Twelve crosses of aromatic rice utilizing four γ-ray induced mutants 88-8-3 and 33-9-15 of Tulaipanja and 124-17-4 and 21-6-1 of Gobindabhog and three basmati varieties were evaluated for heterosis and inbreeding depression for different panicle characters. All the hybrids except the two hybrids of 124-17-4 with Pakistan Basmati and Pusa Basmati I manifested significantly positive heterosis for grain yield panicle -1 . High magnitude of heterosis coupled with positive inbreeding depression for panicle length, secondary branches panicle -1 , spikelet number panicle -1 , panicle weight and grain yield panicle -1 in several crosses indicating the presence of nonadditive gene action. The results indicate the scope of exploiting heterosis in aromatic rice. (author)
DEPRESIÓN EN VIGOR POR ENDOGAMIA Y HETEROSIS PARA EL RENDIMIENTO Y SUS COMPONENTES EN ZAPALLO Cucurbita moschata Duch. Ex Poir INBREEDING DEPRESSION AND HETEROSIS FOR YIELD AND ITS COMPONENTS IN PUMPKIN Cucurbita moschata Duch. Ex Poir
Miguel Mariano Espitia Camacho
Full Text Available El estudio tuvo como objetivos estimar la depresión por endogamia (DE y cuatro tipos de heterosis: promedio general (HP, promedio de progenitores (HM, heterobeltiosis (HB y útil (HU, en dos dialélos [uno entre cinco variedades (V y el otro entre cinco líneas endogamicas S1 (LS1, derivadas de éstas], para el rendimiento por planta (PFP, número de frutos por planta (NFP y peso promedio de fruto (PPF. Los 30 genotipos se evaluaron en el municipio de Candelaria (Valle del Cauca, Colombia, en un diseño de bloques completos al azar con cinco repeticiones. Se presentaron diferencias significativas (p 40 % y HU (>60 % en PFP.With the goal of estimating inbreeding depression (DE and the four types of heterosis: general average (HP, mean (HM, heterobeltiosis (HB and standard (HU, in two diallelic [one among five cross pollinated varieties (VAR and the other among five self-pollinated lines S1(LS1, derived from these], for yield/plant (PFP, number of fruits/plant (NFP and weight/fruit (PPF. The 30 genotypes were evaluated using a complete randomized design with five replicates in Candelaria (Valle del Cauca, Colombia . Significant differences (p 40 % and HU (>60 % in PFP.
Strauss, Steven H.
The dependence of heterosis at isozyme loci on inbreeding and crossbreeding was studied in 10-yr-old trees of knobcone pine (Pinus attenuata Lemm.). Heterozygosity was determined at 24 polymorphic isozyme loci and related to the rate of vegetative growth and cone production. The inbreds, created by selfpollination, had 46% of the heterozygosity of their mothers; the crossbreds, created by interpopulation crossing, had 155% of the heterozygosity of their mothers. Within the crossbreds, hetero...
W. J. Libby; B. G. McCutchan; C. I. Millar
Given the polyploid chromosome constitution of Sequoia sempervirens, there was reason to question whether it would exhibit inbreeding depression. Preliminary results from studies of self and related outcross families are reported as a guide to the selection of trees for redwood seed orchards and breeding-orchards. The data indicate that, compared to...
Ana M Tortajada
Full Text Available Inbreeding depression is an important evolutionary factor, particularly when new habitats are colonized by few individuals. Then, inbreeding depression by drift could favour the establishment of later immigrants because their hybrid offspring would enjoy higher fitness. Rotifers are the only major zooplanktonic group where information on inbreeding depression is still critically scarce, despite the fact that in cyclical parthenogenetic rotifers males are haploid and could purge deleterious recessive alleles, thereby decreasing inbreeding depression.We studied the effects of inbreeding in two populations of the cyclical parthenogenetic rotifer Brachionus plicatilis. For each population, we compared both the parental fertilization proportion and F1 fitness components from intraclonal (selfed and interclonal (outcrossed crosses. The parental fertilization proportion was similar for both types of crosses, suggesting that there is no mechanism to avoid selfing. In the F1 generation of both populations, we found evidence of inbreeding depression for the fitness components associated with asexual reproduction; whereas inbreeding depression was only found for one of the two sexual reproduction fitness components measured.Our results show that rotifers, like other major zooplanktonic groups, can be affected by inbreeding depression in different stages of their life cycle. These results suggest that haplodiploidy does not purge efficiently deleterious recessive alleles. The inbreeding depression detected here has important implications when a rotifer population is founded and intraclonal crossing is likely to occur. Thus, during the foundation of new populations inbreeding depression may provide opportunities for new immigrants, increasing gene flow between populations, and affecting genetic differentiation.
Rokouei, M; Torshizi, R Vaez; Shahrbabak, M Moradi
Pedigree information of 852,443 registered Holstein cows and bulls, collected by the Animal Breeding Center of Iran from 1971 to 2007, was used to calculate inbreeding coefficients and their effect on production, reproduction, somatic cell count, calving ease, and longevity traits. The average...... reproductive traits, the observed undesirable effect of inbreeding was not significant, except for the calving interval (0.53 d per 1% increase in inbreeding) in the third parity and age at first calving (0.45 d per 1% increase in inbreeding). Calving ease in heifers and cows was significantly influenced...... by the inbreeding of the dam, indicating that highly inbred cows had a higher incidence of difficult calvings. The estimate of inbreeding depression for somatic cell score was low and significant only for the third lactation. However, animals with high inbreeding coefficient tended to have higher somatic cell...
Tortajada, Ana M.; Carmona, María José; Serra, Manuel
Background Inbreeding depression is an important evolutionary factor, particularly when new habitats are colonized by few individuals. Then, inbreeding depression by drift could favour the establishment of later immigrants because their hybrid offspring would enjoy higher fitness. Rotifers are the only major zooplanktonic group where information on inbreeding depression is still critically scarce, despite the fact that in cyclical parthenogenetic rotifers males are haploid and could purge deleterious recessive alleles, thereby decreasing inbreeding depression. Methodology/Principal Findings We studied the effects of inbreeding in two populations of the cyclical parthenogenetic rotifer Brachionus plicatilis. For each population, we compared both the parental fertilization proportion and F1 fitness components from intraclonal (selfed) and interclonal (outcrossed) crosses. The parental fertilization proportion was similar for both types of crosses, suggesting that there is no mechanism to avoid selfing. In the F1 generation of both populations, we found evidence of inbreeding depression for the fitness components associated with asexual reproduction; whereas inbreeding depression was only found for one of the two sexual reproduction fitness components measured. Conclusions/Significance Our results show that rotifers, like other major zooplanktonic groups, can be affected by inbreeding depression in different stages of their life cycle. These results suggest that haplodiploidy does not purge efficiently deleterious recessive alleles. The inbreeding depression detected here has important implications when a rotifer population is founded and intraclonal crossing is likely to occur. Thus, during the foundation of new populations inbreeding depression may provide opportunities for new immigrants, increasing gene flow between populations, and affecting genetic differentiation. PMID:19997616
Pilakouta, Natalie; Jamieson, Seonaidh; Moorad, Jacob A; Smiseth, Per T
When relatives mate, their inbred offspring often suffer a reduction in fitness-related traits known as "inbreeding depression." There is mounting evidence that inbreeding depression can be exacerbated by environmental stresses such as starvation, predation, parasitism, and competition. Parental care may play an important role as a buffer against inbreeding depression in the offspring by alleviating these environmental stresses. Here, we examine the effect of parental care on the fitness costs of inbreeding in the burying beetle Nicrophorus vespilloides, an insect with facultative parental care. We used a 2 × 2 factorial design with the following factors: (i) the presence or absence of a caring female parent during larval development and (ii) inbred or outbred offspring. We examined the joint influence of maternal care and inbreeding status on fitness-related offspring traits to test the hypothesis that maternal care improves the performance of inbred offspring more than that of outbred offspring. Indeed, the female's presence led to a higher increase in larval survival in inbred than in outbred broods. Receiving care at the larval stage also increased the lifespan of inbred but not outbred adults, suggesting that the beneficial buffering effects of maternal care can persist long after the offspring have become independent. Our results show that parental care has the potential to moderate the severity of inbreeding depression, which in turn may favor inbreeding tolerance and influence the evolution of mating systems and other inbreeding-avoidance mechanisms.
The objective of this study was to investigate the effect of inbreeding depression on functional herd life in the South African Jersey population based on individual level and rate of inbreeding. A pedigree file of the South African Jersey breed (n = 912 638) was obtained from the Integrated Registration and Genetic ...
Full Text Available ABSTRACT Inbreeding depression, reduction in performance of quantitative traits, including reproduction and survival, caused by inbreeding, is a well-known phenomenon observed in almost all experimental, domesticated, and natural populations. In spite of its importance to the fate of a small population and numerous research performed in the last century, the genetic basis of inbreeding depression is still unclear. Recent fast development of molecular techniques has enabled estimation of a genomic inbreeding coefficient (FROH, which reflects realized autozygosity and can be further partitioned to chromosomes and chromosomal segments. In this review, we first describe classical approach used in the estimation of inbreeding in livestock populations, followed by early concepts of replacing pedigree inbreeding coefficient by individual heterozygosity. Then, we explain runs of homozygosity as key approach in estimating realized autozygosity. Furthermore, we present two different concepts of analysing regions that substantially contribute to the inbreeding depression. Thus, we describe how to identify or map mutations that result in the reduction of performance and, in terms of quantitative genetics, how to analyse the architecture of inbreeding depression. At the end, we discuss future perspectives in eliminating deleterious mutations from livestock populations.
Full Text Available Stature is a classical and highly heritable complex trait, with 80%-90% of variation explained by genetic factors. In recent years, genome-wide association studies (GWAS have successfully identified many common additive variants influencing human height; however, little attention has been given to the potential role of recessive genetic effects. Here, we investigated genome-wide recessive effects by an analysis of inbreeding depression on adult height in over 35,000 people from 21 different population samples. We found a highly significant inverse association between height and genome-wide homozygosity, equivalent to a height reduction of up to 3 cm in the offspring of first cousins compared with the offspring of unrelated individuals, an effect which remained after controlling for the effects of socio-economic status, an important confounder (χ(2 = 83.89, df = 1; p = 5.2 × 10(-20. There was, however, a high degree of heterogeneity among populations: whereas the direction of the effect was consistent across most population samples, the effect size differed significantly among populations. It is likely that this reflects true biological heterogeneity: whether or not an effect can be observed will depend on both the variance in homozygosity in the population and the chance inheritance of individual recessive genotypes. These results predict that multiple, rare, recessive variants influence human height. Although this exploratory work focuses on height alone, the methodology developed is generally applicable to heritable quantitative traits (QT, paving the way for an investigation into inbreeding effects, and therefore genetic architecture, on a range of QT of biomedical importance.
Charpentier, M; Setchell, J M; Prugnolle, F; Wickings, E J; Peignot, P; Balloux, F; Hossaert-McKey, M
Inbreeding depression reflects the negative consequences of increased homozygosity at genes that affect fitness. We investigate inbreeding depression in a semi-free-ranging colony of mandrills (Mandrillus sphinx), using high-quality pedigree data, comprising five maternal generations and 20 years of morphological and demographic data. We examine the relationship between inbreeding coefficients and four fitness correlates: two growth parameters (mass and height for age) and longevity in both sexes, and age at first conception in females. Inbreeding was correlated with both growth parameters, but only in females, with inbred females being smaller than noninbred females. Inbreeding was also correlated significantly with age at first conception, with inbred females giving birth earlier in life than noninbred females. We suggest that sex-biased maternal investment may explain this sex-differential response to inbreeding, although the lack of a significant association between inbreeding and growth in males may also be due to the provisioned nature of the colony. The surprising relationship between age at first conception and inbreeding may be related to smaller adult size in inbred females, or to their being less able to escape from male sexual coercion.
de Boer, Raïssa A; Eens, Marcel; Fransen, Erik; Müller, Wendt
Understanding how the intensity of inbreeding depression is influenced by stressful environmental conditions is an important area of enquiry in various fields of biology. In birds, environmental stress during early development is often related to hatching asynchrony; differences in age, and thus size, impose a gradient in conditions ranging from benign (first hatched chick) to harsh (last hatched chick). Here, we compared the effect of hatching order on growth rate in inbred (parents are full siblings) and outbred (parents are unrelated) canary chicks (Serinus canaria). We found that inbreeding depression was more severe under more stressful conditions, being most evident in later hatched chicks. Thus, consideration of inbreeding-environment interactions is of vital importance for our understanding of the biological significance of inbreeding depression and hatching asynchrony. The latter is particularly relevant given that hatching asynchrony is a widespread phenomenon, occurring in many bird species. The exact causes of the observed inbreeding-environment interaction are as yet unknown, but may be related to a decrease in maternal investment in egg contents with laying position (i.e. prehatching environment), or to performance of the chicks during sibling competition and/or their resilience to food shortage (i.e. posthatching environment). © 2015 The Author(s).
Memon, S.; Baloch, M.J.; Baloch, G.M.
genetically diverse female lines of sunflower were crossed with male testers to get heterotic hybrids. studies were carried-out during 2008-2010 at experiment filed of agriculture research institute, tandojam, sindh, pakistan. six female lines like t-4-0319, pac-0505, ho-i, hysun-33, peshawar-93 and cms-03 and three testers i.e., pac-0306, pac-64-a and sf-187 were crossed in a line * tester mating design, thus 18 f1 and f2 hybrids were developed for evaluation of heterosis and inbreeding depression for days to initial flowering, days to maturity, leaves/plant, plant height (cm), head diameter (cm), 1000-achene weight (g), seed yield kg/ha and oil yield kg/ha. the experiment was conducted in a randomised completeb lock design with four replications. the analysis of variance revealed significant differences among parents, f1s and f2 hybrids for all the traits studied. the existence of significant genetic variability among the plant traits is particularly useful because variations in these traits would allow further improvement in sunflower seed yield and oil traits. the f1 hybrids ho-i * pac-0306 and ho-i pa * c-64-a exhibited desirable negative mid and better parent heterosis for days to initial flowering, days to maturity and plant height. these hybrids also manifested desirable positive heterotic effects for leaves/plant, head diameter, 1000-achene.s weight, seed yield and oil yield. inbreeding depression for phenological, seed yield and oil traits showed that desirable high inbreeding depression was observed in hybrids ho-i * p*ac-64-a, ho-i * pac-0306 and ho-i * sf-187 for days to initial flowering, similarly t-4-0319 * pac-0306, pac-0505 ± sf-187 and ho-i * pac-64-a explicated maximum but rewarding inbreeding depression for days to maturity. the f2 hybrids hysun-33 * sf-187 and peshawer-93 * pac-64-a may be the most desirable ones in the sense that they recorded comparatively moderate inbreeding depression with enough number of leaves to be productive if f2
Full Text Available The purpose of this study was to investigate inbreeding depression (DE in castor bean. From a population derived from the Guarani cultivar, 60 mother plants were sampled. Three types of progenies were obtained from each one: from self-pollination (AU, from crosses (CR and from open pollination (PL. Grain yield of the progenies was evaluated in two locations. There was a strong interaction of progenies x locations, which led to obtaining estimates within each location. Broad variation was observed in inbreeding depression, with mean values of 6.7% and 13.4%, comparing AU progenies with PL progenies. It was observed that the population has high potential for selecting promising inbred lines. The frequency of mother plants generating progenies with simultaneous high general combination capacity and low inbreeding depression was low. Recurrent selection will increase the occurrence of parent plants associating these two properties, which is necessary for obtaining superior synthetic varieties.
Bocedi, Greta; Reid, Jane M
Ongoing ambitions are to understand the evolution of costly polyandry and its consequences for species ecology and evolution. Emerging patterns could stem from feed-back dynamics between the evolving mating system and its genetic environment, defined by interactions among kin including inbreeding. However, such feed-backs are rarely considered in nonselfing systems. We use a genetically explicit model to demonstrate a mechanism by which inbreeding depression can select for polyandry to mitigate the negative consequences of mating with inbred males, rather than to avoid inbreeding, and to elucidate underlying feed-backs. Specifically, given inbreeding depression in sperm traits, costly polyandry evolved to ensure female fertility, without requiring explicit inbreeding avoidance. Resulting sperm competition caused evolution of sperm traits and further mitigated the negative effect of inbreeding depression on female fertility. The evolving mating system fed back to decrease population-wide homozygosity, and hence inbreeding. However, the net overall decrease was small due to compound effects on the variances in sex-specific reproductive success and paternity skew. Purging of deleterious mutations did not eliminate inbreeding depression in sperm traits or hence selection for polyandry. Overall, our model illustrates that polyandry evolution, both directly and through sperm competition, might facilitate evolutionary rescue for populations experiencing sudden increases in inbreeding. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.
To study the genetic potential, heterotic effects and inbreeding depression, 8 X 8 F/sub 2/diallel populations with parental lines of upland cotton were grown during crop season 2010 in a randomized complete block design at Khyber Pakhtunkhwa Agricultural University Peshawar, Pakistan. Highly significant ( p = 0.01 ) variations were noticed among parental lines and F/sub 2/ populations for all the traits. According to genotypes mean performance for various traits, plant height varied from 101.60 to 126.30 cm and 98.60 to 140.60 cm, bolls plant/sup -1/ (12.87 to 19.53; 12.13 to 22.60), boll weight (3.80 to 5.01 g; 3.04 to 5.38 g) and seed cotton yield plant/sup -1/ varied from 55.74 to 85.47 g and 45.57 to 96.05 g in parental cultivars and their F/sub 2/ populations, respectively. However, 12 and 7 F/sub 2/ populations manifested significant heterosis over mid and better parents for plant height, 7 and 3 for bolls plant/sup -1/, 13 and 9 for boll weight and 13 and 5 F/sub 2/ populations for seed cotton yield plant/sup -1/, respectively. F/sub 2/ populations i.e. CIM-554 X CIM-473, CIM-554 X CIM-499, CIM-496 X SLH-284, CIM-473 X CIM-446 and CIM-554 X SLH-284 with low mean values for plant height performed better and manifested highly significant heterotic values over mid and better parents for bolls per plant, boll weight and seed cotton yield. By comparing F/sub 2/ mean values with F/sub 1/s, inbreeding depression was observed for plant height (0.66 to 23. 99%), bolls per plant (5.00 to 63.16%), boll weight (0.20 to 23.24%) and seed cotton yield (0.44 to 75.52%). However, 62% of F/sub 2/ populations revealed negative values for inbreeding depression, 14% for bolls per plant, 77% for boll weight and 21% for yield, revealed that these F/sub 2/ populations were more stable and performed better than F/sub 1/s even after segregation. Although, F/sub 2/ populations may display less heterosis as compared to F/sub 1/, but still better than high parents and can be used as
Liberg, Olof; Andrén, Henrik; Pedersen, Hans-Christian; Sand, Håkan; Sejberg, Douglas; Wabakken, Petter; Kesson, Mikael; Bensch, Staffan
The difficulty of obtaining pedigrees for wild populations has hampered the possibility of demonstrating inbreeding depression in nature. In a small, naturally restored, wild population of grey wolves in Scandinavia, founded in 1983, we constructed a pedigree for 24 of the 28 breeding pairs established in the period 1983-2002. Ancestry for the breeding animals was determined through a combination of field data (snow tracking and radio telemetry) and DNA microsatellite analysis. The population was founded by only three individuals. The inbreeding coefficient F varied between 0.00 and 0.41 for wolves born during the study period. The number of surviving pups per litter during their first winter after birth was strongly correlated with inbreeding coefficients of pups (R2=0.39, pwolf population.
Cleso Antônio Patto Pacheco
Full Text Available The study of inbreeding depression is important for breeding strategies such as use of inbred progenies or extraction of inbreed lines. A diallel of 28 maize open-pollinated varieties was evaluated in 10 environments in the early 1990s. At the same time, S1 populations for each of the 28 varieties were evaluated in the same 10 experiments (environments. Yield reductions of the populations from S0 to S1 (mean of the 10 environments, varied from 34.6% (CMS-01 to 59.2% (CMS-30, with an average of 49.1%. Inbreeding depression was greater in populations with a wider genetic base, which had never been exposed to inbreeding (CMS-30, BR-107, PH4, Cunha, Saracura, Nitrodent, and Nitroflint. Inbred lines with greater yield means should be obtained from the BR-105, BR-111, CMS-01, CMS-03, BR-106, CMS-14c, and CMS-28 populations. The use of parameter estimates generated by analysis of inbreeding depression, allow to make inferences about frequencies of deleterious alleles in the population. The frequencies of favorable alleles in the parents can be obtained by diallel analysis. The association of these two types of information, can provide a better interpretation of the genetic parameters and also can improve the process of selection of parents for either an intra- or an inter-populational breeding program.
Barringer, Brian C; Geber, Monica A
Inbreeding depression is the reduction in offspring fitness associated with inbreeding and is thought to be one of the primary forces selecting against the evolution of self-fertilization. Studies suggest that most inbreeding depression is caused by the expression of recessive deleterious alleles in homozygotes whose frequency increases as a result of self-fertilization or mating among relatives. This process leads to the selective elimination of deleterious alleles such that highly selfing species may show remarkably little inbreeding depression. Genome duplication (polyploidy) has also been hypothesized to influence levels of inbreeding depression, with polyploids expected to exhibit less inbreeding depression than diploids. We studied levels of inbreeding depression in allotetraploid and diploid species of Clarkia (Onagraceae) that vary in mating system (each cytotype was represented by an outcrossing and a selfing species). The outcrossing species exhibited more inbreeding depression than the selfing species for most fitness components and for two different measures of cumulative fitness. In contrast, though inbreeding depression was generally lower for the polyploid species than for the diploid species, the difference was statistically significant only for flower number and one of the two measures of cumulative fitness. Further, we detected no significant interaction between mating system and ploidy in determining inbreeding depression. In sum, our results suggest that a taxon's current mating system is more important than ploidy in influencing levels of inbreeding depression in natural populations of these annual plants.
Vermeulen, Cornelius J.; Bijlsma, R.; Loeschcke, Volker
Background: The study of inbreeding depression has major relevance for many disciplines, including conservation genetics and evolutionary biology. Still, the molecular genetic basis of this phenomenon remains poorly characterised, as knowledge on the mechanistic causes of inbreeding depression and
Restoux, Gwendal; Huot de Longchamp, Priscille; Fady, Bruno; Klein, Etienne K
Inbreeding depression is a key factor affecting the persistence of natural populations, particularly when they are fragmented. In species with mixed mating systems, inbreeding depression can be estimated at the population level by regressing the average progeny fitness by the selfing rate of their mothers. We applied this method using simulated populations to investigate how population genetic parameters can affect the detection power of inbreeding depression. We simulated individual selfing rates and genetic loads from which we computed fitness values. The regression method yielded high statistical power, inbreeding depression being detected as significant (5 % level) in 92 % of the simulations. High individual variation in selfing rate and high mean genetic load led to better detection of inbreeding depression while high among-individual variation in genetic load made it more difficult to detect inbreeding depression. For a constant sampling effort, increasing the number of progenies while decreasing the number of individuals per progeny enhanced the detection power of inbreeding depression. We discuss the implication of among-mother variability of genetic load and selfing rate on inbreeding depression studies.
Pilakouta, Natalie; Smiseth, Per T
A maternal effect is a causal influence of the maternal phenotype on the offspring phenotype over and above any direct effects of genes. There is abundant evidence that maternal effects can have a major impact on offspring fitness. Yet, no previous study has investigated the potential role of maternal effects in influencing the severity of inbreeding depression in the offspring. Inbreeding depression is a reduction in the fitness of inbred offspring relative to outbred offspring. Here, we tested whether maternal effects due to body size alter the magnitude of inbreeding depression in the burying beetle Nicrophorus vespilloides We found that inbreeding depression in larval survival was more severe for offspring of large females than offspring of small females. This might be due to differences in how small and large females invest in an inbred brood because of their different prospects for future breeding opportunities. To our knowledge, this is the first evidence for a causal effect of the maternal phenotype on the severity of inbreeding depression in the offspring. In natural populations that are subject to inbreeding, maternal effects may drive variation in inbreeding depression and therefore contribute to variation in the strength and direction of selection for inbreeding avoidance. © 2016 The Author(s).
Pedersen, Kamilla Sofie; Pedersen, Louise Dybdahl; Sorensen, Anders Christian; Nielsen, Anna Busch; Kristensen, Torsten Nygaard
Mating between closely related individuals often causes reduced fitness, which is termed "inbreeding depression". Inbreeding is, therefore, a threat towards the persistence of animal and plant populations. Here we present methods and results from a practical for high-school and first-year university students and discuss learning outcomes…
Jensen, Charlotte; Ørsted, Michael; Kristensen, Torsten Nygaard
Habitat fragmentation and small population sizes can lead to inbreeding and loss of genetic variation, which can potentially cause inbreeding depression and decrease the ability of populations to adapt to altered environmental conditions. One solution to these genetic problems is the implementation...... of genetic rescue, which re-establishes gene flow between separated populations. Similar techniques are being used in animal and plant breeding to produce superior production animals and plants. To optimize fitness benefits in genetic rescue programs and to secure high yielding domestic varieties in animal...... exceptions to this pattern. The best predictor of heterosis was performance of parental lines with poorly performing parental lines showing higher hybrid vigour when crossed, i.e. the potential for heterosis was proportional to the level of inbreeding depression. Overall, our results show that outcrossing...
Keser Lidewij H
Full Text Available Abstract Background Solanum carolinense (horsenettle is a highly successful weed with a gametophytic self-incompatibility (SI system. Previous studies reveal that the strength of SI in S. carolinense is a plastic trait, associated with particular S-alleles. The importance of this variation in self-fertility on the ability of horsenettle to found and establish new populations will depend, to a large extent, on the magnitude of inbreeding depression. We performed a series of greenhouse and field experiments to determine the magnitude of inbreeding depression in S. carolinense, whether inbreeding depression varies by family, and whether the estimates of inbreeding depression vary under field and greenhouse conditions. We performed a series of controlled self- and cross-pollinations on 16 genets collected from a large population in Pennsylvania to obtain progeny with different levels of inbreeding. We grew the selfed and outcrossed progeny in the greenhouse and under field conditions and recorded various measures of growth and reproductive output. Results In the greenhouse study we found (1 a reduction in flower, fruit and seed production per fruit in inbred (selfed progeny when compared to outbred (outcrossed progeny; (2 a reduction in growth of resprouts obtained from rhizome cuttings of selfed progeny; and (3 an increase in the ability to self-fertilize in the selfed progeny. In the field, we found that (1 outcrossed progeny produced more leaves than their selfed siblings; (2 herbivory seems to add little to inbreeding depression; and (3 outcrossed plants grew faster and were able to set more fruits than selfed plants. Conclusion Solanum carolinense experiences low levels of inbreeding depression under greenhouse conditions and slightly more inbreeding depression under our field conditions. The combined effects of low levels of inbreeding depression and plasticity in the strength of SI suggest that the production of selfed progeny may play an
Full Text Available Inbreeding depression occurs when the offspring produced as a result of matings between relatives show reduced fitness, and is generally understood as a consequence of the elevated expression of deleterious recessive alleles. How inbreeding depression varies across environments is of importance for the evolution of inbreeding avoidance behaviour, and for understanding extinction risks in small populations. However, inbreeding-by-environment (IxE interactions have rarely been investigated in wild populations.We analysed 41 years of breeding events from a wild great tit (Parus major population and used 11 measures of the environment to categorise environments as relatively good or poor, testing whether these measures influenced inbreeding depression. Although inbreeding always, and environmental quality often, significantly affected reproductive success, there was little evidence for statistically significant I x E interactions at the level of individual analyses. However, point estimates of the effect of the environment on inbreeding depression were sometimes considerable, and we show that variation in the magnitude of the I x E interaction across environments is consistent with the expectation that this interaction is more marked across environmental axes with a closer link to overall fitness, with the environmental dependence of inbreeding depression being elevated under such conditions. Hence, our analyses provide evidence for an environmental dependence of the inbreeding x environment interaction: effectively an I x E x E.Overall, our analyses suggest that I x E interactions may be substantial in wild populations, when measured across relevant environmental contrasts, although their detection for single traits may require very large samples, or high rates of inbreeding.
Michalczyk, Łukasz; Martin, Oliver Y.; Millard, Anna L.; Emerson, Brent C.; Gage, Matthew J. G.
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
Tien, N.S.H.; Sabelis, M.W.; Egas, M.
Compared with diploid species, haplodiploids suffer less inbreeding depression because male haploidy imposes purifying selection on recessive deleterious alleles. However, alleles of genes only expressed in the diploid females are protected in heterozygous individuals. This leads to the prediction
Tien, N.S.H.; Sabelis, M.W.; Egas, M.
Compared with diploid species, haplodiploids suffer less inbreeding depression because male haploidy imposes purifying selection on recessive deleterious alleles. However, alleles of genes only expressed in the diploid females are protected in heterozygous individuals. This leads to the prediction
Ahmad, M.; Khan, S.; Ahmad, F.; Shah, N.H.; Akhtar, N.
The research was conducted to evaluate the performance of S1 lines for inbreeding depression regarding different parameters, using maize variety Azam. The maize variety was self-pollinated for one generation in spring season and in the next sowing season 99 S1 lines obtained from selfing was sown with a parental line. Days to silking, pollen-shedding, plant height , ear-height, ear-length, ear-diameter, number of ears/row, kernel rows/ear and 100 kernel weight showed inbreeding depression with varying degrees while yield kg/ha showed severe inbreeding depression with an average of 362.08 kg/ha. Average value of inbreeding depression for days to silking and pollen-shedding was calculated as 2.02 and 2.21 days, respectively. Average values of inbreeding depression for plant height and ear-height were recorded as 21.50 cm and 4.87 cm, respectively. While, for earlength, ear-diameter, number of ears/row, kernel rows/ear and 100 grain weight, the average value of inbreeding depression was recorded as 1.80 cm, 0.2 cm, 2.5, 2.11 and 3.89 g, respectively. Grain yield was positively and significantly correlated with plant height, ear height and yield components. Maturity traits were positively and significantly linked with each other. It is concluded that by subjecting the maize to self-pollination nearly all the lines were affected; however, some lines were affected severely and others tolerated inbreeding to some extent. The lines showing tolerance against inbreeding depression was selected for further maize breeding. (author)
Deoclecio Domingos Garbuglio
Full Text Available Inbreeding can potentially be used for the development of inbred lines containing alleles of interest, but the genetic causes that control inbreeding depression are not completely known, and there are few studies found in the literature. The present study aimed to obtain estimates of inbreeding depression for eight traits in seven tropical maize populations, analyze the effects of inbreeding over generations and environments, and predict the behavior of inbred lines in future generation S? through linear regression methods. It was found that regardless of the base population used, prediction values could vary when the model was based on only 2 generations of inbreeding due to the environmental component. The influence of the environment in this type of study could be reduced when considering 3 generations of inbreeding, allowing greater precision in predicting the phenotypes of inbred lines. The use of linear regression was effective for inbred line prediction for the different agronomic traits evaluated. The use of 3 levels of inbreeding minimizes the effects of the environmental component in inbred line prediction for grain yield. GO-S was the most promising population for inbred line extraction.
