addition, in men genetically deficient in aromatase, it is reported that alterations of spermatogenesis occur both in terms of the number and motility of spermatozoa. All together, these observations suggest that endogenous estrogens are important in male reproduction.
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Directory of Open Access Journals (Sweden)
Özgür ERİKOĞLU
2015-09-01
Full Text Available The aim of this study was to compare physical fitness parameters of male adolescent soccer players and sedentary counterparts. A total of 26 male adolescents participated in this study voluntarily: Active soccer players (n: 3, age x : 13,00 ± 0,00 and sedentary counterparts (n: 13, age x :12,92 ± 0,75. The EUROFIT test battery was used to determine physical fitness. The test battery includes body height and weight measurements, touching the discs, flamingo balan ce, throwing health ball, vertical jumping, sit and reach, sit - up for 30 s, 20 meter sprint run, and 20 meter shuttle run tests. Data were analyzed by Mann Whitney U test. Significance was defined as p.05. In conclusion, children who do sports are more successful on most of the fitness parameters than sedentary children.
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Directory of Open Access Journals (Sweden)
Heather M. Clarke
2018-05-01
Full Text Available Research demonstrates the bias faced by individuals engaged in occupations that are perceived as inconsistent with their gender. The lack of fit model and role congruity theory explain how gender stereotypes give rise to the perception that an individual lacks the attributes necessary to be successful in a gender-incongruent job. Men employed in jobs traditionally held by women are perceived as wimpy and undeserving of respect. The majority of studies in this area have, however, failed to account for the sexual orientation of the individual being rated. Therefore, we carried out an experiment where 128 adults with experience in recruitment and selection, recruited through Qualtrics, rated heterosexual and gay male applicants applying for a gender-typed job. The heterosexual male was rated less effectual, less respect-worthy, and less hirable in the female-typed job condition than in the male-typed job condition. The gay male applicant, however, was rated similarly on all criteria across job gender-types, suggesting the gay male applicant was viewed as androgynous rather than high in femininity and low in masculinity as inferred by implicit inversion theory. The implications of these findings are discussed.
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Clarke, Heather M; Arnold, Kara A
2018-01-01
Research demonstrates the bias faced by individuals engaged in occupations that are perceived as inconsistent with their gender. The lack of fit model and role congruity theory explain how gender stereotypes give rise to the perception that an individual lacks the attributes necessary to be successful in a gender-incongruent job. Men employed in jobs traditionally held by women are perceived as wimpy and undeserving of respect. The majority of studies in this area have, however, failed to account for the sexual orientation of the individual being rated. Therefore, we carried out an experiment where 128 adults with experience in recruitment and selection, recruited through Qualtrics, rated heterosexual and gay male applicants applying for a gender-typed job. The heterosexual male was rated less effectual, less respect-worthy, and less hirable in the female-typed job condition than in the male-typed job condition. The gay male applicant, however, was rated similarly on all criteria across job gender-types, suggesting the gay male applicant was viewed as androgynous rather than high in femininity and low in masculinity as inferred by implicit inversion theory. The implications of these findings are discussed.
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DEFF Research Database (Denmark)
Kristensen, David Møbjerg; Hass, Ulla; Lesné, Laurianne
2011-01-01
; BACKGROUND: More than half of pregnant women in the Western world report intake of mild analgesics, and some of these drugs have been associated with anti-androgenic effects in animal experiments. Intrauterine exposure to anti-androgens is suspected to contribute to the recent increase in male ...... results suggest that intrauterine exposure to mild analgesics is a risk factor for development of male reproductive disorders.......; BACKGROUND: More than half of pregnant women in the Western world report intake of mild analgesics, and some of these drugs have been associated with anti-androgenic effects in animal experiments. Intrauterine exposure to anti-androgens is suspected to contribute to the recent increase in male...... reproductive problems, and many of the anti-androgenic compounds are like the mild analgesics potent inhibitors of prostaglandin synthesis. Therefore, it appears imperative to further investigate the potential endocrine disrupting properties of mild analgesics. ; METHODS: In a prospective birth cohort study...
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Matusali, G.; Dereuddre-Bosquet, N.; Le Tortorec, A.; Moreau, M.; Satie, A.-P.; Mahé, D.; Roumaud, P.; Bourry, O.; Sylla, N.; Bernard-Stoecklin, S.; Pruvost, A.; Le Grand, R.
2015-01-01
ABSTRACT A number of men receiving prolonged suppressive highly active antiretroviral therapy (HAART) still shed human immunodeficiency virus (HIV) in semen. To investigate whether this seminal shedding may be due to poor drug penetration and/or viral production by long-lived cells within male genital tissues, we analyzed semen and reproductive tissues from macaques chronically infected with simian immunodeficiency virus mac251 (SIVmac251) who were treated for 4 months with HAART, which was intensified over the last 7 weeks with an integrase inhibitor. We showed that a subset of treated animals continued shedding SIV in semen despite efficient HAART. This shedding was not associated with low antiretroviral drug concentrations in semen or in testis, epididymis, seminal vesicles, and prostate. HAART had no significant impact on SIV RNA in the urethra, whereas it drastically reduced SIV RNA levels in the prostate and vas deferens and to a lesser extent in the epididymis and seminal vesicle. The only detectable SIV RNA-positive cells within the male genital tract after HAART were urethral macrophages. SIV DNA levels in genital tissues were not decreased by HAART, suggesting the presence throughout the male genital tract of nonproductively infected cells. In conclusion, our results demonstrate that 4 months of HAART induced variable and limited control of viral infection in the male reproductive organs, particularly in the urethra, and suggest that infected long-lived cells in the male genital tract may be involved in persistent seminal shedding during HAART. These results pave the way for further investigations of male genital organ infection in long-term-treated infected individuals. IMPORTANCE A substantial subset of men receiving prolonged HAART suppressing viral loads in the blood still harbor HIV in semen, and cases of sexual transmission have been reported. To understand the origin of this persistence, we analyzed the semen and male reproductive tissues from SIV
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Directory of Open Access Journals (Sweden)
Nuno Prista
2014-03-01
Full Text Available Reproductive stage determination of male gonads has received sparse attention in fish biology literature with few studies detailing the building of gross anatomical- and histologic scales. The meagre (Argyrosomus regius is one of the world’s largest sciaenids and supports a significant regional fishery in European and North African waters whose reproductive patterns are yet to be fully investigated. In the present study, we derive a macroscopic grading system for meagre testis using semi-quantitative graphs that feature the testis variability along the species size range and time of the year. We then describe the histological stages and reproductive phases of male testes and determine the extent to which they corroborate the anatomical scale. Our results indicate that gross anatomical analyses are accurate in assessments of the meagre spawning season but may not precisely distinguish the testes of well-mature fish and first spawning virgins. Furthermore, we show that milt expression varies widely with size and misclassifies as immature many smaller fish in spawning-capable condition. We discuss these findings in terms of their contribution to the understanding of testes development and the uncertainties involved in determining the size-at-maturity of male fish using gross anatomical scales.
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Fletcher, Quinn E; Dantzer, Ben; Boonstra, Rudy
2015-12-01
Activation of the hypothalamic-pituitary-adrenal (HPA) axis culminates in the release of glucocorticoids (henceforth CORT), which have wide-reaching physiological effects. Three hypotheses potentially explain seasonal variation in CORT. The enabling hypothesis predicts that reproductive season CORT exceeds post-reproductive season CORT because CORT enables reproductive investment. The inhibitory hypothesis predicts the opposite because CORT can negatively affect reproductive function. The costs of reproduction hypothesis predicts that HPA axis condition declines over and following the reproductive season. We tested these hypotheses in wild male red-backed voles (Myodes rutilus) during the reproductive and post-reproductive seasons. We quantified CORT levels in response to restraint stress tests consisting of three blood samples (initial, stress-induced, and recovery). Mineralocorticoid (MR) and glucocorticoid (GR) receptor mRNA levels in the brain were also quantified over the reproductive season. Total CORT (tCORT) in the initial and stress-induced samples were greater in the post-reproductive than in the reproductive season, which supported the inhibitory hypothesis. Conversely, free CORT (fCORT) did not differ between the reproductive and post-reproductive seasons, which was counter to both the enabling and inhibitory hypotheses. Evidence for HPA axis condition decline in CORT as well as GR and MR mRNA over the reproductive season (i.e. costs of reproduction hypothesis) was mixed. Moreover, all of the parameters that showed signs of declining condition over the reproductive season did not also show signs of declining condition over the post-reproductive season suggesting that the costs resulting from reproductive investment had subsided. In conclusion, our results suggest that different aspects of the HPA axis respond differently to seasonal changes and reproductive investment. Copyright © 2015 Elsevier Inc. All rights reserved.
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Osadchuk, L V; Salomacheva, I N; Osadchuk, A V
2010-01-01
The study was designed to investigate genetic differences in reproductive consequences of social hierarchy using inbred mice strains BALB/cLac, PT and CBA/Lac. Two adult males of different genotypes were housed together for 5 days. Hierarchical status of both partners was determined by asymmetry in agonistic behavior. The number of epididymal sperm and a proportion of abnormal sperm, weights of reproductive organs, serum concentration and testicular content of testosterone, and the testosterone response to introduction of a receptive female were determined. The testosterone measures were significantly decreased in the PT strain, the epididymal sperm number was significantly decreased in the BALB/cLac strain and a proportion of abnormal sperm heads was significantly increase in the CBA/Lac (in both dominants and subordinates) as compared to control mice. The testicular testosterone response to a receptive female and precopulatory behavior was unchanged in dominants and suppressed in subordinates of the BALB/cLac strain. The results indicate that in laboratory mice the pattern of reproductive response to social hierarchy is determined by genetic background.
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International Nuclear Information System (INIS)
Arfsten, Darryl P.; Schaeffer, David J.; Johnson, Eric W.; Robert Cunningham, J.; Still, Kenneth R.; Wilfong, Erin R.
2006-01-01
Depleted uranium (DU) projectiles have been used in battle in Iraq and the Balkans and will continue to be a significant armor-penetrating munition for the US military. As demonstrated in the Persian Gulf War, battle injury from DU projectiles and shrapnel is a possibility, and removal of embedded DU fragments from the body is not always practical because of their location in the body or their small size. Previous studies in rodents have demonstrated that implanted DU mobilizes and translocates to the gonads, and natural uranium may be toxic to spermatazoa and the male reproductive tract. In this study, the effects of implanted DU pellets on sperm concentration, motility, and male reproductive success were evaluated in adult (P1) Sprague-Dawley rats implanted with 0, 12, or 20, DU pellets of 1x2 mm or 12 or 20 tantalum (Ta) steel pellets of 1x2 mm. Twenty DU pellets of 1x2 mm (760 mg) implanted in a 500-g rat are equal to approximately 0.2 pound of DU in a 154-lb (70-kg) person. Urinary analysis found that male rats implanted with DU were excreting uranium at postimplantation days 27 and 117 with the amount dependent on dose. No deaths or evidence of toxicity occurred in P1 males over the 150-day postimplantation study period. When assessed at postimplantation day 150, the concentration, motion, and velocity of sperm isolated from DU-implanted animals were not significantly different from those of sham surgery controls. Velocity and motion of sperm isolated from rats treated with the positive control compound α-chlorohydrin were significantly reduced compared with sham surgery controls. There was no evidence of a detrimental effect of DU implantation on mating success at 30-45 days and 120-145 days postimplantation. The results of this study suggest that implantation of up to 20 DU pellets of 1x2 mm in rats for approximately 21% of their adult lifespan does not have an adverse impact on male reproductive success, sperm concentration, or sperm velocity
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Nair, M K C; Thankachi, Yamini; Leena, M L; George, Babu; Russell, Paul Swamidhas Sudhakar
2013-11-01
To examine reproductive and sexual knowledge of young married men and women between (15-24 y) in Kerala and to compare the reproductive health knowledge and sexual health knowledge among young married men and women of 20-24 y. This cross sectional community survey was conducted in three districts in Kerala. The married young adults were stratified into age groups of 15-19 y and 20-24 y. Data was collected using separate pretested structured interview schedule. There were no married males below the age of 20 y and only 24 females below the age of 20 y. More proportion of males had statistically significant knowledge about masturbation (72.3%), night emission in boys as an indicator of adolescence (92.6%), the fact that there is no relation between size of penis and sexual performance (78.8%) and condom prevents pregnancy and HIV/AIDS. Among the married 20-24 y group higher proportion of males had knowledge on safe period (47.9%) and condom use (97.9%) whereas higher proportion of females had knowledge on copper-T. With regard to sexual health higher percentage females talked about satisfactory sexual life (83.5%) and good sexual hygiene practices (81.5%). This study on reproductive sexual health knowledge of married men and women between 15 and 24 y, conducted in three districts of Kerala suggests a gap in knowledge level of reproductive health between married men and women. However, with regard to sexual health the opinion expressed are more open in content but not necessarily healthy, suggesting the need for both premarital and newlywed counseling.
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Current indirect fitness and future direct fitness are not incompatible.
Brahma, Anindita; Mandal, Souvik; Gadagkar, Raghavendra
2018-02-01
In primitively eusocial insects, many individuals function as workers despite being capable of independent reproduction. Such altruistic behaviour is usually explained by the argument that workers gain indirect fitness by helping close genetic relatives. The focus on indirect fitness has left open the question of whether workers are also capable of getting direct fitness in the future in spite of working towards indirect fitness in the present. To investigate this question, we recorded behavioural profiles of all wasps on six naturally occurring nests of Ropalidia marginata , and then isolated all wasps in individual plastic boxes, giving them an opportunity to initiate nests and lay eggs. We found that 41% of the wasps successfully did so. Compared to those that failed to initiate nests, those that did were significantly younger, had significantly higher frequency of self-feeding behaviour on their parent nests but were not different in the levels of work performed in the parent nests. Thus ageing and poor feeding, rather than working for their colonies, constrain individuals for future independent reproduction. Hence, future direct fitness and present work towards gaining indirect fitness are not incompatible, making it easier for worker behaviour to be selected by kin selection or multilevel selection. © 2018 The Author(s).
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Prenatal exposure to diesel exhaust particles and effect on the male reproductive system in mice
DEFF Research Database (Denmark)
Hemmingsen, Jette Gjerke; Hougaard, Karin Sørig; Talsness, Chris
2009-01-01
In utero exposure to diesel exhaust particles may reduce sperm production in adulthood. We investigated the effect of prenatal exposure to diesel exhaust particles on the male reproductive system and assessed endocrine disruption and regulation of aquaporin expression as possible mechanisms...... of action. Dams inhaled 20 mg/m(3) of diesel exhaust particle standard reference material 2975 (SRM2975) or clean air for 1h/day on day 7-19 during pregnancy. Male offspring were killed on day 170 after birth. The dams that had inhaled SRM2975 delivered offspring, which in adulthood had reduced daily sperm...
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Directory of Open Access Journals (Sweden)
Poonam Singh
2013-01-01
Full Text Available Background: Metronidazole (MTZ is commonly used as an antibacterial and antiprotozoaldrug. Various doses of MTZ have been reported to inhibit spermatogenic activityand sperm indices.Materials and Methods: In this experimental study, dose-dependent effects of MTZ onthe structural and functional integrity of the testis and accessory reproductive organshave been investigated. Adult male mice of Swiss strain were administered orally withMTZ at the doses of 250 mg/kgBW/day and 500 mg/kgBW/day for 28 consecutive daysto study the changes in the testis, epididymis, seminal vesicle, sperm indices and fertility.Reversal effects of the drug were also studied on the same mice, 42 days after cessationof the treatment.Results: Therapeutic dose of MTZ (250 mg/kgBW/day neither altered the weights ofthe testis, epididymis and seminal vesicle nor their histoarchitecture and sperm indices.The drug at the high dose (500 mg/kg BW/day caused significant reductions in theweights of the testis and epididymis. Histoarchitecture of the testis and epididymis at thehigh dose revealed marked regressive changes while that of seminal vesicle remainedunaffected. Significant reductions were noticed in the motility, viability and count ofepididymal spermatozoa while the concentrations of epididymal sialic acid and seminalvesicular fructose remained unaltered after the treatment. No significant changes werenoticed in the mating ability as well as in the level of serum testosterone in the treatedmice. Fertility of the male mice treated with high dose of MTZ declined markedly leadingto an increase in pre- and postimplantation loss while a significant decrease wasnoticed in the number of live blastocysts in females impregnated with such males. MTZinducedchanges in the male reproductive organs and fertility were reinstated 42 daysafter cessation of the treatment.Conclusion: High dose of MTZ induced reversible deleterious effects on the male reproductionand fertility.
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Notes on the Diet of Reproductively Active Male Rafinesque's Big Eared Bats
Energy Technology Data Exchange (ETDEWEB)
Menzel, M.A.; Carter, T.C.; Menzel, J.M.; Edwards, J.W.; Ford, W.M.
2002-01-01
Diet examination through the use of fecal samples, of five reproductively active male Rafinesque's big-eared bats from the Upper Coastal Plain of South Carolina during August and September 1999. Diets of these individuals in upland pine stands were similar to diets of Rafinesque's big-eared bats in bottomland and upland hardwood habitats. Although fecal samples had three insect orders, the diet consisted primarily of lepidopterans.