Willi, Yvonne; Dietrich, Stefan; van Kleunen, Mark; Fischer, Markus
Hypothesis: Stressful inter-specific competition enhances inbreeding depression.Organisms: Creeping spearwort (Ranunculus reptans L.) and its common competitor, thecreeping bentgrass (Agrostis stolonifera L.).Field site: Outdoor common garden experiment at the University of Potsdam.Methods: We collected plants of 12 natural populations of R. reptans differing in mean parental inbreeding coefficient (0.01–0.26). We performed within-population crosses for twogenerations and kept the offspring i...
Full Text Available Avoidance of mating between related individuals is usually considered adaptive because it decreases the probability of inbreeding depression in offspring. However, mating between related partners can be adaptive if outbreeding depression is stronger than inbreeding depression or if females gain inclusive fitness benefits by mating with close kin. In the present study, we used microsatellite data to infer the parentage of juveniles born in a French colony of feral pigeons, which allowed us to deduce parent pairs. Despite detectable inbreeding depression, we found that pairwise relatedness between mates was significantly higher than between nonmates, with a mean coefficient of relatedness between mates of 0.065, approximately half the theoretical value for first cousins. This higher relatedness between mates cannot be explained by spatial genetic structure in this colonial bird; it therefore probably results from an active choice. As inbreeding but not outbreeding depression is observed in the study population, this finding accords with the idea that mating with genetically similar mates can confer a benefit in terms of inclusive fitness. Our results and published evidence suggest that preference for related individuals as mates might be relatively frequent in birds.
Frank C. Sorensen
Seft and cross families from three populatons (A, low-density, ecologically marginal site for lodgepole pine, and B + C, normal sites) were cultured in a common outdoor nursery for 2 yrs. Previous results results had shown higher natural selfing rates and lower inbreeding depression in embryo survival in A than in B + C. In the nursery test, selfing decreased means of...
Meunier, J; Kölliker, M
Although inbreeding is commonly known to depress individual fitness, the severity of inbreeding depression varies considerably across species. Among the factors contributing to this variation, family interactions, life stage and sex of offspring have been proposed, but their joint influence on inbreeding depression remains poorly understood. Here, we demonstrate that these three factors jointly shape inbreeding depression in the European earwig, Forficula auricularia. Using a series of cross-breeding, split-clutch and brood size manipulation experiments conducted over two generations, we first showed that sib mating (leading to inbred offspring) did not influence the reproductive success of earwig parents. Second, the presence of tending mothers and the strength of sibling competition (i.e. brood size) did not influence the expression of inbreeding depression in the inbred offspring. By contrast, our results revealed that inbreeding dramatically depressed the reproductive success of inbred adult male offspring, but only had little effect on the reproductive success of inbred adult female offspring. Overall, this study demonstrates limited effects of family interactions on inbreeding depression in this species and emphasizes the importance of disentangling effects of sib mating early and late during development to better understand the evolution of mating systems and population dynamics. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.
Full Text Available Cognitive ability tests are widely assumed to measure maximal intellectual performance and predictive associations between intelligence quotient (IQ scores and later mental health problems. Very few epidemiologic studies have been done to demonstrate the relationship between familial inbreeding and modest cognitive impairments in children.We aimed to estimate the effect of inbreeding on children's cognitive behavior in comparison with non-inbred children.A cohort of 408 children (6 to 15 years of age was selected from inbred and non-inbred families of five Muslim populations of Jammu region. The Wechsler Intelligence Scales for Children (WISC was used to measure the verbal IQ (VIQ, performance IQ (PIQ and full scale IQ (FSIQ. Family pedigrees were drawn to access the family history and children's inbred status in terms of coefficient of inbreeding (F.We found significant decline in child cognitive abilities due to inbreeding and high frequency of mental retardation among offspring from inbred families. The mean differences (95% C.I. were reported for the VIQ, being -22.00 (-24.82, -19.17, PIQ -26.92 (-29.96, -23.87 and FSIQ -24.47 (-27.35,-21.59 for inbred as compared to non-inbred children (p<0.001 [corrected].The higher risk of being mentally retarded was found to be more obvious among inbred categories corresponding to the degree of inbreeding and the same accounts least for non-inbred children (p<0.0001. We observed an increase in the difference in mean values for VIQ, PIQ and FSIQ with the increase of inbreeding coefficient and these were found to be statistically significant (p<0.05. The regression analysis showed a fitness decline (depression for VIQ (R2 = 0.436, PIQ (R2 = 0.468 and FSIQ (R2 = 0.464 with increasing inbreeding coefficients (p<0.01.Our comprehensive assessment provides the evidence for inbreeding depression on cognitive abilities among children.
Krebs, S L; Hancock, J F
Tetraploid Vaccinium corymbosum genotypes exhibit wide variability in seed set following self- and cross-pollinations. In this paper, a post-zygotic mechanism (seed abortion) under polygenic control is proposed as the basis for fertility differences in this species. A pollen chase experiment indicated that self-pollen tubes fertilize ovules, but are also 'outcompeted' by foreign male gametes in pollen mixtures. Matings among cultivars derived from a pedigree showed a linear decrease in seed number per fruit, and increase in seed abortion, with increasing relatedness among parents. Selfed (S1) progeny from self-fertile parents were largely self-sterile. At zygotic levels of inbreeding of F>0.3 there was little or no fertility, suggesting that an inbreeding threshold regulates reproductive success in V. corymbosum matings. Individuals below the threshold are facultative selfers, while those above it are obligate outcrossers. Inbreeding also caused a decrease in pollen viability, and reduced female fertility more rapidly than male fertility. These phenomena are discussed in terms of two models of genetic load: (1) mutational load - homozygosity for recessive embryolethal or sub-lethal mutations and (2) segregational load - loss of allelic interactions essential for embryonic vigor. Self-infertility in highbush blueberries is placed in the context of 'late-acting' self-incompatibility versus 'early-acting' inbreeding depression in angiosperms.
Kenney, John; Allendorf, Fred W; McDougal, Charles; Smith, James L D
The number and size of tiger populations continue to decline owing to habitat loss, habitat fragmentation and poaching of tigers and their prey. As a result, tiger populations have become small and highly structured. Current populations have been isolated since the early 1970s or for approximately seven generations. The objective of this study is to explore how inbreeding may be affecting the persistence of remaining tiger populations and how dispersal, either natural or artificial, may reduce the potentially detrimental effect of inbreeding depression. We developed a tiger simulation model and used published levels of genetic load in mammals to simulate inbreeding depression. Following a 50 year period of population isolation, we introduced one to four dispersing male tigers per generation to explore how gene flow from nearby populations may reduce the negative impact of inbreeding depression. For the smallest populations, even four dispersing male tigers per generation did not increase population viability, and the likelihood of extinction is more than 90% within 30 years. Unless habitat connectivity is restored or animals are artificially introduced in the next 70 years, medium size wild populations are also likely to go extinct, with only four to five of the largest wild tiger populations likely to remain extant in this same period without intervention. To reduce the risk of local extinction, habitat connectivity must be pursued concurrently with efforts to increase population size (e.g. enhance habitat quality, increase habitat availability). It is critical that infrastructure development, dam construction and other similar projects are planned appropriately so that they do not erode the extent or quality of habitat for these populations so that they can truly serve as future source populations. © 2014 The Author(s) Published by the Royal Society. All rights reserved.
Thiele, Jan; Hansen, Thomas Møller; Siegismund, Hans Redlef
The magnitude and variation of inbreeding depression (ID) within populations is important for the evolution and maintenance of mixed mating systems. We studied ID and its genetic variation in a range of floral and fitness traits in a small and large population of the perennial herb Silene nutans......, using controlled pollinations in a fully factorial North Carolina II design. Floral traits and early fitness traits, that is seed mass and germination rate, were not much affected by inbreeding (delta0.4). Lack of genetic correlations indicated that ID in floral, early and late traits is genetically...... was statistically significant in most floral and all seed traits, but not in late fitness traits. However, some paternal families had delta...
Vermeulen, Corneel J.; Bijlsma, R.; Loeschcke, Volker
of inbreeding effects in specific traits, such as age-specific mortality and life span, provide a good starting point, as a limited set of genes is expected to be involved. Results Here we report on a QTL mapping study on inbreeding related and temperature sensitive lethality in male Drosophila melanogaster...... and the molecular properties of genes that give rise to or modulate its deleterious effects is lacking. These questions warrant the detailed study of genetic loci giving rise to inbreeding depression. However, the complex and polygenic nature of general inbreeding depression makes this a daunting task. Study...... simple, being due mainly to a single recessive QTL on the left arm of chromosome 2. This locus colocalised with a QTL that conditioned variation in female life span, acting as an overdominant locus for this trait. Male life span was additionally affected by variation at the X-chromosome. Conclusion...
Bjelland, D W; Weigel, K A; Vukasinovic, N; Nkrumah, J D
The effects of increased pedigree inbreeding in dairy cattle populations have been well documented and result in a negative impact on profitability. Recent advances in genotyping technology have allowed researchers to move beyond pedigree analysis and study inbreeding at a molecular level. In this study, 5,853 animals were genotyped for 54,001 single nucleotide polymorphisms (SNP); 2,913 cows had phenotypic records including a single lactation for milk yield (from either lactation 1, 2, 3, or 4), reproductive performance, and linear type conformation. After removing SNP with poor call rates, low minor allele frequencies, and departure from Hardy-Weinberg equilibrium, 33,025 SNP remained for analyses. Three measures of genomic inbreeding were evaluated: percent homozygosity (FPH), inbreeding calculated from runs of homozygosity (FROH), and inbreeding derived from a genomic relationship matrix (FGRM). Average FPH was 60.5±1.1%, average FROH was 3.8±2.1%, and average FGRM was 20.8±2.3%, where animals with larger values for each of the genomic inbreeding indices were considered more inbred. Decreases in total milk yield to 205d postpartum of 53, 20, and 47kg per 1% increase in FPH, FROH, and FGRM, respectively, were observed. Increases in days open per 1% increase in FPH (1.76 d), FROH (1.72 d), and FGRM (1.06 d) were also noted, as well as increases in maternal calving difficulty (0.09, 0.03, and 0.04 on a 5-point scale for FPH, FROH, and FGRM, respectively). Several linear type traits, such as strength (-0.40, -0.11, and -0.19), rear legs rear view (-0.35, -0.16, and -0.14), front teat placement (0.35, 0.25, 0.18), and teat length (-0.24, -0.14, and -0.13) were also affected by increases in FPH, FROH, and FGRM, respectively. Overall, increases in each measure of genomic inbreeding in this study were associated with negative effects on production and reproductive ability in dairy cows. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc
Luijten, S.H.; Kery, M.; Oostermeijer, J.G.B.; Den, Nijs H.J.C.M.
1. The genetic constitution of populations may significantly affect demography. Founder populations or isolated remnants may show inbreeding depression, while established populations can be strongly adapted to the local environment. Gene exchange between populations can lead to better performance if heterozygosity levels are restored (heterosis), or to reduced performance if coadapted gene complexes are disrupted (outbreeding depression). 2. Five populations of the self-incompatible perennial Arnica montana (Asteraceae) were analysed for the demographic consequences of inbreeding and of intra- and interpopulation outcrossing, using both small and large populations as donors for the latter. We analysed seed production and seed weight and monitored growth, survival and flowering of offspring introduced as seeds and as 4-week-old seedlings in a 4-year field experiment. 3. Reduced seed set after selfing was probably due to the self-incompatibility system rather than to inbreeding depression. There was a significant increase for seed set after interpopulation crosses, which resulted from the alleviation of low mate availability in one of the small populations. 4. Significant inbreeding depression was observed for growth rates of plants introduced as seedlings. We found significant heterosis for flowering probability of plants introduced as seeds, but for plants introduced as seedlings, heterosis for seedling size and flowering probability was only marginally significant. Outbreeding depression was not observed. 5. The results of this study are important for reinforcement measures in small, remnant populations. Significant differences among populations for all measured fitness components suggest that reinforcement is best achieved using material from several populations. 6. The observed higher survival of seedlings as compared with seeds suggests that it is better to plant individuals than to sow. Sowing, however, is easier and cheaper, and was more likely to eliminate
Hofer, Michal; Pospíšil, Milan; Dušek, L.; Holá, Jiřina; Hoferová, Zuzana; Weiterová, Lenka
Roč. 235, č. 8 (2010), s. 928-931 ISSN 1535-3702 R&D Projects: GA ČR(CZ) GA305/08/0158 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : hematopoiesis * outbred mice * inbreeding depression Subject RIV: BO - Biophysics Impact factor: 2.954, year: 2010
Inbreeding has been incriminated as a cause of decrease in reproductive performance in cattle. This negative correlation is known as ‘inbreeding depression’, and evidence supporting this hypothesis was generated from association studies between reproductive traits and estimates of inbreeding coeffic...
Full Text Available Angiosperms evolved different systems to attract effective pollinators while reducing selfing in hermaphroditic flowers. Selfing ability can be advantageous when pollinators and/or mates are scarce, although inbreeding depression may largely reduce those advantages. Recent comparative analyses suggested endemic species tend to evolve self-compatibility but a better understanding of the associated reproductive and genetic tradeoffs is required. Experimental hand-pollinations under greenhouse conditions were conducted to investigate the selfing ability and estimate inbreeding depression up to the offspring’ first reproductive event in Ero dium cazorlanum, a narrow endemic species restricted to dolomite outcrops in SE Spanish mountains. We found autonomous selfing ineffective. Further, when experimentally applied, pollen of the same flower produced significantly fewer fruits and seeds compared to geitonogamous and cross pollinations. The number of seeds per fruit was significantly higher after cross pollinations and strong inbreeding depression accumulated through the life-cycle. Interestingly, individual plants exhibited broad variation in selfing ability with six out of 14 individuals producing no seed after geitonogamy. Understanding the consequences of individual variation in self compatibility deserves further investigation in the field now that we know that strong inbreeding depression may limit recruitment of selfed progeny.Las Angiospermas han desarrollado diversos sistemas para atraer polinizadores eficientes y al mismo tiempo reducir la posibilidad de autopolinización asociada al hermafroditismo. La capacidad de autopolinización puede ser ventajosa en situaciones de escasez de polinizadores y/o individuos reproductores, beneficios que pueden reducirse ampliamente a causa de la depresión por endogamia. Análisis filogenéticos recientes indicaron que las especies endémicas tienden a presentar sistemas de autocompatibilidad, por tanto
Gargano, D; Gullo, T; Bernardo, L
We studied inbreeding depression, growth context and maternal influence as constraints to fitness in the self-compatible, protandrous Dianthus guliae Janka, a threatened Italian endemic. We performed hand-pollinations to verify outcomes of self- and cross-fertilisation over two generations, and grew inbred and outbred D. guliae offspring under different conditions - in pots, a common garden and field conditions (with/without nutrient addition). The environment influenced juvenile growth and flowering likelihood/rate, but had little effect on inbreeding depression. Significant interactions among genetic and environmental factors influenced female fertility. Overall, genetic factors strongly affected both early (seed mass, seed germination, early survival) and late (seed/ovule ratio) life-history traits. After the first pollination experiment, we detected higher mortality in the selfed progeny, which is possibly a consequence of inbreeding depression caused by over-expression of early-acting deleterious alleles. The second pollination induced a strong loss of reproductive fitness (seed production, seed mass) in inbred D. guliae offspring, regardless of the pollination treatment (selfing/crossing); hence, a strong (genetic) maternal influence constrained early life-history traits of the second generation. Based on current knowledge, we conclude that self-compatibility does not prevent the detrimental effects of inbreeding in D. guliae populations, and may increase the severe extinction risk if out-crossing rates decrease. © 2010 German Botanical Society and The Royal Botanical Society of the Netherlands.
Gao, Li-Zhi; Gao, Cheng-Wen
The distribution of genetic variability from the interior towards the periphery of a species' range is of great interest to evolutionary biologists. Although it has been long presumed that population genetic variation should decrease as a species' range is approached, results of empirical investigations still remain ambiguous. Knowledge regarding patterns of genetic variability as well as affected factors is particularly not conclusive in plants. To determine genetic divergence in peripheral populations of the wild rice Oryza rufipogon Griff. from China, genetic diversity and population structure were studied in five northern & northeastern peripheral and 16 central populations using six microsatellite loci. We found that populations resided at peripheries of the species possessed markedly decreased microsatellite diversity than those located in its center. Population size was observed to be positively correlated with microsatellite diversity. Moreover, there are significantly positive correlations between levels of microsatellite diversity and distances from the northern and northeastern periphery of this species. To investigate genetic structure and heterozygosity variation between generations of O. rufipogon, a total of 2382 progeny seeds from 186 maternal families were further assayed from three peripheral and central populations, respectively. Peripheral populations exhibited significantly lower levels of heterozygosities than central populations for both seed and maternal generations. In comparisons with maternal samples, significantly low observed heterozygosity (HO) and high heterozygote deficit within populations (FIS) values were detected in seed samples from both peripheral and central populations. Significantly lower observed heterozygosity (HO) and higher FIS values were further observed in peripheral populations than those in central populations for seed samples. The results indicate an excess of homozygotes and thus high inbreeding depression in
Hardy Olivier J
Full Text Available Abstract Background Understanding the mechanisms that control species genetic structure has always been a major objective in evolutionary studies. The association between genetic structure and species attributes has received special attention. As species attributes are highly taxonomically constrained, phylogenetically controlled methods are necessary to infer causal relationships. In plants, a previous study controlling for phylogenetic signal has demonstrated that Wright's FST, a measure of genetic differentiation among populations, is best predicted by the mating system (outcrossing, mixed-mating or selfing and that plant traits such as perenniality and growth form have only an indirect influence on FST via their association with the mating system. The objective of this study is to further outline the determinants of plant genetic structure by distinguishing the effects of mating system on gene flow and on genetic drift. The association of biparental inbreeding and inbreeding depression with population genetic structure, mating system and plant traits are also investigated. Results Based on data from 263 plant species for which estimates of FST, inbreeding (FIS and outcrossing rate (tm are available, we confirm that mating system is the main influencing factor of FST. Moreover, using an alternative measure of FST unaffected by the impact of inbreeding on effective population size, we show that the influence of tm on FST is due to its impact on gene flow (reduced pollen flow under selfing and on genetic drift (higher drift under selfing due to inbreeding. Plant traits, in particular perenniality, influence FST mostly via their effect on the mating system but also via their association with the magnitude of selection against inbred individuals: the mean inbreeding depression increases from short-lived herbaceous to long-lived herbaceous and then to woody species. The influence of perenniality on mating system does not seem to be related to
Silva, Marcel Müller Fernandes Pereira da; Diniz-Filho, José Alexandre Felizola
Despite methodological and theoretical advances in conservation genetics, data on genetic variation on broad regional spatial scales are still scarce, leading conservation planners to use general heuristic or simulation models for an integrated analysis of genetic, demographic and landscape parameters. Here, we extended previous results by evaluating spatial patterns of extinction by inbreeding depression under stochastic variation of environments for mammalian populations in 31 conservation ...
E. G. Kozar
Full Text Available The protected cultivation technology, through which the various inbred generations with the combination of economic valuable traits and different level of sterility can be produced, is used in order to accelerate the breeding program. However, there is a negative effect of inbreeding depression and self-incompatibility can often occur and cause the loss of valuable breeding forms. The aim of the work was to study the influence of steroidal glycosides capsicoside (SGC on exhibition of CMS, and morphobiological parameters of 13 inbred generations that were produced from fertile plant and partly sterile plants with level of sterility 10% and 50%. The seeds were soaked for 24 hours in water solution of SGC with concentration 10-3%, and in water control. Then the seeds were dried up and sown in the greenhouse. The stecklings and roots obtained were vernalized at 3-5Co. Mother plants were grown under 18 hour photoperiod in greenhouse with supplementary lighting. Inbreeding seeds were obtained in individual cloth isolators. It was shown that for all generations the treatment with SGC improved the seed germination (4-8% more, increased the root index and its length (12-24% more, decreased betanin content (22-48% less in comparison with control. The action of SGC on the other morphological and biochemical traits such as height of leaf rosette, leaf number, plant and root weight, head size, number of generative buds, and nitrate content was defined by the level of sterility of mother plant. The most expressed effect for all traits mentioned was seen in inbreeding generations of sterile plants with high level of sterility. After action effect of seed treatment with SGC on development of seed plants from inbreeding generations, not depending on sterility level of mother plants, showed the positive influence on plant habitus of seed mother plants, decreasing the plant height, but increasing stem number and functional parameters of microgametophyte in fertile
João Costa E Silva
Full Text Available Using native trees from near the northern and southern extremities of the relatively continuous eastern distribution of Eucalyptus globulus in Tasmania, we compared the progenies derived from natural open-pollination (OP with those generated from within-region and long-distance outcrossing. Controlled outcrossing amongst eight parents - with four parents from each of the northern and southern regions - was undertaken using a diallel mating scheme. The progeny were planted in two field trials located within the species native range in southern Tasmania, and their survival and diameter growth were monitored over a 13-year-period. The survival and growth performances of all controlled cross types exceeded those of the OP progenies, consistent with inbreeding depression due to a combination of selfing and bi-parental inbreeding. The poorer survival of the northern regional (♀N♂N outcrosses compared with the local southern regional outcrosses (♀S♂S indicated differential selection against the former. Despite this mal-adaptation of the non-local ♀N♂N crosses at both southern sites, the survival of the inter-regional hybrids (♀N♂S and ♀S♂N was never significantly different from that of the local ♀S♂S crosses. Significant site-dependent heterosis was detected for the growth of the surviving long-distance hybrids. This was expressed as mid-parent heterosis, particularly at the more northern planting site. Heterosis increased with age, while the difference between the regional ♀N♂N and ♀S♂S crosses remained insignificant at any age at either site. Nevertheless, the results for growth suggest that the fitness of individuals derived from long-distance crossing may be better at the more northern of the planting sites. Our results demonstrate the potential for early-age assessments of pollen dispersal to underestimate realised gene flow, with local inbreeding under natural open-pollination resulting in selection favouring the
Full Text Available An assessment of reproductive behavior and inbreeding depression, if any, in critically endangered Eremostachys superba Royle ex Benth. (Labiatae was made to unveil the factors playing vital role in it’s reproductive biology and which may be responsible for the loss of fitness, viability and vigor of the species. Breeding experiments portrayed a failure of self-fertilization and a strong tendency towards out-breeding as seed set by xenogamy was highest (44.4%. However, the narrow restricted population of the type locality in Dehra Dun Siwaliks was just a ramet population sustained by clonal propagation of rhizomatous root stock, hence any out-crossing within these homozygous individuals also amounted to inbreeding. Further, there is no other population available within the range of normal seed dispersal mechanism or insect-pollinator-flight-range. The other populations reported are only from geographically distant region of Jammu and Kashmir state of India, which is too far a distance to be covered by the Nomia rustica West. and Ceratina heiroglyphica Sm., the oligophilic pollinators of E. superba, hence any crossing taking place also amounts to selfing in strict sense. Chances of induction of genetic variation by crossing between two different populations are remote. This was also supported by the data of seed production and germination experiments. Even the healthy seeds suffered from loss of fitness and failed to germinate under natural conditions. This strongly indicated prevalence of inbreeding depression and loss of fitness of the progeny right from the stage of germination, a phenomenon hazardous for sustenance and perpetuation of species leading to rarity.
Pedersen, Kamilla Sofie; Pedersen, Louise Dybdahl; Sørensen, Anders Christian
Mating between closely related individuals often causes reduced fitness, which is termed ‘inbreeding depression’. Inbreeding is, therefore, a threat towards the persistence of animal and plant populations. Here we present methods and results from a practical for high-school and first-year univers......Mating between closely related individuals often causes reduced fitness, which is termed ‘inbreeding depression’. Inbreeding is, therefore, a threat towards the persistence of animal and plant populations. Here we present methods and results from a practical for high-school and first......-year university students and discuss learning outcomes of the exercise as an example of inquiry-based science teaching. We use the model organism Drosophila melanogaster to test the ability of inbred and control (non-inbred) females to survive heat stress exposure. Flies were anaesthetised and collected...... into vials before exposure to 38°C heat stress in a water bath for 1 h. Half an hour later the number of comatose inbred and control flies were scored and chi-square statistic procedures were used to test for different degrees of heat stress tolerance between the two lines of flies. The practical introduces...
Hauser, Thure Pavlo; Siegismund, H.R.
inbreeding depression, oubreeding effects, outcrossing, pollen fitness, selfing, Silene nutans, zygote survival......inbreeding depression, oubreeding effects, outcrossing, pollen fitness, selfing, Silene nutans, zygote survival...
Flávia Melo Rodrigues
Full Text Available A frequently addressed question in conservation biology is what is the chance of survival for a population for a given number of years under certain conditions of habitat loss and human activities. This can be estimated through an integrated analysis of genetic, demographic and landscape processes, which allows the prediction of more realistic and precise models of population persistence. In this study, we modeled extinction in stochastic environments under inbreeding depression for two canid species, the maned wolf (Chrysocyon brachiurus and the crab-eating fox (Cerdocyon thous, in southwest Goiás State. Genetic parameters were obtained from six microsattelite loci (Short Tandem Repeats - STR, which allowed estimates of inbreeding levels and of the effective population size under a stepwise mutation model based on heterozygosis. The simulations included twelve alternative scenarios with varying rates of habitat loss, magnitude of population fluctuation and initial inbreeding levels. ANOVA analyses of the simulation results showed that times to extinction were better explained by demographic parameters. Times to extinction ranged from 352 to 844, in the worst and best scenario, respectively, for the large-bodied maned wolf. For the small-bodied crab-eating fox, these same estimates were 422 and 974 years. Simulations results are within the expectation based on knowledge about species' life history, genetics and demography. They suggest that populations can persist through a reasonable time (i.e., more than 200 years even under the worst demographic scenario. Our analyses are a starting point for a more focused evaluation of persistence in these populations. Our results can be used in future research aiming at obtaining better estimates of parameters that may, in turn, be used to achieve more appropriate and realist population viability models at a regional scale.
Kristensen, Torsten Nygård; Loeschcke, Volker; Bilde, Trine
stressful temperatures, but whether adaptation to thermal stress through plastic responses also is affected by inbreeding is so far not clear. In this study, we test inherent cold resistance and the ability to respond plastically to temperature changes through developmental cold acclimation in inbred...... the ability to respond adaptively to temperature acclimation, and (3) tropical species with low basal resistance show stronger adaptive plastic responses to developmental acclimation compared to widespread species...
Todd, Evelyn T; Ho, Simon Y W; Thomson, Peter C; Ang, Rachel A; Velie, Brandon D; Hamilton, Natasha A
The Thoroughbred horse has played an important role in both sporting and economic aspects of society since the establishment of the breed in the 1700s. The extensive pedigree and phenotypic information available for the Thoroughbred horse population provides a unique opportunity to examine the effects of 300 years of selective breeding on genetic load. By analysing the relationship between inbreeding and racing performance of 135,572 individuals, we found that selective breeding has not efficiently alleviated the Australian Thoroughbred population of its genetic load. However, we found evidence for purging in the population that might have improved racing performance over time. Over 80% of inbreeding in the contemporary population is accounted for by a small number of ancestors from the foundation of the breed. Inbreeding to these ancestors has variable effects on fitness, demonstrating that an understanding of the distribution of genetic load is important in improving the phenotypic value of a population in the future. Our findings hold value not only for Thoroughbred and other domestic breeds, but also for small and endangered populations where such comprehensive information is not available.
of depression and the increase in individual genetic diversity is the cause of heterosis. ... Keywords. nonsense gene; vital gene; gene products; individual genetic diversity; number ..... These values of a variety created by hybrid method as well.
Hammerly, Susan C; Morrow, Michael E; Johnson, Jeff A
The primary goal of captive breeding programmes for endangered species is to prevent extinction, a component of which includes the preservation of genetic diversity and avoidance of inbreeding. This is typically accomplished by minimizing mean kinship in the population, thereby maintaining equal representation of the genetic founders used to initiate the captive population. If errors in the pedigree do exist, such an approach becomes less effective for minimizing inbreeding depression. In this study, both pedigree- and DNA-based methods were used to assess whether inbreeding depression existed in the captive population of the critically endangered Attwater's Prairie-chicken (Tympanuchus cupido attwateri), a subspecies of prairie grouse that has experienced a significant decline in abundance and concurrent reduction in neutral genetic diversity. When examining the captive population for signs of inbreeding, variation in pedigree-based inbreeding coefficients (f(pedigree)) was less than that obtained from DNA-based methods (f(DNA)). Mortality of chicks and adults in captivity were also positively correlated with parental relatedness (r(DNA)) and f(DNA), respectively, while no correlation was observed with pedigree-based measures when controlling for additional variables such as age, breeding facility, gender and captive/release status. Further, individual homozygosity by loci (HL) and parental rDNA values were positively correlated with adult mortality in captivity and the occurrence of a lethal congenital defect in chicks, respectively, suggesting that inbreeding may be a contributing factor increasing the frequency of this condition among Attwater's Prairie-chickens. This study highlights the importance of using DNA-based methods to better inform management decisions when pedigrees are incomplete or errors may exist due to uncertainty in pairings. © 2013 John Wiley & Sons Ltd.
VANTREUREN, R; BIJLSMA, R; OUBORG, NJ; VANDELDEN, W
The effects of self-fertilization, within-population crosses (WPC) and between-population crosses (BPC) on progeny fitness were investigated in the greenhouse for Scabiosa columbaria populations of varying size. Plants grown from field collected seeds were hand pollinated to produce selfed, WPC, and
Ketola, T; Kotiaho, J S
In energetic terms, fitness may be seen to be dependent on successful allocation of energy between life-history traits. In addition, fitness will be constrained by the energy allocation ability, which has also been defined as condition. We suggest here that the allocation ability, estimated as the difference between total energy budget and maintenance metabolism, may be used as a measure of condition. We studied this possibility by measuring the resting metabolic rate and metabolism during forced exercise in Gryllodes sigillatus crickets. To verify that these metabolic traits are closely related to fitness, we experimentally manipulated the degree of inbreeding of individuals belonging to the same pedigree, hence enabling analysis of both inbreeding depression and heritability of traits. We found that inbreeding increased maintenance metabolism, whereas total energy budget was rather insensitive to inbreeding. Despite this, inbreeding led to decreased allocation ability. Overall, metabolic traits exhibited strong inbreeding depression and rather low heritabilities, a pattern that is typical of traits under strong selection. However, traditionally used condition indices were not affected by inbreeding and did not covary with metabolic traits. Moreover, in contrast to the common, but largely untested, tenet, it seems that high resting metabolic rate is indicative of low rather than high quality.
Full Text Available Abstract We assessed the expected relationship between the level and the cost of inbreeding, measured either in terms of fitness, inbreeding depression or probability of extinction. First, we show that the assumption of frequent, slightly deleterious mutations do agree with observations and experiments, on the contrary to the assumption of few, moderately deleterious mutations. For the same inbreeding coefficient, populations can greatly differ in fitness according to the following: (i population size; larger populations show higher fitness (ii the history of population size; in a population that recovers after a bottleneck, higher inbreeding can lead to higher fitness and (iii population demography; population growth rate and carrying capacity determine the relationship between inbreeding and extinction. With regards to the relationship between inbreeding depression and inbreeding coefficient, the population size that minimizes inbreeding depression depends on the level of inbreeding: inbreeding depression can even decrease when population size increases. It is therefore clear that to infer the costs of inbreeding, one must know both the history of inbreeding (e.g. past bottlenecks and population demography.
Nov 1, 2010 ... ISSN 1684–5315 ©2010 Academic Journals. Full Length ... Key words: Hybrid vigor, inbreeding depression, cottonseed traits, cottonseed oil, Gossypium hirsutum. ... in yield and superior performance than well-adapted.
In the variety TKM6 a high yielding semidwarf mutant has been induced. This TKM6 mutant was used in test crosses with a number of other varieties and mutants to examine the extent of heterosis of dwarfs in rice and to select superior crosses. An excerpt of the published data is given. It appears from the backcross of the mutant with its original variety, that an increase in number of productive tillers occurs in the hybrid, leading to a striking grain yield increase, while the semi-dwarf culm length (the main mutant character) reverts to the normal phenotype. In the cross with IR8 on the other hand, there is only a minimal increase in tiller number but a substantial increase in TGW leading to more than 30% yield increase over the better parent
Pujol, B; McKey, D
The effects of competition on the genetic composition of natural populations are not well understood. We combined demography and molecular genetics to study how intraspecific competition affects microevolution in cohorts of volunteer plants of cassava (Manihot esculenta) originating from seeds in slash-and-burn fields of Palikur Amerindians in French Guiana. In this clonally propagated crop, genotypic diversity is enhanced by the incorporation of volunteer plants into farmers' stocks of clonal propagules. Mortality of volunteer plants was density-dependent. Furthermore, the size asymmetry of intraspecific competition increased with local clustering of plants. Size of plants was correlated with their multilocus heterozygosity, and stronger size-dependence of survival in clusters of plants, compared with solitary plants, increased the magnitude of inbreeding depression when competition was severe. The density-dependence of inbreeding depression of volunteer plants helps explain the high heterozygosity of volunteers that survive to harvest time and thus become candidates for clonal propagation. This effect could help favour the maintenance of sex in this 'vegetatively' propagated crop plant.
Bilde, T.; Maklakov, A.A.; Schilling, Nadia
avoidance can be because of low risk of inbreeding, variation in tolerance to inbreeding or high costs of outbreeding. We examined the relationship between inbreeding depression and inbreeding avoidance adaptations under two levels of inbreeding in the spider Oedothorax apicatus, asking whether preference...... for unrelated sperm via pre- and/or post-copulatory mechanisms could restore female fitness when inbreeding depression increases. Using inbred isofemale lines we provided female spiders with one or two male spiders of different relatedness in five combinations: one male sib; one male nonsib; two male sibs; two...
Rymer, P D; Sandiford, M; Harris, S A; Billingham, M R; Boshier, D H
Habitat fragmentation is extensive throughout the world, converting natural ecosystems into fragments of varying size, density and connectivity. The potential value of remnant trees in agricultural landscapes as seed sources and in connecting fragments has formed a fertile area of debate. This study contrasted the mating patterns of bat-pollinated Pachira quinata trees in a continuous forest to those in pasture through microsatellite-based paternity analysis of progeny. The breeding system was determined by analysis of pollen tube growth and seed production from controlled pollinations. Fitness of selfed and outcrossed seed was compared by germination and seedling growth. There was more inbreeding within pasture trees (outcrossing=0.828±0.015) compared with forest trees (0.926±0.005). Pasture trees had fewer sires contributing to mating events, but pollen dispersal distances were greater than those in the forest. Paternity analysis showed variation in outcrossing rates among pasture trees with high proportions of external and self pollen sources detected. A leaky self-incompatibility system was found, with self pollen having reduced germination on stigmas and slower growth rate through the style. Controlled pollinations also showed a varied ability to self among trees, which was reflected in the selfing rates among pasture trees shown by the paternity analysis (0-80% selfing). Self pollination resulted in lower seed set, germination and seedling growth compared with outcrossing. While remnant trees in agricultural landscapes are involved in broader mating patterns, they show increased but varied levels of inbreeding, which result in reduced fitness.
Vermeulen, C.J.; Pedersen, Kamilla Sofie; Beck, Hans C.
insight into the molecular interplay between intrinsic stress responses, inbreeding depression and temperature tolerance, we performed a proteomic characterization of a well-defined conditional inbreeding effect in a single line of Drosophila melanogaster, which suffers from extreme cold sensitivity...
Kristensen, Torsten Nygård; Knudsen, Morten Ravn; Loeschcke, Volker
Selection may reduce the deleterious consequences of inbreeding. This may be due to purging of recessive deleterious alleles or balancing selection favouring heterozygote offspring. Such selection is expected to be more efficient at slower compared to at faster rates of inbreeding. In this study ...
Ceballos, F C; Alvarez, G
The European royal dynasties of the Early Modern Age provide a useful framework for human inbreeding research. In this article, consanguineous marriage, inbreeding depression and the purging of deleterious alleles within a consanguineous population are investigated in the Habsburgs, a royal dynasty with a long history of consanguinity over generations. Genealogical information from a number of historical sources was used to compute kinship and inbreeding coefficients for the Habsburgs. The marriages contracted by the Habsburgs from 1450 to 1750 presented an extremely high mean kinship (0.0628±0.009), which was the result of the matrimonial policy conducted by the dynasty to establish political alliances through marriage. A strong inbreeding depression for both infant and child survival was detected in the progeny of 71 Habsburg marriages in the period 1450-1800. The inbreeding load for child survival experienced a pronounced decrease from 3.98±0.87 in the period 1450-1600 to 0.93±0.62 in the period 1600-1800, but temporal changes in the inbreeding depression for infant survival were not detected. Such a reduction of inbreeding depression for child survival in a relatively small number of generations could be caused by elimination of deleterious alleles of a large effect according with predictions from purging models. The differential purging of the infant and child inbreeding loads suggest that the genetic basis of inbreeding depression was probably very different for infant and child survival in the Habsburg lineage. Our findings provide empirical support that human inbreeding depression for some fitness components might be purged by selection within consanguineous populations.
Jensen, Charlotte; Ørsted, Michael; Kristensen, Torsten Nygaard
Habitat fragmentation and small population sizes can lead to inbreeding and loss of genetic variation, which can potentially cause inbreeding depression and decrease the ability of populations to adapt to altered environmental conditions. One solution to these genetic problems is the implementati...
Mikkelsen, Karina Aarup; Loeschcke, Volker; Kristensen, Torsten Nygaard
or 2 generations. These inbred lines were contrasted to non-inbred control lines. We investigated the effect of inbreeding and inbreeding rate in traits associated with fitness including heat, cold and desiccation stress resistance, egg-to-adult viability, development time, productivity, metabolic rate......The increased homozygosity due to inbreeding leads to expression of deleterious recessive alleles, which may cause inbreeding depression in small populations. The severity of inbreeding depression has been suggested to depend on the rate of inbreeding, with slower inbreeding being more effective...... and heat stress conditions. Reduced viability and increased developmental time were observed at stressful temperatures and inbreeding depression was on average more severe at stressful compared to benign temperatures...
T79/467 showed good aptitudes for the combination of characters because their ... distinguished themselves by better levels of mid-parent heterosis values. ... contained in cocoa seeds are catechins (3.0-6.0%), ...... in melon (Cucumismelo L.).
This manual, written for extension workers, aquaculturists, and those who work with inbreeding in cultured fish populations and describes management techniques that can be used to prevent or minimize inbreeding...
Inbreeding depression (delta) is a major selective force favoring outcrossing in flowering plants. Many phenotypic and genetic models of the evolution of selfing conclude that complete outcrossing should evolve whenever inbreeding depression is greater than one-half, otherwise selfing should evolve.
Inbreeding depression (delta) is a major selective force favoring outcrossing in flowering plants. Many phenotypic and genetic models of the evolution of selfing conclude that complete outcrossing should evolve whenever inbreeding depression is greater than one-half, otherwise selfing should evolve.
Full Text Available Inbreeding is the mating of relatives that produce progeny having more homozygous alleles than non-inbred animals. Inbreeding increases numbers of recessive alleles, which is often associated with decreased performance known as inbreeding depression. The magnitude of inbreeding depression depends on the level of inbreeding in the animal. Level of inbreeding is expressed by the inbreeding coefficient. One breeding goal in livestock is uniform productivity while maintaining acceptable inbreeding levels, especially keeping inbreeding less than 20%. However, in closed herds without the introduction of new genetic sources high levels of inbreeding over time are unavoidable. One method that increases selection response and minimizes inbreeding is selection of individuals by weighting estimated breeding values with average relationships among individuals. Optimum genetic contribution theory (OGC uses relationships among individuals as weighting factors. The algorithm is as follows: i Identify the individual having the best EBV; ii Calculate average relationships ( r j ¯ between selected and candidates; iii Select the individual having the best EBV adjusted for average relationships using the weighting factor k, E B V * = E B V j ( 1 - k r j ¯ . iv Repeat process until the number of individuals selected equals number required. The objective of this study was to compare simulated results based on OGC selection under different conditions over 30 generations. Individuals (n = 110 were generated for the base population with pseudo random numbers of N~ (0, 3, ten were assumed male, and the remainder female. Each male was mated to ten females, and every female was assumed to have 5 progeny resulting in 500 individuals in the following generation. Results showed the OGC algorithm effectively controlled inbreeding and maintained consistent increases in selection response. Difference in breeding values between selection with OGC algorithm and by EBV only was 8
Marr, A B; Arcese, P; Hochachka, W M; Reid, J M; Keller, L F
1. Conservation biologists are concerned about the interactive effects of environmental stress and inbreeding because such interactions could affect the dynamics and extinction risk of small and isolated populations, but few studies have tested for these interactions in nature. 2. We used data from the long-term population study of song sparrows Melospiza melodia on Mandarte Island to examine the joint effects of inbreeding and environmental stress on four fitness traits that are known to be affected by the inbreeding level of adult birds: hatching success, laying date, male mating success and fledgling survival. 3. We found that inbreeding depression interacted with environmental stress to reduce hatching success in the nests of inbred females during periods of rain. 4. For laying date, we found equivocal support for an interaction between parental inbreeding and environmental stress. In this case, however, inbred females experienced less inbreeding depression in more stressful, cooler years. 5. For two other traits, we found no evidence that the strength of inbreeding depression varied with environmental stress. First, mated males fathered fewer nests per season if inbred or if the ratio of males to females in the population was high, but inbreeding depression did not depend on sex ratio. Second, fledglings survived poorly during rainy periods and if their father was inbred, but the effects of paternal inbreeding and rain did not interact. 6. Thus, even for a single species, interactions between the inbreeding level and environmental stress may not occur in all traits affected by inbreeding depression, and interactions that do occur will not always act synergistically to further decrease fitness.
Bebbington, Kat; Spurgin, Lewis G.; Fairfield, Eleanor A.; Dugdale, Hannah L.; Komdeur, Jan; Burke, Terry; Richardson, David S.
Inbreeding results in more homozygous offspring that should suffer reduced fitness, but it can be difficult to quantify these costs for several reasons. First, inbreeding depression may vary with ecological or physiological stress and only be detectable over long time periods. Second, parental
Reid, Jane M; Arcese, Peter; Keller, Lukas F; Germain, Ryan R; Duthie, A Bradley; Losdat, Sylvain; Wolak, Matthew E; Nietlisbach, Pirmin
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.
Mattey, S N; Strutt, L; Smiseth, P T
Inbreeding depression is the reduction in fitness caused by mating between related individuals. Inbreeding is expected to cause a reduction in offspring fitness when the offspring themselves are inbred, but outbred individuals may also suffer a reduction in fitness when they depend on care from inbred parents. At present, little is known about the significance of such intergenerational effects of inbreeding. Here, we report two experiments on the burying beetle Nicrophorus vespilloides, an insect with elaborate parental care, in which we investigated inbreeding depression in offspring when either the offspring themselves or their parents were inbred. We found substantial inbreeding depression when offspring were inbred, including reductions in hatching success of inbred eggs and survival of inbred offspring. We also found substantial inbreeding depression when parents were inbred, including reductions in hatching success of eggs produced by inbred parents and survival of outbred offspring that received care from inbred parents. Our results suggest that intergenerational effects of inbreeding can have substantial fitness costs to offspring, and that future studies need to incorporate such costs to obtain accurate estimates of inbreeding depression. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.
Johnson, K.; Butts, I. A. E.; Smith, J. L.
The effects of inbreeding in both captive and wild‐caught species and populations have been reported to affect a wide variety of life history traits. Recently, the effects of inbreeding on reproductive traits such as sperm quality have become a subject of particular interest for conservation...... biology, evolutionary ecology, and management of captive populations. This study investigated the effects of inbreeding on sperm quality in a captive population of experimentally inbred and outbred lake trout, Salvelinus namaycush. It was found for moderately to highly inbred males (males with half......‐sib and full‐sib parents, respectively), that sperm quality traits (velocity, motility, linearity, longevity, spermatocrit and morphology) showed no apparent inbreeding depression. The apparent lack of inbreeding effects on sperm quality traits may be due to several factors including (i) no inbreeding...
Tavares, Orlanda; Cardoso, Sónia; Carvalho, Teresa; Sousa, Sofia Branco; Santiago, Rui
This paper analyses the inbreeding phenomena in Portuguese public universities. Inbreeding is defined as the recruitment of academics by the same institution that awarded their PhDs. Focusing on 1,217 PhD-holding Portuguese academics, belonging to four public universities and to six disciplinary areas, inbreeding is analysed in order to understand…
Jul 5, 2010 ... heterosis; LSD, least significant difference; CV, co-variance. ... The North West Frontier Province of the country .... Mean squares for flowers per cluster, fruits per cluster, fruit length, fruit width, fruit weight and yield per plant.
Rantala, Markus J; Viitaniemi, Heidi; Roff, Derek A
Although numerous studies on vertebrates suggest that inbreeding reduces their resistance against parasites and pathogens, studies in insects have found contradictory evidence. In this study we tested the effect of 1 generation of brother-sister mating (inbreeding) on potential and realized immune responses and other life-history traits in Tenebrio molitor. We found that inbreeding reduced adult mass, pre-adult survival and increased development time, suggesting that inbreeding reduced the condition of the adults and thus potentially made them more susceptible to physiological stress. However, we found no significant effect of inbreeding on the potential immune response (encapsulation response), but inbreeding reduced the realized immune response (resistance against the entomopathogenic fungi, Beauveria bassiana). There was a significant family effect on encapsulation response, but no family effect on the resistance against the entomopathogenic fungi. Given that this latter trait showed significant inbreeding depression and that the sample size for the family-effect analysis was small it is likely that the lack of a significant family effect is due to reduced statistical power, rather than the lack of a heritable basis to the trait. Our study highlights the importance of using pathogens and parasites in immunoecological studies.
Silva Ricardo Machado da
Full Text Available The phenomenon of heterosis has been exploited extensively in maize (Zea mays L. breeding. The objective of this study was to evaluate the genetic potential of ten maize populations for ear yield following the diallel mating scheme. Six parental populations were obtained through phenotypic selection of open-pollinated ears in Rio Verde, GO, Brazil, (GO populations and four parental populations were synthesized in Piracicaba, SP, Brazil (GN populations: GO-D (DENTADO, GO- F (FLINT, GO-A (AMARELO, GO-B (BRANCO, GO-L (LONGO, GO-G (GROSSO, GN-01, GN-02, GN-03 and GN-04. Experiments were carried out in three environments: Anhembi (SP and Rio Verde (GO in 1998/99 (normal season crop and Piracicaba (SP in 1999 (off-season crop. All experiments were in completely randomized blocks with six replications. Analysis of variance grouped over environments showed high significance for heterosis and its components, although mid-parent heterosis and average heterosis were of low expression. The interaction treatments x environments was not significant. Total mid-parent heterosis effects ranged from de -4.3% to 17.3% with an average heterosis of 3.37%. Population with the highest yield (7.4 t ha-1 and with the highest effect of population (v i = 0.746 was GN-03, while the highest yielding cross was GO-B x GN-03 with 7,567 t ha-1. The highest specific heterosis effect (s ii' = 0.547 was observed in the cross GO-B x GN-03.
Vermeulen, Corneel J.; Bijlsma, R.; Loeschcke, Volker
of inbreeding-related and conditionally expressed lethality in Drosophila melanogaster. The lethal effect was triggered by exposure to a cold shock. We used a North Carolina crossing Design 3 to establish the mapping population, as well as to estimate the average dominance ratio and heritability. We found two......Inbreeding depression is a central theme within genetics, and is of specific interest for researchers within evolutionary and conservation genetics and animal and plant breeding. Inbreeding effects are thought to be caused by the joint expression of conditional and unconditional deleterious alleles....... Whenever the expression of deleterious alleles is conditional, this can result in extreme environmental sensitivity in certain inbred lineages. Analysis of conditional lethal effects can reveal some of the loci that are sensitive to inbreeding. We performed a QTL (quantitative trait locus) mapping study...
Munir, S; Hussain, S B; Manzoor, H; Quereshi, M K; Zubair, M; Nouman, W; Shehzad, A N; Rasul, S; Manzoor, S A
Interspecific and intraspecific hybrids show varying degrees of heterosis for yield and yield components. Yield-component traits have complex genetic relationships with each other. To determine the relationship of yield-component traits and fiber traits with seed cotton yield, six lines (Bt. CIM-599, CIM-573, MNH-786, CIM-554, BH-167, and GIZA-7) and three test lines (MNH-886, V4, and CIM-557) were crossed in a line x tester mating design. Heterosis was observed for seed cotton yield, fiber traits, and for other yield-component traits. Heterosis in interspecific hybrids for seed cotton yield was more prominent than in intraspecific hybrids. The interspecific hybrid Giza-7 x MNH-886 had the highest heterosis (114.77), while among intraspecific hybrids, CIM-554 x CIM-557 had the highest heterosis (61.29) for seed cotton yield. A major trait contributing to seed cotton yield was bolls/plant followed by boll weight. Correlation studies revealed that bolls/plant, boll weight, lint weight/boll, lint index, seed index, lint/seed, staple length, and staple strength were significantly and positively associated with seed cotton yield. Selection based on boll weight, boll number, lint weight/boll, and lint index will be helpful for improving cotton seed yield.
This report discusses the clonal planting stock offers many advantages to the forest products industry. Advanced-generation breeding strategies should be designed to maximize within-family variance and at the same time allow the capture of heterosis. Certainly there may be a conflict in the choice of breeding strategy based on the trait of interest. It may be that the majority of the traits express heterosis due to overdominance. Alternatively, disease resistance is expressed as the lack of a specific metabolite or infection court then the homozygous recessive genotype may be the most desirable. Nonetheless, as the forest products industry begins to utilize the economic advantages of clonal forestry, breeding strategies will have to be optimized for these commercial plant materials. Here, molecular markers can be used to characterize the nature of heterosis and therefore define the appropriate breeding strategy.
In this study, five inbred maize lines and ten F1 cross combinations were evaluated in a completely randomized block, in three recursions, placed in unirrigable conditions at the Agricultural Research Development Station (ARDS) Simnic, in 2009. After the heterosis of the F1 cross combinations was evaluated, high genetic differences between parents were noticed. The obtained results suggested that among the six studied parameters, only two the grain yield and the plant heights are relevant for an objective evaluation of heterosis phenomenon. It is recommended that the 4 x 5 and 1 x 5 cross combinations which recorded (for most of the analyzed parameters) the highest degrees of occurrence, both for heterosis over mid parent and for heterobeltiosis, should be used in the maize breeding program to exploit the hybrid vigor. (author)
Zhu, Chen; Zhang, Xiaohui; Zhao, Qiran; Chen, Qihui
In genetics, heterosis refers to the phenomenon that cross-breeding within species leads to offspring that are genetically fitter than their parents and exhibit improved phenotypic characteristics. Based on the theory of heterosis and existing genetic evidence, offspring of "hybrid" marriages (spouses originating from different states/provinces/countries/areas), though relatively rare due to physical boundaries, may exhibit greater genetic fitness in terms of intelligence, height, or physical attractiveness (the "distance-performance" hypothesis). This study explores whether heterosis is a contributing factor to offspring's educational attainment in China by applying a high-dimensional fixed effects (HDFE) modelling framework to the unique 0.1% micro-sample of the 2000 Chinese Population Census data. Concerning potential endogeneity of hybrid marriages, we conduct a series of robustness checks. Reassuringly, the estimated heterosis effect remains significantly positive across various measurements, after controlling for parental educational attainments/height, environmental influences, and over a thousand region and region-by-year fixed effects. The effects in male and higher-educated offspring are found to be stronger. Results are replicated when analyzing body height using data from the China Health and Nutrition Survey. Although endogeneity of "hybrid marriages" may not be completely ruled out, the current study sheds light on the potentially beneficial effects of interprovincial migration on population-level human capital accumulation, and we hope that this paper can intrigue future studies that further address endogeneity. The implied heterosis effect could, therefore, be profound for Homo sapiens as a species from an evolutionary point of view. An additional important implication is that the overall genetic influences of parents on offspring's performance may be further decomposed into a conventional heredity effect and a heterosis effect that has been
R. McQuillan (Ruth); N. Eklund (Niina); N. Pirastu (Nicola); M. Kuningas (Maris); B.P. McEvoy (Brian); T. Esko (Tõnu); T. Corre (Tanguy); G. Davies (Gail); M. Kaakinen (Marika); L.-P. Lyytikäinen (Leo-Pekka); K. Kristiansson (Kati); A.S. Havulinna (Aki); M. Gögele (Martin); V. Vitart (Veronique); A. Tenesa (Albert); Y.S. Aulchenko (Yurii); C. Hayward (Caroline); A. Johansson (Åsa); M. Boban (Mladen); S. Ulivi (Shelia); A. Robino (Antonietta); V. Boraska (Vesna); W. Igl (Wilmar); S.H. Wild (Sarah); L. Zgaga (Lina); N. Amin (Najaf); E. Theodoratou (Evropi); O. Polasek (Ozren); S. Girotto; L.M. Lopez (Lorna); C. Sala (Cinzia); J. Lahti (Jari); T. Laatikainen (Tiina); I. Prokopenko (Inga); M. Kals (Mart); J. Viikari (Jorma); J. Yang (Joanna); A. Pouta (Anneli); K. Estrada Gil (Karol); A. Hofman (Albert); N.B. Freimer (Nelson); N.G. Martin (Nicholas); M. Kähönen (Mika); L. Milani (Lili); M. Heliovaara (Markku); E. Vartiainen (Erkki); K. Räikkönen (Katri); C. Masciullo (Corrado); J.M. Starr (John); A.A. Hicks (Andrew); L. Esposito (Laura); I. Kolcic (Ivana); S.M. Farrington (Susan); B.A. Oostra (Ben); T. Zemunik (Tatijana); H. Campbell (Harry); M. Kirin (Mirna); M. Pehlic (Marina); F. Faletra (Flavio); D.J. Porteous (David J.); G. Pistis (Giorgio); E. Widen (Elisabeth); V. Salomaa (Veikko); S. Koskinen (Seppo); K. Fischer (Krista); T. Lehtimäki (Terho); A.C. Heath (Andrew); M.I. McCarthy (Mark); F. Rivadeneira Ramirez (Fernando); G.W. Montgomery (Grant); H.W. Tiemeier (Henning); A.L. Hartikainen; P.A.F. Madden (Pamela); P. d' Adamo (Pio); N. Hastie (Nick); U. Gyllensten (Ulf); A.F. Wright (Alan); C.M. van Duijn (Cornelia); M.G. Dunlop (Malcolm); I. Rudan (Igor); P. Gasparini (Paolo); P.P. Pramstaller (Peter Paul); I.J. Deary (Ian); D. Toniolo (Daniela); K. Hagen (Knut); A. Jula (Antti); O. Raitakari (Olli); A. Metspalu (Andres); M. Perola (Markus); M.-R. Jarvelin (Marjo-Riitta); A.G. Uitterlinden (André); P.M. Visscher (Peter); J.F. Wilson (James)
textabstractStature is a classical and highly heritable complex trait, with 80%-90% of variation explained by genetic factors. In recent years, genome-wide association studies (GWAS) have successfully identified many common additive variants influencing human height; however, little attention has
Full Text Available Captive breeding of endangered species often aims at preserving genetic diversity and to avoid the harmful effects of inbreeding. However, deleterious alleles causing inbreeding depression can be purged when inbreeding persists over several generations. Despite its great importance both for evolutionary biology and for captive breeding programmes, few studies have addressed whether and to which extent purging may occur. Here we undertake a longitudinal study with the largest captive population of Cuvier's gazelle managed under a European Endangered Species Programme since 1975. Previous results in this population have shown that highly inbred mothers tend to produce more daughters, and this fact was used in 2006 to reach a more appropriate sex-ratio in this polygynous species by changing the pairing strategy (i.e., pairing some inbred females instead of keeping them as surplus individuals in the population. Here, by using studbook data we explore whether purging has occurred in the population by investigating whether after the change in pairing strategy a inbreeding and homozygosity increased at the population level, b fitness (survival increased, and c the relationship between inbreeding and juvenile survival, was positive. Consistent with the existence of purging, we found an increase in inbreeding coefficients, homozygosity and juvenile survival. In addition, we showed that in the course of the breeding programme the relationship between inbreeding and juvenile survival was not uniform but rather changed over time: it was negative in the early years, flat in the middle years and positive after the change in pairing strategy. We highlight that by allowing inbred individuals to mate in captive stocks we may favour sex-ratio bias towards females, a desirable managing strategy to reduce the surplus of males that force most zoos to use ethical culling and euthanizing management tools. We discuss these possibilities but also acknowledge that many
Kristensen, Torsten N; Pedersen, Kamilla S; Vermeulen, Cornelis J
Developments in molecular and systems biology have enabled novel approaches to be used in the study of inbreeding. Mechanistic and functional studies using ‘omic' technologies can increase the understanding of the consequences of inbreeding, from the level of DNA to that of population growth...
Kristensen, Torsten Nygård; Barker, J. Stuart F.; Pedersen, Kamilla Sofie
when compared with non-inbred lines of Drosophila melanogaster under different temperature conditions. Egg-to-adult viability, developmental time and sex ratio of emerging adults are studied under low, intermediate and high temperatures under laboratory as well as semi-natural conditions. The results...... show inbreeding depression for egg-to-adult viability. The level of inbreeding depression is highly dependent on test temperature and is observed only at low and high temperatures. Inbreeding did not affect the developmental time or the sex ratio of emerging adults. However, temperature affected...... the sex ratio with more females relative to males emerging at low temperatures, suggesting that selection against males in pre-adult life stages is stronger at low temperatures. The coefficient of variation (CV) of egg-to-adult viability within and among lines is higher for inbred flies and generally...
Jun 11, 2014 ... Izge AU, Kadams AM, Gungula DT (2007). Heterosis and inheritance of quantitative characters in diallel cross of pearl millet (Pennisetum glaucam L.). J. Agron. 62:278-285. Jaliya MM, Babaji BA, Sani BM, Aminu D, Ibrahim A (2011). Effects of nitrogen and sulfur fertilizers on sulfur content in soil, ear leaf, ...
A crossbreeding experiment using Cameroon indigenous (CF) and German Dahlem Red (GR) chickens was undertaken to determine production performance and heterosis estimates of body weight of cockerels and laying hens at various ages and and egg production traits in layers. Four genetic groups were involved, ...
May 3, 2012 ... Heterosis or hybrid vigor can play a vital role in increasing the yield quality of pumpkin. It refers to the phenomenon in which F1 hybrid obtained by crossing of two genetically dissimilar inbred lines or genotypes, shows increased or decreased vigor over the better parent or mid parent value . In cucurbits,.
Standard heterosis of the crop parameters ranged from -8.22% for harvest index to 191.57% for number of pods per plant, while for seed yield per plant it ranged from -16.64 to 66.09%. Both additive and non additive gene actions were important in controlling days to 50% flowering, pod length, percent oil content, plant ...
Karin J H Verweij
Full Text Available Across animal species, offspring of closely related mates exhibit lower fitness, a phenomenon called inbreeding depression. Inbreeding depression in humans is less well understood because mating between close relatives is generally rare and stigmatised, confounding investigation of its effect on fitness-relevant traits. Recently, the availability of high-density genotype data has enabled quantification of variation in distant inbreeding in 'outbred' human populations, but the low variance of inbreeding detected from genetic data in most outbred populations means large samples are required to test effects, and only a few traits have yet been studied. However, it is likely that isolated populations, or those with a small effective population size, have higher variation in inbreeding and therefore require smaller sample sizes to detect inbreeding effects. With a small effective population size and low immigration, Northern Finland is such a population. We make use of a sample of ∼5,500 'unrelated' individuals in the Northern Finnish Birth Cohort 1966 with known genotypes and measured phenotypes across a range of fitness-relevant physical and psychological traits, including birth length and adult height, body mass index (BMI, waist-to-hip ratio, blood pressure, heart rate, grip strength, educational attainment, income, marital status, handedness, health, and schizotypal features. We find significant associations in the predicted direction between individuals' inbreeding coefficient (measured by proportion of the genome in runs of homozygosity and eight of the 18 traits investigated, significantly more than the one or two expected by chance. These results are consistent with inbreeding depression effects on a range of human traits, but further research is needed to replicate and test alternative explanations for these effects.
Ginn, B R
Identifying the physical basis of heterosis (or "hybrid vigor") has remained elusive despite over a hundred years of research on the subject. The three main theories of heterosis are dominance theory, overdominance theory, and epistasis theory. Kacser and Burns (1981) identified the molecular basis of dominance, which has greatly enhanced our understanding of its importance to heterosis. This paper aims to explain how overdominance, and some features of epistasis, can similarly emerge from the molecular dynamics of proteins. Possessing multiple alleles at a gene locus results in the synthesis of different allozymes at reduced concentrations. This in turn reduces the rate at which each allozyme forms soluble oligomers, which are toxic and must be degraded, because allozymes co-aggregate at low efficiencies. The model developed in this paper can explain how heterozygosity impacts the metabolic efficiency of an organism. It can also explain why the viabilities of some inbred lines seem to decline rapidly at high inbreeding coefficients (F > 0.5), which may provide a physical basis for truncation selection for heterozygosity. Finally, the model has implications for the ploidy level of organisms. It can explain why polyploids are frequently found in environments where severe physical stresses promote the formation of soluble oligomers. The model can also explain why complex organisms, which need to synthesize aggregation-prone proteins that contain intrinsically unstructured regions (IURs) and multiple domains because they facilitate complex protein interaction networks (PINs), tend to be diploid while haploidy tends to be restricted to relatively simple organisms. Copyright © 2017 Elsevier Ltd. All rights reserved.
1970-01-01Solanum verrucosum (2n = 24) is a self-compatible, highly fertile species. This conclusion is drawn from the results of studies on 21 various introductions of this species. In spite of self-compatibility and good male and female fertility, the species generally needs a pollinating agent to
and serious genetic variation in the population. Inbreeding depression was observed for survival trait although the levels of inbreeding coefficient were acceptable in all of the breeds investigated in this study. Therefore, the general policy in the flocks should be continued to avoid mating between close relative parents and use of enough sires and dams selected per annum. Estimated inbreeding coefficients for Baluchi and Iranblack breeds showed high degree of close mating in these herd and due to the significant effect of inbreeding on survival, it is suggested that this breeding stations should use a breeding plan to avoid mating of close relative animals.