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REPRODUCTIVE HORMONES AND CORTISOL RESPONSES TO PLYOMETRIC TRAINING IN MALES
Directory of Open Access Journals (Sweden)
Serife Vatansever Ozen
2012-07-01
Full Text Available Plyometric training activities are commonly used by a wide range of athletes to increase jump performance and improve explosive power and muscular activation patterns. The purpose of the study was to evaluate the effects of plyometric training on male reproductive hormones. Nineteen recreationally active males volunteered to participate in this study and were randomly assigned to plyometrically trained (n=10, 21.2 ±2.3 years and control groups (n=9, 21.4± 2.1. The plyometric training group performed in a six-week plyometric training programme and the control group did not perform any plyometric training techniques. Resting serum levels of testosterone, prolactin, follicle stimulating hormone (FSH, luteinising hormone (LH, and cortisol were measured in each subject at t0 (before the training, t1 (end of third week and t2 (end of training. Two-way ANOVA revealed significant (P<0.05 interaction effects for testosterone, prolactin, FSH and cortisol. Six-week plyometric training decreased serum levels of testosterone, cortisol and FSH and increased serum levels of prolactin. These results suggest the presence of alterations in anabolic and catabolic hormonal responses to resistance exercise in men.
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Directory of Open Access Journals (Sweden)
Giuseppe Latini
2008-01-01
Full Text Available There is growing evidence that male as well as female reproductive function has been declining in human and wildlife populations over the last 40 years. Several factors such as lifestyle or environmental xenobiotics other than genetic factors may play a role in determining adverse effects on reproductive health. Among the environmental xenobiotics phthalates, a family of man-made pollutants are suspected to interfere with the function of the endocrine system and therefore to be endocrine disruptors. The definition of endocrine disruption is today extended to broader endocrine regulations, and includes activation of metabolic sensors, such as the peroxisome proliferator-activated receptors (PPARs. Toxicological studies have shown that phthalates can activate a subset of PPARs. Here, we analyze the epidemiological and experimental evidence linking phthalate exposure to both PPAR activation and adverse effects on male and female reproductive health.
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Pan, Chien-Yu
2014-01-01
This study compared components of motor proficiency and physical fitness in adolescents with and without autism spectrum disorders, and assessed the associations between the two measures within each group. A total of 62 adolescent males with ("n" = 31) and without ("n" = 31) autism spectrum disorders aged 10-17 years completed…
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When the Seasons Don't Fit: Speedy Molt as a Routine Carry-Over Cost of Reproduction
Dietz, M.W.; Rogers, K.G.; Piersma, T.
2013-01-01
The failure of animals to fit all life-cycle stages into an annual cycle could reduce the chances of successful breeding. In some cases, non-optimal strategies will be adopted in order to maintain the life-cycle within the scope of one year. We studied trade-offs made by a High Arctic migrant shorebird, the red knot Calidris canutus islandica, between reproduction and wing feather molt carried out in the non-breeding period in the Dutch Wadden Sea. We compared primary molt duration between bi...
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Comeault, Aaron A.; Venkat, Aarti; Matute, Daniel R.
2016-01-01
Selection against maladaptive hybridization can drive the evolution of reproductive isolation in a process called reinforcement. While the importance of reinforcement in evolution has been historically debated, many examples now exist. Despite these examples, we typically lack a detailed understanding of the mechanisms limiting the spread of reinforced phenotypes throughout a species' range. Here we address this issue in the fruit fly Drosophila yakuba, a species that hybridizes with its sister species D. santomea and is undergoing reinforcement in a well-defined hybrid zone on the island of São Tomé. Within this region, female D. yakuba show increased postmating-prezygotic (gametic) isolation towards D. santomea when compared with females from allopatric populations. We use a combination of natural collections, fertility assays, and experimental evolution to understand why reinforced gametic isolation in D. yakuba is confined to this hybrid zone. We show that, among other traits, D. yakuba males from sympatric populations sire fewer progeny than allopatric males when mated to allopatric D. yakuba females. Our results provide a novel example of reinforcement acting on a postmating-prezygotic trait in males, resulting in a cascade of reproductive isolation among conspecific populations. PMID:27440664
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Hyperprolactinemia and male reproductive functions
R.F.A. Weber (Robert)
1983-01-01
textabstractIn this thesis some effects of PRL on reproductive functions have been investigated PRL-secreting pituitary adenoma. animal model has been used: For in men with a comparison an In. rats hyperprolactinemia has been induced by sub-cutaneous inoculation of a PRL- and
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Behavioral and physiological polymorphism in males of the austral lizard Liolaemus sarmientoi.
Fernández, Jimena B; Bastiaans, Elizabeth; Medina, Marlin; Méndez De la Cruz, Fausto R; Sinervo, Barry R; Ibargüengoytía, Nora R
2018-02-01
Integrative behavioral studies show that the interplay between individual physiology and social behavior influences the ecology of the species, ultimately affecting individual fitness. Particularly in lizards, color polymorphism is associated with differential behaviors and reproductive strategies, which are evident in mature males during the mating season. Dominant males generally have greater endurance, higher body temperature, and larger bodies than submissive males, so they can acquire and defend larger territories and have greater access to females for mating. We studied whether the color morphs observed in males of one of the world's southernmost reptiles, Liolaemus sarmientoi, are related to behavioral variation during agonistic interactions, thermal physiology, morphology, and/or locomotor stamina. Liolaemus sarmientoi males exhibit three color morphs: red (RR), red-yellow (RY), and yellow (YY). These lizards exhibit subtle behavioral displays and we did not observe stamina differences among morphs. However, we found that RR males are more aggressive than YY males during agonistic encounters. In addition, greater body temperature change during trials, higher field body temperatures, and greater head sizes of RR males compared to RY or YY indicate that RR is a dominant morph, which may influence their ability to acquire and defend territory and tactics for achieving reproductive success.
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Li, Xiao-Wei; Jiang, Hong-Xue; Zhang, Xiao-Chen; Shelton, Anthony M; Feng, Ji-Nian
2014-01-01
Post-mating, sexual interactions of opposite sexes differ considerably in different organisms. Post-mating interactions such as re-mating behavior and male harassment can affect the fitness of both sexes. Echinothrips americanus is a new insect pest in Mainland China, and little is known about its post-mating interactions. In this study, we observed re-mating frequency and male harassment frequency and their effects on fitness parameters and offspring sex ratios of E. americanus females. Furthermore, we tested the impact of mating and post-mating interactions on fitness parameters of males. Our results revealed that the re-mating frequency in female adults was extremely low during a 30-day period. However, post-mating interactions between females and males, consisting mainly of male harassment and female resistance, did occur and significantly reduced female longevity and fecundity. Interestingly, increased access to males did not affect the ratio of female offspring. For males, mating dramatically reduced their longevity. However, post-mating interactions with females had no effects on the longevity of mated males. These results enrich our basic knowledge about female and male mating and post-mating behaviors in this species and provide important information about factors that may influence population regulation of this important pest species.
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Directory of Open Access Journals (Sweden)
Xiao-Wei Li
Full Text Available Post-mating, sexual interactions of opposite sexes differ considerably in different organisms. Post-mating interactions such as re-mating behavior and male harassment can affect the fitness of both sexes. Echinothrips americanus is a new insect pest in Mainland China, and little is known about its post-mating interactions. In this study, we observed re-mating frequency and male harassment frequency and their effects on fitness parameters and offspring sex ratios of E. americanus females. Furthermore, we tested the impact of mating and post-mating interactions on fitness parameters of males. Our results revealed that the re-mating frequency in female adults was extremely low during a 30-day period. However, post-mating interactions between females and males, consisting mainly of male harassment and female resistance, did occur and significantly reduced female longevity and fecundity. Interestingly, increased access to males did not affect the ratio of female offspring. For males, mating dramatically reduced their longevity. However, post-mating interactions with females had no effects on the longevity of mated males. These results enrich our basic knowledge about female and male mating and post-mating behaviors in this species and provide important information about factors that may influence population regulation of this important pest species.
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Wengaard, Eivind Johannessen; Kristoffersen, Morten; Harris, Anette; Gundersen, Hilde
2017-01-01
Background: Previous studies have shown associations of physical fitness and cognition in children and in younger and older adults. However, knowledge about associations in high-school adolescents and young adults is sparse. Thus, the aim of this study was to evaluate the association of physical fitness, measured as maximal oxygen uptake (V⋅O2max), muscle mass, weekly training, and cognitive function in the executive domains of selective attention and inhibitory control, in healthy male ...
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Knapp, Rosemary; Neff, Bryan D
2007-12-22
The proximate mechanisms underlying the evolution and maintenance of within-sex variation in mating behaviour are still poorly understood. Species characterized by alternative reproductive tactics provide ideal opportunities to investigate such mechanisms. Bluegill (Lepomis macrochirus) are noteworthy in this regard because they exhibit two distinct cuckolder (parasitic) morphs (called sneaker and satellite) in addition to the parental males that court females. Here we confirm previous findings that spawning cuckolder and parental males have significantly different levels of testosterone and 11-ketotestosterone. We also report, for the first time, that oestradiol and cortisol levels are higher in cuckolders than in parental males. The two cuckolder morphs did not differ in average levels of any of the four hormones. However, among satellite males which mimic females in appearance and behaviour, there was a strong negative relationship between oestradiol levels and body length, a surrogate for age. This finding suggests that for satellite males, oestradiol dependency of mating behaviour decreases with increasing mating experience. Although such decreased hormone dependence of mating behaviour has been reported in other taxa, our data represent the first suggestion of the relationship in fishes.
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Zika Virus Trafficking and Interactions in the Human Male Reproductive Tract.
da Silva, Lucia Regina Cangussu
2018-05-11
Sexual transmission of Zika virus (ZIKV) is a matter of great concern. Infectious viral particles can be shed in semen for as long as six months after infection and can be transferred to male and female sexual partners during unprotected sexual intercourse. The virus can be found inside spermatozoa and could be directly transferred to the oocyte during fertilization. Sexual transmission of ZIKV can contribute to the rise in number of infected individuals in endemic areas as well as in countries where the mosquito vector does not thrive. There is also the possibility, as has been demonstrated in mouse models, that the vaginal deposition of ZIKV particles present in semen could lead to congenital syndrome. In this paper, we review the current literature to understand ZIKV trafficking from the bloodstream to the human male reproductive tract and viral interactions with host cells in interstitial spaces, tubule walls, annexed glands and semen. We hope to highlight gaps to be filled by future research and potential routes for vaccine and antiviral development.
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[Roles of G protein-coupled estrogen receptor in the male reproductive system].
Chen, Kai-hong; Zhang, Xian; Jiang, Xue-wu
2016-02-01
The G protein-coupled estrogen receptor (GPER), also known as G protein-coupled receptor 30 (GPR30), was identified in the recent years as a functional membrane receptor different from the classical nuclear estrogen receptors. This receptor is widely expressed in the cortex, cerebellum, hippocampus, heart, lung, liver, skeletal muscle, and the urogenital system. It is responsible for the mediation of nongenomic effects associated with estrogen and its derivatives, participating in the physiological activities of the body. The present study reviews the molecular structure, subcellular localization, signaling pathways, distribution, and function of GPER in the male reproductive system.
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Clancy, Lisa M; Cooper, Amy L; Griffith, Gareth W; Santer, Roger D
2017-07-18
Same-sex sexual behaviour occurs across diverse animal taxa, but adaptive explanations can be difficult to determine. Here we investigate male-male mounting (MMM) behaviour in female-deprived desert locust males infected with the entomopathogenic fungus Metarhizium acridum. Over a four-week period, infected locusts performed more MMM behaviours than healthy controls. Among infected locusts, the probability of MMM, and the duration of time spent MMM, significantly increased with the mounting locust's proximity to death. In experimental trials, infected locusts were also significantly more likely than controls to attempt to mount healthy males. Therefore, we demonstrate that MMM is more frequent among infected than healthy male locusts, and propose that this may be explained by terminal reproductive effort and a lowered mate acceptance threshold in infected males. However, during experimental trials mounting attempts were more likely to be successful if the mounted locusts were experimentally manipulated to have a reduced capacity to escape. Thus, reduced escape capability resulting from infection may also contribute to the higher frequency of MMM among infected male locusts. Our data demonstrate that pathogen infection can affect same-sex sexual behaviour, and suggest that the impact of such behaviours on host and pathogen fitness will be a novel focus for future research.
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Wengaard, Eivind; Kristoffersen, Morten; Harris, Anette; Gundersen, Hilde
2017-01-01
Background : Previous studies have shown associations of physical fitness and cognition in children and in younger and older adults. However, knowledge about associations in high-school adolescents and young adults is sparse. Thus, the aim of this study was to evaluate the association of physical fitness, measured as maximal oxygen uptake ([Formula: see text]), muscle mass, weekly training, and cognitive function in the executive domains of selective attention and inhibitory control, in healthy male high-school students. Methods : Fifty-four males (17.9 ± 0.9 years, 72 ± 11 kg and 182 ± 7 cm) completed a [Formula: see text] test, a body composition test and a visual cognitive task based on the Posner cue paradigm with three types of stimuli with different attentional demands (i.e., stimuli presentation following no cue, valid cue or invalid cue presentations). The task consisted of 336 target stimuli, where 56 (17%) of the target stimuli appeared without a cue (no cue), 224 (67%) appeared in the same rectangle as the cue (valid cue) and 56 (17%) appeared in the rectangle opposite to the cue (invalid cue). Mean reaction time (RT) and corresponding errors was calculated for each stimuli type. Total task duration was 9 min and 20 s In addition, relevant background information was obtained in a questionnaire. Results : Linear mixed model analyses showed that higher [Formula: see text] was associated with faster RT for stimuli following invalid cue (Estimate = -2.69, SE = 1.03, p = 0.011), and for stimuli following valid cue (Estimate = -2.08, SE = 1.03, p = 0.048). There was no association of muscle mass and stimuli ( F = 1.01, p = 0.397) or of weekly training and stimuli ( F = 0.99, p = 0.405). Conclusion : The results suggest that cardiorespiratory fitness is associated with cognitive performance in healthy male high-school students in the executive domains of selective attention.
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Directory of Open Access Journals (Sweden)
Eivind Wengaard
2017-06-01
Full Text Available Background: Previous studies have shown associations of physical fitness and cognition in children and in younger and older adults. However, knowledge about associations in high-school adolescents and young adults is sparse. Thus, the aim of this study was to evaluate the association of physical fitness, measured as maximal oxygen uptake (V·O2max, muscle mass, weekly training, and cognitive function in the executive domains of selective attention and inhibitory control, in healthy male high-school students.Methods: Fifty-four males (17.9 ± 0.9 years, 72 ± 11 kg and 182 ± 7 cm completed a V·O2max test, a body composition test and a visual cognitive task based on the Posner cue paradigm with three types of stimuli with different attentional demands (i.e., stimuli presentation following no cue, valid cue or invalid cue presentations. The task consisted of 336 target stimuli, where 56 (17% of the target stimuli appeared without a cue (no cue, 224 (67% appeared in the same rectangle as the cue (valid cue and 56 (17% appeared in the rectangle opposite to the cue (invalid cue. Mean reaction time (RT and corresponding errors was calculated for each stimuli type. Total task duration was 9 min and 20 s In addition, relevant background information was obtained in a questionnaire.Results: Linear mixed model analyses showed that higher V·O2max was associated with faster RT for stimuli following invalid cue (Estimate = −2.69, SE = 1.03, p = 0.011, and for stimuli following valid cue (Estimate = −2.08, SE = 1.03, p = 0.048. There was no association of muscle mass and stimuli (F = 1.01, p = 0.397 or of weekly training and stimuli (F = 0.99, p = 0.405.Conclusion: The results suggest that cardiorespiratory fitness is associated with cognitive performance in healthy male high-school students in the executive domains of selective attention.
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Mechanisms of toxicity of di(2-ethylhexyl) phthalate on the reproductive health of male zebrafish
Energy Technology Data Exchange (ETDEWEB)
Uren-Webster, Tamsyn M.; Lewis, Ceri; Filby, Amy L.; Paull, Gregory C. [Hatherly Laboratories, School of Biosciences, University of Exeter, Prince of Wales Road, Exeter, Devon EX4 4PS (United Kingdom); Santos, Eduarda M., E-mail: e.santos@exeter.ac.uk [Hatherly Laboratories, School of Biosciences, University of Exeter, Prince of Wales Road, Exeter, Devon EX4 4PS (United Kingdom)
2010-09-01
Phthalates are ubiquitous in the aquatic environment and are known to adversely affect male reproductive health in mammals through interactions with multiple receptor systems. However, little is known about the risks they pose to fish. This project investigated the effects of di(2-ethylhexyl) phthalate (DEHP), the most commonly used phthalate, on the reproductive health of male zebrafish (Danio rerio). Males were treated with 0.5, 50 and 5000 mg DEHP kg{sup -1} (body weight) for a period of 10 days via intraperitoneal injection. The effects of the exposure were assessed by analysing fertilisation success, testis histology, sperm DNA integrity and transcript profiles of the liver and testis. A significant increase in the hepatosomatic index and levels of hepatic vitellogenin transcript were observed following exposure to 5000 mg DEHP kg{sup -1}. Exposure to 5000 mg DEHP kg{sup -1} also resulted in a reduction in fertilisation success of oocytes spawned by untreated females. However, survival and development of the resulting embryos were unaffected by all treatments, and no evidence of DEHP-induced sperm DNA damage was observed. Exposure to 50 and 5000 mg DEHP kg{sup -1} caused alterations in the proportion of germ cells at specific stages of spermatogenesis in the testis, including a reduction in the proportion of spermatozoa and an increase in the proportion of spermatocytes, suggesting that DEHP may inhibit the progression of meiosis. In parallel, exposure to 5000 mg DEHP kg{sup -1} increased the levels of two peroxisome proliferator-activated receptor (PPAR) responsive genes (acyl-coenzyme A oxidase 1 (acox1) and enoyl-coenzyme A, hydratase/3-hydroxyacyl coenzyme A dehydrogenase (ehhadh). These data demonstrated that exposure to high concentrations of DEHP disrupts spermatogenesis in adult zebrafish with a consequent decrease in their ability to fertilise oocytes spawned by untreated females. Furthermore, our data suggest that the adverse effects caused by
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Directory of Open Access Journals (Sweden)
Pacheco JI
2017-08-01
Full Text Available The taruca is the largest species of cervid native of the Peruvian Andes, which is in a vulnerable state, a circumstance by which it is necessary to carry out studies regarding its anatomy and reproductive physiology, in the future, to implement reproductive biotechnologies for its conservation. The anatomy and histological structure of the reproductive organs of an adult male Hippocamelus antisensis specimen is described and sent to the IVITA Maranganí, UNMSM station by the SERFOR Cusco with custody act No. 042-2015-SERFOR-ATFFS CUSCO for Research purposes, the same one that died in the Zoo of Tipon - Cusco. The external reproductive organs are described, which present anatomical disposition similar to other artiodactyls, with the peculiarity of being covered with secretions and odors characteristic of the species; Have vesicles of the deferent, testicles represent 3.4% of the body weight, there are three adjoining glands: vesicular glands, prostate and bulbourethral glands, fibroelastic penis without sigmoid flexure, glans does not present urethral process, histologically the testis presents The structure similar to other species of artiodactyls, the epididymis shows sperm content, the vas deferens presents a broad muscular tunica, in conclusion the characteristics are similar to other cervids and also to domestic species like the ram and the goat
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Hoving, Hendrik Jan T.; Lipinski, Marek R.; Dam, Lammertjan
2010-01-01
Squid are semelparous organisms. Much of what we know about squid reproduction relates to females, because few studies have addressed males and, although males are similarly challenged by semelparity, it remains virtually unknown what tactics squid have evolved to allocate sperm to spermatophores.