Aug 26, 2016 ... My results indicate that levels of inbreeding in parasites are impacted by demographic and/or transmission dynamics (subdivided mating, aggregated transmission dynamics and host spatial structure), and that this inbreeding is poorly estimated by 'equilibrium' levels of inbreeding calculated assuming ...
Echeverri A. Álvaro
Full Text Available El objetivo del presente estudio fue estimar la heterosis, la aptitud combinatoria general (ACG y la aptitud combinatoria específica (ACE en un cruzamiento dialélico entre diez cultivares de pimentón usando las metodología propuesta por Griffing (1956b, método experimental 4, Modelo I (modificado por Hallauer y Miranda, 1988. Los parentales con valores más altos de heterosis relativa (HR y heterobelriosis (HB fueron LPUNAL (155,87% y 138,69%, Avelar (136,84% y 119,18%, y L363-46-672 (130,95% y 113,22%, los que participaron en la formación de cuatro de los diez cruzamientos más destacados por rendimiento. El análisis de varianza para aptitud combinatoria, mostró que en la transmisión y expresión de los caracteres evaluados, actúan en forma conjunta y altamente significativa tanto los efectos génicos aditivos (ACG como los 110 aditivos (A CE, pero con predominio de los primeros (Griffing, 1956. Los mayores valores de ACG para rendimiento fueron observados en LPUNAL-Palmira y Avelar (87.0 y 79.9, respectivamente.
Jingade, A.H.; Vijayan, K.; Somasundaram, P.; Srivasababu, G.K.; Kamble, C.K.
Silkworm genebanks assume paramount importance as the reservoirs of biodiversity and source of alleles that can be easily retrieved for genetic enhancement of popular breeds. More than 4000 Bombyx mori L (Lepidoptera: Bombycidae) strains are currently available and these strains are maintained through continuous sibling mating. This repeated sibling mating makes the populations of each strain more homozygous, but leads to loss of unique and valuable genes through the process of inbreeding depression. Hence, it is essential to maintain a minimal degree of heterozygosity within the population of each silkworm strain, especially in the traditional geographic strains, to avoid such loss. As a result, accurate estimation of genetic diversity is becoming more important in silkworm genetic resources conservation. Application of molecular markers help estimate genetic diversity much more accurately than that of morphological traits. Since a minimal amount of heterozygosity in each silkworm strain is essential for better conservation by avoiding inbreeding depression, this article overviews both theoretical and practical importance of heterozygosity together with impacts of inbreeding depression and the merits and demerits of neutral molecular markers for measurements of both heterozygosity and inbreeding depression in the silkworm Bombyx mori. PMID:21521139
Groszmann, Michael; Gonzalez-Bayon, Rebeca; Greaves, Ian K; Wang, Li; Huen, Amanda K; Peacock, W James; Dennis, Elizabeth S
Heterosis is important for agriculture; however, little is known about the mechanisms driving hybrid vigor. Ultimately, heterosis depends on the interactions of specific alleles and epialleles provided by the parents, which is why hybrids can exhibit different levels of heterosis, even within the same species. We characterize the development of several intraspecific Arabidopsis (Arabidopsis thaliana) F1 hybrids that show different levels of heterosis at maturity. We identify several phases of heterosis beginning during embryogenesis and culminating in a final phase of vegetative maturity and seed production. During each phase, the hybrids show different levels and patterns of growth, despite the close relatedness of the parents. For instance, during the vegetative phases, the hybrids develop larger leaves than the parents to varied extents, and they do so by exploiting increases in cell size and cell numbers in different ratios. Consistent with this finding, we observed changes in the expression of genes known to regulate leaf size in developing rosettes of the hybrids, with the patterns of altered expression differing between combinations. The data show that heterosis is dependent on changes in development throughout the growth cycle of the hybrid, with the traits of mature vegetative biomass and reproductive yield as cumulative outcomes of heterosis at different levels, tissues, and times of development. © 2014 American Society of Plant Biologists. All Rights Reserved.
Elzo, M A; Johnson, D D; Wasdin, J G; Driver, J D
Additive genetic Angus-Brahman differences, heterosis effects, and least squares means for six carcass and six meat palatability traits were estimated using data from 1367 steers from the Angus-Brahman multibreed herd of the University of Florida collected from 1989 to 2009. Brahman carcasses had higher dressing percent (PAngus carcasses. Brahman beef was less tender (PAngus beef. Heterosis increased hot carcass weight (PAngus-Brahman crossbred steers. Results indicated that crossbred animals with up to 50% Brahman showed limited negative impact on meat quality while maximizing meat yield due to heterosis. Copyright © 2011 Elsevier Ltd. All rights reserved.
Stoilov, M.; Daskaloff, S.
The literature on the combined use of induced mutations and heterosis in cultivated species is reviewed. Data from studies of the general and specific combining ability of induced mutations for gene markers both obtained and used in hybrid seed production, translocation lines for development of seedless fruits, male sterile forms, etc., are supplied. The authors give data from their own experimental material for use of mutant lines in heterosis breeding and hybrid seed production. It is concluded that the combined use of induced mutations and heterosis in both self- and cross-pollinating species is very promising. (author)
Penny A Becker
Full Text Available The conservation of many fragmented and small populations of endangered African wild dogs (Lycaon pictus relies on understanding the natural processes affecting genetic diversity, demographics, and future viability. We used extensive behavioural, life-history, and genetic data from reintroduced African wild dogs in South Africa to (1 test for inbreeding avoidance via mate selection and (2 model the potential consequences of avoidance on population persistence. Results suggested that wild dogs avoided mating with kin. Inbreeding was rare in natal packs, after reproductive vacancies, and between sibling cohorts (observed on 0.8%, 12.5%, and 3.8% of occasions, respectively. Only one of the six (16.7% breeding pairs confirmed as third-order (or closer kin consisted of animals that were familiar with each other, while no other paired individuals had any prior association. Computer-simulated populations allowed to experience inbreeding had only a 1.6% probability of extinction within 100 years, whereas all populations avoiding incestuous matings became extinct due to the absence of unrelated mates. Populations that avoided mating with first-order relatives became extinct after 63 years compared with persistence of 37 and 19 years for those also prevented from second-order and third-order matings, respectively. Although stronger inbreeding avoidance maintains significantly more genetic variation, our results demonstrate the potentially severe demographic impacts of reduced numbers of suitable mates on the future viability of small, isolated wild dog populations. The rapid rate of population decline suggests that extinction may occur before inbreeding depression is observed.
Full Text Available Fixed heterosis resulting from favorable interactions between the genes on their homoeologous genomes in an allopolyploid is considered analogous to classical heterosis accruing from interactions between homologous chromosomes in heterozygous plants of a diploid species. It has been hypothesized that fixed heterosis may be one of the causes of low classical heterosis in allopolyploids. We used Indian mustard (Brassica juncea, 2n = 36; AABB as a model system to analyze this hypothesis due to ease of its resynthesis from its diploid progenitors, B. rapa (2n = 20; AA and B. nigra (2n = 16; BB. Both forms of heterosis were investigated in terms of ploidy level, gene action and genetic diversity. To facilitate this, eleven B. juncea genotypes were resynthesized by hybridizing ten near inbred lines of B. rapa and nine of B. nigra. Three half diallel combinations involving resynthesized B. juncea (11×11 and the corresponding progenitor genotypes of B. rapa (10×10 and B. nigra (9×9 were evaluated. Genetic diversity was estimated based on DNA polymorphism generated by SSR primers. Heterosis and genetic diversity in parental diploid species appeared not to predict heterosis and genetic diversity at alloploid level. There was also no association between combining ability, genetic diversity and heterosis across ploidy. Though a large proportion (0.47 of combinations showed positive values, the average fixed heterosis was low for seed yield but high for biomass yield. The genetic diversity was a significant contributor to fixed heterosis for biomass yield, due possibly to adaptive advantage it may confer on de novo alloploids during evolution. Good general/specific combiners at diploid level did not necessarily produce good general/specific combiners at amphiploid level. It was also concluded that polyploidy impacts classical heterosis indirectly due to the negative association between fixed heterosis and classical heterosis.
Sidharth Prasad Mishra
Full Text Available A study was carried out on the captive tigers of Nandankanan zoo, Odisha, India, to conclude any deleterious effect of inbreeding on mortality. A pedigree path analysis of 342 tigers was done to estimate the inbreeding coefficient of each tiger from the available pedigree information since the inception of zoological park in 1964. Percentage of animal with different range of inbreeding coefficient was classified based on their normal and white body coat colour. The correlation values between sex, colour and inbreeding coefficient with mortality were also estimated. The colour and inbreeding coefficient was found to be significantly (p<0.05 correlated with the mortality. The inbreeding was found to be significant (p<0.05 with white colour of tiger.
Revealing gene action for production characteristics by inbreeding, based on a long-term selection ... The gene action involved in the expression of production characters was investigated, using the effect of the theoretical inbreeding ..... and predicted selection responses for growth, fat and lean traits in mice. J. Anim. Sci.
Alipova, Olga; Lovakov, Andrey
The literature on the consequences of academic inbreeding shows ambiguous results: some papers show that inbreeding positively influences research productivity measured by the quantity and quality of publications, while others demonstrate the opposite effect. There are contradictory results both in the studies of different countries and within…
Ret:ieved 6 Octoher 1991; ut:cepted I8 Mur- 1995. The eff'ect of migration on inbreeding is moclelled fbr small populations with immigrants from a large unrelated population. Different migration rates and numbers fbr the two sexes are assumed, and a general recursion equation for inbreeding progress derived, which can ...
In South Africa, the Dairy Swiss breed, which originated in Switzerland, consists of 27 breeders and 1135 breeding cows. Pedigree information on the breed was analysed to determine its effective population size (Ne) and rate of inbreeding. The rate of inbreeding was 0.08% per year and 0.38% per generation.
192 individual inbreeding coefficients on natural and artificial selection cannot be ruled out. The effect of inbreeding on production and reproduction traits in Merino sheep has been the subject of many studies and reviews (Morley, 1954; Doney,. 1957; Lax & Brown, 1967; Turner & Young, 1969; Dolling,. 1970' Lamberson ...
Tabadkani, Seyed Mohammad; Nozari, Jamasb; Lihoreau, Mathieu
Animals have evolved strategies to optimally balance costs and benefits of inbreeding. In social species, these adaptations can have a considerable impact on the structure, the organization, and the functioning of groups. Here, we consider how selection for inbreeding avoidance fashions the social behavior of arthropods, a phylum exhibiting an unparalleled richness of social lifestyles. We first examine life histories and parental investment patterns determining whether individuals should actively avoid or prefer inbreeding. Next, we illustrate the diversity of inbreeding avoidance mechanisms in arthropods, from the dispersal of individuals to the rejection of kin during mate choice and the production of unisexual broods by females. Then, we address the particular case of haplodiploid insects. Finally, we discuss how inbreeding may drive and shape the evolution of arthropods societies along two theoretical pathways.
Full Text Available Plant height, which shows dynamic development and heterosis, is a major trait affecting plant architecture and has an indirect influence on economic yield related to biological yield in cotton. In the present study, we carried out dynamic analysis for plant height and its heterosis by quantitative trait loci (QTL mapping at multiple developmental stages using two recombinant inbred lines (RILs and their backcross progeny. At the single-locus level, 47 QTL were identified at five developmental stages in two hybrids. In backcross populations, QTL identified at an early stage mainly showed partial effects and QTL detected at a later stage mostly displayed overdominance effects. At the two-locus level, we found that main effect QTL played a more important role than epistatic QTL in the expression of heterosis in backcross populations. Therefore, this study implies that the genetic basis of plant height heterosis shows dynamic character and main effect QTL with dominance determines heterosis for plant height in Upland cotton.
Hou Guangyun; Jing Liling
A complete delia cross (no reciprocal hybrid) was made using 5 wheat mutants with distinctive characters. The heterosis and combining ability of 8 agronomic characters were studied in 10 crosses F 1 and 5 parents. The dominance degree of F 1 indicated that except for the remarkable negative heterosis for heading-date, the positive heterosis was remarkable for all the other 7 characters. The performance of parents was significantly related to the gca effects. However, gca effects were not completely consistent with the value of heterosis. As germplasm resources, dwarf-stalk mutant 890376 was the best for reducing plant height. A large grain mutant, Hesheng 2, was the best for increasing 1000-grain weight. An early maturity mutant 890236 was the best for earlier heading and fillering ability. A large head mutant 890018 was the best for improving head length, number of spikelets per head, number of grain per head and grain weight per head. To sum up, the above 4 distinctive mutants were very useful for improving the characters corresponding with their mutated characters. For some characters, the cross will have a bigger sca effects if its parents have a bigger gca effects. However, it is not the same for all their characters. Sca effects of crosses were significantly related to the heterosis over mean parent
Amuzu-Aweh, E.N.; Bijma, P.; Kinghorn, B.P.; verreijken, A.; Arendonk, van J.A.M.; Bovenhuis, H.
Prediction of heterosis has a long history with mixed success, partly due to low numbers of genetic markers and/or small data sets. We investigated the prediction of heterosis for egg number, egg weight and survival days in domestic white Leghorns, using ~400¿000 individuals from 47 crosses and
The explanation for heterosis phenomenon is based on ideas: (i) every trait of an organism depends on many genes. (ii) Inbreeding depression and heterosis are related to individual genetic diversity. To assess individual genetic diversity ofan organism, I suggest the term number of genetic properties. Assessing the ...
Hari Prasad Sharma
Full Text Available A field experiment was conducted at National Maize Research Program, Rampur, Chitwan, Nepal during winter season from 6th October, 2015 to 5th March 2016 to estimate different heterosis on single cross maize hybrids . Thirteen maize hybrids were tested randomized complete block design with three replications. Hybrid namely RML-98/RL-105 gave the highest standard heterosis (57.5% for grain yield over CP-666 followed by RML-4/NML-2 (32.6%, RML-95/RL-105 (29% and RML-5/RL-105 (20.6%. The hybrid RML-98/RL-105 produced the highest standard heterosis (75.1% for grain yield over Rajkumar followed by RML-4/NML-2(50.2%, RML-95/RL-105(46.6%, RML-5/RL-105 and (35.7%. Mid and better parent heterosis were significantly higher for yield and yield attributes viz. ear length, ear diameter, no of kernel row per ear, no of kernel per row and test weight. The highest positive mid-parent heterosis for grain yield was found in RML-98/RL-105 followed by RML-5/RL-105, RML-95/RL-105, and RML-4/NML-2. For the grain yield the better parent heterosis was the highest in RML-98/RL-105, followed by RML-5/RL-105, RML-95/RL-105, and RML-4/NML-2. These results suggested that maize production can be maximized by cultivating hybrids namely RML-98/RL-105, RML-5/RL-105, RML-95/RL-105, and RML-4/NML-2 .
... in the winter. Depression is one part of bipolar disorder. There are effective treatments for depression, including antidepressants, talk therapy, or both. NIH: National Institute of Mental Health
... reasons why a woman may have depression: Family history . Women with a family history of depression may be more at risk. But depression can also happen in women who don’t have a family history of depression. Brain changes. The brains of people ...
Woolliams, J.A.; Bijma, P.
Tractable forms of predicting rates of inbreeding (F) in selected populations with general indices, nonrandom mating, and overlapping generations were developed, with the principal results assuming a period of equilibrium in the selection process. An existing theorem concerning the relationship
Woodley, Michael A.
In this ecological study, a robust negative correlation of r = - 0.62 (P less than 0.01) is reported between national IQs and consanguinity as measured by the log10 transformed percentage of consanguineous marriages for 72 countries. This correlation is reduced in magnitude, when IQ is controlled for GDP per capita (r = - 0.41, P less than 0.01);…
Orchids are among the most beautiful flowers and endangered due to habitat destruction and overcollection. Cattleya walkeriana is one of the most beautiful flowers joining the small sized plant with medium large and heavily scented flowers. It is widely known and appreciated by its beautiful clones and it has much to offer ...
Liu, Chao; Wang, Mingbo; Wang, Lingli; Guo, Qigao; Liang, Guolu
We aim to overcome the unclear origin of the loquat and elucidate the heterosis mechanism of the triploid loquat. Here we investigated the genetic and epigenetic variations between the triploid plant and its parental lines using amplified fragment length polymorphism (AFLP) and methylation-sensitive amplified fragment length polymorphism (MSAP) analyses. We show that in addition to genetic variations, extensive DNA methylation variation occurred during the formation process of triploid loquat, with the triploid hybrid having increased DNA methylation compared to the parents. Furthermore, a correlation existed between genetic variation and DNA methylation remodeling, suggesting that genome instability may lead to DNA methylation variation or vice versa. Sequence analysis of the MSAP bands revealed that over 53% of them overlap with protein-coding genes, which may indicate a functional role of the differential DNA methylation in gene regulation and hence heterosis phenotypes. Consistent with this, the genetic and epigenetic alterations were associated closely to the heterosis phenotypes of triploid loquat, and this association varied for different traits. Our results suggested that the formation of triploid is accompanied by extensive genetic and DNA methylation variation, and these changes contribute to the heterosis phenotypes of the triploid loquats from the two cross lines.
Woodley, Michael A.
Mingroni proposed that heterosis or hybrid vigor may be the principal driver of the Flynn effect--the tendency for IQ scores to increase at a rate of approximately 3 points per decade. This model was presented as a resolution to the IQ paradox--the observation that IQ scores have been increasing despite their high adult heritability--on the basis…
Lauss, Kathrin; Wardenaar, René; Oka, Rurika; van Hulten, Marieke H A; Guryev, Victor; Keurentjes, Joost J B; Stam, Maike; Johannes, Frank
Despite the importance and wide exploitation of heterosis in commercial crop breeding, the molecular mechanisms behind this phenomenon are not completely understood. Recent studies have implicated changes in DNA methylation and small RNAs in hybrid performance, however, it remains unclear whether
Lauss, K.; Wardenaar, R.; Oka, R.; van Hulten, M.H.A.; Guryev, V.; Keurentjes, J.J.B.; Stam, M.; Johannes, F.
Despite the importance and wide exploitation of heterosis in commercial crop breeding, the molecular mechanisms behind this phenomenon are not completely understood. Recent studies have implicated changes in DNA methylation and small RNAs in hybrid performance; however, it remains unclear whether
Lauss, Kathrin; Wardenaar, R.; Oka, Rurika; Hulten, M.H.A.; Guryev, Victor; Keurentjes, J.J.B.; Stam, Maike; Johannes, Frank
Despite the importance and wide exploitation of heterosis in commercial crop breeding, the molecular mechanisms behind this phenomenon are not completely understood. Recent studies have implicated changes in DNA methylation and small RNAs in hybrid performance, however, it remains unclear whether
Garbe, John R; Prakapenka, Dzianis; Tan, Cheng; Da, Yang
Inbreeding and relatedness in wild panda populations are important parameters for panda conservation. Habitat loss and fragmentation are expected to increase inbreeding but the actual inbreeding levels in natural panda habitats were unknown. Using 150,025 SNPs and 14,926 SNPs selected from published whole-genome sequences, we estimated genomic inbreeding coefficients and relatedness of 49 pandas including 34 wild pandas sampled from six habitats. Qinling and Liangshan pandas had the highest levels of inbreeding and relatedness measured by genomic inbreeding and coancestry coefficients, whereas the inbreeding levels in Qionglai and Minshan were 28-45% of those in Qinling and Liangshan. Genomic coancestry coefficients between pandas from different habitats showed that panda populations from the four largest habitats, Minshan, Qionglai, Qinling and Liangshan, were genetically unrelated. Pandas between these four habitats on average shared 66.0-69.1% common alleles and 45.6-48.6% common genotypes, whereas pandas within each habitat shared 71.8-77.0% common alleles and 51.7-60.4% common genotypes. Pandas in the smaller populations of Qinling and Liangshan were more similarly to each other than pandas in the larger populations of Qionglai and Minshan according to three genomic similarity measures. Panda genetic differentiation between these habitats was positively related to their geographical distances. Most pandas separated by 200 kilometers or more shared no common ancestral alleles. The results provided a genomic quantification of the actual levels of inbreeding and relatedness among pandas in their natural habitats, provided genomic confirmation of the relationship between genetic diversity and geographical distances, and provided genomic evidence to the urgency of habitat protection.
Inbreeding and relatedness in wild panda populations are important parameters for panda conservation. Habitat loss and fragmentation are expected to increase inbreeding but the actual inbreeding levels in natural panda habitats were unknown. Using 150,025 SNPs and 14,926 SNPs selected from published whole-genome sequences, we estimated genomic inbreeding coefficients and relatedness of 49 pandas including 34 wild pandas sampled from six habitats. Qinling and Liangshan pandas had the highest levels of inbreeding and relatedness measured by genomic inbreeding and coancestry coefficients, whereas the inbreeding levels in Qionglai and Minshan were 28–45% of those in Qinling and Liangshan. Genomic coancestry coefficients between pandas from different habitats showed that panda populations from the four largest habitats, Minshan, Qionglai, Qinling and Liangshan, were genetically unrelated. Pandas between these four habitats on average shared 66.0–69.1% common alleles and 45.6–48.6% common genotypes, whereas pandas within each habitat shared 71.8–77.0% common alleles and 51.7–60.4% common genotypes. Pandas in the smaller populations of Qinling and Liangshan were more similarly to each other than pandas in the larger populations of Qionglai and Minshan according to three genomic similarity measures. Panda genetic differentiation between these habitats was positively related to their geographical distances. Most pandas separated by 200 kilometers or more shared no common ancestral alleles. The results provided a genomic quantification of the actual levels of inbreeding and relatedness among pandas in their natural habitats, provided genomic confirmation of the relationship between genetic diversity and geographical distances, and provided genomic evidence to the urgency of habitat protection. PMID:27494031
Kessing, Lars Veddel; Bukh, Jens Drachmann
The prevalence of depression is not clearly established, but estimated to 3-4% in a Danish questionnaire study. Lifetime's prevalences of 12-17% are reported in other community samples. In the current diagnostic system depression is defined categorically and operationally. It has been argued......, that these diagnostic criteria represent an oversimplification, which has blurred the concept of depression. We suggest a greater emphasis on the depressed mood as the core symptom of depression, which may increase the specificity of the diagnosis. Furthermore, basic principles for the treatment of depression...
Nausheen; Farhatullah; Hussain, I.; Khalil, I.; Amanullah
An experiment was carried out at the University of Agriculture, Peshawar during 2012-13 using a set of F /sub 1/ hybrids of B. carinata for estimating heterosis and heterobeltiosis for important yield and quality parameters. The experimental material comprised of six B. carinata parental genotypes viz. C-88, C-89, C-90, C-93, C-95, C-97 and their 30 F /sub 1/ hybrids as direct crosses. A randomized complete block design with two replicates was used for field evaluation of 36 B. carinata genotypes (6 parental lines and 30 F /sub 1/ hybrids). Significant genetic variation was observed for primary branches plant /sup 1/, main raceme length, seed yield plant /sup 1/, oil and protein content among parents as well as F /sub 1/ hybrids. The highest heterosis and heterobeltiosis for primary branches (24.25 vs. 12.30 percentage) and main raceme length (37.31 vs. 22.93 percentage) was recorded for F /sub 1/ hybrids C-88 * C-93 and C-89 * C-97, respectively. Hybrid C-93 * C-90 had the highest positive heterosis for seed yield plant /sup 1/ (23.33 percentage). For protein content, the maximum heterosis was recorded for hybrid C-88 * C-89 (11.34 percentage). Similarly, F /sub 1/ hybrid C-88 * C-97 showed maximum heterosis for oil content (14.41 percentage). The highest heterobeltiosis was exhibited by hybrids C-90 * C-97 for seed yield (9.53 percentage) , C-89 * C-90 for oil content (7.61 percentage) and C-93 * C-97 for protein content (4.11 percentage). Based on high mean performance and heterotic values, aforemntioned hybrids and their corresponding parental lines will be exploited further for commercial hybrid production. (author)
Full Text Available Jiyan-1 puffer, the F1 hybrid of Takifugu rubripes and Takifugu flavidus, displays obvious heterosis in the growth performance, flavor and stress tolerance. In the present study, comparative analysis for the transcriptomes of T. rubripes, T. flavidus and Jiyan-1 was performed aiming to reveal the possible mechanisms of heterosis in pufferfish. Whole transcriptomes were sequenced using the SOLiD4 platform, and a total of 44,305 transcripts corresponding to 18,164 genes were identified collectively. A total of 14,148 transcripts were differentially expressed. By comparing the gene expression patterns of the three samples, the coexistence of overdominance, dominance, underdominance and additivity was observed in the gene action modes of Jiyan-1. There were 2,237 transcripts in the intersection of the differentially expressed transcripts from Jiyan-1 versus T. rubripes and Jiyan-1 versus T. flavidus, among which 213 transcripts were also in the T. rubripes versus T. flavidus. The potential functions of the remaining 2,024 transcripts were mainly associated with metabolic process, nucleotide binding and catalytic activity. The enrichment results indicated metabolism was the most activated biological function in the heterosis. In addition, 35 KEGG pathways were retrieved as affiliated with more than three differentially expressed transcripts and 8,579 potentially novel transcript isoforms were identified for Jiyan-1. The present study revealed the coexistence of multiple gene actions in the hybrid puffer, indicated the importance of metabolism, ion binding function and kinase activity, as well as provided a list of candidate genes and pathways for heterosis. It could be helpful for the better understanding of the determination and regulation mechanisms of heterosis.
... For Teens / Depressants Print en español Depresores del sistema nervioso What They Are: Tranquilizers and other depressants ... of Use Notice of Nondiscrimination Visit the Nemours Web site. Note: All information on TeensHealth® is for ...
Individual inbreeding coefficient (F) and pairwise relatedness (r) are fundamental parameters in population genetics and have important applications in diverse fields such as human medicine, forensics, plant and animal breeding, conservation and evolutionary biology. Traditionally, both parameters are calculated from pedigrees, but are now increasingly estimated from genetic marker data. Conceptually, a pedigree gives the expected F and r values, FP and rP, with the expectations being taken (hypothetically) over an infinite number of individuals with the same pedigree. In contrast, markers give the realised (actual) F and r values at the particular marker loci of the particular individuals, FM and rM. Both pedigree (FP, rP) and marker (FM, rM) estimates can be used as inferences of genomic inbreeding coefficients FG and genomic relatedness rG, which are the underlying quantities relevant to most applications (such as estimating inbreeding depression and heritability) of F and r. In the pre-genomic era, it was widely accepted that pedigrees are much better than markers in delineating FG and rG, and markers should better be used to validate, amend and construct pedigrees rather than to replace them. Is this still true in the genomic era when genome-wide dense SNPs are available? In this simulation study, I showed that genomic markers can yield much better estimates of FG and rG than pedigrees when they are numerous (say, 10(4) SNPs) under realistic situations (e.g. genome and population sizes). Pedigree estimates are especially poor for species with a small genome, where FG and rG are determined to a large extent by Mendelian segregations and may thus deviate substantially from their expectations (FP and rP). Simulations also confirmed that FM, when estimated from many SNPs, can be much more powerful than FP for detecting inbreeding depression in viability. However, I argue that pedigrees cannot be replaced completely by genomic SNPs, because the former allows for
Cizza, G; Ravn, Pernille; Chrousos, G P
Existing studies of the relationship between depression and osteoporosis have been heterogeneous in their design and use of diagnostic instruments for depression, which might have contributed to the different results on the comorbidity of these two conditions. Nevertheless, these studies reveal...... a strong association between depression and osteoporosis. Endocrine factors such as depression-induced hypersecretion of corticotropin-releasing hormone and hypercortisolism, hypogonadism, growth hormone deficiency and increased concentration of circulating interleukin 6, might play a crucial role...... in the bone loss observed in subjects suffering from major depression....
Thirstrup, Janne Pia; Pertoldi, Cino; Larsen, Peter Foged
Litter sizes in a cross between Brown and Black mink color types were observed through six generations. Litter size was significantly affected by yearly environmental variations. After adjusting for year effects, we found significant increases in litter size in the second and third generations (F2...... caused by an increase in litter size compared to the Black parental line. This indicates that the Black line was affected by inbreeding depression prior to crossing. We also found that two-year old F1 females had significantly more offspring compared to one-year old F1 females...
There is ample evidence that depression is000 a common comorbid health issue in people with type 1 or type 2 diabetes. Reviews have also concluded that depression in diabetes is associated with higher HbA1c levels, less optimal self-care behaviours, lower quality of life, incident vascular...... complications and higher mortality rates. However, longitudinal studies into the course of depression in people with type 1 diabetes remain scarce. In this issue of Diabetologia, Kampling and colleagues (doi: 10.1007/s00125-016-4123-0 ) report the 5 year trajectories of depression in adults with newly diagnosed...... type 1 diabetes (mean age, 28 years). Their baseline results showed that shortly after the diagnosis of type 1 diabetes a major depressive episode was diagnosed in approximately 6% of participants, while 8% suffered from an anxiety disorder. The longitudinal depression data showed that, in a 5 year...
LU Xia; LUAN Sheng; CAO Baoxiang; SUI Juan; DAI Ping; MENG Xianhong; LUO Kun; KONG Jie
The aim of the present study is to detect the potential of the base population from diallel crosses of eight introduced strains of the Pacific white shrimp (Litopenaeus vannamei) for improving the yield. Heterosis and heritability were estimated for pond survival at commercial farm conditions for the base population that included 207 full-sib families from a nested mating design by artificial insemination. Among all the hybrids, the heterosis ranged from–11.37%(UA1×UA2) to 20.53%(UA3×SIN) with an average of 0.953%. The results showed that more than half of the hybrids (51.85%) have negative heterosis for survival rate, but most of the hybrids with positive heterosis have high estimates. The high proportion of negative heterosis for survival rate reminders us that the survival trait also should be considered in the crossbreeding program to avoid yield decrease. However, high positive heterosis manifested in most of the hybrids for survival indicates the usefulness of these hybrids for improving the survival to obtain higher yield by crossbreeding in this breeding program. The heritability estimate for pond survival was 0.092±0.043 when genetic groups were included in the pedigree, and it was significantly different from zero (P<0.05). The results from this study also indicated that significant improvement for survival is possible through selection in L. vannamei.
Islam, Md. Shofiqul
ryegrass for the development of improved varieties. During his PhD studies, Mohammad Shofiqul Islam studied the feasibility of developing novel hybrid breeding schemes based on cytoplasmic male sterility (CMS) systems in perennial ryegrass. He successfully completed the assembly and annotation of a male......-fertile perennial ryegrass mitochondrial genome, and identified candidate genes responsible for the CMS phenotype by comparing male-fertile and male-sterile mitochondrial genomes. His findings constitute a good basis for continuing research to produce hybrid grass varieties to address the future needs......, breeding activities have been carried out to improve the population and develop synthetic varieties. This does not fully exploit the potential of heterosis, however. Hybrid breeding is an alternative strategy and provides opportunities to fully exploit the genetically available heterosis in perennial...
Full Text Available Hibridisasi merupakan salah satu teknik pemuliaan ikan dalam rangka mendapatkan varietas unggul sehingga mampu meningkatkan nilai produksi suatu komoditas ikan yang dibudidayakan. Tujuan penelitian ini adalah untuk mengevaluasi performa pertumbuhan, koefisien variasi, dan nilai heterosis dari hasil persilangan tiga spesies ikan patin sebagai tetua, yaitu patin siam (Pangasianodon hypophthalmus, patin jambal (Pangasius djambal, dan patin nasutus (Pangasius nasutus pada tahap pendederan II. Induk ikan patin siam dan patin jambal yang digunakan merupakan ikan yang sudah dirilis sebagai ikan budidaya, sedangkan induk ikan patin nasutus berasal dari perairan umum dan sedang dalam proses domestikasi sebagai ikan budidaya. Persilangan yang dibuat adalah: A f patin jambal >0,05. Ikan patin SN memiliki performa yang lebih baik dari tetuanya dengan nilai heterosis bobot akhir, LPS bobot, panjang total, LPS panjang total, dan sintasan berturut-turut sebesar 110,87%; 19,78%; 36,14%, 36,09%; dan 15,04%; serta nilai koefisien variasi berkisar antara 0,00-11,08. Bobot akhir, panjang total dan sintasan ikan patin SJ juga lebih baik dari tetuanya dengan nilai heterosis berturut-turut sebesar 46,00%; 11,27%; dan 2,27%; namun untuk heterosis LPS bobot dan LPS panjang total bernilai negatif (-6,65% dan -1,01%, serta nilai koefisien variasi berkisar antara 0,00-12,75. Berdasarkan hasil penelitian tersebut menunjukkan bahwa ikan patin hibrida SN berpotensi sebagai ikan budidaya dalam rangka peningkatan produksi ikan patin daging putih selain dari ikan patin hibrida SJ (pasupati yang telah dirilis ke masyarakat. Hybridization is a fish breeding technique in order to obtain high yielding varieties as to increase the production value of a farmed fish. The purpose of this study was to evaluate the growth performance, the coefficient of variation and heterosis value of the result of crossing three species of catfish as a parent, which was striped catfish
Full Text Available Evaluasi keragaan ikan lele hibrida dari hasil persilangan antara Masamo (M, Sangkuriang (S, dan Paiton (P telah dilakukan untuk mendapatkan benih unggul ikan lele untuk budidaya di daerah Provinsi Nusa Tenggara Barat. Persilangan secara resiprokal telah dilakukan dengan menggunakan tiga strain ikan lele yaitu Masamo, Sangkuriang, dan Paiton masing-masing dengan empat ulangan. Pemijahan dilakukan secara alami dengan bantuan suntikan ovaprim. Nilai heterosis tertinggi pada tingkat pembenihan dan pembesaran ada pada pasangan hibrida S-M. Heterosis hibrida S-M di tingkat pembenihan adalah 6,68% (sintasan dan 2,79% (pertambahan panjang benih, sedangkan di tingkat pembesaran 6,90% (sintasan, 24,03% (pertumbuhan bobot harian dan -3,79% (konversi pakan. Perkawinan betina Sangkuriang - jantan Masamo mempunyai nilai “heterosis” tertinggi pada semua parameter di tingkat pembenihan dan pembesaran
Majumder, P P; Malhotra, K C
Data on the distance between the birthplaces of spouses (matrimonial distance) were collected from 2,260 married individuals belonging to 21 endogamous castes of the Dhangar (shepherd) cast-cluster of Maharashtra, India. The general form of the distribution of matrimonial distances is one which is extremely positively skewed and leptokurtic. The percentage of intra-village marriages generally decreases from the southern areas of Maharashtra to the northern areas of the state, as does the inbreeding coefficient. This situation is in conformity with the socio-cultural norms regulating matrimonial choice in south and north India. An attempt has been made to relate the degree of inbreeding to the mean matrimonial distance and population size. The mean matrimonial distance is more useful in predicting the degree of inbreeding than population size.
Johansen, Jon O. J.
Nyhederne er fulde af historier om depression. Overskrifter som: ’Danskerne propper sig med lykkepiller’ eller ‘depression er stadigvæk tabu’ går tit igen i dagspressen. Men hvor er nuancerne, og hvorfor gider vi læse de samme historier igen og igen? Måske er det fordi, vores egne forestillinger er...
Berger-Tal, Reut; Tuni, Cristina; Lubin, Yael; Smith, Deborah; Bilde, Trine
Inbreeding mating systems are uncommon because of inbreeding depression. Mating among close relatives can evolve, however, when outcrossing is constrained. Social spiders show obligatory mating among siblings. In combination with a female-biased sex ratio, sib-mating results in small effective populations. In such a system, high genetic homozygosity is expected, and drift may cause population divergence. We tested the effect of outcrossing in the social spider Stegodyphus dumicola. Females were mated to sib-males, to a non-nestmate within the population, or to a male from a distant population, and fitness traits of F1s were compared. We found reduced hatching success of broods from between-population crosses, suggesting the presence of population divergence at a large geographical scale that may result in population incompatibility. However, a lack of a difference in offspring performance between inbred and outbred crosses indicates little genetic variation between populations, and could suggest recent colonization by a common ancestor. This is consistent with population dynamics of frequent colonizations by single sib-mated females of common origin, and extinctions of populations after few generations. Although drift or single mutations can lead to population divergence at a relatively short time scale, it is possible that dynamic population processes homogenize these effects at longer time scales. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.
David E Carr
Full Text Available Inbreeding in plants typically reduces individual fitness but may also alter ecological interactions. This study examined the effect of inbreeding in the mixed-mating annual Mimulus guttatus on visitation by pollinators (Bombus impatiens in greenhouse experiments. Previous studies of M. guttatus have shown that inbreeding reduced corolla size, flower number, and pollen quantity and quality. Using controlled crosses, we produced inbred and outbred families from three different M. guttatus populations. We recorded the plant genotypes that bees visited and the number of flowers probed per visit. In our first experiment, bees were 31% more likely to visit outbred plants than those selfed for one generation and 43% more likely to visit outbred plants than those selfed for two generations. Inbreeding had only a small effect on the number of flowers probed once bees arrived at a genotype. These differences were explained partially by differences in mean floral display and mean flower size, but even when these variables were controlled statistically, the effect of inbreeding remained large and significant. In a second experiment we quantified pollen viability from inbred and self plants. Bees were 37-54% more likely to visit outbred plants, depending on the population, even when controlling for floral display size. Pollen viability proved to be as important as floral display in predicting pollinator visitation in one population, but the overall explanatory power of a multiple regression model was weak. Our data suggested that bees use cues in addition to display size, flower size, and pollen reward quality in their discrimination of inbred plants. Discrimination against inbred plants could have effects on plant fitness and thereby reinforce selection for outcrossing. Inbreeding in plant populations could also reduce resource quality for pollinators, potentially resulting in negative effects on pollinator populations.
Full Text Available Heritability, potential ratio, and heterosis of soybean (Glycine max [L.] Merrill resistance to soybean mosaic virus. The use of soybean cultivars with resistance to SMV is a way for controlling soybean mosaic disease. The objective of this research was to estimate the disease severity, the narrow sense heritability, potential ratio and heterosis of resistance character and number of pithy pods, number of healthy seeds, and healthy seeds weight per plant of ten F1 populations of soybean crossing result to SMV infection. The experiment was arranged in a randomized complete block design in two replications. Observed characters were disease severity, number of pithy pods, number of healthy seeds, and healthy seeds weight per plant. The result of this research showed that 1 the crossing combinations those which were resistant to SMV (lower disease severity were Yellow Bean x Tanggamus, Tanggamus x Orba, and Tanggamus x Taichung, 2 the narrow sense heritability of disease severity was included in medium criteria, 3 number of pithy pods belonged to high criteria, and 4 number of healthy seeds and healthy seeds weight per plant were included in low criteria. The crossing combinations that had low estimation value of heterosis and heterobeltiosis of resistance to SMV infection were Yellow Bean x Taichung, Bean x Tanggamus and Tanggamus x B3570. Disease severity or resistance to SMV is influenced by genetic and environmental factors.
Jeremiah Monday Nwenya
Full Text Available Forty-four (44 birds (about 50 weeks old male and female inbred naked necked and frizzle feathered chickens were crossed to generate F1 crossbred chicken that were used to evaluate the performance and heterosis effects. Data taken on 180 chicks (97 NN and 83 FF day-old chick weight (BWT0, body weight (BWT, daily average feed intake (AFI, feed conversion ratio (FCR, brooding and rearing mortalities, linear body measurements (LBM: body length, wing length, keel length, shank length and breast width were used to estimate heterosis and performance of F1 progenies. Results of the experiment showed positive heterosis with significant differences among the F1 progenies over their parents in body weight, average feed intake and feed conversion ratio. The reciprocal cross (i.e. frizzle feather rooster x naked neck hen showed a significant improvement in their performances genetically, explaining that better results are achieved through crossbreeding of these indigenous breeds. With reference to their body linear parameters, the reciprocal cross of naked neck and frizzle feathered chickens developed higher body length, whereas the main crosses performed better in their wing length, keel length, shank length and body width respectively, mainly after 8 weeks suggesting that earlier performance was attributable to maternal influences.
Eldik, van P.; Waaij, van der E.H.; Ducro, B.J.; Kooper, A.W.; Stout, T.A.E.; Colenbrander, B.
Inbreeding is widely believed to negatively affect reproductive performance. Indeed, in some species, high levels of inbreeding are thought to be the major cause of poor semen quality. It is, however, not clear whether inbreeding affects fertility in horses. In this study, the relationship between
Ma, Qian; Hedden, Peter; Zhang, Qifa
Despite the accumulation of data on the genetic and molecular understanding of heterosis, there is little information on the regulation of heterosis at the physiological level. In this study, we performed a quantitative analysis of endogenous gibberellin (GA) content and expression profiling of the GA metabolism and signaling genes to investigate the possible relationship between GA signaling and heterosis for seedling development in rice (Oryza sativa). The materials used were an incomplete diallele set of 3 × 3 crosses and the six parents. In the growing shoots of the seedlings at 20 d after sowing, significant positive correlations between the contents of some GA species and performance and heterosis based on shoot dry mass were detected. Expression analyses of GA-related genes by real-time reverse transcription-polymerase chain reaction revealed that 13 out of the 16 GA-related genes examined exhibited significant differential expression among the F1 hybrid and its parents, acting predominantly in the modes of overdominance and positive dominance. Expression levels of nine genes in the hybrids displayed significant positive correlations with the heterosis of shoot dry mass. These results imply that GAs play a positive role in the regulation of heterosis for rice seedling development. In shoots plus root axes of 4-d-old germinating seeds that had undergone the deetiolation, mimicking normal germination in soil, the axis dry mass was positively correlated with the content of GA₂₉ but negatively correlated with that of GA₁₉. Our findings provide supporting evidence for GAs playing an important regulatory role in heterosis for rice seedling development.
Manenti, Tommaso; Pertoldi, Cino; Nasiri Moghadam, Neda
The ability to move is essential for many behavioural traits closely related to fitness. Here we studied the effect of inbreeding on locomotor activity (LA) of Drosophila melanogaster at different ages under both dark and light regimes. We expected to find a decreased LA in inbred lines compared...
Sørensen, Anders Christian; Norberg, Elise
In Denmark there are small populations of five Nordic sheep breeds, two of which are Danish in origin. The purpose of this study was to estimate trends in inbreeding for these breeds. All five breeds have been recording pedigrees for decades, so pedigree completeness is adequate. The rate of inbr...
Abaskuliev, A A; Skoblo, G V
An increased frequency of consanguineous marriages among the parents of schizophrenic patients in comparison with the control group of exogenous-somatic patients (infections, trauma) was found. Endogamy among the parents of schizophrenic patients and the control group was practically the same. The data obtained indicate a certain, but not the leading, role of inbreeding in the etiology of schizophrenia.
inbreeding coefficient on the mean of the characters in a two-way selection experiment for the slope (b) and intercept. (Ln (a)) of the ... ln (a) selection group, as well as average daily f-eed intake (Phase I and 2) of the b selection group. Die genewerking wat ..... exposed to natural selection for an extended period under con-.
Short communication: Effective population size and inbreeding rate of indigenous Nguni cattle under in situ conservation in the low-input communal production ... as not at risk of extinction, while the individual enterprises were classified as being endangered-maintained without the exchange of germ plasm among them.
Presence of inbreeding during a selection experiment with Merino sheep. GJ Erasmus, AO de Lange, GJ Delport, JJ Olivier. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL.
Thirstrup, Janne Pia; Larsen, Peter Foged; Pertoldi, Cino
animals originating from different farms. Effect of heterosis, color type, and variance components were estimated using Average information REML (AI-REML) algorithm implemented in the DMU package for analyzing multivariate mixed models. Females from 7 generations that gave birth to at least 1 offspring...... positive effect of crossing between lines of the same color type. Estimates of variance components revealed h2 levels for farm A, B, and C of 0.15, 0.06, and 0.09, respectively; thus litter size could be selected for in the future. The effect of common environment on litter size was also considerable...
Full Text Available Se estimó la media y la heterosis de la longevidad en obreras de abejas Apis mellifera. El expe-rimento fue desarrollado en el Apiario del Departamento de Genética de la Facultad de Medi-cina de la USP-Ribeirão Preto-Brasil y en Jaboticabal-SP, de 03/1997 a 05/1999. Seleccionamos 8 matrices inseminadas del apiário-USP (2africanizadas, 2italianas, 2cárnicasy 2italianas*cárnicos y 2 matrices (grupo-testigo de abejas Africanizadas-Silvestres.
Full Text Available Brassinosteroids (BRs and Gibberellins (GAs are two classes of plant hormones affecting plant height (PHT. Thus, manipulation of BR and GA levels or signaling enables optimization of crop grain and biomass yields. We established backcross (BC families, selected for increased PHT, in two elite maize inbred backgrounds. Various exotic accessions used in the germplasm enhancement in maize project served as donors. BC1-derived doubled haploid lines in the same two elite maize inbred backgrounds established without selection for plant height were included for comparison. We conducted genome-wide association studies to explore the genetic control of PHT by BR and GA. In addition, we used BR and GA inhibitors to compare the relationship between PHT, BR, and GA in inbred lines and heterozygotes from a physiological and biological perspective. A total of 73 genomic loci were discovered to be associated with PHT, with seven co-localized with GA, and two co-localized with BR candidate genes. PHT determined in field trials was significantly correlated with seedling stage BR and GA inhibitor responses. However, this observation was only true for maize heterozygotes, not for inbred lines. Path analysis results suggest that heterozygosity increases GA levels, which in turn promote BR levels. Thus, at least part of heterosis for PHT in maize can be explained by increased GA and BR levels, and seedling stage hormone inhibitor response is promising to predict heterosis for PHT.
Full Text Available Deleterious alleles have long been proposed to play an important role in patterning phenotypic variation and are central to commonly held ideas explaining the hybrid vigor observed in the offspring of a cross between two inbred parents. We test these ideas using evolutionary measures of sequence conservation to ask whether incorporating information about putatively deleterious alleles can inform genomic selection (GS models and improve phenotypic prediction. We measured a number of agronomic traits in both the inbred parents and hybrids of an elite maize partial diallel population and re-sequenced the parents of the population. Inbred elite maize lines vary for more than 350,000 putatively deleterious sites, but show a lower burden of such sites than a comparable set of traditional landraces. Our modeling reveals widespread evidence for incomplete dominance at these loci, and supports theoretical models that more damaging variants are usually more recessive. We identify haplotype blocks using an identity-by-decent (IBD analysis and perform genomic prediction analyses in which we weigh blocks on the basis of complementation for segregating putatively deleterious variants. Cross-validation results show that incorporating sequence conservation in genomic selection improves prediction accuracy for grain yield and other fitness-related traits as well as heterosis for those traits. Our results provide empirical support for an important role for incomplete dominance of deleterious alleles in explaining heterosis and demonstrate the utility of incorporating functional annotation in phenotypic prediction and plant breeding.
Yang, Jinliang; Mezmouk, Sofiane; Baumgarten, Andy; Buckler, Edward S; Guill, Katherine E; McMullen, Michael D; Mumm, Rita H; Ross-Ibarra, Jeffrey
Deleterious alleles have long been proposed to play an important role in patterning phenotypic variation and are central to commonly held ideas explaining the hybrid vigor observed in the offspring of a cross between two inbred parents. We test these ideas using evolutionary measures of sequence conservation to ask whether incorporating information about putatively deleterious alleles can inform genomic selection (GS) models and improve phenotypic prediction. We measured a number of agronomic traits in both the inbred parents and hybrids of an elite maize partial diallel population and re-sequenced the parents of the population. Inbred elite maize lines vary for more than 350,000 putatively deleterious sites, but show a lower burden of such sites than a comparable set of traditional landraces. Our modeling reveals widespread evidence for incomplete dominance at these loci, and supports theoretical models that more damaging variants are usually more recessive. We identify haplotype blocks using an identity-by-decent (IBD) analysis and perform genomic prediction analyses in which we weigh blocks on the basis of complementation for segregating putatively deleterious variants. Cross-validation results show that incorporating sequence conservation in genomic selection improves prediction accuracy for grain yield and other fitness-related traits as well as heterosis for those traits. Our results provide empirical support for an important role for incomplete dominance of deleterious alleles in explaining heterosis and demonstrate the utility of incorporating functional annotation in phenotypic prediction and plant breeding.
Bierne, N; Tsitrone, A; David, P
Associative overdominance, the fitness difference between heterozygotes and homozygotes at a neutral locus, is classically described using two categories of models: linkage disequilibrium in small populations or identity disequilibrium in infinite, partially selfing populations. In both cases, only equilibrium situations have been considered. In the present study, associative overdominance is related to the distribution of individual inbreeding levels (i.e., genomic autozygosity). Our model integrates the effects of physical linkage and variation in inbreeding history among individual pedigrees. Hence, linkage and identity disequilibrium, traditionally presented as alternatives, are summarized within a single framework. This allows studying nonequilibrium situations in which both occur simultaneously. The model is applied to the case of an infinite population undergoing a sustained population bottleneck. The effects of bottleneck size, mating system, marker gene diversity, deleterious genomic mutation parameters, and physical linkage are evaluated. Bottlenecks transiently generate much larger associative overdominance than observed in equilibrium finite populations and represent a plausible explanation of empirical results obtained, for instance, in marine species. Moreover, the main origin of associative overdominance is random variation in individual inbreeding whereas physical linkage has little effect.
Vuylsteke, M.; Kuiper, M.; Stam, P.
In this paper, a novel approach towards the prediction of hybrid performance and heterosis is presented. Here, we describe an approach based on: (i) the assessment of associations between AFLPÒ22 AFLPÒ is a registered trademark of Keygene N.V. ,33 The methylation AFLPÒ method is subject to a patent
Norberg, Elise; Sørensen, Lydia Henriette; Byskov, Kenneth
Use of systematic crossbreeding in dairy cattle has been increasing the last decades. The aim of this study was to estimate the effect of breed and heterosis on protein yield (PY), somatic cell score (SCS) and days from calving to first insemination (CFI) in first lactation crosses between Danish...
Full Text Available The nature and magnitude of heterosis and combining ability was studied in 18 F1 hybrids involving three CMS lines and six testers using line × tester analysis. The analysis of variance for combining ability of all the traits showed that variances due to treatments, parents, hybrids were highly significant. The line ‘CRMS 32A’ and testers viz. ‘Super rice-8’, ‘R 1099-2569-1-1’ and ‘Jitpiti’ were identified as good general combiners. The significant differences between lines x testers interaction indicates that SCA attributed heavily in the expression of these traits and demonstrates the importance of dominance or non additive variances for all the traits. The hybrid ‘CRMS 32A’/‘R 1099-2569-1-1’ and ‘APMS 6A’/‘Super rice-8’ were promising for grain yield. The magnitude of relative heterosis, heterobeltiosis and standard heterosis were also estimated for different characters. A high degree of relative heterosis was observed for grain yield (20.45- 82.37% in the hybrids viz., ‘CRMS 32A’/‘Super rice-8’, ‘APMS 6A’/‘Super rice-8’, ‘APMS 6A’/‘Jitpiti’ and ‘CRMS 32A’/‘R 1099-2569-1-1’. While, a higher degree of: heterobeltiosis (13.60 -68.37% was observed for grain yield in the hybrids viz., ‘CRMS 32A’/‘Super rice-8’, ‘CRMS 32A’/‘R 1099-2569-1-1’, ‘APMS 6A’/’Super rice-8’ and ‘APMS 6A’/’Jitpiti’. A high degree of standard heterosis was observed for grain yield in the hybrid ‘CRMS 32A’/‘R 1099-2569-1-1’. The hybrid ‘CRMS 32A’/ ‘R 1099-2569-1-1’ recorded a high degree of relative heterosis (62.01%, heterobeltiosis (57.35% and standard heterosis (15.05 and 25.51% over check hybrids, ‘Mahamaya’ and ‘Indirasona’, respectively that can be tested on yield trials for its further testing over locations.
James H. Haido
Full Text Available Steel fiber is considered as the most commonly used constructional fibers in concrete structures. The formulation of new nonlinearities to predict the static performance of steel fiber concrete composite structures is considered essential. Present study is devoted to investigate the efficiency of utilizing heterosis finite elements analysis in static analysis of steel fibrous beams. New and simple material nonlinearities are proposed and used in the formulation of these elements. A computer program coded in FORTRAN was developed to perform current finite element static analysis with considering four cases of elements stiffness matrix determination. The results are compared with the experimental data available in literature in terms of central deflections, strains, and failure form, good agreement was found. Suitable outcomes have been observed in present static analysis with using of tangential stiffness matrix and stiffness matrix in second iteration of the load increment.
Full Text Available Combining ability and heterosis were estimated for ornamental and vegetative traits of four petunia (Petunia hybrida Hort. inbred lines viz. L5 (P1, L8 (P2, L11 (P3 and L17 (P4 and their diallel hybrids in horticultural research farm of Ferdowsi University of Mashhad, Iran in 2011. The measured traits were plant height at first flower, number of leaf to first flower, flower diameter, flower tube length, internode length, stem diameter, plant height at flowering stage, plant spreading, number of branches per plant, leaf length and width. The results of combining ability for all studied traits revealed that both additive and non-additive gene effects contributed to the inheritance of the traits. Estimates of general combining ability effects showed that parent P3 was a good general combiner for most of the studied traits. For flower diameter, hybrid combination P1 � P2 had the highest significant positive specific combining ability effects. Reciprocal effects were significant for all traits and hybrid combination P1 � P2 had the highest significant positive reciprocal effects for flower tube length and plant height. Heterosis was found significant relative to both the mid parent and batter parent for all traits. For flower diameter, the highest positive values of heterotic effects were recorded in hybrid combination P2 � P3 both relative to the parental mean (37.3% and relative to the better parent (33.9%. It is obvious that heterotic effects represent an important resource in hybrid breeding of petunia.
Full Text Available Combining ability and heterosis were estimated for ornamental and vegetative traits of four petunia (Petunia hybrida Hort. inbred lines viz. L5 (P1, L8 (P2, L11 (P3 and L17 (P4 and their diallel hybrids in horticultural research farm of Ferdowsi University of Mashhad, Iran in 2011. The measured traits were plant height at first flower, number of leaf to first flower, flower diameter, flower tube length, internode length, stem diameter, plant height at flowering stage, plant spreading, number of branches per plant, leaf length and width. The results of combining ability for all studied traits revealed that both additive and non-additive gene effects contributed to the inheritance of the traits. Estimates of general combining ability effects showed that parent P3 was a good general combiner for most of the studied traits. For flower diameter, hybrid combination P1 P2 had the highest significant positive specific combining ability effects. Reciprocal effects were significant for all traits and hybrid combination P1 P2 had the highest significant positive reciprocal effects for flower tube length and plant height. Heterosis was found significant relative to both the mid parent and batter parent for all traits. For flower diameter, the highest positive values of heterotic effects were recorded in hybrid combination P2 P3 both relative to the parental mean (37.3% and relative to the better parent (33.9%. It is obvious that heterotic effects represent an important resource in hybrid breeding of petunia.
Eikenaar, C.; Komdeur, J.; Richardson, D. S.
In this study, we test whether patterns of territory inheritance, social mate choice and female-biased natal dispersal act as inbreeding avoidance mechanisms in the cooperatively breeding Seychelles warbler. Our results show that Seychelles warblers do not reduce the likelihood of inbreeding by
Perez, B C; Balieiro, J C C; Ventura, R V; Bruneli, F A T; Peixoto, M G C D
Inbreeding has been associated with the impairment of reproductive performance in many cattle breeds. Although the usage of reproductive biotechnologies has been increasing in bovine populations, not much attention has been given to the impact of inbreeding over cow's performance on artificial reproduction. The objective of this study was to estimate the impact of inbreeding on in vitro embryo production in a Guzerá breed population. The inbreeding coefficient (F), calculated as half of the co-ancestry of the individual's parents, was used as an estimate of inbreeding. The inbreeding coefficients of the donor, sire (used on in vitro fertilization) and of the embryos were included, separately, in the proposed models either as classificatory or continuous variables (linear and quadratic effects). The percentage of non-inbred individuals (or embryos) and mean F of donors, embryos and sires were 29.38%; 35.76%; 42.86% and 1.98±2.68; 1.32±3.13; 2.08±2.79, respectively. Two different models were considered, one for oocyte production traits and other for embryo production traits. The increase of F of the donor significantly (P0.05) effects were observed for the sire (father of the embryos) inbreeding coefficient over the traits analysed. Embryo's F influenced (Ptechnology. High levels of inbreeding should be avoided when selecting Guzerá female donors and planning in vitro fertilization mating.
Horta, Hugo; Sato, Machi; Yonezawa, Akiyoshi
This study analyses why and how academic inbreeding as a recruitment practice continues to prevail in Japan, a country with a mature higher education system, where high rates of academic inbreeding endure in most of the research-oriented universities in spite of several higher education reforms. Based on a qualitative analysis, we disclose three…
Trotta, Vincenzo; Cavicchi, Sandro; Guerra, Daniela
Inbreeding is expected to increase the variability in size and shape within populations. The distinct effects of inbreeding on size and shape suggest that they are governed by different developmental pathways. One unresolved question is whether the non-allometric shape component is partially unco...
Julie B. Fiévet
Full Text Available Heterosis, the superiority of hybrids over their parents for quantitative traits, represents a crucial issue in plant and animal breeding as well as evolutionary biology. Heterosis has given rise to countless genetic, genomic and molecular studies, but has rarely been investigated from the point of view of systems biology. We hypothesized that heterosis is an emergent property of living systems resulting from frequent concave relationships between genotypic variables and phenotypes, or between different phenotypic levels. We chose the enzyme-flux relationship as a model of the concave genotype-phenotype (GP relationship, and showed that heterosis can be easily created in the laboratory. First, we reconstituted in vitro the upper part of glycolysis. We simulated genetic variability of enzyme activity by varying enzyme concentrations in test tubes. Mixing the content of “parental” tubes resulted in “hybrids,” whose fluxes were compared to the parental fluxes. Frequent heterotic fluxes were observed, under conditions that were determined analytically and confirmed by computer simulation. Second, to test this model in a more realistic situation, we modeled the glycolysis/fermentation network in yeast by considering one input flux, glucose, and two output fluxes, glycerol and acetaldehyde. We simulated genetic variability by randomly drawing parental enzyme concentrations under various conditions, and computed the parental and hybrid fluxes using a system of differential equations. Again we found that a majority of hybrids exhibited positive heterosis for metabolic fluxes. Cases of negative heterosis were due to local convexity between certain enzyme concentrations and fluxes. In both approaches, heterosis was maximized when the parents were phenotypically close and when the distributions of parental enzyme concentrations were contrasted and constrained. These conclusions are not restricted to metabolic systems: they only depend on the
Lefort-Buson, Marianne; Guillot-Lemoine, Brigitte; Dattée, Yvette
The paper deals with a comparison of different indicators of genetic divergence between rapeseed parental lines : the relationship coefficient defined by MALÈCOT the generalized distance D2 of Mahalanobis, and a new G2 parameter close to HANSON & CASAS' R2. The purpose of the authors is to discuss the advantages of their simultaneous use in the prediction of both heterosis values and F1 performances of hybrids from parental lines. Relationships between heterosis values and genetic distanc...
Dipierri, José; Rodríguez-Larralde, Alvaro; Barrai, Italo; Camelo, Jorge López; Redomero, Esperanza Gutiérrez; Rodríguez, Concepción Alonso; Ramallo, Virginia; Bronberg, Rubén; Alfaro, Emma
Population isolates are an important tool in identifying and mapping genes of Mendelian diseases and complex traits. The geographical identification of isolates represents a priority from a genetic and health care standpoint. The purpose of this study is to analyze the spatial distribution of consanguinity by random isonymy (F ST) in Argentina and its relationship with the isolates previously identified in the country. F ST was estimated from the surname distribution of 22.6 million electors registered for the year 2001 in the 24 provinces, 5 geographical regions, and 510 departments of the country. Statistically significant spatial clustering of F ST was determined using the SaTScan V5.1 software. F ST exhibited a marked regional and departamental variation, showing the highest values towards the North and West of Argentina. The clusters of high consanguinity by random isonymy followed the same distribution. Recognized Argentinean genetic isolates are mainly localized at the north of the country, in clusters of high inbreeding. Given the availability of listings of surnames in high-capacity storage devices for different countries, estimating F ST from them can provide information on inbreeding for all levels of administrative subdivisions, to be used as a demographic variable for the identification of isolates within the country for public health purposes.
Full Text Available BACKGROUND: Combining ability effects are very effective genetic parameters in deciding the next phase of breeding programs. Although some breeding strategies on the basis of evaluating combining ability have been utilized extensively in hybrid breeding, little is known about the genetic basis of combining ability. Combining ability is a complex trait that is controlled by polygenes. With the advent and development of molecular markers, it is feasible to evaluate the genetic bases of combining ability and heterosis of elite rice hybrids through QTL analysis. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we first developed a QTL-mapping method for dissecting combining ability and heterosis of agronomic traits. With three testcross populations and a BCRIL population in rice, biometric and QTL analyses were conducted for ten agronomic traits. The significance of general combining ability and special combining ability for most of the traits indicated the importance of both additive and non-additive effects on expression levels. A large number of additive effect QTLs associated with performance per se of BCRIL and general combining ability, and dominant effect QTLs associated with special combining ability and heterosis were identified for the ten traits. CONCLUSIONS/SIGNIFICANCE: The combining ability of agronomic traits could be analyzed by the QTL mapping method. The characteristics revealed by the QTLs for combining ability of agronomic traits were similar with those by multitudinous QTLs for agronomic traits with performance per se of BCRIL. Several QTLs (1-6 in this study were identified for each trait for combining ability. It demonstrated that some of the QTLs were pleiotropic or linked tightly with each other. The identification of QTLs responsible for combining ability and heterosis in the present study provides valuable information for dissecting genetic basis of combining ability.