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Sharma, Poonam; Huq, Amir Ul; Singh, Rambir
2013-09-01
The present study was designed to investigate role of ethanolic extract of Tribulus terrestris (EETT) against alpha-cypermethrin induced reproductive toxicity in male Wistar rats. 24 male Wistar rats weighing about 250-300g were divided in four groups. Group-I was control. alpha-cypermethrin (3.38 mg kg-1b.wt.) was given to group-IlI for 28 days. In Group-Ill, alpha-cypermethrin and EETT (100 mg kg -1b.wt.) were administered in combination for 28 days. Rats in group-IV were given EETT for 28 days. At the end of the experiment, rats were sacrificed, testes and epididymis were removed and sperm characteristics, sex hormones and various biochemical parameters were studied. Decrease in weight of testes and epididymis, testicular sperm head count, sperm motility, live sperm count, serum testosterone (T), follicle stimulating hormone (FSH), leutinizing hormone (LH), catalase (CAT), superoxide dismutase (SOD), glutathione S transferase (GST), glutathione reductase (GR), glutathione peroxidase (GPx), total protein content and increase in sperm abnormalities and lipid peroxidation (LPO) level was observed in rats exposed to cypermethrin. In combination group-Ill, EETT treatment ameliorated alpha-cypermethrin induced damage. EETT treatment in group-IV increased testes and epididymis weight, sperm head counts, sperm motility, live sperm counts, testosterone, FSH, LH, GSH, CAT, SOD, GST, GR, GPx and total protein content. The study suggested that Tribulus terrestris plant possess reproductive system enhancement and antioxidant activity.
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Davies, Scott; Behbahaninia, Hirbod; Giraudeau, Mathieu; Meddle, Simone L; Waites, Kyle; Deviche, Pierre
2015-12-01
Urban animals inhabit an environment considerably different than do their non-urban conspecifics, and to persist urban animals must adjust to these novel environments. The timing of seasonal reproductive development (i.e., growth of gonads and secondary sex organs) is a fundamental determinant of the breeding period and is frequently advanced in urban bird populations. However, the underlying mechanism(s) by which birds adjust the timing of reproductive development to urban areas remain(s) largely unknown. Here, we compared the timing of vernal reproductive development in free-ranging urban and non-urban male Abert's Towhees, Melozone aberti, in Phoenix, Arizona, USA, and tested the non-mutually exclusive hypotheses that earlier reproductive development is due to improved energetic status and/or earlier increase in endocrine activity of the reproductive system. We found that urban birds initiated testicular development earlier than non-urban birds, but this disparity was not associated with differences in body condition, fat stores, or innate immune performance. These results provide no support for the hypothesis that energetic constraints are responsible for delayed reproductive development of non-urban relative to urban male Abert's Towhees. Urban birds did, however, increase their plasma luteinizing hormone, but not plasma testosterone, earlier than non-urban birds. These findings suggest that adjustment to urban areas by Abert's Towhees involves increases in the endocrine activity of the anterior pituitary gland and/or hypothalamus earlier than non-urban towhees. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.
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Hamilton's inclusive fitness maintains heritable altruism polymorphism through rb = c.
Wang, Changcao; Lu, Xin
2018-02-20
How can altruism evolve or be maintained in a selfish world? Hamilton's rule shows that the former process will occur when rb > c -the benefits to the recipients of an altruistic act b , weighted by the relatedness between the social partners r , exceed the costs to the altruists c -drives altruistic genotypes spreading against nonaltruistic ones. From this rule, we infer that altruistic genotypes will persist in a population by forming a stable heritable polymorphism with nonaltruistic genotypes if rb = c makes inclusive fitness of the two morphs equal. We test this prediction using the data of 12 years of study on a cooperatively breeding bird, the Tibetan ground tit Pseudopodoces humilis , where helping is performed by males only and kin-directed. Individual variation in ever acting as a helper was heritable ( h 2 = 0.47), and the resultant altruism polymorphism remained stable as indicated by low-level annual fluctuation of the percentage of helpers among all adult males (24-28%). Helpers' indirect fitness gains from increased lifetime reproductive success of related breeders statistically fully compensated for their lifetime direct fitness losses, suggesting that rb = c holds. While our work provides a fundamental support for Hamilton's idea, it highlights the equivalent inclusive fitness returns to altruists and nonaltruists mediated by rb = c as a theoretically and realistically important mechanism to maintain social polymorphism.
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Immunity and fitness in a wild population of Eurasian kestrels Falco tinnunculus
Parejo, Deseada; Silva, Nadia
2009-10-01
The immune system of vertebrates consists of several components that partly interact and complement each other. Therefore, the assessment of the overall effectiveness of immune defence requires the simultaneous measurement of different immune components. In this study, we investigated intraspecific variability of innate [i.e. natural antibodies (NAb) and complement] and acquired (i.e. leucocyte profiles) immunity and its relationship with fitness correlates (i.e. blood parasite load and reproductive success in adults and body mass and survival until fledging in nestlings) in the Eurasian kestrel Falco tinnunculus. Immunity differed between nestlings and adults and also between adult males and females. Adult kestrels with higher levels of complement were less parasitised by Haemoproteus, and males with higher values of NAbs showed a higher reproductive success. In nestlings, the H/L ratio was negatively related to body mass. Survival until fledging was predicted by all measured immunological variables of nestlings as well as by their fathers' level of complement. This is the first time that innate immunity is linked to survival in a wild bird. Thus, intraspecific variation in different components of immunity predicts variation in fitness prospects in kestrels, which highlights the importance of measuring innate immune components together with components of the acquired immunity in studies assessing the effectiveness of the immune system in wild animals.
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Fit to father? Online accounts of lifestyle changes and help-seeking on a male infertility board.
Hanna, Esmée; Gough, Brendan; Hudson, Nicky
2018-04-06
The reproductive realm is routinely viewed as a feminised space requiring women's commitment and labour. By contrast, men's procreative contributions and 'reproductive masculinity' is represented as unproblematic, with men assumed to be fertile across the lifespan. Recent scientific research has, however, cast doubt over these longstanding assumptions, suggesting that a link does exist between 'lifestyle' factors and male fertility. The notion that fertility can be improved with effort (for both women and men) can be located within wider cultural and political shifts which construct individuals as increasingly responsible for acting on health messages and engaging in self-disciplining body projects. Through an exploration of 'lifestyle changes' within a men's online infertility discussion forum board, this paper examines how discourses of individualisation healthism and masculinity are reproduced and interlinked. Our thematic analysis indicates that 'lifestyle work' is construed as crucial for achieving conception - and as a means to demonstrate men's commitment to the dyadic goal of parenthood, which in turn may challenge and extend previous notions of 'reproductive masculinity'. © 2018 Foundation for the Sociology of Health & Illness.
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Noguera, José C.; Metcalfe, Neil B.; Monaghan, Pat
2017-12-01
Poor early-life nutrition could reduce adult reproductive success by negatively affecting traits linked to sexual attractiveness such as song complexity. If so, this might favor strategic mate choice, allowing males with less complex songs to tailor their mating tactics to maximize the reproductive benefits. However, this possibility has been ignored in theoretical and empirical studies. By manipulating the micronutrient content of the diet (e.g., low or high) during the postnatal period of male zebra finches, we show for the first time (1) that males reared on a poor (low) micronutrient diet had less complex songs as adults; (2) that these males, in contrast to the high micronutrient diet group, were more selective in their mating strategies, discriminating against those females most likely to reduce their clutch size when paired with males having less complex songs; and (3) that by following different mating strategies, males reared on the contrasting diets obtained similar reproductive benefits. These results suggest that early-life dietary conditions can induce multiple and long-lasting effects on male and female reproductive traits. Moreover, the results seem to reflect a previously unreported case of adaptive plasticity in mate choice in response to a nutritionally mediated reduction in sexual attractiveness.
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Broquet, Thomas; Barranger, Audrey; Billard, Emmanuelle; Bestin, Anastasia; Berger, Rémy; Honnaert, Gaelle; Viard, Frédérique
2015-09-01
Sequential hermaphroditism is adaptive when the reproductive value of an individual varies with size or age, and this relationship differs between males and females. In this case, theory shows that the lifetime reproductive output of an individual is increased by changing sex (a hypothesis referred to as the size-advantage model). Sex-linked differences in size-fitness curves can stem from differential costs of reproduction, the mating system, and differences in growth and mortality between sexes. Detailed empirical data is required to disentangle the relative roles of each of these factors within the theory. Quantitative data are also needed to explore the role of sperm storage, which has not yet been considered with sequential hermaphrodites. Using experimental rearing and paternity assignment, we report relationships between size and reproductive success of Crepidula fornicata, a protandrous (male-first) gastropod. Male reproductive success increased with size due to the polygamous system and stacking behavior of the species, but females nonetheless had greater reproductive success than males of the same size, in agreement with the size-advantage theory. Sperm storage appeared to be a critical determinant of success for both sexes, and modeling the effect of sperm storage showed that it could potentially accelerate sex change in protandrous species.
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Testicular dysgenesis syndrome and the development and occurrence of male reproductive disorders
International Nuclear Information System (INIS)
Virtanen, H.E.; Rajpert-De Meyts, E.; Main, K.M.; Skakkebaek, N.E.; Toppari, J.
2005-01-01
Patients with 45,X0/46XY karyotype often present with intersex phenotype and testicular dysgenesis. These patients may also have undescended testes (cryptorchidism), hypospadias and their spermatogenesis is severely disrupted. They have a high risk for testicular cancer. These patients have the most severe form of testicular dysgenesis syndrome (TDS). We have hypothesized that testicular cancer, cryptorchidism, hypospadias and poor spermatogenesis are all signs of a developmental disturbance that was named as testicular dysgenesis syndrome. The hypothesis is based on clinical and epidemiological findings and on biological and experimental evidence. Signs of TDS share several risk factors, such as small birth weight (particularly being small for gestational age), and they are risk factors for each other. All of them have background in fetal development. They show strong epidemiological links so that countries with high incidence of testicular cancer, such as Denmark, tend to also have high prevalence rates of cryptorchidism and hypospadias and poor semen quality. Vice versa, in countries with good male reproductive health, e.g., in Finland, all these aspects are better than in Denmark. Although genetic abnormalities can cause these disorders, in the majority of cases, the reasons remain unclear. Adverse trends in the incidence of male reproductive disorders suggest that environmental and life style factors contribute to the problem. Endocrine disrupters are considered as prime candidates for environmental influence. Fetal exposure to high doses of dibutyl phthalate was shown to cause a TDS-like phenotype in the rats. Studies are underway to assess whether there is any exposure-outcome relation with selected chemicals (persistent organic pollutants, pesticides, phthalates) and cryptorchidism
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Body size, performance and fitness in galapagos marine iguanas.
Wikelski, Martin; Romero, L Michael
2003-07-01
Complex organismal traits such as body size are influenced by innumerable selective pressures, making the prediction of evolutionary trajectories for those traits difficult. A potentially powerful way to predict fitness in natural systems is to study the composite response of individuals in terms of performance measures, such as foraging or reproductive performance. Once key performance measures are identified in this top-down approach, we can determine the underlying physiological mechanisms and gain predictive power over long-term evolutionary processes. Here we use marine iguanas as a model system where body size differs by more than one order of magnitude between island populations. We identified foraging efficiency as the main performance measure that constrains body size. Mechanistically, foraging performance is determined by food pasture height and the thermal environment, influencing intake and digestion. Stress hormones may be a flexible way of influencing an individual's response to low-food situations that may be caused by high population density, famines, or anthropogenic disturbances like oil spills. Reproductive performance, on the other hand, increases with body size and is mediated by higher survival of larger hatchlings from larger females and increased mating success of larger males. Reproductive performance of males may be adjusted via plastic hormonal feedback mechanisms that allow individuals to assess their social rank annually within the current population size structure. When integrated, these data suggest that reproductive performance favors increased body size (influenced by reproductive hormones), with an overall limit imposed by foraging performance (influenced by stress hormones). Based on our mechanistic understanding of individual performances we predicted an evolutionary increase in maximum body size caused by global warming trends. We support this prediction using specimens collected during 1905. We also show in a common
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Directory of Open Access Journals (Sweden)
VU Cromberg
2007-09-01
Full Text Available The aim of this research study was to evaluate the reproductive performance of tinamous submitted to five different male:female ratios. The study was carried out with 72 birds in a randomized experimental design with 4 replications. Tinamous were housed in cages, using the ratios of one (1:1, two (2:1, three (3:1 and four (4:1 females per male, and also one male was housed with three females individually (3R:1, in a rotational system. Reproductive records of the breeding season from September 2004 to March 2005 were used. The reproductive traits studied were: number of eggs laid, fertility, and percentage of eggs damaged and cracked by pecking. Nonparametric analyses of these traits were performed using Kruskal-Wallis test. Two replications of treatments 1:1 and 4:1, and one of treatment 2:1 were video-taped for three days, 12 hours/day. The videotapes were sampled according to the scan method to fit an ethogram. Birds were also watched for one hour per day to study dominance and agonistic behavior. None of the reproductive traits was affected by mating sex ratio (p<0.05. Female dominance could be related to displacement behavior (r=1.00, and male sitting in immobility plus sitting in activity behaviors were related to lower number of damaged eggs (r=-0.90. Social dominance was indirectly determined by displacement behavior in the study situation. A large number of damaged eggs occurred in all treatments, thereby not allowing a clear conclusion on the best male:female ratio.
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Occupational causes of male infertility
DEFF Research Database (Denmark)
Bonde, Jens P E
2013-01-01
To highlight and discuss the new evidence on occupational and environmental risk to male reproductive function.......To highlight and discuss the new evidence on occupational and environmental risk to male reproductive function....
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Directory of Open Access Journals (Sweden)
Valladares-Rodríguez Santiago
2017-12-01
Full Text Available The purpose of this study was to determine the reliability and usefulness of the 30-15 Intermittent Fitness Test (30-15IFT in professional male and female futsal players. Thirteen male (24.4 ± 5.6 years; 174.5 ± 10.3 cm; 70.3 ± 9.9 kg and fourteen female (23.3 ± 4.5 years; 165.8 ± 6.2 cm; 61.7 ± 5.5 kg professional futsal players performed the 30-15IFT on two occasions, separated by 5 days. Maximal intermittent running velocity (VIFT and heart rate at exhaustion (HRpeak data were collected for both tests. Reliability was assessed by the intraclass correlation coefficient (ICC, typical error (TE expressed as a coefficient of variation (CV, and smallest worthwhile change (SWC. VIFT demonstrated very good reliability between sessions, both for male (ICC = 0.92 and female (ICC = 0.96 players. As the TE for VIFT and HRpeak was similar to the calculated SWC for both male and female players, the usefulness of the test was rated as “medium”. A change in performance of at least 2 stages in male players, or a change of more than 1 stage in female players could be interpreted as a meaningful change in aerobic futsal fitness. The results of this study demonstrate that the 30-15IFT is both a reliable and useful test for male and female professional futsal players.
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DEFF Research Database (Denmark)
Alexander, Marcalee S; New, Peter W; Biering-Sørensen, Fin
2017-01-01
S Scientific and Executive Committees and ASIA board of directors. RESULTS: The data sets were modified to a self-report format. They were reviewed for appropriateness for the pediatric age group and adapted to include a new variable to address the issue of sexual orientation. A clarification of the difference......STUDY DESIGN: Data set review and modification. OBJECTIVE: To describe modifications in the International Spinal Cord Injury (SCI) Male Sexual Function Basic Data Set Version 2.0 and the International SCI Female Sexual and Reproductive Function Basic Data Set Version 2.0. SETTING: International...... expert work group using on line communication. METHODS: An international team of experts was compiled to review and revise the International SCI Male Sexual Function and Female Sexual and Reproductive Function Basic Data Sets Version 1.0. The group adapted Version 1.0 based upon review of published...
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Effects on the reproductive system of young male rats of subcutaneous exposure to n-butylparaben.