M. P. Patel, A. R. Patel, J.B. Patel and J.A.Patel
Heterosis for green fruits and related characters in chilli was studied in line × tester fashion involving five GMS lines and 10 testers. The hybridsdiffered significantly for all the characters, as evident from their highly significant mean square values. Mean squares due to hybrids ×environments were significant for all the characters except average fruit weight, which indicated more sensitivity of hybrids to environments. Thehybrids ACMS 8 ×IPS -2005 -15, ACMS 5 × IPS -2005 -15, ACMS 6 × A...
Full Text Available Evaluated was effect of mating (random vs. maximum avoidance of inbreeding under BLUP EBV selection strategy. Existing population structure was under Monte Carlo stochastic simulation analyzed from the point to minimize increase of inbreeding. Maximum avoidance of inbreeding under BLUP selection resulted into comparable increase of inbreeding then random mating in average of 10 generation development. After 10 generations of simulation of mating strategy was observed ΔF= 6,51 % (2 sires, 5,20 % (3 sires, 3,22 % (4 sires resp. 2,94 % (5 sires. With increased number of sires selected, decrease of inbreeding was observed. With use of 4, resp. 5 sires increase of inbreeding was comparable to random mating with phenotypic selection. For saving of genetic diversity and prevention of population loss is important to minimize increase of inbreeding in small populations. Classical approach was based on balancing ratio of sires and dams in mating program. Contrariwise in the most of commercial populations small number of sires was used with high mating ratio.
Mattey, Sarah N; Richardson, Jon; Ratz, Tom; Smiseth, Per T
There is mounting evidence that inbreeding can have complex effects on social interactions among inbred and outbred individuals. Here, we investigate effects of offspring and maternal inbreeding on parent-offspring communication in the burying beetle Nicrophorus vespilloides. We find effects of the interaction between offspring and maternal inbreeding on maternal behavior. Outbred females provided more direct care toward inbred larvae, while inbred females provided similar levels of direct care toward inbred and outbred larvae. Furthermore, we find direct and indirect effects of offspring inbreeding on offspring begging and maternal behavior, respectively. Inbred larvae spent less time begging than outbred larvae, and (outbred) females provided more direct care and less indirect care toward inbred larvae. Finally, we find effects of the interaction between offspring and maternal inbreeding on larval body mass. Inbred and outbred offspring grew to a similar size when the female was outbred, while inbred offspring were of a smaller size when the female was inbred. Our results suggest that outbred females provided more care toward inbred offspring to compensate for their poor genetic quality. Our study advances our understanding of inbreeding by showing that inbreeding can have direct effects on the behavior of inbred individuals and indirect effects on the behavior of outbred individuals and that indirect effects on outbred individuals may in turn influence the fitness of inbred individuals.
José Jaime Vasconcelos Cavalcanti
Full Text Available Esse trabalho foi conduzido com o objetivo de avaliar a heterose no cajueiro (Anacardium occidentale L. anão precoce. O experimento foi composto por seis clones parentais (CCP 06, CCP 09, CCP 76, CCP 1001, C1P3 e P399E e 18 combinações híbridas. Utilizou-se delineamento de blocos casualizados, com duas repetições e cinco plantas por parcela. A heterose média foi de 12,09%, 19,38%, 98,01%, 96,97% e -2,11%, respectivamente, para altura da planta, diâmetro da copa, número de castanha por planta, produtividade de castanha e peso médio de castanha, indicando presença de vigor híbrido nos cruzamentos, para todos os caracteres, exceto para peso médio de castanha, demonstrando a importância de sua exploração, com perspectivas de avanços genéticos sobre caracteres da cultura do caju. A conseqüência seria a obtenção de clones comerciais com características de produção desejáveis e a formação de populações-base para o programa de melhoramento populacional. Os híbridos CCP 06 x C1P3, CCP 09 x P399E e CCP 09 x CCP 06 são os mais promissores.The objective of this work was to evaluate the heterosis in dwarf cashew (Anacardium occidentale L.. The experiment had six parent clones (CCP 06, CCP 09, CCP 76, CCP 1001, C1P3, and P399E and 18 hybrid plants. A randomized complete block experimental design with two replications and five plants per plot was used. The average heterosis was 12%, 19%, 98%, 97%, and -2%, for the parent clones, based on the traits plant height, canopy diameter, number of nuts per plant, nut yield, and nut weight. It should be pointed out the presence of hybrid vigor in all crosses for all traits, except nut weight. This stresses the importance of hybrid vigor exploration, with perspectives of significant genetic improvement of the cashew culture, by obtaining superior commercial clones and establishing base-populations for the population breeding program. The hybrid combinations CCP 06 x C1P3, CCP 09 x P399E
Abdel-Moneam, M A
Five bread wheat varieties with different characteristics were crossed in a half-diallel model in 2005/2006 season. The five parents and their 10 F1 hybrids were evaluated under normal and water stress conditions during 2006/2007 season, to estimate heterosis of some wheat crosses for drought tolerance and selecting the crosses which could be useful in breeding programs for drought tolerance. The results indicated that, the best crosses over their mid parents at water stress condition for days to heading was Sakha-61 x Sakha-93; for flag leaf area were Giza-168 x Gemmeiza-9 and Sakha-61 x Gemmeiza-9 and for plant height was Sakha-61 x Sakha-93. The best crosses over their mid parents at both normal and stress conditions for days to maturity was Sakha-61 x Gemmeiza-9; for flag leaf area were Giza-168 x Sakha-61, Sakha-8 x Gemmeiza-9 and Sakha-93 x Gemmeiza-9; for spikes/plant were Sakha-8 x Sakha-61, Sakha-8 x Gemmeiza-9 and Sakha-61 x Sakha-93; for kernels/spike were Giza-168 x Sakha-8, Giza-168 x Sakha-61, Giza-168 x Sakha-93 and Sakha-8 x Gemmeiza-9; for 100-kernel weight were Giza-168 x Gemmeiza-9, Sakha-61 x Sakha-93 and Sakha-93 x Gemmeiza-9 and for grain yield/plant were Giza-168 x Sakha-93, Sakha-8 x Gemmeiza-9 and Sakha-93 x Gemmeiza-9. The best crosses over their better parents at water stress condition for flag leaf area were Giza-168 x Sakha-8, Giza-168 x Gemmeiza-9 and Sakha-8 x Gemmeiza-9; for plant height were Giza-168 x Gemmeiza-9 and Sakha-8 x Sakha-61. The best crosses over better parents at both normal and stress conditions for plant height were Giza-168 x Sakha-8, Sakha-8 x Gemmeiza-9 and Sakha-93 x Gemmeiza-9; for spikes/plant were Sakha-8xSakha-61, Sakha-61 x Sakha-93 and Sakha-8 x Gemmeiza-9; forkernels/spike were Giza-168 x Sakha-61 and Giza-168 x Sakha-93 and for grain yield/plant were Sakha-61 x Sakha-93 and Sakha-93 x Gemmeiza-9. Estimation of useful heterosis over better parent for grain yield/plant proved that it never exceeds 10.16% at
Ma (马谦), Qian; Hedden, Peter; Zhang (张启发), Qifa
Despite the accumulation of data on the genetic and molecular understanding of heterosis, there is little information on the regulation of heterosis at the physiological level. In this study, we performed a quantitative analysis of endogenous gibberellin (GA) content and expression profiling of the GA metabolism and signaling genes to investigate the possible relationship between GA signaling and heterosis for seedling development in rice (Oryza sativa). The materials used were an incomplete diallele set of 3 × 3 crosses and the six parents. In the growing shoots of the seedlings at 20 d after sowing, significant positive correlations between the contents of some GA species and performance and heterosis based on shoot dry mass were detected. Expression analyses of GA-related genes by real-time reverse transcription-polymerase chain reaction revealed that 13 out of the 16 GA-related genes examined exhibited significant differential expression among the F1 hybrid and its parents, acting predominantly in the modes of overdominance and positive dominance. Expression levels of nine genes in the hybrids displayed significant positive correlations with the heterosis of shoot dry mass. These results imply that GAs play a positive role in the regulation of heterosis for rice seedling development. In shoots plus root axes of 4-d-old germinating seeds that had undergone the deetiolation, mimicking normal germination in soil, the axis dry mass was positively correlated with the content of GA29 but negatively correlated with that of GA19. Our findings provide supporting evidence for GAs playing an important regulatory role in heterosis for rice seedling development. PMID:21693671
Full Text Available When breeding alfalfa for yield performance, it is necessary to use high-yielding parents obtained by different breeding methods. The assumption at the onset of this research was that crossing highest-yielding domestic cultivars with divergent populations from geographically distant breeding centers could result in the expression of heterotic effects in their hybrids contributing to increased alfalfa yield. The objective of this study was to determine yield and yield components and heterotic effects in hybrid progenies obtained by crossing the domestic cultivars NS Banat ZMS II and NS Mediana ZMS V with the cultivars Pella, Dolichi and Hyliki from Greece, UMSS 2001 from Bolivia and Jogeva 118 from Estonia in two series. The field trial planted in 2006, included 13 F1 hybrids and 6 of 7 initial parents in both series. Heterotic effects for yields of forage and hay were observed in 4 combinations (C NS Banat ZMS II x E Hyliki; C NS Banat ZMS II x E UMSS 2001; C NS Mediana ZMS V x E Hyliki; C NS Mediana ZMS V x E Dolichi. The populations that exhibited heterosis in a set of crossings are recommended for use as parent components for development of high-yielding synthetic alfalfa cultivars. .
Keywords: Dairy cattle, genetic diversity, pedigree analysis ... inbreeding and effective population sizes for the four major South African ... breeding programs and therefore L was computed as an average of generation intervals for the four.
Full Text Available The ovulatory shift modulates emotions related to female sexuality. Because fertility status only affects the individual's own opportunity cost, the adaptive value of this shift is expected to stem from self-regulation. To test this assumption we asked women to contemplate various inbreeding descriptions: 1 they themselves having sex with male relatives; 2 their sister having sex with their common male relatives; and 3 an unrelated woman having sex with her male relatives (in 1, but not 2 and 3, negative fitness consequences are affected by the participant's fertility. We dichotomized the dependent variable disgust (ceiling vs. non-ceiling and analyzed the interaction between fertility status and description type. The ovulatory shift was stronger in descriptions where they themselves were described as engaging in inbreeding. A smaller increase was also found in reactions to others engaging in inbreeding. We explain the latter effect as due to self-reflection.
Using data from parish records from 1712 to 1982 in a Spanish Pyrenean village, Ansó, the effects of the raw nuptiality, the types of consanguineous marriages and the rate and evolution of inbreeding on the mating structure have been studied. This structure has been modified in the course of time mostly through the secular variations in the frequency of consanguineous marriages. Recent inbreeding decrease in Ansó is related to the population diminution and cultural changes associated with isolate breakdown.
Gama, L T; Bressan, M C; Rodrigues, E C; Rossato, L V; Moreira, O C; Alves, S P; Bessa, R J B
Physicochemical properties and fatty acid profiles of meat from Bos indicus, Bos taurus and crossbred B. taurus×B. indicus bullocks (n=216), finished on pasture or grain, were used to estimate the effects of heterosis. Meat quality and fatty acid profiles generally benefited with crossbreeding, but the advantages from heterosis differed among finishing systems. The Warner-Bratzler shear-force in fresh and aged meat was reduced due to heterosis in pasture-finishing, but the effect was minor under grain-finishing. With pasture-finishing, heterosis caused an increase of 5% in CLA concentration, but few other changes in fatty acid profiles. In grain-finishing, heterosis caused a reduction in intramuscular fat and cholesterol, increased amounts of PUFA, n-6 fatty acids and PUFA/SFA ratio, and a decline in atherogenic index. The Δ(9) desaturase estimated activity in crossbreds showed a behavior close to B. indicus, suggesting the existence of few loci and a dominance genetic effect on enzymes involved in fatty acid synthesis and metabolism. Copyright © 2012 Elsevier Ltd. All rights reserved.
Full Text Available Introduction: Cucumber (Cucumis sativus L. is one of the most widely cultivated vegetables. Plant length is a quantitative trait is controlled by many genes. These traits are difficult to study due to the complex nature of their inheritance. The combining ability estimation is useful in determining the breeding value of cucumber lines by suggesting the appropriate use in a breeding program. In studying combining ability, the most commonly utilized experimental approach is the diallel design. General combining ability is a measure of additive genetic action; and specific combining ability (SCA is deviation from additivity. General combining ability is a main effect and SCA is an interaction. The aim is to determine the breeding value of the cross. Heterosis has been utilized to exploit dominance variance through production of hybrids. There are reports on positive and negative heterosis in cucumber however, there are differences between reports. This research was conducted to estimate general and specific combining ability and heterosis in cucumber inbred lines and hybrids to produce hybrids with high yield and quality. Material and Methods: In the spring of 2014, the seven parental lines and their 21 F1 hybrid were planted at the University of Guilan, in loamy sand field. Three replications were arranged in a randomized complete block design. The sandy loam soil was prepared by plowing and disking and formed into raised beds by plowed and harrow prior to plant establishment. Rows were on 1 m centers and plants were about 25 cm apart in the row. Prior to planting 150 kg·ha-1 of nitrogen from urea and 100 kg·ha-1 of phosphorous from triple superphosphate and 80 kg·ha-1 of potassium sulfate was applied. Side dressing with the same amount of nitrogen and phosphorus occurred at 50% flowering stage. Irrigation with 250 m3·ha-1, three times weekly, was begun at plant first flowering. In each replication, 12 individuals of each line or hybrid were
Full Text Available Abstract This study was designed to reveal any differences in effects of fast created versus total inbreeding on reproduction and body weights in mice. A line selected for large litter size for 124 generations (H and a control line (K maintained without selection for the same number of generations were crossed (HK and used as a basis for the experiment. Within the HK cross, full sib, cousin or random mating were practised for two generations in order to create new inbreeding (IBF at a fast rate. In the first generation of systematic mating, old inbreeding was regenerated in addition to creation of new inbreeding from the mating design giving total inbreeding (IBT. The number of pups born alive (NBA and body weights of the animals were then analysed by a model including both IBT and IBF. The IBT of the dam was in the present study found to reduce the mean NBA with -0.48 (± 0.22 (p F was -0.42 (± 0.27. For the trait NBA per female mated, the effect of IBT was estimated to be -0.45 (± 0.29 per 10% increase in the inbreeding coefficient and the effect of IBF was -0.90 (± 0.37 (p F of the dam could be found on sex-ratio and body weights at three and six weeks of age in a population already adjusted for IBT.
Lin, Zibei; Shi, Fan; Hayes, Ben J; Daetwyler, Hans D
Heuristic genomic inbreeding controls reduce inbreeding in genomic breeding schemes without reducing genetic gain. Genomic selection is increasingly being implemented in plant breeding programs to accelerate genetic gain of economically important traits. However, it may cause significant loss of genetic diversity when compared with traditional schemes using phenotypic selection. We propose heuristic strategies to control the rate of inbreeding in outbred plants, which can be categorised into three types: controls during mate allocation, during selection, and simultaneous selection and mate allocation. The proposed mate allocation measure GminF allocates two or more parents for mating in mating groups that minimise coancestry using a genomic relationship matrix. Two types of relationship-adjusted genomic breeding values for parent selection candidates ([Formula: see text]) and potential offspring ([Formula: see text]) are devised to control inbreeding during selection and even enabling simultaneous selection and mate allocation. These strategies were tested in a case study using a simulated perennial ryegrass breeding scheme. As compared to the genomic selection scheme without controls, all proposed strategies could significantly decrease inbreeding while achieving comparable genetic gain. In particular, the scenario using [Formula: see text] in simultaneous selection and mate allocation reduced inbreeding to one-third of the original genomic selection scheme. The proposed strategies are readily applicable in any outbred plant breeding program.
A. HUSSAIN, P. AKHTAR, S. ALI, M. YOUNAS1 AND M. SHAFIQ2
Full Text Available Pedigree records of 17250 Thalli sheep with 17030 lambings maintained at the Livestock Experiment Station, Rakh Ghulaman, Distt. Bhakkar, Pakistan during the period from 1975 to 2004 were utilized in the present study. Average values for birth weight, weights at 60 and 90 days of age, weaning weight and pre-weaning average daily gain were 4.11 ± 0.82, 11.58 ± 3.57, 14.92 ± 4.56, 18.95 ± 4.56 and 0.12 ± 0.04 kg, respectively. Coefficients of inbreeding ranged from 10.15 to 37.50 percent for 295 animals, being 1.70 percent of the flock. Inbreeding significantly (P<0.01 affected birth and 60 days weight. Birth weight and 60 days weight decreased by 0.051 and 0.048 kg for each 1 percent increase in the level of inbreeding. However, inbreeding had non significant effect on weight at 90 days of age, weaning weight and pre-weaning average daily gain. The regression values for these traits were 0.010, 0.083 and 0.105, respectively. It was concluded that inbreeding showed deleterious effects only in early stages of life but as the lambs grew older the effect of inbreeding on pre-weaning traits diminished.
Bruna R.S Menezes
Full Text Available With a high growth rate and a DM yield of up to 80 t ha-1 yr¹, elephant grass (Pennisetum purpureum Schumach. has been utilized as an alternative source of energy. However, genotypes adapted to and productive in the different regions of Brazil need to be developed. Thus, the objectives of the present study were to estimate and evaluate heterotic effects in elephant-grass hybrids obtained in a partial diallel cross (5 x 5, with the aim of assisting the superior hybrids selection for bioenergy production. The experiment was conducted in Campos dos Goytacazes, Rio de Janeiro, Brazil. The following traits were evaluated: plant height (HGT, stem diameter (SD, leaf blade width (LBW, number of tillers per linear meter (NT, percentage of DM (%DM, and DM yield (DMY. The experiment was conducted in a randomized block design, with 35 treatments (five female parents, five male parents, and 25 hybrid combinations and three replicates. The adopted statistical model was that of Miranda Filho and Geraldi, in an adaptation of Gardner and Eberhart. Significant heterosis was observed for most traits in the rainy and dry seasons. Hybrid combinations H1 ('Cubano Pinda' x 'Mercker', H7 ('Cameroon-Piracicaba' x 'Três Rios', H8 ('Cameroon-Piracicaba' x 'Mercker 86-Mexico', H17 ('IAC-Campinas' x 'Três Rios', H18 ('IAC-Campinas' x 'Mercker 86-Mexico', and H25 ('Guacu/IZ.2' x 'Roxo' showed potential for use in breeding programs that aiming at develop clones with a energy biomass production capacity high.
Full Text Available Kernel shape related traits (KSRTs have been shown to have important influences on grain yield. The previous studies that emphasize kernel length (KL and kernel width (KW lack a comprehensive evaluation of characters affecting kernel shape. In this study, materials of the basic generations (B73, Mo17, and B73 × Mo17, 82 intermated B73 × Mo17 (IBM individuals, and the corresponding triple testcross (TTC populations were used to evaluate heterosis, investigate correlations, and characterize the quantitative trait loci (QTL for six KSRTs: KL, KW, length to width ratio (LWR, perimeter length (PL, kernel area (KA, and circularity (CS. The results showed that the mid-parent heterosis (MPH for most of the KSRTs was moderate. The performance of KL, KW, PL, and KA exhibited significant positive correlation with heterozygosity but their Pearson's R values were low. Among KSRTs, the strongest significant correlation was found between PL and KA with R values was up to 0.964. In addition, KW, PL, KA, and CS were shown to be significant positive correlation with 100-kernel weight (HKW. 28 QTLs were detected for KSRTs in which nine were augmented additive, 13 were augmented dominant, and six were dominance × additive epistatic. The contribution of a single QTL to total phenotypic variation ranged from 2.1% to 32.9%. Furthermore, 19 additive × additive digenic epistatic interactions were detected for all KSRTs with the highest total R2 for KW (78.8%, and nine dominance × dominance digenic epistatic interactions detected for KL, LWR, and CS with the highest total R2 (55.3%. Among significant digenic interactions, most occurred between genomic regions not mapped with main-effect QTLs. These findings display the complexity of the genetic basis for KSRTs and enhance our understanding on heterosis of KSRTs from the quantitative genetic perspective.
Urfer Silvan R
Full Text Available Abstract Background Given that no influence of inbreeding on life expectancy could be demonstrated in Irish Wolfhounds in a previous study, it was decided to test the influence of inbreeding and other parameters on fertility in this breed. Methods The study was based on all Irish Wolfhound litters registered in Sweden between 1976 and 2007 (n = 822 litters as provided by the Swedish Kennel Club (SKK and combined with a pedigree database going back to 1862. Analyses were performed using linear regression in a Generalised Linear Model and other tests in the SAS system®. Results Mean number of pups per litter was 6.01 ± 2.65, with a maximum of 13. There were no significant differences in either the number of litters or the number of pups between years of birth. Males were used for breeding at a significantly earlier age than females. Mean number of litters per parent was 2.96 ± 3.14 for males and 1.59 ± 0.87 for females. No influence of Wright's inbreeding coefficients over 5, 10, 20 and 30 generations and/or Meuwissen's inbreeding coefficients on litter size was detected. In the Generalised Linear Model, highly significant, but weak (coefficient of determination (R2 = 0.0341 influences were found for maternal age at mating as well as maternal inbreeding measured by Wright's inbreeding coefficient over 30 generations and Meuwissen's inbreeding coefficient. Paternal inbreeding coefficients over 5, 10, 20 and 30 generations and calculated after Meuwissen, as well as maternal inbreeding coefficients over 5, 10 and 20 generations did not have significant effects on litter size. Conclusion The low coefficient of determination (R2 value of the Generalised Linear Model indicates that inbreeding does not have a strong influence on fertility in Irish Wolfhounds, which is consistent with earlier results and the breed's genetic history. These results likely reflect the aforementioned genetic history and should not be extrapolated to other breeds without
Deng, Yuewen; Liu, Xiao; Zhang, Guofan; Wu, Fucun
We conducted a complete diallel cross among three geographically isolated populations of Pacific abalone Haliotis discus hannai Ino to determine the heterosis and the combining ability of growth traits at the spat stage. The three populations were collected from Qingdao (Q) and Dalian (D) in China, and Miyagi (M) in Japan. We measured the shell length, shell width, and total weight. The magnitude of the general combining ability (GCA) variance was more pronounced than the specific combining ability (SCA) variance, which is evidenced by both the ratio of the genetic component in total variation and the GCA/SCA values. The component variances of GCA and SCA were significant for all three traits ( P<0.05), indicating the importance of additive and non-additive genetic effects in determining the expression of these traits. The reciprocal maternal effects (RE) were also significant for these traits ( P<0.05). Our results suggest that population D was the best general combiner in breeding programs to improve growth traits. The DM cross had the highest heterosis values for all three traits.
Nowak, Carsten; Jost, Daniel; Vogt, Christian; Oetken, Matthias; Schwenk, Klaus; Oehlmann, Joerg
Inbreeding and loss of genetic variation are considered to be major threats to small and endangered populations. The reduction of fitness due to inbreeding is believed to be more severe under stressful environmental conditions. We generated nine strains of the ecotoxicological model organism Chironomus riparius of different inbreeding levels in order to test the hypothesis that the inbreeding level and thus the degree of genome-wide homozygosity influences the life-history under cadmium exposure. Therefore, midge populations were exposed to a gradient of sediment-bound cadmium. The level of genetic variation in the used strains was assessed using microsatellite markers. In the life-cycle tests, inbreeding reduced fitness within C. riparius populations both under control and stressed conditions. However, differences between genetically diverse and impoverished strains were greatest at high cadmium exposure. Overall, inbreeding effects were not only dependent on cadmium concentrations in the sediment, but also on the life-history trait investigated. While some parameters where only affected by inbreeding, others were altered by both, inbreeding and cadmium. For the larval developmental time, a significant interaction was found between inbreeding and cadmium stress. While all strains showed a similar developmental time under control conditions, high rates of inbreeding led to a significantly delayed emergence time under high cadmium concentrations, resulting in longer generation periods and reduced population growth rates as population-relevant effects. The results show, that bioassays with C. riparius are affected by the level of inbreeding within Chironomus test strains. Pollution stress is therefore likely to affect the survival of rare and endangered populations more severe than that of large and genetically diverse ones
Jensen, Palle; Overgaard, Johannes; Loeschcke, Volker
in replicated lines of inbred and outbred Drosophila melanogaster at stressful low, benign and stressful high temperatures. The lowest measurements of metabolic rate in our study are always associated with the low activity period of the diurnal cycle and these measurements therefore serve as good estimates...... of standard metabolic rate. Due to the potentially added costs of genetic stress in inbred lines we hypothesized that inbred individuals have increased metabolic rate compared to outbred controls and that this is more pronounced at stressful temperatures due to synergistic inbreeding by environment...... interactions. Contrary to our hypothesis we found no significant difference in metabolic rate between inbred and outbred lines and no interaction between inbreeding and temperature. Inbreeding however effected the variance; the variance in metabolic rate was higher between the inbred lines compared...
Full Text Available An observed case of inbreeding in a pack ot wild dogs Lycaon pictus in the Kruger National Park, Republic of South Africa, provides evidence for the phenomenon of dominance reversal in this species. This is believed to be the first recorded instance of inbreeding in Lycaon. Emigration of subordinate females from established packs of wild dogs has been documented in the Serengeti National Park and Ngorongoro Conservation Area in northern Tanzania, as well as in the Kruger National Park. However, the newly subordinate (ex-dominant female in the pack in which inbreeding has occurred has not emigrated in the 16 months since the change in her status. A possible explanation for this behaviour is given. As a result of this reversal, the pack contains at least two females capable of breeding, the subordinate of which is at least two years older than the dominant. This is considered the first record of such a breeding structure in Lycaon.
Windig, J.J.; Lansbergen, L.M.T.E.
Within breeds and other captive populations, the risk of high inbreeding rates and loss of diversity can be high within (small) herds or subpopulations. When exchange of animals between different subpopulations is organised according to a rotational mating scheme, inbreeding rates can be restricted.
Full Text Available The degree of homozygosity of some 39 Thoroughbred horses was estimated from microsatellite analysis data. The power of inbreeding was detected towards horse pedigree. We suggested the use of genetic analysis of microsatellite loci of DNA for the determination of actual level of inbreeding.
Müller-Unterberg, Maarit; Wallmann, Sandra; Distl, Ottmar
The Black Forest Draught horse (BFDH) is an endangered German coldblood breed with its origin in the area of the Black Forest in South Germany. In this retrospective study, the influence of the inbreeding coefficient on foaling rates was investigated using records from ten breeding seasons. Due to the small population size of BFDH, the level of inbreeding is increasing and may have an effect on foaling rates.The data of the present study included all coverings reported for 1024 BFDH mares in the years 2001-2009. These mares were covered by 32 BFDH stallions from the State Stud Marbach. Data from 4534 estrus cycles was used to calculate per cycle foaling rate (CFR). Pedigree data contained all studbook data up to the foundation of the breed as early as 1836. The level of inbreeding of the mare, stallion and expected foal along with other systematic effects on CFR were analysed using a generalized linear mixed model approach. Stallion was employed as a random effect. Systematic fixed effects were month of mating, mating type, age of the mare and stallion, reproductive status of the mare and stallion line of the mare. Inbreeding coefficients of the stallion, mare and expected foal were modelled as linear covariates. The average CFR was 40.9%. The mean inbreeding coefficients of the mares, stallions and expected foals were 7.46, 7.70 and 9.66%. Mating type, age of the mare, reproductive status of the mare and stallion line of the mare had a significant effect. The results showed that the mating type, stallion line of the mare, sire, age and reproductive status of the mare exerted the largest influences on CFR in BFDH. Inbreeding coefficients of the stallion, mare and expected foal were not significantly related with CFR.
König, S; Tsehay, F; Sitzenstock, F; von Borstel, U U; Schmutz, M; Preisinger, R; Simianer, H
Due to consistent increases of inbreeding of on average 0.95% per generation in layer populations, selection tools should consider both genetic gain and genetic relationships in the long term. The optimum genetic contribution theory using official estimated breeding values for egg production was applied for 3 different lines of a layer breeding program to find the optimal allocations of hens and sires. Constraints in different scenarios encompassed restrictions related to additive genetic relationships, the increase of inbreeding, the number of selected sires and hens, and the number of selected offspring per mating. All these constraints enabled higher genetic gain up to 10.9% at the same level of additive genetic relationships or in lower relationships at the same gain when compared with conventional selection schemes ignoring relationships. Increases of inbreeding and genetic gain were associated with the number of selected sires. For the lowest level of the allowed average relationship at 10%, the optimal number of sires was 70 and the estimated breeding value for egg production of the selected group was 127.9. At the highest relationship constraint (16%), the optimal number of sires decreased to 15, and the average genetic value increased to 139.7. Contributions from selected sires and hens were used to develop specific mating plans to minimize inbreeding in the following generation by applying a simulated annealing algorithm. The additional reduction of average additive genetic relationships for matings was up to 44.9%. An innovative deterministic approach to estimate kinship coefficients between and within defined selection groups based on gene flow theory was applied to compare increases of inbreeding from random matings with layer populations undergoing selection. Large differences in rates of inbreeding were found, and they underline the necessity to establish selection tools controlling long-term relationships. Furthermore, it was suggested to use
Powell, Jeffrey R.; Evans, Benjamin R.
Deriving strains of mosquitoes with reduced genetic variation is useful, if not necessary, for many genetic studies. Inbreeding is the standard way of achieving this. Full-sib inbreeding the mosquito Aedes aegypti for seven generations reduced heterozygosity to 72% of the initial heterozygosity in contrast to the expected 13%. This deviation from expectations is likely due to high frequencies of deleterious recessive alleles that, given the number of markers studied (27,674 single nucleotide polymorphisms [SNPs]), must be quite densely spread in the genome. PMID:27799643
Pedersen, Kamilla Sofie; Kristensen, Torsten Nygård; Loeschcke, Volker
-line variation in metabolite profiles compared to outbred lines. In contrast to previous observations revealing interactions between inbreeding and environmental stress on gene expression patterns and life-history traits, the effect of inbreeding on the metabolite profile was similar across the different...... and five inbred lines were studied by nuclear magnetic resonance spectroscopy after exposure to benign temperature, heat stress, or cold stress. In both the absence and the presence of temperature stress, metabolite levels were significantly different among inbred and outbred lines. The major effect...
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En Colombia se carece de información referente al tipo de control genético en la arveja que gobierna la precocidad, el rendimiento y sus componentes. El objetivo de este trabajo fue evaluar la habilidad combinatoria y heterosis en cuatro líneas y tres variedades comerciales de arveja, para once variables agronómicas. Se desarrolló un diseño dialélico (Griffing, método 1, modelo 1 con siete materiales, bajo condiciones de la Sabana de Bogotá. Se hizo el análisis de varianza y se obtuvieron los valores estimados para habilidad combinatoria general (HCG y específica (HCE, y se calcularon los valores de heterosis sobre la media parental (HMP y sobre el mejor padre (HBP. La HCG fue altamente significativa para ocho de los caracteres evaluados y la HCE fue significativa para: nudos hasta la primera flor, longitud de vaina, número de semillas por vaina y peso de 100 semillas. Las variedades ‘Pequinegra’, ‘Santa Isabel’ e ‘ICA Tominé’ fueron los mejores combinadores generales. La variedad ‘Pequinegra’ tuvo efectos recíprocos altamente significativos en caracteres asociados con precocidad. En cuanto a la evaluación de heterosis, los híbridos F1 tuvieron un mejor comportamiento que la media de sus parentales en cinco de los componentes de rendimiento. Aún cuando sólo tres de las progenies en estudio fueron más precoces que el mejor padre, para la HMP se hallaron valores negativos que indican precocidad para más de la mitad de los cruces evaluados. Se encontró una asociación importante entre el tamaño de la vaina y el peso de 100 semillas.
del Giacco Stefano
Full Text Available Abstract Background Association studies consist in identifying the genetic variants which are related to a specific disease through the use of statistical multiple hypothesis testing or segregation analysis in pedigrees. This type of studies has been very successful in the case of Mendelian monogenic disorders while it has been less successful in identifying genetic variants related to complex diseases where the insurgence depends on the interactions between different genes and the environment. The current technology allows to genotype more than a million of markers and this number has been rapidly increasing in the last years with the imputation based on templates sets and whole genome sequencing. This type of data introduces a great amount of noise in the statistical analysis and usually requires a great number of samples. Current methods seldom take into account gene-gene and gene-environment interactions which are fundamental especially in complex diseases. In this paper we propose to use a non-parametric additive model to detect the genetic variants related to diseases which accounts for interactions of unknown order. Although this is not new to the current literature, we show that in an isolated population, where the most related subjects share also most of their genetic code, the use of additive models may be improved if the available genealogical tree is taken into account. Specifically, we form a sample of cases and controls with the highest inbreeding by means of the Hungarian method, and estimate the set of genes/environmental variables, associated with the disease, by means of Random Forest. Results We have evidence, from statistical theory, simulations and two applications, that we build a suitable procedure to eliminate stratification between cases and controls and that it also has enough precision in identifying genetic variants responsible for a disease. This procedure has been successfully used for the beta-thalassemia, which is
Reid, Jane M; Duthie, A Bradley; Wolak, Matthew E; Arcese, Peter
One hypothesis explaining extra-pair reproduction is that socially monogamous females mate with extra-pair males to adjust the coefficient of inbreeding (f) of extra-pair offspring (EPO) relative to that of within-pair offspring (WPO) they would produce with their socially paired male. Such adjustment of offspring f requires non-random extra-pair reproduction with respect to relatedness, which is in turn often assumed to require some mechanism of explicit pre-copulatory or post-copulatory kin discrimination. We propose three demographic processes that could potentially cause mean f to differ between individual females' EPO and WPO given random extra-pair reproduction with available males without necessarily requiring explicit kin discrimination. Specifically, such a difference could arise if social pairings formed non-randomly with respect to relatedness or persisted non-randomly with respect to relatedness, or if the distribution of relatedness between females and their sets of potential mates changed during the period through which social pairings persisted. We used comprehensive pedigree and pairing data from free-living song sparrows (Melospiza melodia) to quantify these three processes and hence investigate how individual females could adjust mean offspring f through instantaneously random extra-pair reproduction. Female song sparrows tended to form social pairings with unrelated or distantly related males slightly less frequently than expected given random pairing within the defined set of available males. Furthermore, social pairings between more closely related mates tended to be more likely to persist across years than social pairings between less closely related mates. However, these effects were small and the mean relatedness between females and their sets of potential extra-pair males did not change substantially across the years through which social pairings persisted. Our framework and analyses illustrate how demographic and social structuring within
Depression - major; Depression - clinical; Clinical depression; Unipolar depression; Major depressive disorder ... providers do not know the exact causes of depression. It is believed that chemical changes in the ...
Pedersen, Louise Dybdahl; Pedersen, Asger Roer; Bijlsma, Kuke
in benign and stressful environments using Drosophila melanogaster as a model organism. Male sterility was compared in 21 inbred lines and five non-inbred control lines at 25.0 and 29.0 °C. The effect of inbreeding on sterility was significant only at 29.0 °C. This stress-induced increase in sterility...
Stahlhut, J K; Cowan, D P
The Hymenoptera have arrhenotokous haplodiploidy in which males normally develop from unfertilized eggs and are haploid, while females develop from fertilized eggs and are diploid. Multiple sex determination systems are known to underlie haplodiploidy, and the best understood is single-locus complementary sex determination (sl-CSD) in which sex is determined at a single polymorphic locus. Individuals heterozygous at the sex locus develop as females; individuals that are hemizygous (haploid) or homozygous (diploid) at the sex locus develop as males. sl-CSD can be detected with inbreeding experiments that produce diploid males in predictable proportions as well as sex ratio shifts due to diploid male production. This sex determination system is considered incompatible with inbreeding because the ensuing increase in homozygosity increases the production of diploid males that are inviable or infertile, imposing a high cost on matings between close relatives. However, in the solitary hunting wasp Euodynerus foraminatus, a species suspected of having sl-CSD, inbreeding may be common due to a high incidence of sibling matings at natal nests. In laboratory crosses with E. foraminatus, we find that sex ratios and diploid male production (detected as microsatellite heterozygosity) are consistent with sl-CSD, but not with other sex determination systems. This is the first documented example of sl-CSD in a hymenopteran with an apparent natural history of inbreeding, and thus presents a paradox for our understanding of hymenopteran genetics.
Agarwala, R; Schäffer, A A; Tomlin, J F
We describe a large genealogy data base, which can be searched by computer, of 295,095 Amish and Mennonite individuals. The data base was constructed by merging our existing Anabaptist Genealogy Database 2.0 containing approximately 85,000 individuals with a genealogy file containing approximately 242,000 individuals, kindly provided by Mr. James Hostetler. The merging process corrected thousands of inconsistencies and eliminated hundreds of duplicate individuals. Geneticists have long been interested in Anabaptist populations because they are closed and have detailed written genealogies. The creation of an enlarged and unified data base affords the opportunity to examine inbreeding trends and correlates in these populations. We show the following results. The frequency of consanguineous marriages shows steady increase over time and reached approximately 85% for individuals born in 1940-1959. Among consanguineous marriages, the median kinship coefficient stayed stable in the 19th century, but rose from 0.0115 to 0.0151 in the 20th century. There are statistically significant associations (p < 0.0001) between inbreeding and family size and interbirth intervals in the 20th century. There is an association (p < 0.0005) between inbreeding and early death for individuals born in 1920-1959. However, this association reverses dramatically (p < 0.0005 in the opposite direction) for individuals born in 1960-1979. We tested for an association between inbreeding and being the mother of twins, but found none.
Koelewijn, H.P.; Damme, van J.M.M.
1 Male steriles (MS) must have a fitness advantage relative to hermaphrodites (H) if they are to be maintained in gynodioecious species. We report experiments in which we disentangle the relative contributions of seed size, inbreeding and maternal sex to the fitness advantage of male steriles in
Swillen, Ine; Vanoverbeke, Joost; De Meester, Luc
Several studies have emphasized that inbreeding depression (ID) is enhanced under stressful conditions. Additionally, one might imagine a loss of adaptively plastic responses which may further contribute to a reduction in fitness under environmental stress. Here, we quantified ID in inbred families of the cyclical parthenogen Daphnia magna in the absence and presence of fish predation risk. We test whether predator stress affects the degree of ID and if inbred families have a reduced capacity to respond to predator stress by adaptive phenotypic plasticity. We obtained two inbred families through clonal selfing within clones isolated from a fish pond. After mild purging under standardized conditions, we compared life history traits and adaptive plasticity between inbred and outbred lineages (directly hatched from the natural dormant egg bank of the same pond). Initial purging of lineages under standardized conditions differed among inbred families and exceeded that in outbreds. The least purged inbred family exhibited strong ID for most life history traits. Predator-induced stress hardly affected the severity of ID, but the degree to which the capacity for adaptive phenotypic plasticity was retained varied strongly among the inbred families. The least purged family overall lacked the capacity for adaptive phenotypic plasticity, whereas the family that suffered only mild purging exhibited a potential for adaptive plasticity that was comparable to the outbred population. We thus found that inbred offspring may retain the capacity to respond to the presence of fish by adaptive phenotypic plasticity, but this strongly depends on the parental clone engaging in selfing. PMID:26257883
Verhoeven, K.J.F.; Macel, M.; Wolfe, L.M.; Biere, A.
When previously isolated populations meet and mix, the resulting admixed population can benefit from several genetic advantages, including increased genetic variation, the creation of novel genotypes and the masking of deleterious mutations. These admixture benefits are thought to play an important
Opatová, Pavlína; Ihle, M.; Albrechtová, Jana; Tomášek, Oldřich; Kempenaers, B.; Forstmeier, W.; Albrecht, Tomáš
Roč. 6, č. 1 (2016), s. 295-304 ISSN 2045-7758 R&D Projects: GA ČR(CZ) GAP506/12/2472 Institutional support: RVO:68081766 Keywords : gamete performance * genetic quality * sperm abnormality * sperm morphology * sperm velocity Subject RIV: EG - Zoology Impact factor: 2.440, year: 2016
Amanda Regina Godoy
Full Text Available Este trabalho teve por objetivo verificar se existe depressão por endogamia para produção de sementes com sucessivas gerações de autofecundações em uma população de pepino caipira, obtida a partir da geração F2 do cruzamento (Safira x Hatem x Safira. O delineamento experimental utilizado foi em blocos ao acaso, com seis tratamentos (diferentes gerações de autofecundação - S0 a S5, quatro repetições e cinco plantas por parcela. Não houve diferença estatística para todas as características avaliadas (número de frutos por planta, massa de sementes por planta, massa de sementes por fruto, número de sementes por planta, número de sementes por fruto, massa de 100 sementes, teste-padrão de germinação, primeira contagem do teste-padrão de germinação e índice de velocidade de germinação, observando-se que a endogamia não afetou a produção e qualidade das sementes nessa população.The objective of this work was to evaluate the inbreeding depression after successive generations of self-pollination in a cucumber population, generation F2 from the cross (Safira x Hatem x Safira. Experimental design was randomized blocks with six treatments (different generations of self-pollination - S0 to S5, four replicates and five plants per plot. There was no statistical difference among all evauated characteristics (fruit number per plant, number and weight of seeds per plant and per fruit, germination test, first count of germinated seeds, index of germination a and weight of 100 seeds, showing that inbreeding did not affect seed production and quality in this population.
Full Text Available Maintaining genetic variation and controlling the increase in inbreeding are crucial requirements in animal conservation programs. The most widely accepted strategy for achieving these objectives is to maximize the effective population size by minimizing the global coancestry obtained from a particular pedigree. However, for most natural or captive populations genealogical information is absent. In this situation, microsatellites have been traditionally the markers of choice to characterize genetic variation, and several estimators of genealogical coefficients have been developed using marker data, with unsatisfactory results. The development of high-throughput genotyping techniques states the necessity of reviewing the paradigm that genealogical coancestry is the best parameter for measuring genetic diversity. In this study, the Illumina PorcineSNP60 BeadChip was used to obtain genome-wide estimates of rates of coancestry and inbreeding and effective population size for an ancient strain of Iberian pigs that is now in serious danger of extinction and for which very accurate genealogical information is available (the Guadyerbas strain. Genome-wide estimates were compared with those obtained from microsatellite and from pedigree data. Estimates of coancestry and inbreeding computed from the SNP chip were strongly correlated with genealogical estimates and these correlations were substantially higher than those between microsatellite and genealogical coefficients. Also, molecular coancestry computed from SNP information was a better predictor of genealogical coancestry than coancestry computed from microsatellites. Rates of change in coancestry and inbreeding and effective population size estimated from molecular data were very similar to those estimated from genealogical data. However, estimates of effective population size obtained from changes in coancestry or inbreeding differed. Our results indicate that genome-wide information represents a
Fuster, V; Jiménez, A M; Colantonio, S E
The present paper examines consanguineous marriages occurring between 1874 and 1975 in three valleys (Tormes, Alberche, and Tiétar) in the Sierra de Gredos mountain range, Avila province, Spain. Information was obtained from parish registers of 42 localities, corresponding to a total of 41,696 weddings. Consanguineous marriages were defined as those up to the third degree of consanguinity (second cousins). From 1874 to 1975 the percentage of related mates was 4.45% and the inbreeding coefficient was 0.0011868 (for 1874 to 1917 corresponding figures up to the fourth degree were 16.44% and 0.00 19085, respectively). In order to ascertain the characteristics and evolution of mating patterns in Gredos, the contribution of each degree of kinship was analyzed as a whole and then for each valley separately. Regarding total consanguineous marriages in Gredos, there is a low frequency of uncle-niece matings (0.21%) and a first-second cousin mating ratio (C22/C33) of 0.23 (up to the third degree of consanguinity). Before 1918 multiple matings (i.e., those involving more than a single relationship) accounted for 19.16% of consanguineous marriages (up to the fourth degree). The observed frequencies of multiple consanguineous marriages was, on average, about twice that expected at random, and the proportion of such marriages to total inbreeding was 34.65%. The temporal change of the Gredos inbreeding pattern was characterized by a recent decrease; the highest inbreeding levels correspond to the period from 1915 to 1944. Finally, intervalley differences (maximum inbreeding coefficient in the Tormes, minimum in the Tiétar) are interpreted considering the geography, population size, and population mobility for each valley
Li, Yangyang; Wang, Cheng; Liu, Xinye; Song, Jian; Li, Hongjian; Sui, Zhipeng; Zhang, Ming; Fang, Shuang; Chu, Jinfang; Xin, Mingming; Xie, Chaojie; Zhang, Yirong; Sun, Qixin; Ni, Zhongfu
Heterosis has been widely used in agriculture, but the underlying molecular principles are still largely unknown. During seed germination, we observed that maize (Zea mays) hybrid B73/Mo17 was less sensitive than its parental inbred lines to exogenous abscisic acid (ABA), and endogenous ABA content in hybrid embryos decreased more rapidly than in the parental inbred lines. ZmABA8ox1b, an ABA inactivation gene, was consistently more highly up-regulated in hybrid B73/Mo17 than in its parental inbred lines at early stages of seed germination. Moreover, ectopic expression of ZmABA8ox1b obviously promoted seed germination in Arabidopsis Remarkably, microscopic observation revealed that cell expansion played a major role in the ABA-mediated maize seed germination heterosis, which could be attributed to the altered expression of cell wall-related genes. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.
Herrera-Paz, Edwin Francisco
The isonymic method has been amply used to assess the approximate genetic structure of human communities. The objective of the study was to evaluate the magnitude of genetic isolation and inbreeding customs in 57 communities from three rural municipalities of Honduras using isonymy techniques. The list of 408 different surnames from 20712 voters registered in the national electoral organism, residing in the 57 Honduran communities, was used for this study. For each community, random (IR), non-random (IN), and total (IT) isonymy values were calculated in order to assess inbreeding coefficients FST, FIS and FIT. High consanguinity due to isolation and to endogamous customs was unveiled in many communities. Significant deviation from the exogamous behavior typical of many human populations was observed in the three studied municipalities, when compared to other Honduran populations. The studied communities present high consanguinity due to isolation, ethnic segregation and/or endogamous customs.
Andreev, D.; Breilid, H.; Kirkendall, L.; Brun, Luc-Olivier; French-Constant, R.H.
The coffee berry borer beetle #Hypothenemus hampei$ (Ferrari) (#Curculionidae$ : #Scolytinae$) is the major insect pest of coffee and has spread to most of the coffee-growing countries of the world. This beetle also displays an usual life cycle, with regular sibling mating. This regular inbreeding and the population bottlenecks occuring on colonization of new regions should lead to low levels of genetic diversity. We were therefore interested in determining the level of nucleotide variation i...
Fuster, Vicente; Colantonio, Sonia Edith
The contribution of consanguineous marriages corresponding to uncle-niece or aunt-nephew (C12), first cousin (C22), first cousin once removed (C23), and second cousin (C33) to the inbreeding coefficient (alpha) was analyzed from a sample of Spanish areas and periods. Multiple regressions were performed taking as independent variables the different degrees of consanguinity previously selected (C12, C22, C23, and C33) and as dependent variable the inbreeding coefficient (alpha). According to the results obtained for any degree and period, rural frequencies always surpass urban. However, the pattern is similar in both areas. In the period where consanguinity was more elevated (1890-1929) the C22/C33 ratio increased. Its variation is not due to C22 and C33 changes in the same way. In rural areas, this ratio surpasses the expected value by a factor of 2-3, but in urban areas it was 7-10 times larger, in some cases due to migration. While in rural Spain the C33 frequency was approximately 1.5 times C22, in cities C22 was 1.5 times C33. The best fit among the various types of consanguineous matings and alpha involves a lineal relationship. Regardless of the number of variables contributing significantly to alpha, C22 matings are always present. Moreover, their standardized (beta) coefficients are the highest. The above indicates that this consanguineous relationship conditions the inbreeding coefficient the most. In the period of greater consanguinity, close relationships, uncle-niece C12, and first cousin once removed (C23) make a significant contribution to alpha. In rural Spain second cousins (C33) always significantly determined alpha; however, in cities the inbreeding variation was mainly due to C12 and C23. Copyright 2003 Wiley-Liss, Inc.
G. Q. Tang
Full Text Available The accumulation of inbreeding and the loss of genetic diversity is a potential problem in the modern swine breeds in China. Therefore, the purpose of this study was to analyze the pedigrees of Chinese Duroc (CD, Landrace (CL and Yorkshire (CY swine to estimate the past and current rates of inbreeding, and to identify the main causes of genetic diversity loss. Pedigree files from CD, CL and CY containing, 4529, 16,776 and 22,600 records, respectively, were analyzed. Pedigree completeness indexes of the three breeds, accounting for one generation back, were 83.72, 93.93 and 93.59%, respectively. The estimated average annual inbreeding rates for CD, CL and CY in recent three years were 0.21, 0.19 and 0.13%, respectively. The estimated average percentage of genetic diversity loss within each breed in recent three years was about 8.92, 2.19, and 3.36%, respectively. The average relative proportion of genetic diversity loss due to unequal contributions of founders in CD, CL and CY was 69.09, 57.95 and 60.57%, and due to random genetic drift was 30.91, 42.05 and 39.43%, respectively. The estimated current effective population size for CD, CL and CY was 76, 117 and 202, respectively. Therefore, CD has been found to have lost considerable genetic diversity, demanding priority for optimizing the selection and mating to control future coancestry and inbreeding. Unequal contribution of founders was a major cause of genetic diversity loss in Chinese swine breeds and random genetic drift also showed substantial impact on the loss of diversity.
Andreev, D; Breilid, H; Kirkendall, L; Brun, L O; ffrench-Constant, R H
The coffee berry borer beetle Hypothenemus hampei (Ferrari) (Curculionidae: Scolytinae) is the major insect pest of coffee and has spread to most of the coffee-growing countries of the world. This beetle also displays an unusual life cycle, with regular sibling mating. This regular inbreeding and the population bottlenecks occurring on colonization of new regions should lead to low levels of genetic diversity. We were therefore interested in determining the level of nucleotide variation in nuclear and mitochondrial genomes of this beetle worldwide. Here we show that two nuclear loci (Resistance to dieldrin and ITS2) are completely invariant, whereas some variability is maintained at a mitochondrial locus (COI), probably corresponding to a higher mutation rate in the mitochondrial genome. Phylogenetic analysis of the mitochondrial data shows only two clades of beetle haplotypes outside of Kenya, the proposed origin of the species. These data confirm that inbreeding greatly reduces nucleotide variation and suggest the recent global spread of only two inbreeding lines of this bark beetle.
Pölkki, Mari; Krams, Indrikis; Kangassalo, Katariina; Rantala, Markus J
In many species of animals, individuals advertise their quality with sexual signals to obtain mates. Chemical signals such as volatile pheromones are species specific, and their primary purpose is to influence mate choice by carrying information about the phenotypic and genetic quality of the sender. The deleterious effects of consanguineous mating on individual quality are generally known, whereas the effect of inbreeding on sexual signalling is poorly understood. Here, we tested whether inbreeding reduces the attractiveness of sexual signalling in the mealworm beetle, Tenebrio molitor, by testing the preferences for odours of inbred and outbred (control) individuals of the opposite sex. Females were more attracted to the odours produced by outbred males than the odours produced by inbred males, suggesting that inbreeding reduces the attractiveness of male sexual signalling. However, we did not find any difference between the attractiveness of inbred and outbred female odours, which may indicate that the quality of females is either irrelevant for T. molitor males or quality is not revealed through female odours.
Full Text Available The buffalo is a native animal of Iran and there were 500,000 buffaloes in Iran that over 80 per cent of its population concentrated in the north and north- west (Azerbaijan province and 18 per cent in the south (Khuzestan province of the country. Buffaloes reread in rural condition as multi purpose animals in Khuzestan. For mating, farmer use owns herd sire also artificial insemination is limited in the rural condition that may be inbred animals so affect the production performance. The aim of this investigation was estimate the inbreeding coefficient and its affect on some production performance. Data of 200 herds were used from the record sheets of herds under recording program of Animal Breeding Center during period 1990 to 2002 in the Khuzestan province. These results showed mostly herds only one sir and rarely two sires have been used. Inbreeding coefficient was 25 percent in some progeny and high-inbred buffaloes had a low performance. According to results of this study it could be concluded that farmers to avoid inbreeding should use other herd sire and artificial insemination also practical recording scheme and genetically selection to genetic improvement should be included in buffaloes of Iran.
Full Text Available Inbreeding is often an inevitable outcome of strong directional artificial selection but on average it reduces population fitness with increased frequency of recessive deleterious alleles. Runs of homozygosity (ROH representing genomic autozygosity that occur from mating between selected and genomically related individuals may be able to reveal the regions affecting fitness. To examine the influence of genomic autozygosity on fitness, we used a genome-wide association test to evaluate potential negative correlations between ROH and daughter pregnancy rate (DPR or somatic cell score (SCS in US Jersey cattle. In addition, relationships between changes of local ROH and inbreeding coefficients (F were assessed to locate genomic regions with increased inbreeding. Despite finding some decreases in fertility associated with incremental increases in F, most emerging local ROH were not significantly associated with DPR or SCS. Furthermore, the analyses of ROH could be approximated with the most frequent haplotype(s, including the associations of ROH and F or traits. The analysis of the most frequent haplotype revealed that associations of ROH and fertility could be accounted for by the additive genetic effect on the trait. Thus, we suggest that a change of autozygosity is more likely to demonstrate footprints of selected haplotypes for production rather than highlight the possible increased local autozygosity of a recessive detrimental allele resulting from the mating between closely related animals in Jersey cattle.
Full Text Available Theoretical models of sexual selection predict that both males and females of many species should benefit by selecting their mating partners. However, empirical evidence testing and validating this prediction is scarce. In particular, whereas inbreeding avoidance is expected to induce sexual conflicts, in some cases both partners could benefit by acting in concert and exerting mutual mate choice for non-assortative pairings. We tested this prediction with the gregarious cockroach Blattella germanica (L.. We demonstrated that males and females base their mate choice on different criteria and that choice occurs at different steps during the mating sequence. Males assess their relatedness to females through antennal contacts before deciding to court preferentially non-siblings. Conversely, females biased their choice towards the most vigorously courting males that happened to be non-siblings. This study is the first to demonstrate mutual mate choice leading to close inbreeding avoidance. The fact that outbred pairs were more fertile than inbred pairs strongly supports the adaptive value of this mating system, which includes no "best phenotype" as the quality of two mating partners is primarily linked to their relatedness. We discuss the implications of our results in the light of inbreeding conflict models.
Nasim, A.; Farhatullah, A.; Khan, N.U.; Afzal, M.; Azam, S.M.
Combining ability was studied for yield and yield contributing traits in 5 * 5 diallel cross in Brassica rapa (L.) ssp. dichotoma (Roxb.) Hanelt. Primary branches plant-1, pods main raceme-1, pod length, 100-seed weight and seed yield plant-1 were significantly different. Heritability and genetic advance estimates were moderate for primary branches plant-1, pods main raceme-1, 100 seed weight whereas were high for seed yield plant-1. Parental line G-909 for primary branches plant-1, pods main raceme-1 and seed yield plant-1, genotype G-902 for pod length and genotype G-403 for 100-seed weight were the best general combiners. Based on combing ability and heterosis, the F1 hybrids G-909 * G-265 (for primary branches plant-1), G-265 * G- 403, G-1500 * G-909 (for pods main raceme-1), G-403 * G-909 (for pod length), G-265 * G-1500 (for 100-seed weight) and G-1500 * G-902, G-909 * G-902 (for seed yield plant-1) can be utilized in future breeding endeavors. Non-additive genetic control, as predominant mechanism, for all the traits necessitates the use of schemes like bi-parental mating design, diallel selective mating followed by recurrent or reciprocal recurrent selection. (author)
Full Text Available The aim of this research was to compare genetic parameters for traits related with seed germination and seedling vigour of single cross (SCH vs. three-way (TWH sorghum hybrids. The study was conducted in a sand bed under a greenhouse; 67 genotypes (four pairs of A- and B- lines, four R- lines, 13 SCH and 42 TWH were allocated in a randomized complete blocks experimental design with three replications. Statistical analysis included ANOVA’s and Student “t” tests, while Tukey test (p £ 0.05 was applied for mean comparisons. The R-lines showed better physiological seed quality attributes than the A- and B- lines. The seed quality and heterosis values of SCH vs. that of TWH did not show significant differences (p > 0.05 for any variable; however, heterobeltiosis of SCH was higher than that of TWY for normal seedlings, dry weight of plumule and seedling emergence rate. The A2- line and R14 restorer line showed the highest GCA values in both types of hybrids. No differences (p ≤ 0.05 were found between maternal and paternal effects of the A- and B- lines involved in the male sterile cross (female parent of the TWH, except for plumule length in Line 5.
... generally miserable or unhappy without really knowing why. Depression symptoms in children and teens Common signs and ... in normal activities, and avoidance of social interaction. Depression symptoms in older adults Depression is not a ...
Makram J. Geha
Full Text Available Milk yield records (305d, 2X, actual milk yield of 123,639 registered first lactation Holstein cows were used to compare linear regression (y = β0 + β1X + e ,quadratic regression, (y = β0 + β1X + β2X2 + e cubic regression (y = β0 + β1X + β2X2 + β3X3 + e and fixed factor models, with cubic-spline interpolation models, for estimating the effects of inbreeding on milk yield. Ten animal models, all with herd-year-season of calving as fixed effect, were compared using the Akaike corrected-Information Criterion (AICc. The cubic-spline interpolation model with seven knots had the lowest AICc, whereas for all those labeled as "traditional", AICc was higher than the best model. Results from fitting inbreeding using a cubic-spline with seven knots were compared to results from fitting inbreeding as a linear covariate or as a fixed factor with seven levels. Estimates of inbreeding effects were not significantly different between the cubic-spline model and the fixed factor model, but were significantly different from the linear regression model. Milk yield decreased significantly at inbreeding levels greater than 9%. Variance component estimates were similar for the three models. Ranking of the top 100 sires with daughter records remained unaffected by the model used.
In line with inbreeding theory, genetic diversity at a set of molecular markers may explain variation in fitness-associated traits in partially inbred populations, and such associations will appear as 'genotype-fitness correlations'. An individual genetic diversity index specifically used for microsatellites is 'mean d(2)', i.e. the mean squared distance between alleles. The original hypothesis for mean d(2)-fitness correlations assumes that mean d(2) captures fitness effects at both ends of the inbreeding-outbreeding spectrum. This hypothesis received strong criticism from work showing that even a plain diversity estimate such as multi-locus heterozygosity (MLH) outperforms mean d(2) as a predictor of the inbreeding coefficient and fitness in most realistic situations. Despite this critique, the mean d(2)-approach is still used frequently in ecological and evolutionary research, producing results suggesting that mean d(2) sometimes provides a stronger prediction of fitness than does MLH. In light of the critique, such results are unexpected, but potential explanations for them may exist (at least hypothetically), including scenarios based on close linkage and recent admixture. Nevertheless, a major caveat is that it is very difficult to predict a priori if mean d(2) will improve the genotype-fitness correlation, which in turn makes objective interpretations difficult. Mean d(2)-fitness associations are potentially interesting, but the fact that we cannot easily understand them is problematic and should be thoroughly addressed in each study. Therefore, instead of hastily reached interpretations of mean d(2)-fitness correlations, conclusions need support from complementary analyses, e.g. verifying admixture of genetically structured populations.
Signer-Hasler, Heidi; Burren, Alexander; Neuditschko, Markus; Frischknecht, Mirjam; Garrick, Dorian; Stricker, Christian; Gredler, Birgit; Bapst, Beat; Flury, Christine
Domestication, breed formation and intensive selection have resulted in divergent cattle breeds that likely exhibit their own genomic signatures. In this study, we used genotypes from 27,612 autosomal single nucleotide polymorphisms to characterize population structure based on 9214 sires representing nine Swiss dairy cattle populations: Brown Swiss (BS), Braunvieh (BV), Original Braunvieh (OB), Holstein (HO), Red Holstein (RH), Swiss Fleckvieh (SF), Simmental (SI), Eringer (ER) and Evolèner (EV). Genomic inbreeding (F ROH ) and signatures of selection were determined by calculating runs of homozygosity (ROH). The results build the basis for a better understanding of the genetic development of Swiss dairy cattle populations and highlight differences between the original populations (i.e. OB, SI, ER and EV) and those that have become more popular in Switzerland as currently reflected by their larger populations (i.e. BS, BV, HO, RH and SF). The levels of genetic diversity were highest and lowest in the SF and BS breeds, respectively. Based on F ST values, we conclude that, among all pairwise comparisons, BS and HO (0.156) differ more than the other pairs of populations. The original Swiss cattle populations OB, SI, ER, and EV are clearly genetically separated from the Swiss cattle populations that are now more common and represented by larger numbers of cows. Mean levels of F ROH ranged from 0.027 (ER) to 0.091 (BS). Three of the original Swiss cattle populations, ER (F ROH : 0.027), OB (F ROH : 0.029), and SI (F ROH : 0.039), showed low levels of genomic inbreeding, whereas it was much higher in EV (F ROH : 0.074). Private signatures of selection for the original Swiss cattle populations are reported for BTA4, 5, 11 and 26. The low levels of genomic inbreeding observed in the original Swiss cattle populations ER, OB and SI compared to the other breeds are explained by a lesser use of artificial insemination and greater use of natural service. Natural service
Full Text Available The complex analysis of the pedigree records of Czech Landrace (CLA, Czech Large White-dam line (CLWd, Czech Large White-sire line (CLWs, Duroc (DC, and Pietrain (PN was performed to determine trends of genetic diversity (GD, and to find the main sources of the GD loss. The total size of the pedigree was 132,365, 391,151, 32,913, 13,299, and 7,160 animals in CLA, CLWd, CLWs, DC, and PN, respectively. Animals born in the years 2011 through 2013 were assumed as the reference population. The average pedigree completeness index for one generation back was 95.9%, 97.4%, 91.2%, 89.8%, and 94.2% for appropriate breeds. Number of ancestors explaining 100% of gene pool was 186, 373, 125, 157, and 37 in CLA, CLWd, CLWs, DC, and PN, respectively. The relative proportion of inbred animals (58%, 58%, 54%, 47%, and 25%, the average inbreeding (2.7%, 1.4%, 2.5%, 3.6%, and 1.3% and the average co-ancestry (3.1%, 1.6%, 3.3%, 4.2%, and 3.3% were found over the past decade in analysed breeds. The expected inbreeding under random mating increased during the last 10 years in CLWs and PN and varied from 1.27% to 3.2%. The effective population size computed on the basis of inbreeding was 76, 74, 50, 35, and 83 in 2012 in CLA, CLWd, CLWs, DC, and PN, respectively. The shortest generation interval (1.45 was observed for CLWd in sire to son selection pathway. The longest generation interval obtained PN (1.95 in sire to daughter pathway. The average relative GD loss within last generation interval was 7.05%, 4.70%, 9.81%, 7.47%, and 10.46%, respectively. The relative proportion of GD loss due to genetic drift on total GD loss was 85.04%, 84.51%, 89.46%, 86.19%, and 83.68% in CLA, CLWd, CLWs, DC, and PN, respectively. All breeds were characterized by a high proportion of inbred animals, but the average inbreeding was low. The most vulnerable breeds to loss of GD are DC and PN. Therefore, a breeding program should be more oriented to prevent the increase of GD loss in these
Schroeder Fabian; Muschiol Daniel; Traunspurger Walter
Abstract Background The free-living nematode Caenorhabditis elegans is the predominant model organism in biological research, being used by a huge number of laboratories worldwide. Many researchers have evaluated life-history traits of C. elegans in investigations covering quite different aspects such as ecotoxicology, inbreeding depression and heterosis, dietary restriction/supplement, mutations, and ageing. Such traits include juvenile growth rates, age at sexual maturity, adult body size, ...