Garcia, Tania; Schreiber, Elga; Kumar, Vikas; Prasad, Raju; Sirvent, Juan J; Domingo, Jose L; Gómez, Mercedes
2017-08-01
This study was aimed at determining whether an in vivo subcutaneous exposure to n-butylparaben (n-ButP) during one complete spermatogenic cycle could be harmful to the reproductive system of young male rats. Animals were subcutaneously given 0, 150, 300 and 600 mg/kg/day of n-ButP with vehicle (peanut oil). Body and organ weights, n-ButP excretion, biochemical parameters, sperm and spermatid count, sperm motility, viability, maturity and morphology were examined. Results showed that after a completed spermatogenic cycle, although n-ButP did not induce dose-related changes in the different biochemical parameters, a significant decrease of triacylglicerides (TAG) -due to the vehicle-was found. Furthermore, no effects of n-ButP on body weight gain and relative organ weight changes were noted. Regarding sexual organs, prostate relative weight was significantly increased at the high dose of n-ButP. On the other hand, a significant increase of abnormal sperm morphology due to n-ButP exposure, accompanied by different alterations in sexual organs histopathology, was found. The current results indicate that subcutaneous exposure of n-ButP in young male rats induced toxic effects on the reproductive system, which could affect the capacity of fertilization of animals. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Michalczyk, Łukasz; Martin, Oliver Y.; Millard, Anna L.; Emerson, Brent C.; Gage, Matthew J. G.
2010-01-01
As populations decline to levels where reproduction among close genetic relatives becomes more probable, subsequent increases in homozygous recessive deleterious expression and/or loss of heterozygote advantage can lead to inbreeding depression. Here, we measure how inbreeding across replicate lines of the flour beetle Tribolium castaneum impacts on male reproductive fitness in the absence or presence of male–male competition. Effects on male evolution from mating pattern were removed by enforcing monogamous mating throughout. After inbreeding across eight generations, we found that male fertility in the absence of competition was unaffected. However, we found significant inbreeding depression of sperm competitiveness: non-inbred males won 57 per cent of fertilizations in competition, while inbred equivalents only sired 42 per cent. We also found that the P2 ‘offence’ role in sperm competition was significantly more depressed under inbreeding than sperm ‘defence’ (P1). Mating behaviour did not explain these differences, and there was no difference in the viability of offspring sired by inbred or non-inbred males. Sperm length variation was significantly greater in the ejaculates of inbred males. Our results show that male ability to achieve normal fertilization success was not depressed under strong inbreeding, but that inbreeding depression in these traits occurred when conditions of sperm competition were generated. PMID:20554548
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The Effect of Pollen on Some Reproductive Parameters of Male Rats
Directory of Open Access Journals (Sweden)
Güldeniz Selmanoğlu
2009-01-01
Full Text Available Honeybee pollen is consumed as natural food in healthy human diet in many European and Asian countries. The aim of this study was to investigate the effect of pollen use on some reproductive parameters. In this study, mature male rats were fed on pollen of three different plant sources (Trifolium spp., Raphanus spp. and Cistus spp. at 60 mg/per animal/ per day over a 30-day period. At the end of the treatment, testosterone levels of rats were analysed and weights of testis, epididymis, prostate and seminal vesicle were recorded. In addition, epididymal sperms were counted. There were increases in testosterone levels, sperm counts and daily sperm production of rats fed with pollen of Raphanus spp. and Cistus spp. There were no significant changes in absolute weights, except in prostate weights. Also there were no changes in relative testis,prostate and seminal vesicle weights of rats fed on pollen, but relative epididymis weights of rats in pollen groups decreased. The results of this study show that bee pollen caused an increase in testosterone level and sperm counts of male rats. We suggest that bee pollen has an androgenic effect.
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Szentirmai, I.; Szekely, T.; Komdeur, J.
A fundamental tenet of sexual conflict theory is that one sex may increase its reproductive success (RS) even if this harms the other sex. Several studies supported this principle by showing that males benefit from reduced paternal care whereas females suffer from it. By investigating penduline tits
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The Explanatory Value of Inclusive Fitness for Evolutionary Theory
Rubin, Hannah
2017-01-01
At the heart of evolutionary theory is the concept of 'fitness', which is, standardly, an organism's reproductive success. Many evolutionary theorists argue, however, that to explain the evolution of social traits, such as altruism, we must use a different notion of fitness. This 'inclusive fitness', which includes the reproductive success of relatives, is seen as indispensable for studying social evolution. Recently, however, both biologists and philosophers have critically scrutinized its s...
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Leisure-time physical activity and physical fitness of male adolescents in Oman.
Khoo, Selina; Al-Shamli, Ali Khalifa
2012-01-01
This study investigated the relationship between leisure-time physical activity and physical fitness (cardiovascular fitness, body fat percentage, flexibility, muscle strength, and endurance) of 10th-grade male students in Oman. Data were collected from 330 students. All participants completed a descriptive questionnaire, a 1 mile walk/run test; a skinfold analysis of the chest, abdomen, and thigh; a sit and reach test; a hand grip test; and a 1-minute sit-up test. Students spent an average of 19.20 ± 6.77 hours on sedentary activities, 3.46 ± 2.11 hours on sports activities, and 11.22 ± 9.24 hours working per week. The students had an average body fat percentage of 6.38% ± 4.67%, muscle strength 38.04 ± 7.55 kg, flexibility 38.01 ± 7.41 cm, abdominal muscle endurance 38.85 ± 8.15 times/min, and cardiovascular endurance 8.10 ± 1.65 minutes.
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Comparison between Salivary Cortisol Release in Rest and Training Days in Male Fitness Trainee
Directory of Open Access Journals (Sweden)
Ardalan Shariat
2013-03-01
Full Text Available Background: The aim behind the current study was a comparison between salivary cortisol release in rest and training days in male fitness trainers. Methods: In such balanced crossover research, 15 healthy fitness-trained participants (with the mean age, weight and Height of 20.35 ± 1.20 years, 74.15 ± 3.20 kg and 177.30 ± 3.45 cm, respectively who had a four-year-previous experience in fitness exercise were chosen. While performing the research, the subjects were involved in a fitness training. The protocol contained three times of fitness training in a week, which would totally be alternative days of “rest” and “exercise” in the period of training. It means that they did training on Monday, Wednesday and Friday, and rested on the other days. To ensure the validity of this study, the participants were selected randomly, in both control and experimental groups. In the meantime, the protocol for fitness exercise was made up of four sets of 15 repetitions utilizing 65% of 1 repetition maximum (1 RM. Within each testing time, saliva samples were taken once in two hours for a maximum of 16 hours. In this study, the ANOVA was followed by a Post-hoc LSD test. Also, the significance level was deemed as (P≤0.05. Results: It was shown that there was a statistically significant addition in the salivary cortisol level right away after the fitness exercise session (P ≤ 0.05. However, no statistically significant difference was observed between exercise and control days in the circadian rhythm of salivary cortisol (P > 0.05. Conclusion: The present research demonstrated that while there was a significant influence of fitness exercise on cortisol right away after exercise, no statistically significant effect has been observed on the circadian secretion of cortisol in fitness sportsmen.
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Johnson, M G; Shaw, A J
2016-06-01
A major question in evolutionary biology is how mating patterns affect the fitness of offspring. However, in animals and seed plants it is virtually impossible to investigate the effects of specific gamete genotypes. In bryophytes, haploid gametophytes grow via clonal propagation and produce millions of genetically identical gametes throughout a population. The main goal of this research was to test whether gamete identity has an effect on the fitness of their diploid offspring in a population of the aquatic peat moss Sphagnum macrophyllum. We observed a heavily male-biased sex ratio in gametophyte plants (ramets) and in multilocus microsatellite genotypes (genets). There was a steeper relationship between mating success (number of different haploid mates) and fecundity (number of diploid offspring) for male genets compared with female genets. At the sporophyte level, we observed a weak effect of inbreeding on offspring fitness, but no effect of brood size (number of sporophytes per maternal ramet). Instead, the identities of the haploid male and haploid female parents were significant contributors to variance in fitness of sporophyte offspring in the population. Our results suggest that intrasexual gametophyte/gamete competition may play a role in determining mating success in this population.
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Sun, Hongxia; Wu, Wenjing; Guo, Jixing; Xiao, Rong; Jiang, Fengze; Zheng, Lingyan; Zhang, Guren
2016-04-01
Nickel is an environmental pollutant that adversely affects the male reproductive system. In the present study, the effects of nickel exposure on Spodoptera litura Fabricius were investigated by feeding larvae artificial diets containing different doses of nickel for three generations. Damage to testes and effects on male reproduction were examined. The amount of nickel that accumulated in the testes of newly emerged males increased as the nickel dose in the diet increased during a single generation. Nickel exposure increased the amount of thiobarbituric acid reactive substances and decreased the amount of glutathione in treatment groups compared with the control. The activity levels of the antioxidant response indices superoxide dismutases, catalase, and glutathione peroxidase in the testes showed variable dose-dependent relationships with nickel doses and duration of exposure. Nickel doses also disrupted the development of the testes by decreasing the weight and volume of testes and the number of eupyrene and apyrene sperm bundles in treatment groups compared with the control. When the nickel-treated males mated with normal females, fecundity was inhibited by the higher nickel doses in all three generations, but fecundity significantly increased during the second generation, which received 5 mg kg(-1) nickel. Hatching rates in all treatments significantly decreased in a dose-dependent manner in the three successive generations. The effects of nickel on these parameters correlated with the duration of nickel exposure. Results indicate assays of testes may be a novel and efficient means of evaluating the effects of heavy metals on phytophagous insects in an agricultural environment. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Chang, Yu-Ting; Hayter, Mark; Lin, Mei-Ling
2012-02-01
To explore male students' attitudes towards menstruation. Menstruation is a biological event that is often surrounded by secrecy and social stigma that causes anxiety amongst many young girls. A key element of this is the attitudes of young males towards this reproductive health issue. However, the literature around what young males think and feel about menstruation is limited. Qualitative. A sample of 27 male students aged between 10-12 years participated in five focus groups. Data were then subject to a thematic analysis. Five themes emerged from the data analysis that reflected the boys' feelings, experiences and attitudes towards menstruation: 'A silent topic', 'An unimportant issue', 'Errant information about menstruation'. In addition, according to their experience, participants gradually came to see menstruation from the 'menstrual stereotype' viewpoint. In their social life, they made choices that resulted in gradually regulating their behaviour that affected their 'relationships with girls'. Young boys have misguided knowledge about menstruation and this helps to perpetuate the stigma surrounding this element of reproductive health. Boys also express a desire to learn more but are often restricted in this by home and school. School nurses are the best placed professionals to address this issue. Menstrual education with boys should take a greater prominence than it often does in sexual health education in schools. Such inclusion will provide boys with a balanced and accurate knowledge base and therefore help towards reducing the social stigma around menstruation that is often experienced by young girls. © 2011 Blackwell Publishing Ltd.
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Bajaj, Vijay Kumar; Gupta, Radhey S
2013-08-01
Male contraceptive development in the present scenario is most viable aspect of research due to uncontrolled population growth in the world. In this respect investigators are busy to find out a safe male contraceptive drug. Researchers have started their finding for a suitable drug from natural sources because these are safe and easily acceptable for common man, most of natural sources are plants and their products. In this review 137 plants and their effects on reproduction and reproductive physiology are summarized. Some of them have intense effect on male reproductive system and do not produce any side effects. Reproductive toxicological studies are also important aspects of these kinds of researches, so it is important that drugs are safe and widely acceptable. An ideal male contraceptive can influence semen, testes, hormone level, accessory reproductive organs and general physiology of animals and produced some alterations. Many plants in this review are showing antifertility as well as antispermatogenic effects, so these may be used for further study for contraceptives development but it is important to find out the mechanism of reaction and further laboratory and clinical research on some plants are needed for final male contraceptive drug development. In conclusion this review will help for finding suitable plant products for male contraceptive clinical and laboratory studies.
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Karkarey, Rucha; Zambre, Amod; Isvaran, Kavita; Arthur, Rohan
2017-02-28
At high densities, terrestrial and marine species often employ alternate reproductive tactics (ARTs) to maximize reproductive benefits. We describe ARTs in a high-density and unfished spawning aggregation of the squaretail grouper (Plectropomus areolatus) in Lakshadweep, India. As previously reported for this species, territorial males engage in pair-courtship, which is associated with a pair-spawning tactic. Here, we document a previously unreported school-courtship tactic; where territorial males court multiple females in mid-water schools, which appears to culminate in a unique 'school-spawning' tactic. Courtship tactics were conditional on body size, local mate density and habitat, likely associated with changing trade-offs between potential mating opportunities and intra-sexual competition. Counter-intuitively, the aggregation showed a habitat-specific inverse size-assortment: large males courted small females on the reef slope while small males courted equal-sized or larger females on the shelf. These patterns remained stable across two years of observation at high, unfished densities. These unique density-dependent behaviours may disappear from this aggregation as overall densities decline due to increasing commercial fishing pressure, with potentially large consequences for demographics and fitness.
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Effects of plant sex on range distributions and allocation to reproduction.
Johnson, Marc T J; Smith, Stacey D; Rausher, Mark D
2010-05-01
Despite an abundance of theory, few empirical studies have explored the ecological and evolutionary consequences of sex. We used a comparative phylogenetic approach to examine whether transitions between sexual and asexual reproduction are associated with changes in the size and distribution of species' geographical ranges, and their investment in reproduction. Here, we reconstructed the phylogeny of the genus Oenothera sections Oenothera and Calylophus (Onagraceae), which contain 35 sexual and 30 functionally asexual species. From each species, we collected data on the geographical distribution and variation in plant traits related to reproduction. Functionally asexual species occurred at higher latitudes, but did not differ in range size, compared with sexual species. Transitions to asexuality were associated with decreased investment in floral structures, including the length of petals, floral tubes and styles. Decreased anther size and increased seed size within asexual species also suggest altered allocation to male and female fitness. The observed range shifts are consistent with superior colonization of environments by asexual species following glaciation, and the observed changes in reproductive allocation support predictions made by models relating to the evolution of selfing. Our results suggest that the evolutionary consequences of asexual reproduction might be less restrictive than previously thought.
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Dai, Xin; Jiang, Lian Yu; Han, Mei; Ye, Man Hong; Wang, Ai Qin; Wei, Wan Hong; Yang, Sheng Mei
2016-04-01
The plant secondary metabolite 6-methoxybenzoxazolinone (6-MBOA) can stimulate and enhance animal reproduction. This compound has been successfully detected in Leymus chinensis, which is the main diet of Brandt's voles. The aim of this study was to investigate the effect of different 6-MBOA doses on the reproductive physiology of male Brandt's voles under a short photoperiod. The results showed that 6-MBOA administration increased relative testis weight, regardless of the dose, but it had little effect on the body mass. Low and middle doses of 6-MBOA increased the concentrations of luteinizing hormone and testosterone in the serum and the mRNA levels of StAR and CYP11a1 in the testes. However, 6-MBOA did not cause any significant increase in the mRNA levels of KiSS-1, GPR54, and GnRH compared to those in the control group. The mRNA level of KiSS-1 in the arcuate nucleus (ARC) was higher than that in the anteroventral periventricular nucleus (AVPV). Collectively, our results demonstrated that the number of KiSS-1-expressing neurons located in the ARC was the highest, and that 6-MBOA, which might modulate the reproductive activity along the hypothalamic-pituitary-gonadal axis, had a dose-dependent stimulatory effect on the reproductive activity of Brandt's voles under a short photoperiod. Our study provided insights into the mechanism of 6-MBOA action and the factors influencing the onset of reproduction in Brandt's voles.
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International Nuclear Information System (INIS)
Shantharam, K.; Tamhankar, A.J.; Harwalkar, M.R.
1995-01-01
Studies were conducted on mating behaviour and reproductive performance of a) Earias vittella (F.) males rendered sterile by exposing them to 300 Gy gamma rays and b) F 1 sterile males obtained by exposing parent male to 100 Gy gamma rays. For the study, males were allowed only one mating with a normal female. Results revealed that premating period, period in copula and per cent insects mating were not adversely affected in case of both types of sterile males and fecundity also remained unaffected. However, in both types of sterile males, incidence of spermatophore transfer without sperm was very large and such an occurrence (including reduced spermatophore transfer) was significantly higher in case of radiation sterilized males compared to the F 1 sterile males. Inability to produce and transfer spermatophore and/or sperm appeared to be a major cause behind the reduced mating competitiveness of both types of males. (author). 22 refs., 2 tabs
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Effects of cocaine hydrochloride on the male reproductive system
International Nuclear Information System (INIS)
Berul, C.I.; Harclerode, J.E.
1989-01-01
The reproductive system effects of cocaine were studied in male rats. The analysis included measurements of circulating levels of luteinizing hormone (LH) and testosterone (T) by radioimmunoassay (RIA). The weights of the testes and sex accessory organs were also assessed and compared with control animals. Dosage level, duration of treatment, and interval between injection and sacrifice were the parameters examined. Following a single intraperitoneal (IP) injection, LH levels decreased over a 3-hour period. At a high dosage, cocaine caused a significant elevation in serum T followed by a significant depression of T for at least 2 hours. When administered chronically for 15 days, the low dose group did not vary significantly from the vehicle controls. However, the high dose group had lower LH and T levels, as well as correspondingly lighter weight seminal vesicles and epididymus. No changes were noted in the weights of the ventral prostate or testes. This research suggests that cocaine acts primarily at the hypothalamic-hypophyseal axis with a possible secondary action at the gonadal level
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Dotolo, Raffaele; Kim, Jung Dae; Pariante, Paolo; Minucci, Sergio; Diano, Sabrina
2016-03-01
Prolyl endopeptidase (PREP) is a serine protease which has been implicated in many biological processes, such as the maturation and degradation of peptide hormones and neuropeptides, learning and memory, cell proliferation and differentiation, and glucose metabolism. A small number of reports have also suggested PREP participation in both male and female reproduction-associated processes. In the present work, we examined PREP distribution in male germ cells and studied the effects of its knockdown (Prep(gt/gt)) on testis and sperm in adult mice. The protein is expressed and localized in elongating spermatids and luminal spermatozoa of wild type (wt) mice, as well as Sertoli, Leydig, and peritubular cells. PREP is also expressed in the head and midpiece of epididymal spermatozoa, whereas the remaining tail region shows a weaker signal. Furthermore, testis weight, histology of seminiferous tubules, and epididymal sperm parameters were assessed in wt and Prep(gt/gt) mice: wild type testes have larger average tubule and lumen diameter; in addition, lumenal composition of seminiferous tubules is dissimilar between wt and Prep(gt/gt), as the percentage of spermiated tubules is much higher in wt. Finally, total sperm count, sperm motility, and normal morphology are also higher in wt than in Prep(gt/gt). These results show for the first time that the expression of PREP could be necessary for a correct reproductive function, and suggest that the enzyme may play a role in mouse spermatogenesis and sperm physiology. © 2015 Wiley Periodicals, Inc.
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Khendek, A; Chakraborty, A; Roche, J; Ledoré, Y; Personne, A; Policar, T; Żarski, D; Mandiki, R; Kestemont, P; Milla, S; Fontaine, P
2018-02-08
Pikeperch (Sander lucioperca) is a highly valuable fish in Europe. However, development of aquaculture of pikeperch is highly limited due to seasonality of production. This can be overcome by the controlled reproduction of domesticated fish. The first steps of domestication process may induce changes at anatomical, physiological and molecular levels, thereby affecting a variety of biological functions. While there is abundant literature on their effects on stress and growth for example, these effects on reproduction received limited attention notably in pikeperch, a promising candidate for the development of aquaculture. To answer the question of this life-history effect on pikeperch's reproduction, we compared two groups (weight: 1 kg) originated from Czech Republic and with the same domestication level (F0). The first group was a recirculating aquatic system cultured one (2 years, previously fed with artificial diet, never exposed to natural changes in temperature/photoperiod conditions) and the second one was a pond cultured group (3 to 4 years, bred under natural feeding and temperature/photoperiod). The wild group successfully spawned, while the farmed one did not spawn at all. During the program, gonadosomatic indexes of both males and females were significantly higher for the wild fish, as well as the sexual steroids. Gene expression analysis revealed significantly lower LH transcript levels at the pituitary level for the farmed females and lower FSH transcript levels at the pituitary level for the males. In conclusion this study showed that the previous rearing conditions (e.g. culture system, age, diet, etc.) alter the further progress of gametogenesis and the reproductive performances in response to controlled photothermal program for both sexes in pikeperch.
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Factors influencing reproductive performance of northern bobwhite in South Florida
Rolland, V.; Hostetler, J.A.; Hines, T.C.; Percival, H.F.; Oli, M.K.
2011-01-01
Reproductive success is a critical component of individual fitness, and also an important determinant of growth rates of populations characterized by early maturity and high fecundity. We used radiotelemetry data collected during 2003-2008 to estimate reproductive parameters in a declining northern bobwhite (Colinus virginianus) population in South Florida, and to test hypotheses regarding factors influencing these parameters. The overall clutch size was 12.10 ?? 0.22, but females laid more eggs in their first clutch (12.43 ?? 0.24) than in subsequent clutches (10.19 ?? 0.53) within a nesting season. Daily nest survival was higher for first (0.966 ?? 0.003) than subsequent nests (0.936 ?? 0.011). Hatchability (proportion of laid eggs that hatched conditional upon nest survival to hatching) was 0.853 ?? 0.008, but was higher for nests incubated by females (0.873 ?? 0.009) than those incubated by males (0.798 ?? 0.018). The proportion of individuals attempting a second nest was 0.112 ?? 0.024 and 0.281 ?? 0.040 when the first nest was successful and failed, respectively. Hatchability was lower when the nesting habitat was burned the previous winter. We found no evidence that food strip density (a management practice to provide supplemental food) influenced any of the reproductive parameters. Mean summer temperature affected hatchability, nest survival, and proportion of nests incubated by males. Overall, the reproductive output in our study population was lower than that reported for most other bobwhite populations, indicating that low reproductive performance may have contributed to bobwhite population declines in our study site. These results suggest that current management practices, particularly those related to habitat and harvest management, need careful evaluation. ?? 2010 Springer-Verlag.
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Dose-dependent adverse effects of salinomycin on male reproductive organs and fertility in mice.
Directory of Open Access Journals (Sweden)
Olajumoke Omolara Ojo
Full Text Available Salinomycin is used as an antibiotic in animal husbandry. Its implication in cancer therapy has recently been proposed. Present study evaluated the toxic effects of Salinomycin on male reproductive system of mice. Doses of 1, 3 or 5 mg/kg of Salinomycin were administered daily for 28 days. Half of the mice were sacrificed after 24 h of the last treatment and other half were sacrificed 28 days after withdrawal of treatment. Effects of SAL on body and reproductive organ weights were studied. Histoarchitecture of testis and epididymis was evaluated along with ultrastructural changes in Leydig cells. Serum and testicular testosterone and luteinizing hormones were estimated. Superoxide dismutase, reduced glutathione, lipid peroxidation, catalase and lactate dehydrogenase activities were measured. Spermatozoa count, morphology, motility and fertility were evaluated. Expression patterns of steroidogenic acute regulatory protein (StAR and cytochrome P450 side chain cleavage proteins (CYP11A1 were assessed by Western blotting. Salinomycin treatment was lethal to few mice and retarded body growth in others with decreased weight of testes and seminal vesicles in a dose dependent manner. Seminiferous tubules in testes were disrupted and the epithelium of epididymis showed frequent occurrence of vacuolization and necrosis. Leydig cells showed hypertrophied cytoplasm with shrunken nuclei, condensed mitochondria, proliferated endoplasmic reticulum and increased number of lipid droplets. Salinomycin decreased motility and spermatozoa count with increased number of abnormal spermatozoa leading to infertility. The testosterone and luteinizing hormone levels were decreased in testis but increased in serum at higher doses. Depletion of superoxide dismutase and reduced glutathione with increased lipid peroxidation in both testis and epididymis indicated generation of oxidative stress. Suppressed expression of StAR and CYP11A1 proteins indicates inhibition of
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Herting, Megan M; Keenan, Madison F; Nagel, Bonnie J
2016-01-01
Aerobic exercise has been shown to impact brain structure and cognition in children and adults. Exercise-induced activation of a growth protein known as brain derived neurotrophic factor (BDNF) is thought to contribute to such relationships. To date, however, no study has examined how aerobic fitness relates to cortical brain structure during development and if BDNF genotype moderates these relationships. Using structural magnetic resonance imaging (MRI) and FreeSurfer, the current study examined how aerobic fitness relates to volume, thickness, and surface area in 34 male adolescents, 15 to 18 years old. Moreover, we examined if the val66met BDNF genotype moderated these relationships. We hypothesized that aerobic fitness would relate to greater thickness and volumes in frontal, parietal, and motor regions, and that these relationships would be less robust in individuals carrying a Met allele, since this genotype leads to lower BDNF expression. We found that aerobic fitness positively related to right rostral middle frontal cortical volume in all adolescents. However, results also showed BDNF genotype moderated the relationship between aerobic fitness and bilateral medial precuneus surface area, with a positive relationship seen in individuals with the Val/Val allele, but no relationship detected in those adolescents carrying a Met allele. Lastly, using self-reported levels of aerobic activity, we found that higher-fit adolescents showed larger right medial pericalcarine, right cuneus and left precuneus surface areas as compared to their low-fit peers. Our findings suggest that aerobic fitness is linked to cortical brain development in male adolescents, and that more research is warranted to determine how an individual's genes may influence these relationships.
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Herting, Megan M.; Keenan, Madison F.; Nagel, Bonnie J.
2016-01-01
Aerobic exercise has been shown to impact brain structure and cognition in children and adults. Exercise-induced activation of a growth protein known as brain derived neurotrophic factor (BDNF) is thought to contribute to such relationships. To date, however, no study has examined how aerobic fitness relates to cortical brain structure during development and if BDNF genotype moderates these relationships. Using structural magnetic resonance imaging (MRI) and FreeSurfer, the current study examined how aerobic fitness relates to volume, thickness, and surface area in 34 male adolescents, 15 to 18 years old. Moreover, we examined if the val66met BDNF genotype moderated these relationships. We hypothesized that aerobic fitness would relate to greater thickness and volumes in frontal, parietal, and motor regions, and that these relationships would be less robust in individuals carrying a Met allele, since this genotype leads to lower BDNF expression. We found that aerobic fitness positively related to right rostral middle frontal cortical volume in all adolescents. However, results also showed BDNF genotype moderated the relationship between aerobic fitness and bilateral medial precuneus surface area, with a positive relationship seen in individuals with the Val/Val allele, but no relationship detected in those adolescents carrying a Met allele. Lastly, using self-reported levels of aerobic activity, we found that higher-fit adolescents showed larger right medial pericalcarine, right cuneus and left precuneus surface areas as compared to their low-fit peers. Our findings suggest that aerobic fitness is linked to cortical brain development in male adolescents, and that more research is warranted to determine how an individual’s genes may influence these relationships. PMID:27445764
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Abnormalities in the male reproductive system after exposure to diesel and biodiesel blend.
Kisin, Elena R; Yanamala, Naveena; Farcas, Mariana T; Gutkin, Dmitriy W; Shurin, Michael R; Kagan, Valerian E; Bugarski, Aleksandar D; Shvedova, Anna A
2015-03-01
Altering the fuel source from petroleum-based ultralow sulfur diesel to biodiesel and its blends is considered by many to be a sustainable choice for controlling exposures to particulate material. As the exhaust of biodiesel/diesel blends is composed of a combination of combustion products of polycyclic aromatic hydrocarbons and fatty acid methyl esters, we hypothesize that 50% biodiesel/diesel blend (BD50) exposure could induce harmful outcomes because of its ability to trigger oxidative damage. Here, adverse effects were compared in murine male reproductive organs after pharyngeal aspiration with particles generated by engine fueled with BD50 or neat petroleum diesel (D100). When compared with D100, exposure to BD50 significantly altered sperm integrity, including concentration, motility, and morphological abnormalities, as well as increasing testosterone levels in testes during the time course postexposure. Serum level of luteinizing hormone was significantly depleted only after BD50 exposure. Moreover, we observed that exposure to BD50 significantly increased sperm DNA fragmentation and the upregulation of inflammatory cytokines in the serum and testes on Day 7 postexposure when compared with D100. Histological evaluation of testes sections from BD50 exposure indicated more noticeable interstitial edema, degenerating spermatocytes, and dystrophic seminiferous tubules with arrested spermatogenesis. Significant differences in the level of oxidative stress assessed by accumulation of lipid peroxidation products and depletion of glutathione were detected on exposure to respirable BD50 and D100. Taken together, these results indicate that exposure of mice to inhalable BD50 caused more pronounced adverse effects on male reproductive function than diesel. © 2014 Wiley Periodicals, Inc.
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Directory of Open Access Journals (Sweden)
Jin-Ying Zhuang
Full Text Available Attractiveness judgment in the context of mate preferences is thought to reflect an assessment of mate quality in relation to an absolute scale of genetic fitness and a relative scale of self-similarity. In this study, subjects judged the attractiveness and trustworthiness of faces in composite images that were manipulated to produce self-similar (self-resemblance and dissimilar (other-resemblance images. Males differentiated between self- and other-resemblance as well as among different degrees of self-resemblance in their attractiveness ratings; females did not. Specifically, in Experiment 1, using a morphing technique, we created previously unseen face images possessing different degrees (0%, 30%, 40%, or 50% of incorporation of the subject's images (different degrees of self-resemblance and found that males preferred images that were closer to average (0% rather than more self-similar, whereas females showed no preference for any degree of self-similarity. In Experiment 2, we added a pro-social question about trustworthiness. We replicated the Experiment 1 attractiveness rating results and further found that males differentiated between self- and other-resemblance for the same degree of composites; women did not. Both males and females showed a similar preference for self-resemblances when judging trustworthiness. In conclusion, only males factored self-resemblance into their attractiveness ratings of opposite-sex individuals in a manner consistent with cues of reproductive fitness, although both sexes favored self-resemblance when judging trustworthiness.
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Torres-Vila, L M; Mendiola-Diaz, F J; Conejo-Rodríguez, Y; Sánchez-González, Á
2016-06-01
The longhorn beetle Cerambyx welensii is an emerging pest involved in oak decline episodes, whose damage is increasingly reported in dehesa open woodlands. Knowledge of the reproductive biology of C. welensii is a crucial goal due to its new pest status. In this study, we assess the reproductive traits of both sexes in the laboratory (25°C and 60% relative humidity ). In females, body length was 44.9 ± 0.9 mm (mean ± SE), fecundity 132 ± 12 eggs, fertility 70 ± 1 %, longevity 70 ± 3 days, preoviposition period 2 ± 0.2 days, oviposition period 44 ± 3 days and postoviposition period 19 ± 3 days. Fecundity was positively correlated with female size, longevity and oviposition period. Daily fecundity was 3.0 ± 0.2 eggs/day and showed a fluctuating synovigenic pattern with a slight decreasing trend over time. Egg length was 4.24 ± 0.01 mm and egg volume 8.14 ± 0.04 mm3. Egg size was correlated with female size but the relative size of eggs was larger in smaller females. Incubation time was 13.9 ± 0.1 days and hatching did not depend on egg size. Neonate size was positively correlated with egg length. Females were polyandrous (more than 20 lifetime matings) but multiple mating did not increase fecundity, fertility or longevity. In males, body length was 43.7 ± 0.6 mm and longevity 52 ± 3 days. Unlike with females, longevity was positively correlated with male size. Males were polygynous (up to 30 lifetime matings) but mating history did not affect male longevity. Rather to the contrary, long-lived males mated more times because they had more mating chances. Lastly, C. welensii reproductive traits were compared with those other Cerambycidae species and discussed from an adaptive perspective. Our data will be useful to improve management of C. welensii in order to prevent or mitigate its impact in dehesa woodlands and other oak forests.
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Ros, Albert F.H; Bouton, Niels; Santos, Ricardo S; Oliveira, Rui F
2006-01-01
In the Azorean rock-pool blenny (Parablennius parvicornis) reproductively active males display alternative morphotypes, which differ in the expression of secondary sexual characters (SSC). Males expressing SSC, the M+ morphotype, have high androgen levels and compete for crevices that will be visited by females to spawn. M+ males holding nests court females and care for the eggs. Males with low expression of SSC, the M− morphotype, have low levels of androgens and reproduce by stealing fertilizations from the M+ males. Based on the hypothesis that androgens are immunosuppressive, we expected these morphotypes to differ in immunocompetence. To test this hypothesis, we conducted a field study in which we collected repeated blood samples to monitor leukocyte populations (blood smears), and to measure the primary antibody response of males that were experimentally challenged with a foreign non-pathogenic antigen (sheep red blood cells). Circulating levels of 11-ketotestosterone and testosterone were higher in M+ males than in M− males. Neither granulocyte nor thrombocyte counts did covariate with androgens or male tactic. In contrast, lymphocyte counts and humoral antibody response were negatively correlated with body size, and as expected, both were lower in M+ than in M− males. Interestingly, in M+ males androgen levels decreased after immunization, and this was less in nest-holder males than in M+ males that were floating around in the pools. Within each morphotype we found no relationship between androgens and immunocompetence. The latter result is not supportive for androgen regulated immunosuppression in M+ males. A possible alternative is enhancement of immunity in M− males. These males had relatively high levels of injuries in comparison with M+ males. High immunity might be a consequence of high infection rate because of such injuries. PMID:16627274
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Differences in Patterns of Reproductive Allocation between the Sexes in Nicrophorus orbicollis.
Smith, Ashlee N; Creighton, J Curtis; Belk, Mark C
2015-01-01
Organisms are selected to maximize lifetime reproductive success by balancing the costs of current reproduction with costs to future survival and fecundity. Males and females typically face different reproductive costs, which makes comparisons of their reproductive strategies difficult. Burying beetles provide a unique system that allows us to compare the costs of reproduction between the sexes because males and females are capable of raising offspring together or alone and carcass preparation and offspring care represent the majority of reproductive costs for both sexes. Because both sexes perform the same functions of carcass preparation and offspring care, we predict that they would experience similar costs and have similar life history patterns. In this study we assess the cost of reproduction in male Nicrophorus orbicollis and compare to patterns observed in females. We compare the reproductive strategies of single males and females that provided pre- and post-hatching parental care. There is a cost to reproduction for both males and females, but the sexes respond to these costs differently. Females match brood size with carcass size, and thus maximize the lifetime number of offspring on a given size carcass. Males cull proportionately more offspring on all carcass sizes, and thus have a lower lifetime number of offspring compared to females. Females exhibit an adaptive reproductive strategy based on resource availability, but male reproductive strategies are not adaptive in relation to resource availability.
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Narbona, Eduardo; Dirzo, Rodolfo
2010-08-01
Monoecious plants have the capacity to allocate resources separately to male and female functions more easily than hermaphrodites. This can be advantageous against environmental stresses such as leaf herbivory. However, studies showing effects of herbivory on male and female functions and on the interaction with the plant's pollinators are limited, particularly in tropical plants. Here, the effects of experimental defoliation were examined in the monoecious shrub Croton suberosus (Euphorbiaceae), a wasp-pollinated species from a Mexican tropical dry forest. Three defoliation treatments were applied: 0 % (control), 25 % (low) or 75 % (high) of plant leaf area removed. Vegetative (production of new leaves) and reproductive (pistillate and staminate flower production, pollen viability, nectar production, fruit set, and seed set) performance variables, and the abundance and activity of floral visitors were examined. Defoliated plants overcompensated for tissue loss by producing more new leaves than control plants. Production of staminate flowers gradually decreased with increasing defoliation and the floral sex ratio (staminate : pistillate flowers) was drastically reduced in high-defoliation plants. In contrast, female reproductive performance (pistillate flower production, fruit set and seed set) and pollinator visitation and abundance were not impacted by defoliation. The asymmetrical effects of defoliation on male and female traits of C. suberosus may be due to the temporal and spatial flexibility in the allocation of resources deployed by monoecious plants. We posit that this helps to maintain the plant's pollination success in the face of leaf herbivory stress.
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Immler, Simone; Mazzoldi, Carlotta; Rasotto, Maria Berica
2004-02-01
This study focuses on the consequences of the switch of tactic from parasitic to parental male in the black goby, Gobius niger (Teleostei: Gobiidae), a species showing two alternative male mating tactics. Older and larger males defend nests, court, and perform parental care on eggs, while younger and smaller ones behave as parasites, sneaking into nests while spawning occurs. Males adopting different tactics are known to present differences in primary and secondary sex traits. The social context of sneaker males was manipulated to induce a tactic switch. Sneakers were kept under two different experimental treatments with or without a female, and under exclusion of male-male competition. Males changed tactics, courting females, spawning, and performing parental care. All males showed substantial changes in primary sexual traits, such as a reduction in gonadal development and an increase in the investment in accessory structures. The experimental groups differed in the functionality of gonads and accessory organs and in the development of the secondary sex traits. These results demonstrate that the moment of switching is not genetically fixed in the black goby. Sneaker males are able to quickly reallocate energy in primary and secondary sex traits, in accordance with the adopted tactic. Several aspects of this flexible reproductive pattern resemble the socially controlled sex change found in sequential hermaphrodites. Copyright 2004 Wiley-Liss, Inc.
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Effects of 90-day feeding of transgenic Bt rice TT51 on the reproductive system in male rats.
Wang, Er Hui; Yu, Zhou; Hu, Jing; Xu, Hai Bin
2013-12-01
Rice is a staple food crop; however, the threat of pests leads to a serious decline in its output and quality. The CryAb/CryAc gene, encodes a synthetic fusion Bacillus thuringiensis (Bt) crystal protein, was introduced into rice MingHui63 to produce insect-resistant rice TT51. This study was undertaken to investigate potential unintended effects of TT51 on the reproductive system in male rats. Male rats were treated with diets containing 60% of either TT51 or MingHui63 by weight, nutritionally balanced to an AIN93G diet, for 90days. An additional negative control group of rats were fed with a rice-based AIN93G diet. Body weights, food intake, hematology, serum chemistry, serum hormone levels, sperm parameters and relative organ/body weights were measured, and gross as well as microscopic pathology were examined. No diet-related significant differences in the values of response variables were observed between rats that were fed with diet containing transgenic TT51, MingHui63 and the control in this 90-day feeding study. In addition, necropsy and histopathology examination indicated no treatment-related changes. The results from the present study indicated that TT51 does not appear to exert any effect on the reproductive system in male rats compared with MingHui63 or the control. Copyright © 2013 Elsevier Ltd. All rights reserved.
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Multiple fitness benefits of polyandry in a cephalopod.
Directory of Open Access Journals (Sweden)
Zoe E Squires
Full Text Available Sex differences in reproductive investment play a crucial role in sexual conflict. One intriguing aspect of sexual conflict is the evolution of female multiple mating (polyandry, particularly in systems where females receive no obvious direct benefits from males, and where mating is highly costly. Here, theory predicts that polyandrous females can increase their reproductive success by taking advantage of the genetic benefits of mating with multiple males. Cephalopods provide a model system for addressing this question, as all species mate multiply. Here we examine differences in reproductive success between monandrous, multiply mated (to the same male and polyandrous female dumpling squid (Euprymna tasmanica.We mated females in the laboratory with two different males (polyandrous; controlling for mating order, or with a single male (monandrous. To control for mating frequency, we mated monandrous females either once (monandrous 1, or with the same male twice (monandrous 2, and measured reproductive success for each of the three treatments (polyandrous, monandrous 1, monandrous 2. Females mated to two different males produced eggs faster and had larger hatchlings relative to egg mass than females mated once with a single male.The benefits of polyandry demonstrated here are the first, to our knowledge, in any cephalopod. These benefits may outweigh the significant costs associated with mating and help to explain how multiple mating has evolved (or is maintained in this group.
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Grooming reciprocity in male Tibetan macaques.
Xia, Dong-Po; Li, Jin-Hua; Garber, Paul A; Matheson, Megan D; Sun, Bing-Hua; Zhu, Yong
2013-10-01
In several primate species, adult males are reported to compete for access to reproductive partners as well as forming affiliative and cohesive social bonds based on the exchange of goods or services. We hypothesized that among a broad set of fitness-maximizing strategies, grooming can be used by individual adult males to enhance social relationships through reciprocity and/or through the interchange of grooming for a different but equivalent good or service. We used focal animal sampling and continuously recorded dyadic grooming and agonistic interactions to test a series of predictions regarding male social interactions in a free-ranging group of Tibetan macaques (Macaca thibetana) at Huangshan, China. During the non-mating season or between males of similar rank throughout the year, grooming effort given was matched by grooming effort received. However, lower ranking males groomed higher ranking males at a greater rate and/or for a longer duration during both the mating and non-mating periods. We found that higher ranking males directed less aggression towards males with whom they formed a frequent grooming partnership, indicating that grooming received was interchanged for increased social tolerance. These data suggest that individual male Tibetan macaques employ alternative social strategies associated with grooming reciprocity or interchange depending on dominance rank and rates of aggression, and highlight the importance of both biological markets and grooming reciprocity as behavioral mechanisms used by resident adult males to form and maintain affiliative social bonds. © 2013 Wiley Periodicals, Inc.
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Directory of Open Access Journals (Sweden)
Christine Chevalier
2011-10-01
Full Text Available The endemic Rhodanian percid Zingel asper (Linnaeus, 1758, is usually found throughout the Rhônebasin, but this fish is now in sharp decline. Understanding its reproductive physiology is important so as to be ableto artificially control its reproduction with a view to re-introducing it. This study was carried out on a populationobtained by artificial fertilization and bred in external tanks. Fishes were observed from the juvenile stages throughto adulthood. Patterns of testicular development were defined from histological observations. Testes of Z. asperwere paired, elongated and fusiform dorsocaudal organs. The two lobes of each gonad joined together to forma duct that extended to the urogenital papillae. They showed a lobular structure. The testicular lobules were of theunrestricted spermatogonial type. Up to 10 months-old, most of the males were immature: their testes showed onlytype A spermatogonia. The appearance of type B spermatogonia in the lobules of a testis indicated the beginningof spermatogenesis in 10 months-old fish. Spermiogenesis occurred 24 months after the fertilization and, in 26months-old fish, the cyst opened and released spermatozoa into the lumen of lobules. The spermiation belonged toa cystic type. During the third year, histological observations pointed to the same evolution of adult gonads asduring the second year. Sexual maturity was reached in captive Z. asper after two years. The spawning occurred inMay in the breeding conditions. (Folia Histochemica et Cytobiologica 2011, Vol. 49, No. 3, 486–496
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Chevalier, Christine; de Conto, Christine; Exbrayat, Jean-Marie
2011-01-01
The endemic Rhodanian percid Zingel asper (Linnaeus, 1758), is usually found throughout the Rhône basin, but this fish is now in sharp decline. Understanding its reproductive physiology is important so as to be able to artificially control its reproduction with a view to re-introducing it. This study was carried out on a population obtained by artificial fertilization and bred in external tanks. Fishes were observed from the juvenile stages through to adulthood. Patterns of testicular development were defined from histological observations. Testes of Z. asper were paired, elongated and fusiform dorsocaudal organs. The two lobes of each gonad joined together to form a duct that extended to the urogenital papillae. They showed a lobular structure. The testicular lobules were of the unrestricted spermatogonial type. Up to 10 months-old, most of the males were immature: their testes showed only type A spermatogonia. The appearance of type B spermatogonia in the lobules of a testis indicated the beginning of spermatogenesis in 10 months-old fish. Spermiogenesis occurred 24 months after the fertilization and, in 26 months-old fish, the cyst opened and released spermatozoa into the lumen of lobules. The spermiation belonged to a cystic type. During the third year, histological observations pointed to the same evolution of adult gonads as during the second year. Sexual maturity was reached in captive Z. asper after two years. The spawning occurred in May in the breeding conditions.
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Energy Technology Data Exchange (ETDEWEB)
Makris, Susan L., E-mail: makris.susan@epa.gov [U.S. Environmental Protection Agency, National Center for Environmental Assessment, Office of Research and Development, (Mail code 8623P), 1200 Pennsylvania Ave., NW, Washington, DC 20460 (United States); Euling, Susan Y. [U.S. Environmental Protection Agency, National Center for Environmental Assessment, Office of Research and Development, (Mail code 8623P), 1200 Pennsylvania Ave., NW, Washington, DC 20460 (United States); Gray, L. Earl [U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Office of Research and Development, (MD-72), Highway 54, Research Triangle Park, NC 27711 (United States); Benson, Robert [U.S. Environmental Protection Agency, Region 8, (Mail code 8P-W), 1595 Wynkoop Street, Denver, CO 80202 (United States); Foster, Paul M.D. [National Toxicology Program, National Institute of Environmental Health Sciences, P.O. Box 12233 (MD K2-12), Research Triangle Park, NC 27709 (United States)
2013-09-15
A case study was conducted, using dibutyl phthalate (DBP), to explore an approach to using toxicogenomic data in risk assessment. The toxicity and toxicogenomic data sets relative to DBP-related male reproductive developmental outcomes were considered conjointly to derive information about mode and mechanism of action. In this manuscript, we describe the case study evaluation of the toxicological database for DBP, focusing on identifying the full spectrum of male reproductive developmental effects. The data were assessed to 1) evaluate low dose and low incidence findings and 2) identify male reproductive toxicity endpoints without well-established modes of action (MOAs). These efforts led to the characterization of data gaps and research needs for the toxicity and toxicogenomic studies in a risk assessment context. Further, the identification of endpoints with unexplained MOAs in the toxicity data set was useful in the subsequent evaluation of the mechanistic information that the toxicogenomic data set evaluation could provide. The extensive analysis of the toxicology data set within the MOA context provided a resource of information for DBP in attempts to hypothesize MOAs (for endpoints without a well-established MOA) and to phenotypically anchor toxicogenomic and other mechanistic data both to toxicity endpoints and to available toxicogenomic data. This case study serves as an example of the steps that can be taken to develop a toxicological data source for a risk assessment, both in general and especially for risk assessments that include toxicogenomic data.
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Sanchez-Garrido, Miguel Angel; Ruiz-Pino, Francisco; Velasco, Inmaculada; Barroso, Alexia; Fernandois, Daniela; Heras, Violeta; Manfredi-Lozano, Maria; Vazquez, Maria Jesus; Castellano, Juan Manuel; Roa, Juan; Pinilla, Leonor; Tena-Sempere, Manuel
2018-02-01
Obesity and its comorbidities are reaching epidemic proportions worldwide. Maternal obesity is known to predispose the offspring to metabolic disorders, independently of genetic inheritance. This intergenerational transmission has also been suggested for paternal obesity, with a potential negative impact on the metabolic and, eventually, reproductive health of the offspring, likely via epigenetic changes in spermatozoa. However, the neuroendocrine component of such phenomenon and whether paternal obesity sensitizes the offspring to the disturbances induced by high-fat diet (HFD) remain poorly defined. We report in this work the metabolic and reproductive impact of HFD in the offspring from obese fathers, with attention to potential sex differences and alterations of hypothalamic Kiss1 system. Lean and obese male rats were mated with lean virgin female rats; male and female offspring were fed HFD from weaning onward and analyzed at adulthood. The increases in body weight and leptin levels, but not glucose intolerance, induced by HFD were significantly augmented in the male, but not female, offspring from obese fathers. Paternal obesity caused a decrease in luteinizing hormone (LH) levels and exacerbated the drop in circulating testosterone and gene expression of its key biosynthetic enzymes caused by HFD in the male offspring. LH responses to central kisspeptin-10 administration were also suppressed in HFD males from obese fathers. In contrast, paternal obesity did not significantly alter gonadotropin levels in the female offspring fed HFD, although these females displayed reduced LH responses to kisspeptin-10. Our findings suggest that HFD-induced metabolic and reproductive disturbances are exacerbated by paternal obesity preferentially in males, whereas kisspeptin effects are affected in both sexes. Copyright © 2018 Endocrine Society.
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Art as an indicator of male fitness: does prenatal testosterone influence artistic ability?
Crocchiola, Danae
2014-05-28
In his groundbreaking research, Geoffrey Miller (1999) suggests that artistic and creative displays are male-predominant behaviors and can be considered to be the result of an evolutionary advantage. The outcomes of several surveys conducted on jazz and rock musicians, contemporary painters, English writers (Miller, 1999), and scientists (Kanazawa, 2000) seem to be consistent with the Millerian hypothesis, showing a predominance of men carrying out these activities, with an output peak corresponding to the most fertile male period and a progressive decline in late maturity. One way to evaluate the sex-related hypothesis of artistic and cultural displays, considered as sexual indicators of male fitness, is to focus on sexually dimorphic traits. One of them, within our species, is the 2nd to 4th digit length (2D:4D), which is a marker for prenatal testosterone levels. This study combines the Millerian theories on sexual dimorphism in cultural displays with the digit ratio, using it as an indicator of androgen exposure in utero. If androgenic levels are positively correlated with artistic exhibition, both female and male artists should show low 2D:4D ratios. In this experiment we tested the association between 2D:4D and artistic ability by comparing the digit ratios of 50 artists (25 men and 25 women) to the digit ratios of 50 non-artists (25 men and 25 women). Both male and female artists had significantly lower 2D:4D ratios (indicating high testosterone) than male and female controls. These results support the hypothesis that art may represent a sexually selected, typically masculine behavior that advertises the carrier's good genes within a courtship context.
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Aalto, Esa A; Koelewijn, Hans-Peter; Savolainen, Outi
2013-10-03
In crosses between evolutionarily diverged populations, genomic incompatibilities may result in sterile hybrids, indicating evolution of reproductive isolation. In several plant families, crosses within a population can also lead to male sterile progeny because of conflict between the maternally and biparentally inherited genomes. We examined hybrid fertility between subspecies of the perennial outcrossing self-incompatible Lyrate rockcress (Arabidopsis lyrata) in large reciprocal F2 progenies and three generations of backcrosses. In one of the reciprocal F2 progenies, almost one-fourth of the plants were male-sterile. Correspondingly, almost one-half of the plants in one of the four reciprocal backcross progenies expressed male sterility. In an additional four independent F2 and backcross families, three segregated male sterility. The observed asymmetrical hybrid incompatibility is attributable to male sterility factors in one cytoplasm, for which the other population lacks effective fertility restorers. Genotyping of 96 molecular markers and quantitative trait locus mapping revealed that only 60% of the plants having the male sterile cytoplasm and lacking the corresponding restorers were phenotypically male-sterile. Genotyping data showed that there is only one restorer locus, which mapped to a 600-kb interval at the top of chromosome 2 in a region containing a cluster of pentatricopeptide repeat genes. Male fertility showed no trade-off with seed production. We discuss the role of cytoplasm and genomic conflict in incipient speciation and conclude that cytoplasmic male sterility-lowering hybrid fitness is a transient effect with limited potential to form permanent reproductive barriers between diverged populations of hermaphrodite self-incompatible species.
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Differences in Patterns of Reproductive Allocation between the Sexes in Nicrophorus orbicollis.
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Ashlee N Smith
Full Text Available Organisms are selected to maximize lifetime reproductive success by balancing the costs of current reproduction with costs to future survival and fecundity. Males and females typically face different reproductive costs, which makes comparisons of their reproductive strategies difficult. Burying beetles provide a unique system that allows us to compare the costs of reproduction between the sexes because males and females are capable of raising offspring together or alone and carcass preparation and offspring care represent the majority of reproductive costs for both sexes. Because both sexes perform the same functions of carcass preparation and offspring care, we predict that they would experience similar costs and have similar life history patterns. In this study we assess the cost of reproduction in male Nicrophorus orbicollis and compare to patterns observed in females. We compare the reproductive strategies of single males and females that provided pre- and post-hatching parental care. There is a cost to reproduction for both males and females, but the sexes respond to these costs differently. Females match brood size with carcass size, and thus maximize the lifetime number of offspring on a given size carcass. Males cull proportionately more offspring on all carcass sizes, and thus have a lower lifetime number of offspring compared to females. Females exhibit an adaptive reproductive strategy based on resource availability, but male reproductive strategies are not adaptive in relation to resource availability.
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Prozac Alters Reproductive Performance and Filial Cannibalism in Male Fighting Fish, Betta Splendens
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Mohammad Navid Forsatkar
2014-09-01
Full Text Available Background: Fluoxetine (ProzacTM is one of the most popular antidepressant that can be released to aquatic systems via sewage-treatment effluents. It is suspected to provoke substantial effects in the aquatic environment. Methods: In spawning tanks, specimens were exposed to concentrations of 0 and 0.54 µgl-1 fluoxetine from male introduction until the larvae had hatched. Prior to spawning, nest area and time spent for nest building were measured. Also, spawning duration, number of copulations per spawning and eggs per copulation, total produced eggs and hatching rate were recorded. Results: The number of copulations, eggs per copulation and total produced eggs did not differ between the two treatments. Fluoxetine treatment significantly decreased the nest size, time spent for nest building and spawning duration. Also hatching rate was significantly lower during fluoxetine treatment than in the control condition. Notably, five fluoxetine treated males cannibalized their eggs and larvae. Conclusion: We showed that environmental exposure of fighting fish to fluoxetine potentially alters specific aspects of nest building and sexual behavior and, as a consequence, reproductive output.
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Male mating strategy and the introgression of a growth hormone transgene.
Valosaari, Kata-Riina; Aikio, Sami; Kaitala, Veijo
2008-11-01
Escaped transgenic organisms (GMO's) may threaten the populations of their wild relatives if able to hybridize with each other. The introgression of a growth enhancement transgene into a wild Atlantic salmon population may be affected by the transgene's effects not only on fitness parameters, but also on mating behaviour. Large anadromous GMO males are most preferred in mating, but a transgene can also give the large sneakers a reproductive advantage over the smaller wild individuals. With a simulation model, we studied whether the increase in the proportion and mating success of sneakers in transgenic and hybrid genotypes could facilitate the introgression of a transgene into wild population after the release of GMOs. The model combines population dynamics and Mendelian inheritance of a transgenic trait. We found that the introgression of the transgene is strongly affected by the greater mating preference of large GMO males. Furthermore, the difference in reproductive success between the anadromous versus sneaker strategy defines how much GMO's have to be preferred to be able to invade. These results emphasize the importance of detailed knowledge of reproductive systems and the effect of a transgene on the phenotype and behaviour of GMOs when assessing the consequences of their release or escape to the wild.
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Energy Technology Data Exchange (ETDEWEB)
Santos-Filho, Sebastiao David [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. de Biologia Roberto Alcantara Gomes. Lab. de Radiofarmacia Experimental; Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)]. E-mail: santos-filho@uerj.br; Fonseca, Adenilson de Souza da [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. de Biologia Roberto Alcantara Gomes. Lab. de Radiofarmacia Experimental; Bernardo-Filho, Mario [Instituto Nacional do Cancer, Rio de Janeiro, RJ (Brazil). Coordenadoria de Pesquisa
2007-09-15
Hypericum perforatum (hiperico) is a plant that has been used to treat diseases and also inhibits rat and human vas deferens contractility. In nuclear medicine, stannous chloride (SnCl{sub 2}) is used as a reducing agent to obtain radiopharmaceuticals labeling with technetium-99m. As the SnCl{sub 2} seems to have adverse effects related with the reproductive performance of male rabbits as well as the human consumption of hiperico might affect sexual function. In the present work, consistent results show significant changes on the blood constituents labeled by technetium-99m obtained from young rats under the effect of an hiperico extract as opposed to blood samples equally treated taken from elderly rat. Supposedly, this extract could protect the male reproductive system against action of SnCl{sub 2} at least in young rats. The findings described in this work allow introducing a simple assay to evaluate the action of products that could interfere with the male reproductive system. (author)
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International Nuclear Information System (INIS)
Santos-Filho, Sebastiao David; Fonseca, Adenilson de Souza da; Bernardo-Filho, Mario
2007-01-01
Hypericum perforatum (hiperico) is a plant that has been used to treat diseases and also inhibits rat and human vas deferens contractility. In nuclear medicine, stannous chloride (SnCl 2 ) is used as a reducing agent to obtain radiopharmaceuticals labeling with technetium-99m. As the SnCl 2 seems to have adverse effects related with the reproductive performance of male rabbits as well as the human consumption of hiperico might affect sexual function. In the present work, consistent results show significant changes on the blood constituents labeled by technetium-99m obtained from young rats under the effect of an hiperico extract as opposed to blood samples equally treated taken from elderly rat. Supposedly, this extract could protect the male reproductive system against action of SnCl 2 at least in young rats. The findings described in this work allow introducing a simple assay to evaluate the action of products that could interfere with the male reproductive system. (author)
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Directory of Open Access Journals (Sweden)
Mirre J P Simons
Full Text Available Sexual traits can serve as honest indicators of phenotypic quality when they are costly. Brightly coloured yellow to red traits, which are pigmented by carotenoids, are relatively common in birds, and feature in sexual selection. Carotenoids have been linked to immune and antioxidant function, and the trade-off between ornamentation and these physiological functions provides a potential mechanism rendering carotenoid based signals costly. Mutual ornamentation is also common in birds and can be maintained by mutual mate choice for this ornament or by a correlated response in one sex to selection on the other sex. When selection pressures differ between the sexes this can cause intralocus sexual conflict. Sexually antagonistic selection pressures have been demonstrated for few sexual traits, and for carotenoid-dependent traits there is a single example: bill redness was found to be positively associated with survival and reproductive output in male zebra finches, but negatively so in females. We retested these associations in our captive zebra finch population without two possible limitations of this earlier study. Contrary to the earlier findings, we found no evidence for sexually antagonistic selection. In both sexes, individuals with redder bills showed higher survival. This association disappeared among the females with the reddest bills. Furthermore, females with redder bills achieved higher reproductive output. We conclude that bill redness of male and female zebra finches honestly signals phenotypic quality, and discuss the possible causes of the differences between our results and earlier findings.
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Bedford, J Michael
2014-02-01
Therian (marsupial and eutherian) mammals have evolved a suite of novel reproductive features - seen variously in their gametes, the steps of fertilization and the male reproductive tract - whose adaptive significance remains unclear. Present evidence for the better-understood eutherian mammals suggests that the 'prime mover' in their evolution has been the character of the egg coat, with other such features being adaptations to the consequences of this. Its elastic thickness allows the zona pellucida to stretch to a variable degree and yet remain around the blastocyst during much or all of its expansion before implantation, but its character represents an unusual challenge for spermatozoa. Novel aspects of the acrosome related to this challenge enable it to maintain a relatively prolonged binding after the onset of the acrosome reaction, and the structure, shape and behaviour of the sperm head point to physical thrust as a major element of zona penetration - with the unique configuration of gamete fusion as a sequela of this strategy. In the male, such adaptations are reflected in sperm head formation in the testis and in sperm maturation in the epididymis involving at least the sperm head's structure, plasmalemma and acrosome. This complexity allied to a slow epididymal sperm transport, a relatively modest sperm production and the brief life span of mature spermatozoa kept above the cauda epididymidis could account for the evolution of the sperm storage function - a development seemingly linked, in turn, to the need for sperm capacitation and scrotal evolution.
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DeFilippo, L. B.; Schindler, D.E.; Carter, J.L.; Walsworth, Timothy E.; Cline, T. J.; Larson, Wesley; Buehrens, T.
2018-01-01
In many species, males may exhibit alternative life histories to circumvent the costs of intrasexual competition and female courtship. While the evolution and underlying genetic and physiological mechanisms behind alternative reproductive tactics are well studied, there has been less consideration of the ecological factors that regulate their prevalence. Here, we examine six decades of age composition records from thirty‐six populations of sockeye salmon (Oncorhynchus nerka) to quantify associations between spawning habitat characteristics and the prevalence of precocious sneakers known as ‘jacks’. Jack prevalence was independent of neutral genetic structure among stream populations, but varied among habitat types and as a function of continuous geomorphic characteristics. Jacks were more common in streams relative to beaches and rivers, and their prevalence was negatively associated with stream width, depth, elevation, slope and area, but positively related to bank cover. Behavioural observations showed that jacks made greater use of banks, wood and shallows than guard males, indicating that their reproductive success depends on the availability of such refuges. Our results emphasize the role of the physical habitat in shaping reproductive tactic frequencies among populations, likely through local adaptation in response to variable fitness expectations under different geomorphic conditions.
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Carballo, Matilde; Baldenegro, Fabiana; Bollatti, Fedra; Peretti, Alfredo V; Aisenberg, Anita
2017-07-01
Behavioral plasticity allows individuals to reversibly respond to short-term variations in their ecological and social environment in order to maximize their fitness. Allocosa senex is a burrow-digging spider that inhabits the sandy coasts of South America. This species shows a reversal in typical sex roles expected in spiders: females are wanderers that visit males at their burrows and initiate courtship. They prefer males with long burrows for mating, and males prefer virgin over mated females. We tested whether female sexual rejection induced males to enlarge their burrows and if female reproductive status affected males' responses. We exposed males who had constructed burrows to: a) virgin females or b) mated females, (n=16 for each category). If female rejection occurred, we repeated the trial 48h later with the same female. As control, we maintained a group of males without female exposure (unexposed group, n=32). Rejected males enlarged their burrows more frequently and burrows were longer compared to unexposed males. However, frequency and length of enlargement did not differ according to female reproductive status. Males of A. senex showed plasticity in digging behavior in response to the availability of females, as a way to maximize the possibilities of future mating. Copyright © 2017 Elsevier B.V. All rights reserved.
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Fuller, Rebecca C
2018-01-01
Abstract Selection against hybridization can cause mating traits to diverge between species in sympatry via reproductive character displacement (RCD). Additionally, selection against interspecific fighting can cause aggressive traits to diverge between sympatric species via agonistic character displacement (ACD). By directly affecting conspecific recognition traits, RCD and ACD between species can also incidentally cause divergence in mating and fighting traits among populations within a species [termed cascade RCD (CRCD) and cascade ACD]. Here, we demonstrate patterns consistent with male-driven RCD and ACD in 2 groups of darters (orangethroat darter clade Ceasia and rainbow darter Etheostoma caeruleum). In both groups, males that occur in sympatry (between Ceasia and E. caeruleum) have higher levels of preference for mating and fighting with conspecifics over heterospecifics than do males from allopatry. This is consistent with RCD and ACD. We also found patterns consistent with CRCD and cascade ACD among species of Ceasia. Ceasia males that are sympatric to E. caeruleum (but allopatric to one another) also have heightened preferences for mating and fighting with conspecific versus heterospecific Ceasia. In contrast, Ceasia males that are allopatric to E. caeruleum readily mate and fight with heterospecific Ceasia. We suggest that RCD and ACD between Ceasia and E. caeruleum has incidentally led to divergence in mating and fighting traits among Ceasia species. This study is unique in that male preferences evolve via both RCD (male preference for conspecific females) and ACD (male preference to fight conspecific males) which leads to subsequent divergence among allopatric lineages. PMID:29492043
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Reproduction elevates the corticosterone stress response in common fruit bats.
Klose, Stefan M; Smith, Carolynn L; Denzel, Andrea J; Kalko, Elisabeth K V
2006-04-01
Changes in reproductive state or the environment may affect the sensitivity of the hypothalamic-pituitary-andrenal (HPA) axis. However, little is known about the dynamics of the resulting corticosteroid stress response, in particular in tropical mammals. In this study, we address the modulation of corticosterone release in response to different reproductive conditions and seasonality in 326 free-living common fruit-eating bats (Artibeus jamaicensis) on Barro Colorado Island in Panama during dry and wet seasons. We present strong evidence that stress sensitivity is primarily modulated by reproductive condition. In reproductively active females, corticosterone increases were more rapid and reached higher levels, but also decreased significantly faster than in inactive females. The corticosterone response was weaker in reproducing males than in females and delayed compared to non-reproductive males. Testes volume in reproductively active males was negatively correlated with corticosterone concentrations. Our findings suggest differentiated dynamics in the corticosterone stress response between sexes, potentially reflecting conflicting ecological demands. In females, a strong acute corticosterone response may represent high stress- and risk-sensitivity that facilitates escape and thus helps to protect reproduction. In males, suppression during reproductive activity could reflect lowered stress sensitivity to avoid chronically elevated corticosterone levels in times of frequent aggressive and therefore costly inter-male encounters.
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Nearby grandmother enhances calf survival and reproduction in Asian elephants.
Lahdenperä, Mirkka; Mar, Khyne U; Lummaa, Virpi
2016-06-10
Usually animals reproduce into old age, but a few species such as humans and killer whales can live decades after their last reproduction. The grandmother hypothesis proposes that such life-history evolved through older females switching to invest in their existing (grand)offspring, thereby increasing their inclusive fitness and selection for post-reproductive lifespan. However, positive grandmother effects are also found in non-menopausal taxa, but evidence of their associated fitness effects is rare and only a few tests of the hypothesis in such species exist. Here we investigate the grandmother effects in Asian elephants. Using a multigenerational demographic dataset on semi-captive elephants in Myanmar, we found that grandcalves from young mothers (years) had 8 times lower mortality risk if the grandmother resided with her grandcalf compared to grandmothers residing elsewhere. Resident grandmothers also decreased their daughters' inter-birth intervals by one year. In contrast to the hypothesis predictions, the grandmother's own reproductive status did not modify such grandmother benefits. That elephant grandmothers increased their inclusive fitness by enhancing their daughter's reproductive rate and success irrespective of their own reproductive status suggests that fitness-enhancing grandmaternal effects are widespread, and challenge the view that grandmother effects alone select for menopause coupled with long post-reproductive lifespan.
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Crudgington, Helen S; Beckerman, Andrew P; Brüstle, Lena; Green, Kathleen; Snook, Rhonda R
2005-05-01
Sexual conflict over reproduction can occur between males and females. In several naturally promiscuous insect species, experimental evolution studies that have enforced monogamy found evidence for sexual conflict. Here, we subjected the naturally promiscuous, sperm-heteromorphic fruit fly Drosophila pseudoobscura to enforced monogamy, standard levels of promiscuity, and elevated opportunities for promiscuity in four replicate lines. We examined the effect of male and female selection history and the proximate effect of variation in male density on female fitness parameters. We found that male density rather than male selection history explained a greater degree of female fecundity, egg hatching success, and productivity. Additionally, females selected under elevated promiscuity had greater fecundity and hatching success than did enforced monogamy females. Selection line males do not differ in their capacity to coerce females to remate, suggesting no divergence in precopulatory manipulative ability. However, these males did vary in their ability to suppress female remating, suggesting postcopulatory manipulation. These results indicate that sexual conflict can be manifested through both the proximate effects of male density and the historical levels of sexual selection and that the sexes respond differentially to these factors and further stress the multifarious channels of sexual communication that contribute to fitness.
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Chang, Chawnshang; Lee, Soo Ok; Wang, Ruey-Sheng; Yeh, Shuyuan; Chang, Ta-Min
2013-01-01
ABSTRACT Androgens/androgen receptor (AR) signaling is involved primarily in the development of male-specific phenotypes during embryogenesis, spermatogenesis, sexual behavior, and fertility during adult life. However, this signaling has also been shown to play an important role in development of female reproductive organs and their functions, such as ovarian folliculogenesis, embryonic implantation, and uterine and breast development. The establishment of the testicular feminization (Tfm) mouse model exploiting the X-linked Tfm mutation in mice has been a good in vivo tool for studying the human complete androgen insensitivity syndrome, but this mouse may not be the perfect in vivo model. Mouse models with various cell-specific AR knockout (ARKO) might allow us to study AR roles in individual types of cells in these male and female reproductive systems, although discrepancies are found in results between labs, probably due to using various Cre mice and/or knocking out AR in different AR domains. Nevertheless, no doubt exists that the continuous development of these ARKO mouse models and careful studies will provide information useful for understanding AR roles in reproductive systems of humans and may help us to develop more effective and more specific therapeutic approaches for reproductive system-related diseases. PMID:23782840
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Potapova, O F; Potapov, M A; Kondratyuk, E Yu; Evsikov, V I
2016-05-01
In the blood of male steppe lemmings, relatively low background levels of testosterone were detected, this is characteristic of a monogamous species. A significant increase in testosterone level, more expressed in sexually active males, was observed at the initial stage of formation of reproductive couples. Apparently, in the future, the couple will exist in a stable relationship, and, hence, the maintenance of a high testosterone level becomes excessive. The decrease in, and the relative "normalization" of, the hormone level during the existence of the pair, including raising of the young, promotes higher expression of the male paternal care of the offspring at the species level.
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Age-dependent male mating tactics in a spider mite-A life-history perspective.
Sato, Yukie; Rühr, Peter T; Schmitz, Helmut; Egas, Martijn; Blanke, Alexander
2016-10-01
Males often fight with rival males for access to females. However, some males display nonfighting tactics such as sneaking, satellite behavior, or female mimicking. When these mating tactics comprise a conditional strategy, they are often thought to be explained by resource holding potential (RHP), that is, nonfighting tactics are displayed by less competitive males who are more likely to lose a fight. The alternative mating tactics, however, can also be explained by life-history theory, which predicts that young males avoid fighting, regardless of their RHP, if it pays off to wait for future reproduction. Here, we test whether the sneaking tactic displayed by young males of the two-spotted spider mite can be explained by life-history theory. We tested whether young sneaker males survive longer than young fighter males after a bout of mild or strong competition with old fighter males. We also investigated whether old males have a more protective outer skin-a possible proxy for RHP-by measuring cuticle hardness and elasticity using nanoindentation. We found that young sneaker males survived longer than young fighter males after mild male competition. This difference was not found after strong male competition, which suggests that induction of sneaking tactic is affected by male density. Hardness and elasticity of the skin did not vary with male age. Given that earlier work could also not detect morphometric differences between fighter and sneaker males, we conclude that there is no apparent increase in RHP with age in the mite and age-dependent male mating tactics in the mite can be explained only by life-history theory. Because it is likely that fighting incurs a survival cost, age-dependent alternative mating tactics may be explained by life-history theory in many species when reproduction of old males is a significant factor in fitness.
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Directory of Open Access Journals (Sweden)
Erin Z Aprison
2015-12-01
Full Text Available Pheromones are secreted molecules that mediate animal communications. These olfactory signals can have substantial effects on physiology and likely play important roles in organismal survival in natural habitats. Here we show that a blend of two ascaroside pheromones produced by C. elegans males primes the female reproductive system in part by improving sperm guidance toward oocytes. Worms have different physiological responses to different ratios of the same two molecules, revealing an efficient mechanism for increasing coding potential of a limited repertoire of molecular signals. The endogenous function of the male sex pheromones has an important side benefit. It substantially ameliorates the detrimental effects of prolonged heat stress on hermaphrodite reproduction because it increases the effectiveness with which surviving gametes are used following stress. Hermaphroditic species are expected to lose female-specific traits in the course of evolution. Our results suggest that some of these traits could have serendipitous utility due to their ability to counter the effects of stress. We propose that this is a general mechanism by which some mating-related functions could be retained in hermaphroditic species, despite their expected decay.
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Aprison, Erin Z.; Ruvinsky, Ilya
2015-01-01
Pheromones are secreted molecules that mediate animal communications. These olfactory signals can have substantial effects on physiology and likely play important roles in organismal survival in natural habitats. Here we show that a blend of two ascaroside pheromones produced by C. elegans males primes the female reproductive system in part by improving sperm guidance toward oocytes. Worms have different physiological responses to different ratios of the same two molecules, revealing an efficient mechanism for increasing coding potential of a limited repertoire of molecular signals. The endogenous function of the male sex pheromones has an important side benefit. It substantially ameliorates the detrimental effects of prolonged heat stress on hermaphrodite reproduction because it increases the effectiveness with which surviving gametes are used following stress. Hermaphroditic species are expected to lose female-specific traits in the course of evolution. Our results suggest that some of these traits could have serendipitous utility due to their ability to counter the effects of stress. We propose that this is a general mechanism by which some mating-related functions could be retained in hermaphroditic species, despite their expected decay. PMID:26645097
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High-intensity Fitness Training Among a National Sample of Male Career Firefighters
Directory of Open Access Journals (Sweden)
Sara A. Jahnke
2015-03-01
Full Text Available Obesity and fitness have been identified as key health concerns among USA firefighters yet little is known about the current habits related to exercise and diet. In particular, high-intensity training (HIT has gained increasing popularity among this population but limited quantitative data are available about how often it is used and the relationship between HIT and other outcomes. Using survey methodology, the current study evaluated self-reported HIT and diet practice among 625 male firefighters. Almost one-third (32.3% of participants reported engaging in HIT. Body composition, as measured by waist circumference and percentage body fat, was significantly related to HIT training, with HIT participants being approximately half as likely to be classified as obese using body fat [odds ratio (OR = 0.52, 95% confidence interval (CI = 0.34–0.78] or waist circumference (OR = 0.61, 95% CI = 0.37–0.98. Those who engaged in HIT were more than twice as likely as those who did not (OR = 2.24, 95% CI = 1.42–3.55 to meet fitness recommendations. Findings highlight directions for future prevention and intervention efforts.
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Pallarés, María Eugenia; Adrover, Ezequiela; Baier, Carlos Javier; Bourguignon, Nadia S; Monteleone, Melisa C; Brocco, Marcela A; González-Calvar, Silvia I; Antonelli, Marta C
2013-07-01
Several studies have demonstrated that the presence of stressors during pregnancy induces adverse effects on the neuroendocrine system of the offspring later in life. In the present work, we investigated the effects of early programming on the male reproductive system, employing a prenatal stress (PS) paradigm. This study found that when pregnant dams were placed in a plastic restrainer three times a day during the last week of pregnancy, the offspring showed reduced anogenital distance and delayed testicular descent. Serum luteinising hormone (LH) and follicle-stimulating hormone (FSH) levels were decreased at postnatal day (PND) 28 and testosterone was decreased at PND 75. Increased testosterone plus dihydrotestosterone (T + DHT) concentrations correlated with increased testicular 5α Reductase-1 (5αR-1) mRNA expression at PND 28. Moreover, PS accelerated spermatogenesis at PND 35 and 60, and increased mean seminiferous tubule diameter in pubertal offspring and reduced Leydig cell number was observed at PND 35 and 60. PS offspring had increased androgen receptor (AR) mRNA level at PND 28, and at PND 35 had increased the numbers of Sertoli cells immunopositive for AR. Overall, the results confirm that stress during gestation can induce long-term effects on the male offspring reproductive system. Of particular interest is the pre-pubertal imbalance of circulating hormones that probably trigger accelerated testicular development, followed by an increase in total androgens and a decrease in testosterone concentration during adulthood. Exposure to an unfavourable intrauterine environment might prepare for harsh external conditions by triggering early puberty, increasing reproductive potential.
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Van den Berghe, F; Paris, D B B P; Van Soom, A; Rijsselaere, T; Van der Weyde, L; Bertschinger, H J; Paris, M C J
2012-07-01
The African wild dog (Lycaon pictus) is an endangered exotic canid with less than 5500 animals remaining in the wild. Despite numerous strategies to conserve this species, numbers of free-living animals are in decline. It is a highly social species with a complex pack structure: separate male and female dominant hierarchies with, typically, participation of subdominant adults in the rearing of the dominant breeding pairs' pups. Basic reproductive knowledge is largely missing in this species, with only limited information available on the profile of reproductive hormones, based on non-invasive endocrine monitoring. The dominant or alpha male and female are reproductively active and the subdominants are generally reproductively suppressed. However, the occasional production of litters by subdominant females and evidence of multiple paternity within litters suggests that fertility of subordinates is not completely inhibited. In this respect, there are still considerable gaps in our knowledge about the mechanisms governing reproduction and reproductive suppression in African wild dogs, particularly the influence of dominance and pack structure on both male and female fertility. Given concerns over the long-term survival of this species, further research in this area is essential to provide valuable information for their captive breeding and conservation. Reproductive information can also be applied to the development of Assisted Reproductive Techniques for this species; the utility of which in African wild dog conservation is also discussed. Copyright © 2012 Elsevier B.V. All rights reserved.
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Supriya, Ch.; Reddy, P. Sreenivasula
2015-06-01
studies revealed a significant decrease in the mating index in experimental rats with an increase in the pre- and post-implantation losses in rats mated with prenatal AfB1-exposed males, indicating poor male reproductive performance. These results indicate that in utero exposure to AfB1 severely compromised postnatal development of neonatal rats, and caused a delay in testes descent and reduction in steroidogenesis and spermatogenesis that were accomplished by suppressed reproduction at adulthood.
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Reproductive history of cane rat: a review of the reproduction and ...
African Journals Online (AJOL)
This study evaluates in a review the reproduction and reproductive performance of cane rat. Breeding time in cane rat depends on which part of Africa the Animal is found and the weather. In the wild, cane rat lives in groups of males and females during the breeding season. The wet season of the year is the usual breeding ...
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Directory of Open Access Journals (Sweden)
Hualin Wang
2018-04-01
Full Text Available The present study aims to investigate the protective effects of ω-3 polyunsaturated fatty acids (ω-3PUFAs against high-fat diet induced male mouse reproductive dysfunction and to explore circadian regulation mechanisms. Male C57BL/6 mice were randomly divided into three groups and fed a normal chow diet (control group, CON, a high-fat diet (HFD group or a HFD supplemented with fish oil (FO group for 12 weeks. After 12 weeks of feeding, the body weight and the ratio of perinephric and epididymal fat weight to body weight were significantly higher in the HFD group compared with the CON group. The supplement of fish oil rich in ω-3PUFAs only slightly reduced the HFD-induced obesity but remarkably ameliorated HFD-induced dyslipidemia, sexual hormones disorder, testicle lesions and germ cell apoptosis. Fish oil supplementation restored the expression of steroid synthesis associated genes in HFD fed mouse and flattened the HFD-induced oscillations in circadian genes’ expression. Fish oil supplementation prevented HFD-induced male mouse reproductive dysfunction and modified the rhythmic expression of testosterone synthesis related genes.
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Quantifying inbreeding avoidance through extra-pair reproduction.
Reid, Jane M; Arcese, Peter; Keller, Lukas F; Germain, Ryan R; Duthie, A Bradley; Losdat, Sylvain; Wolak, Matthew E; Nietlisbach, Pirmin
2015-01-01
Extra-pair reproduction is widely hypothesized to allow females to avoid inbreeding with related socially paired males. Consequently, numerous field studies have tested the key predictions that extra-pair offspring are less inbred than females' alternative within-pair offspring, and that the probability of extra-pair reproduction increases with a female's relatedness to her socially paired male. However, such studies rarely measure inbreeding or relatedness sufficiently precisely to detect subtle effects, or consider biases stemming from failure to observe inbred offspring that die during early development. Analyses of multigenerational song sparrow (Melospiza melodia) pedigree data showed that most females had opportunity to increase or decrease the coefficient of inbreeding of their offspring through extra-pair reproduction with neighboring males. In practice, observed extra-pair offspring had lower inbreeding coefficients than females' within-pair offspring on average, while the probability of extra-pair reproduction increased substantially with the coefficient of kinship between a female and her socially paired male. However, simulations showed that such effects could simply reflect bias stemming from inbreeding depression in early offspring survival. The null hypothesis that extra-pair reproduction is random with respect to kinship therefore cannot be definitively rejected in song sparrows, and existing general evidence that females avoid inbreeding through extra-pair reproduction requires reevaluation given such biases. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.
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Mourocq, Emeline; Bize, Pierre; Bouwhuis, Sandra; Bradley, Russell; Charmantier, Anne; de la Cruz, Carlos; Drobniak, Szymon M; Espie, Richard H M; Herényi, Márton; Hötker, Hermann; Krüger, Oliver; Marzluff, John; Møller, Anders P; Nakagawa, Shinichi; Phillips, Richard A; Radford, Andrew N; Roulin, Alexandre; Török, János; Valencia, Juliana; van de Pol, Martijn; Warkentin, Ian G; Winney, Isabel S; Wood, Andrew G; Griesser, Michael
2016-02-01
Fitness can be profoundly influenced by the age at first reproduction (AFR), but to date the AFR-fitness relationship only has been investigated intraspecifically. Here, we investigated the relationship between AFR and average lifetime reproductive success (LRS) across 34 bird species. We assessed differences in the deviation of the Optimal AFR (i.e., the species-specific AFR associated with the highest LRS) from the age at sexual maturity, considering potential effects of life history as well as social and ecological factors. Most individuals adopted the species-specific Optimal AFR and both the mean and Optimal AFR of species correlated positively with life span. Interspecific deviations of the Optimal AFR were associated with indices reflecting a change in LRS or survival as a function of AFR: a delayed AFR was beneficial in species where early AFR was associated with a decrease in subsequent survival or reproductive output. Overall, our results suggest that a delayed onset of reproduction beyond maturity is an optimal strategy explained by a long life span and costs of early reproduction. By providing the first empirical confirmations of key predictions of life-history theory across species, this study contributes to a better understanding of life-history evolution. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.
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Taub-Montemayor, Tina E; Min, Kyung-Jin; Chen, Zhaorigetu; Bartlett, Terri; Rankin, Mary Ann
2005-04-01
Juvenile hormone (JH) is necessary for the production of vitellogenin (Vg) in the boll weevil, Anthonomus grandis. Occurrence of Vg in this species is typically restricted to reproductively competent females, and is not detected in untreated males. However, the JH analog, methoprene stimulates Vg production in intact males and in the isolated abdomens of both male and female boll weevils (where in each case no Vg is detected without treatment), suggesting that males are competent to produce Vg but are normally not stimulated to do so. Preliminary work indicating that male boll weevil corpora allata (CA) produced little or no JH in vitro suggested that failure of males to produce Vg might be due to very low JH levels compared to females. This study re-examines the question of JH in male boll weevils by determining in vitro production of JH III by male CA during the first 10 days after adult emergence, determining hemolymph JH esterase activity during this same time period and hemolymph JH III titers in adults of both sexes. We also re-examine the ability of isolated male abdomens to produce Vg in response to hormonal stimulation, analyzing the effect of a wide range of methoprene and JH III dosages. Results indicate that male A. grandis have circulating JH titers and JH production similar to females. JH esterase activity is slightly but significantly higher in males than females. Vg production by isolated abdomens of both sexes after stimulation with methoprene or JH III was confirmed. Dose response studies indicated that high levels of methoprene were less effective than intermediate doses in stimulating Vg synthesis in both sexes. We conclude that the sexually dimorphic effect of JH on Vg synthesis is not due to differences in JH production or differences in JH titer between the sexes.
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Directory of Open Access Journals (Sweden)
Wenjing eShe
2015-04-01
Full Text Available Unlike animals, where the germline is established early during embryogenesis, plants set aside their reproductive lineage late in development in dedicated floral organs. The specification of pollen mother cells (PMCs committed to meiosis takes place in the sporogenous tissue in anther locules and marks the somatic-to-reproductive cell fate transition towards the male reproductive lineage. Here we show that Arabidopsis PMCs differentiation is accompanied by large-scale changes in chromatin organization. This is characterized by significant increase in nuclear volume, chromatin decondensation, reduction in heterochromatin, eviction of linker histones and the H2AZ histone variant. These structural alterations are accompanied by dramatic, quantitative changes in histone modifications levels compared to that of surrounding somatic cells that do not share a sporogenic fate. All these changes are highly reminiscent of those we have formerly described in female megaspore mother cells (MMCs. This indicates that chromatin reprogramming is a common underlying scenario in the somatic-to-reproductive cell fate transition in both male and female lineages.
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Kuramochi, Asami; Tsutiya, Atsuhiro; Kaneko, Toyoji; Ohtani-Kaneko, Ritsuko
2011-10-01
In tilapia, hormone treatment during the period of sexual differentiation can alter the phenotype of the gonads, indicating that endocrine factors can cause gonadal sex reversal. However, the endocrine mechanism underlying sex reversal of reproductive behaviors remains unsolved. In the present study, we detected sexual dimorphism of gonadotropin-releasing hormone type III (GnRH3) neurons in Mozambique tilapia Oreochromis mossambicus. Our immunohistochemical observations showed sex differences in the number of GnRH3 immunoreactive neurons in mature tilapia; males had a greater number of GnRH3 neurons in the terminal ganglion than females. Treatment with androgen (11-ketotestosterone (11-KT) or methyltestosterone), but not that with 17β-estradiol, increased the number of GnRH3 neurons in females to a level similar to that in males. Furthermore, male-specific nest-building behavior was induced in 70% of females treated with 11-KT within two weeks after the onset of the treatment. These results indicate androgen-dependent regulation of GnRH3 neurons and nest-building behavior, suggesting that GnRH3 is importantly involved in sex reversal of male-specific reproductive behavior.
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Energy Technology Data Exchange (ETDEWEB)
Chen Xuemei [Laboratory of Reproductive Biology, Chongqing Medical University, Chongqing 400016 (China); An Hui; Ao Lin; Sun Lei; Liu Wenbin; Zhou Ziyuan [Department of Hygenic Toxicology, College of Military Preventive Medicine, Key Lab of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Third Military Medical University, Chongqing 400038 (China); Wang Yingxiong, E-mail: wyx61221@yahoo.com.cn [Laboratory of Reproductive Biology, Chongqing Medical University, Chongqing 400016 (China); Cao Jia, E-mail: caojia1962@126.com [Department of Hygenic Toxicology, College of Military Preventive Medicine, Key Lab of Medical Protection for Electromagnetic Radiation, Ministry of Education of China, Third Military Medical University, Chongqing 400038 (China)
2011-02-15
Our previous studies revealed more than 100 pollutants, most of which were endocrine disruptors (EDs) in two Chinese rivers, the Jialing and the Yangtze near Chongqing. Most EDs, such as dibutyl phthalate (DBP) and benzo(a)pyrene (BaP), are known to act individually as reproductive toxicants. However, little is known about the combined toxicity of DBP and BaP. In the current study, male Sprague Dawley rats were subchronically exposed to single doses of DBP (250 mg/kg), single doses of BaP (5 mg/kg) and combined doses of DBP and BaP. Significant adverse effects were observed on the reproductive system, including decreased sperm count, increased production of abnormal sperm, changes in serum testosterone levels and irregular arrangements of the seminiferous epithelium. Biochemical analyses showed that the activities of superoxide dismutase and glutathione peroxidase decreased after exposure to these EDs. Therefore, our data suggest that exposure to DBP and BaP, in either separate or combined doses, can affect the reproductive system of male rats adversely via oxidative stress-related mechanisms. No significant additive effect was observed after combined exposure. These results indicate that exposure to mixtures of EDs have unexpected and elusive effects. Our findings provide preliminary but important data for assessing water safety in China.
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International Nuclear Information System (INIS)
Chen Xuemei; An Hui; Ao Lin; Sun Lei; Liu Wenbin; Zhou Ziyuan; Wang Yingxiong; Cao Jia
2011-01-01
Our previous studies revealed more than 100 pollutants, most of which were endocrine disruptors (EDs) in two Chinese rivers, the Jialing and the Yangtze near Chongqing. Most EDs, such as dibutyl phthalate (DBP) and benzo(a)pyrene (BaP), are known to act individually as reproductive toxicants. However, little is known about the combined toxicity of DBP and BaP. In the current study, male Sprague Dawley rats were subchronically exposed to single doses of DBP (250 mg/kg), single doses of BaP (5 mg/kg) and combined doses of DBP and BaP. Significant adverse effects were observed on the reproductive system, including decreased sperm count, increased production of abnormal sperm, changes in serum testosterone levels and irregular arrangements of the seminiferous epithelium. Biochemical analyses showed that the activities of superoxide dismutase and glutathione peroxidase decreased after exposure to these EDs. Therefore, our data suggest that exposure to DBP and BaP, in either separate or combined doses, can affect the reproductive system of male rats adversely via oxidative stress-related mechanisms. No significant additive effect was observed after combined exposure. These results indicate that exposure to mixtures of EDs have unexpected and elusive effects. Our findings provide preliminary but important data for assessing water safety in China.