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van der Plas-Duivesteijn, Suzanne J.; Smit, Femmie J. L.; van Alphen, Jacques J. M.; Kraaijeveld, Ken
Conservation management in the North Sea is often motivated by the population size of marine mammals, like harbor porpoises Phocoena phocoena. In the Dutch part of the North Sea, sighting and stranding data are used to estimate population sizes, but these data give little insight into genetic structuring of the population. In this study we investigated genetic structure among animals stranded at different locations and times of year. We also tested whether there is a link between stranding and necropsy data, and genetic diversity. We made use of both mitochondrial (mtDNA) and microsatellite DNA analysis of samples from dead stranded porpoises along the Dutch coast during 2007. mtDNA analysis showed 6 variable positions in the control region, defining 3 different haplotypes. mtDNA haplotypes were not randomly distributed along the Dutch coastline. However, microsatellite analysis showed that these mtDNA haplotypes did not represent separate groups on a nuclear level. Furthermore, microsatellite analysis revealed no genotypic differences between seasons, locations or genders. The results of this study indicate that the Dutch population is panmictic. In contrast, heterozygosity levels were low, indicating some level of inbreeding in this population. However, this was not corroborated by other indices of inbreeding. This research provided insight into genetic structuring of stranded porpoises in 2007, but data from multiple years should be included to be able to help estimate population sizes.
Saadat, Mostafa; Zendeh-Boodi, Zahra
The aim of the study is to obtain more insight into the possible association between consanguinity and the incidence of deliberate self-burning. Data were obtained by analysis of medical records of patients hospitalized in two referral burn centers: Chormy Burn Center (Bushehr Province, south of Iran) from March 21, 1998, through March 20, 2004, and Shahid Sadoqi Center of Burns and Injuries (Yazd Province, center of Iran) from March 21, 2000, through March 20, 2004. The incidence of suicidal burns was 6.51 and 2.32/100,000 person-years for Bushehr and Yazd Provinces, respectively. The observed sex ratio of patients in both centers indicated there was a female predominance in patients with self-inflicted burns. Using patients' home addresses, patients were sorted into 16 cities. The incidence of suicide by self-burning ranged from 0.80 (for Tabas, located in Yazd Province) to 12.60/100,000 person-years (for Dilam, located in Bushehr Province). The coefficient of inbreeding defines the probability that an individual received both alleles of a pair from an identical ancestral source. There was a significant correlation between incidences of suicidal burns and mean coefficient of inbreeding (r = 0.782, df = 14, p < 0.001). In addition to other factors, consanguineous marriage may be a risk factor that influences the incidence of suicidal burns in a population.
Lazo, B; Campusano, C; Figueroa, H; Pinto-Cisternas, J; Zambra, E
In order to establish relationships among immigration, inbreeding, and age at marriage in urban and rural zones in Chile, and to formulate an endogamy index, ecclesiastical and civil data on consanguinity from 1865-1914 were analyzed, and a random mating deviation index was developed, with resulting values indicating deviation toward endogamy in both zones. Data grouped by zones and decades include means of population and density, nuptiality, consanguineous marriages (number, types, frequencies, and inbreeding coefficients), and frequencies of immigrants among consanguineous and nonconsanguineous couples. All of these values differ markedly between zones, with values in the rural zone double those in the urban zone. In the 2 zones, there are no clear differences in age at marriage between consanguineous and nonconsanguineous couples, and this is an important finding. From the point of view of fertility, one can expect a similar length period of fertility for both groups of couples. In this case, lower fertility might be expected in consanguineous marriages, only because of a higher probability of homozygosis of deleterious genes.
Arain, B.T.; Baloch, M.J.; Bughio, Q.U.A.; Sial, P.; Arain, M.A.; Baloch, A.
good general combiners covering most of the traits studied and may be preferred for hybridization and selection programmes. The crosses like CRIS-134 x MG-6, IR-3701 x FH-113 and IR-3701 x MG-6 with higher estimates of SCA for almost all the traits also expressed higher heterotic effects, thus these hybrids with dominant and over dominant genes could be potential hybrids for the exploitation of heterosis in cotton. (author)
This paper analyzes the impact of academic inbreeding in relation to academic research, and proposes a new conceptual framework for its analysis. We find that mobility (or lack of) at the early research career stage is decisive in influencing academic behaviors and scientific productivity. Less mobile academics have more inward oriented…
Calderón, R; Hernández, C L; García-Varela, G; Masciarelli, D; Cuesta, P
In this paper, the structure of a southeastern Spanish population was studied for the first time with respect to its inbreeding patterns and its relationship with demographic and geographic factors. Data on consanguineous marriages (up to second cousins) from 1900 to 1969 were taken from ecclesiastic dispensations. Our results confirm that the patterns and trends of inbreeding in the study area are consistent with those previously observed in most non-Cantabrian Spanish populations. The rate of consanguineous marriages was apparently stable between 1900 and 1935 and then sharply decreased since 1940, which coincides with industrialization in Spain. A marked departure from Hardy-Weinberg expectations (0.25) in the ratio of first cousin (M22) to second cousin (M33) marriages in the study population (0.88) was observed. The high levels of endogamy (>80%) and its significant steadiness throughout the twentieth century is noteworthy. Accordingly, our results show that exogamous marriages were not only poorly represented but also that this reduced mobility (relationships between population size and consanguinity rates and inbreeding fit power-law distributions. A significant positive correlation was observed between inbreeding and elevation. Many Spanish populations have experienced a prolonged and considerable isolation across generations, which has led to high proportions of historical and local endogamy that is associated, in general, with high [Formula: see text] values. Thus, assessing genomic inbreeding using runs of homozygosity (ROH) in current Spanish populations could be an additional pertinent strategy for obtaining a more refined perspective regarding the population history inferred from the extent and frequency of ROH regions.
Pedersen, L D; Sørensen, A C; Berg, P
This study investigated whether selection using genotype information reduced the rate and level of true inbreeding, that is, identity by descent, at a selectively neutral locus as well as a locus under selection compared with traditional BLUP selection. In addition, the founder representation...... each of 40 herds. Selection was performed using BLUP, marker-assisted, or gene-assisted selection for a trait with low heritability (h2 = 0.04) only expressed in females, mimicking a health trait. The simulated genome consisted of 2 chromosomes. One biallelic quantitative trait loci (QTL......) with an initial frequency of the favorable allele of 0.1, and initially explaining 25% of the genetic variance as well as 4 markers were simulated in linkage disequilibrium, all positioned at chromosome 1. Chromosome 2 was selectively neutral, and consisted of a single neutral locus. The results showed...
Voges, S; Distl, O
The objective of this study was to analyse genetic diversity for the three scent-hound breeds Bavarian mountain hound (BMH), Hanoverian hound (HH) and Tyrolean hound (TH) using all available pedigree information from scent-hound kennel clubs for these three breeds throughout Europe. The pedigree data of the BMH and the HH date back to 1912 and 1894, respectively. Pedigree data of the TH were available from the 1960s onwards. The reference populations included all BMH (n = 3231), HH (n = 1371) and TH (n = 1167) dogs registered between 1992 and 2004. Average generation intervals were 5.3 years for the BMH and 5.0 years for the HH and TH. Average inbreeding coefficients for the reference populations were 4.5%, 6.8% and 9.5% for the BMH, HH and TH. The effective numbers of founders, ancestors and founder genomes were lowest for the TH and highest for the BMH. The effective numbers of founder genomes were 10.9, 5.6 and 4.3 for the BMH, HH and TH. Effective population size was largest for the BMH with 72.7 effective breeding animals, followed by the HH with 50.9 and TH with 26.5. The most important ten ancestors had genetic contributions to the reference populations of 54.4%, 65.2% and 77.9% in the BMH, HH and TH. The results of our study indicate the need for careful breed management in these highly specialized hound breeds to maintain genetic diversity. European stud books should be established for these dog breeds in order to avoid inbreeding due to missing pedigree records.
Full Text Available Genomic selection (GS provides an attractive option for accelerating genetic gain in perennial ryegrass ( improvement given the long cycle times of most current breeding programs. The present study used simulation to investigate the level of genetic gain and inbreeding obtained from GS breeding strategies compared with traditional breeding strategies for key traits (persistency, yield, and flowering time. Base population genomes were simulated through random mating for 60,000 generations at an effective population size of 10,000. The degree of linkage disequilibrium (LD in the resulting population was compared with that obtained from empirical studies. Initial parental varieties were simulated to match diversity of current commercial cultivars. Genomic selection was designed to fit into a company breeding program at two selection points in the breeding cycle (spaced plants and miniplot. Genomic estimated breeding values (GEBVs for productivity traits were trained with phenotypes and genotypes from plots. Accuracy of GEBVs was 0.24 for persistency and 0.36 for yield for single plants, while for plots it was lower (0.17 and 0.19, respectively. Higher accuracy of GEBVs was obtained for flowering time (up to 0.7, partially as a result of the larger reference population size that was available from the clonal row stage. The availability of GEBVs permit a 4-yr reduction in cycle time, which led to at least a doubling and trebling genetic gain for persistency and yield, respectively, than the traditional program. However, a higher rate of inbreeding per cycle among varieties was also observed for the GS strategy.
Lin, Zibei; Cogan, Noel O I; Pembleton, Luke W; Spangenberg, German C; Forster, John W; Hayes, Ben J; Daetwyler, Hans D
Genomic selection (GS) provides an attractive option for accelerating genetic gain in perennial ryegrass () improvement given the long cycle times of most current breeding programs. The present study used simulation to investigate the level of genetic gain and inbreeding obtained from GS breeding strategies compared with traditional breeding strategies for key traits (persistency, yield, and flowering time). Base population genomes were simulated through random mating for 60,000 generations at an effective population size of 10,000. The degree of linkage disequilibrium (LD) in the resulting population was compared with that obtained from empirical studies. Initial parental varieties were simulated to match diversity of current commercial cultivars. Genomic selection was designed to fit into a company breeding program at two selection points in the breeding cycle (spaced plants and miniplot). Genomic estimated breeding values (GEBVs) for productivity traits were trained with phenotypes and genotypes from plots. Accuracy of GEBVs was 0.24 for persistency and 0.36 for yield for single plants, while for plots it was lower (0.17 and 0.19, respectively). Higher accuracy of GEBVs was obtained for flowering time (up to 0.7), partially as a result of the larger reference population size that was available from the clonal row stage. The availability of GEBVs permit a 4-yr reduction in cycle time, which led to at least a doubling and trebling genetic gain for persistency and yield, respectively, than the traditional program. However, a higher rate of inbreeding per cycle among varieties was also observed for the GS strategy. Copyright © 2016 Crop Science Society of America.
Song, Guicheng; Wang, Miaomiao; Zeng, Bin; Zhang, Jing; Jiang, Chenliang; Hu, Qirui; Geng, Guangtao; Tang, Canming
Pollen tube growth in styles was strongly inhibited by temperature above 35 °C, and the yield of cotton decreased because of the adverse effect of high temperatures during square development. High-temperature stress during flowering influences the square development of upland cotton (Gossypium hirsutum L.) and cotton yield. Although it is well known that square development is sensitive to high temperature, high-temperature sensitive stages of square development and the effects of high temperature on pollen tube growth in the styles are unknown. The effect of high temperature on anther development corresponding to pollen vigor is unknown during anther development. The objectives of this study were to identify the stages of square development that are sensitive to high temperatures (37/30 and 40/34 °C), to determine whether the abnormal development of squares influenced by high temperature is responsible for the variation in the in vitro germination percent of pollen grains at anthesis, to identify the effect of high temperature on pollen germination in the styles, and to determine pollen thermotolerance heterosis. Our results show that the stages from the sporogenous cell to tetrad stage (square length styles was strongly inhibited by temperature above 35 °C, and the yield of cotton decreased because of the effect of high temperature during square development. The thermotolerance of hybrid F1 pollen showed heterosis, and pollen viability could be used as a criterion for screening for high-temperature tolerance cultivars. These results can be used in breeding to develop new cotton cultivars that can withstand high-temperature conditions, particularly in a future warmer climate.
Full Text Available Brassica juncea (AjAjBjBj, is an allotetraploid that arose from two diploid species, B. rapa (ArAr and B. nigra (BnBn. It is an old oilseed crop with unique favorable traits, but the genetic improvement on this species is limited. We developed an approach to broaden its genetic base within several generations by intensive selection. The Ar subgenome from the Asian oil crop B. rapa (ArAr and the Bc subgenome from the African oil crop B. carinata (BcBcCcCc were combined in a synthesized allohexaploid (ArArBcBcCcCc, which was crossed with traditional B. juncea to generate pentaploid F1 hybrids (ArAjBcBjCc, with subsequent self-pollination to obtain newly synthesized B. juncea (Ar/jAr/jBc/jBc/j. After intensive cytological screening and phenotypic selection of fertility and agronomic traits, a population of new-type B. juncea was obtained and was found to be genetically stable at the F6 generation. The new-type B. juncea possesses good fertility and rich genetic diversity and is distinctly divergent but not isolated from traditional B. juncea, as revealed by population genetic analysis with molecular markers. More than half of its genome was modified, showing exotic introgression and novel variation. In addition to the improvement in some traits of the new-type B. juncea lines, a considerable potential for heterosis was observed in inter-subgenomic hybrids between new-type B. juncea lines and traditional B. juncea accessions. The new-type B. juncea exhibited a stable chromosome number and a novel genome composition through multiple generations, providing insight into how to significantly broaden the genetic base of crops with subgenome introgression from their related species and the potential of exploring inter-subgenomic heterosis for hybrid breeding.
Full Text Available A total of 1551 normal lactation records of Egyptian buffaloes, Kept at Mehallet Mousa Farm, belonging to Ministry of Agriculture, during the period from 1960 to 2001 were used. Milk yield, lactation period and age at first calving were studied in order to determine the presence of inbreeding in the herd and to evaluate it is effects as well as the effects of some environmental factors on these traits. In addition, genetic parameters of these traits are also studied. Milk yield, lactation period and age at first calving averaged 1193 ± 522 kg, 282±125 and 39 ± 3 mo, respectively. Among all three traits, only age at first calving was affected by inbreeding. Month of calving and year of calving had a significant effect on all traits studied, while age at first calving had no significant effect on milk yield and lactation period.
Rusfidra, Rusfidra; Zein, R; Hasibuan, A. M. A
This study aims to obtain the effective population size, actual population size and rate of inbreeding of Kamang local duck. In this study used a sample local duck raised from 30 farmers. This research conducted was survey method with purposive random sampling. The variables were calculated in the study, namely the number of adult male ducks (Nm), number of adult female ducks (Nf), number of young male and young female ducks, number of male and female ducklings, actual population size (Na), e...
Costello, Cecily M; Creel, Scott R; Kalinowski, Steven T; Vu, Ninh V; Quigley, Howard B
We tested the hypothesis that sex-biased natal dispersal reduces close inbreeding in American black bears, a solitary species that exhibits nearly complete male dispersal and female philopatry. Using microsatellite DNA and spatial data from reproductively mature bears (>or= 4 years old), we examined the spatial genetic structure of two distinct populations in New Mexico from 1993 to 2000. As predicted, relatedness (r) and the frequency of close relationships (parent-offspring or full siblings) decreased with distance among female dyads, but little change was observed among male or opposite-sex dyads. Neighbouring females were more closely related than neighbouring males. The potential for inbreeding was low. Most opposite-sex pairs that lived sufficiently close to facilitate mating were unrelated, and few were close relatives. We found no evidence that bears actively avoided inbreeding in their selection of mates from this nearby pool, as mean r and relationship frequencies did not differ between potential and actual mating pairs (determined by parentage analysis). These basic patterns were apparent in both study areas despite a nearly two-fold difference in density. However, the sex bias in dispersal was less pronounced in the lower-density area, based on proportions of bears with male and female relatives residing nearby. This result suggests that male bears may respond to reduced competition by decreasing their rate or distance of dispersal. Evidence supports the hypothesis that inbreeding avoidance is achieved by means of male-biased dispersal but also indicates that competition (for mates or resources) modifies dispersal patterns.
Collevatti, Rosane G.; Leite, Kelly C.E.; Miranda, Guilherme H.B. de; Rodrigues, Flavio H.G.
We report the genetic structure, relatedness and mating structure of a population of the endangered giant anteater Myrmecophaga tridactyla Linnaeus, 1758 in the Emas National Park, Brazil, based on variability at five microsatellite loci. Additionally, we addressed the hypothesis that the M. tridactyla population studied has low levels of polymorphism and high levels of inbreeding and relatedness and that animals with overlapping home range are highly related. All five microsatellite loci dis...
Banks, Sam C; Lindenmayer, David B
Animal dispersal is highly non-random and has important implications for the dynamics of populations in fragmented habitat. We identified interpatch dispersal events from genetic tagging, parentage analyses and assignment tests and modelled the factors associated with apparent emigration and post-dispersal settlement choices by individual male agile antechinus (Antechinus agilis, a marsupial carnivore of south-east Australian forests). Emigration decisions were best modelled with on data patch isolation and inbreeding risk. The choice of dispersal destination by males was influenced by inbreeding risk, female abundance, patch size, patch quality and matrix permeability (variation in land cover). Males were less likely to settle in patches without highly unrelated females. Our findings highlight the importance of individual-level dispersal data for understanding how multiple processes drive non-randomness in dispersal in modified landscapes. Fragmented landscapes present novel environmental, demographic and genetic contexts in which dispersal decisions are made, so the major factors affecting dispersal decisions in fragmented habitat may differ considerably from unfragmented landscapes. We show that the spatial scale of genetic neighbourhoods can be large in fragmented habitat, such that dispersing males can potentially settle in the presence of genetically similar females after moving considerable distances, thereby necessitating both a choice to emigrate and a choice of where to settle to avoid inbreeding. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.
Reid, Jane M.; Bocedi, Greta; Nietlisbach, Pirmin; Duthie, A. Bradley; Wolak, Matthew E.; Gow, Elizabeth A.; Arcese, Peter
Female extra‐pair reproduction in socially monogamous systems is predicted to cause cuckolded socially‐paired males to conditionally reduce paternal care, causing selection against extra‐pair reproduction and underlying polyandry. However, existing models and empirical studies have not explicitly considered that cuckolded males might be related to their socially‐paired female and/or to her extra‐pair mate, and therefore be related to extra‐pair offspring that they did not sire but could rear. Selection against paternal care, and hence against extra‐pair reproduction, might then be weakened. We derive metrics that quantify allele‐sharing between within‐pair and extra‐pair offspring and their mother and her socially‐paired male in terms of coefficients of kinship and inbreeding. We use song sparrow (Melospiza melodia) paternity and pedigree data to quantify these metrics, and thereby quantify the joint effects of extra‐pair reproduction and inbreeding on a brood's total allelic value to its socially‐paired parents. Cuckolded male song sparrows were almost always detectably related to extra‐pair offspring they reared. Consequently, although brood allelic value decreased substantially following female extra‐pair reproduction, this decrease was reduced by within‐pair and extra‐pair reproduction among relatives. Such complex variation in kinship within nuclear families should be incorporated into models considering coevolutionary dynamics of extra‐pair reproduction, parental care, and inbreeding. PMID:27174154
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Heinze, Jürgen; Buschinger, Alfred; Poettinger, Theo; Suefuji, Masaki
The socially parasitic ant genus Myrmoxenus varies strongly in fundamental life history traits, such as queen-worker ratio, the timing of sexual production, and mating behavior. Myrmoxenus queens generally take over nests of Temnothorax ants, kill the resident queen by throttling, and force the workers to take care of the social parasite's brood. Young queens of M. ravouxi and other species produce large numbers of workers, which during "slave-raids" pillage host pupae from neighboring Temnothorax colonies to increase the workforce in their own nests. Other species, such as M. corsicus, have lost caste polyphenism and rear only male and female sexual offspring. Using sequences of the genes CO I/CO II and wingless we reconstruct the phylogeny of Myrmoxenus and document that the worker caste was lost convergently at least three times. Furthermore, mating in the nest and inbreeding obviously also evolved in parallel from ancestors whose sexuals presumably mated during nuptial flights. Myrmoxenus might thus provide a suitable model to investigate caste differentiation and the plasticity of mating behavior in Hymenoptera.
Ortega, Encarnación; Martínez-García, Pedro J; Dicenta, Federico; Egea, José
A homozygous self-compatible almond, originated from self-fertilization of a self-compatible genotype and producing a reasonable yield following open pollination, exhibited a very high fruit drop rate when self-pollinated. To investigate whether fruit dropping in this individual is related to an abnormal development of the embryo sac following self-fertilization, histological sections of ovaries from self and cross-pollinated flowers were observed by light microscopy. Additionally, the presence of pollen tubes in the ovary and fruit set were determined for both types of pollination. Despite pollen tubes reached the ovary after both pollinations, differences in embryo sac and endosperm development after fertilization were found. Thus, while for cross-fertilized ovules a pro-embryo and an endosperm with abundant nuclei were generally observed, most self-fertilized ovules remained in a previous developmental stage in which the embryo sac was not elongated and endosperm nuclei were absent. Although 30 days after pollination fruit set was similar for both pollination types, at 60 days it was significantly reduced for self-pollination. These results provide evidence that the high fruit drop in this genotype is the consequence of a disrupted development of the endosperm, what could be an expression of its high level of inbreeding.
Full Text Available The socially parasitic ant genus Myrmoxenus varies strongly in fundamental life history traits, such as queen-worker ratio, the timing of sexual production, and mating behavior. Myrmoxenus queens generally take over nests of Temnothorax ants, kill the resident queen by throttling, and force the workers to take care of the social parasite's brood. Young queens of M. ravouxi and other species produce large numbers of workers, which during "slave-raids" pillage host pupae from neighboring Temnothorax colonies to increase the workforce in their own nests. Other species, such as M. corsicus, have lost caste polyphenism and rear only male and female sexual offspring. Using sequences of the genes CO I/CO II and wingless we reconstruct the phylogeny of Myrmoxenus and document that the worker caste was lost convergently at least three times. Furthermore, mating in the nest and inbreeding obviously also evolved in parallel from ancestors whose sexuals presumably mated during nuptial flights. Myrmoxenus might thus provide a suitable model to investigate caste differentiation and the plasticity of mating behavior in Hymenoptera.
Full Text Available A study of the viability of small populations of Hymenoptera is a matter of importance to gain a better zoological, ethological, genetical and ecological knowledge of these insects, and for conservation purposes, mainly because of the consequences to the survival of colonies of many species of bees, wasps, and ants. Based on the Whiting (1943 principle, Kerr & Vencovski (1982 presented a hypothesis that states that viable populations of stingless bees (Meliponini should have at least 40 colonies to survive. This number was later extended to 44 colonies by Kerr (1985. This would be necessary to avoid any substantial amount of homozygosis in the pair of chromosomic sexual loci, by keeping at least six different sexual gene alleles in a reproductive population. In most cases this would prevent the production of useless diploid males. However, several facts weigh against considering this as a general rule. From 1990 to 2001, 287 colony divisions were made, starting with 28 foundation colonies, in the inbreeding and population experiments with the Meliponini reported here. These experiments constitute the most extensive and longest scientific research ever made with Meliponini bees. In ten different experiments presented here, seven species (one with two subspecies of Meliponini bees were inbred in five localities inside their wide-reaching native habitats, and in two localities far away from these habitats. This was done for several years. On the whole, the number of colonies increased and the loss of colonies over the years was small. In two of these experiments, although these populations were far (1,000 km and 1,200 km from their native habitat, their foundation colonies were multiplied successfuly. It was possible to build up seven strong and three expanding medium populations, starting with one, two, three or even five colonies. However, in six other cases examined here, the Whiting (1943 principle and the hypothesis of Kerr & Vencovski (1982
Stevens, Eric L.; Baugher, Joseph D.; Shirley, Matthew D.; Frelin, Laurence P.; Pevsner, Jonathan
Correct annotation of the genetic relationships between samples is essential for population genomic studies, which could be biased by errors or omissions. To this end, we used identity-by-state (IBS) and identity-by-descent (IBD) methods to assess genetic relatedness of individuals within HapMap phase III data. We analyzed data from 1,397 individuals across 11 ethnic populations. Our results support previous studies (Pemberton et al., 2010; Kyriazopoulou-Panagiotopoulou et al., 2011) assessing unknown relatedness present within this population. Additionally, we present evidence for 1,657 novel pairwise relationships across 9 populations. Surprisingly, significant Cotterman's coefficients of relatedness K1 (IBD1) values were detected between pairs of known parents. Furthermore, significant K2 (IBD2) values were detected in 32 previously annotated parent-child relationships. Consistent with a hypothesis of inbreeding, regions of homozygosity (ROH) were identified in the offspring of related parents, of which a subset overlapped those reported in previous studies (Gibson et al. 2010; Johnson et al. 2011). In total, we inferred 28 inbred individuals with ROH that overlapped areas of relatedness between the parents and/or IBD2 sharing at a different genomic locus between a child and a parent. Finally, 8 previously annotated parent-child relationships had unexpected K0 (IBD0) values (resulting from a chromosomal abnormality or genotype error), and 10 previously annotated second-degree relationships along with 38 other novel pairwise relationships had unexpected IBD2 (indicating two separate paths of recent ancestry). These newly described types of relatedness may impact the outcome of previous studies and should inform the design of future studies relying on the HapMap Phase III resource. PMID:23185369
Brown, Anthony P; Greenway, Ryan; Morgan, Samuel; Quackenbush, Corey R; Giordani, Luca; Arias-Rodriguez, Lenin; Tobler, Michael; Kelley, Joanna L
Populations with limited ranges can be highly vulnerable to changes in their environment and are, thus, of high conservation concern. Populations that experience human-induced range reductions are often highly inbred and lack genetic diversity, but it is unknown whether this is also the case for populations with naturally small ranges. The fishes Poecilia sulphuraria (listed as critically endangered) and Poecilia thermalis, which are endemic to small hydrogen sulphide-rich springs in southern Mexico, are examples of such populations with inherently small habitats. We used geometric morphometrics and population genetics to quantify phenotypic and genetic variation within and among two populations of P. sulphuraria and one population of P. thermalis. Principal component analyses revealed phenotypic and genetic differences among the populations. Evidence for inbreeding was low compared to populations that have undergone habitat reduction. The genetic data were also used to infer the demographic history of these populations to obtain estimates for effective population sizes and migration rates. Effective population sizes were large given the small habitats of these populations. Our results imply that these three endemic extremophile populations should each be considered separately for conservation purposes. Additionally, this study suggests that populations in naturally small habitats may have lower rates of inbreeding and higher genetic diversity than expected, and therefore may be better equipped to handle environmental perturbations than anticipated. We caution, however, that the inferred lack of inbreeding and the large effective population sizes could potentially be a result of colonization by genetically diverse ancestors. © 2017 John Wiley & Sons Ltd.
Rosane G. Collevatti
Full Text Available We report the genetic structure, relatedness and mating structure of a population of the endangered giant anteater Myrmecophaga tridactyla Linnaeus, 1758 in the Emas National Park, Brazil, based on variability at five microsatellite loci. Additionally, we addressed the hypothesis that the M. tridactyla population studied has low levels of polymorphism and high levels of inbreeding and relatedness and that animals with overlapping home range are highly related. All five microsatellite loci displayed low levels of polymorphism and of expected and observed heterozygosity. The low level of polymorphism and high inbreeding showed by the population studied may be the outcome of high mortality and reduction in population size due to recurrent fire events in the Emas National Park, as reported in 1994. The reduction in population size may have led to a higher frequency of mating between closely related animals, augmented by the isolation of the population in the park because of the expansion of agricultural land and fragmentation of the Cerrado environment. The natural history of M. tridactyla and the phylopatric (sex-biased dispersal behavior of females should increase the effects of isolation and bottlenecking, decreasing gene flow and increasing inbreeding. However, the low levels of polymorphism found in this population may simply be due to the natural history and evolution of M. tridactyla as reported for other species. The genetic structure and dynamics of this population needs to be investigated more profoundly in order to provide sound data for the design of conservation strategies for M. tridactyla in the Emas National Park.
Ruzzante, D.E.; Hansen, Michael Møller; Meldrup, Dorte
inbreeding coefficients do not differ among locations within rivers. Relatedness varies between sites within rivers indicating varied local dynamics at a very small geographical scale. Relatedness is sometimes lower than expected among an equal number of simulated individuals with randomized genotypes......, the proportion of locally assigned trout correlates with the populations' stocking histories, with rivers presently subjected to stocking (hatchery trout) showing low mean similar to0.73), and rivers where stocking was discontinued showing high (mean similar to0.84) proportions of local fish, probably reflecting...
Niveles y efectos de la consanguinidad en variables de comportamiento durante la tienta y la lidia en dos ganaderías de reses bravas de Colombia Levels and effects of inbreeding on performance traits during tempt and fight from two fighting bull farms in Colombia
David Calero Quintero
GUA were 6.6 and 5.8%; and 4.2 and 6%, respectively. Means and standard deviations of inbreeding in EGC and GUA were 4.9±6.6 and 4.2±4.2% for the all animals, 4.5±5.8 and 6.0±3.4% for the last time studied , and 10.6±5.8 and 6.51±3.5% taking in to account only those that were related. The effect of some variables with the inbreeding had positive effects in those responsible for the ‘toreabilidad’ and style, and depressive on the force of the animals. The current inbreeding in these populations is medium; however, mating should be planned for an appropriate handling and to reduce increases in inbreeding.
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Calderón, R; Morales, B; Peña, J A; Delgado, J
Pedigree structures of 161 uncle/niece-aunt/nephew and 4420 first cousin consanguineous marriages registered during the 19th and 20th centuries in two large and very different Spanish regions have been analysed and their genetic consequences evaluated. The frequencies of the different pedigree subtypes within each degree of relationship were quite similar in both populations despite significant heterogeneity in inbreeding patterns. The mean X-linked inbreeding coefficient (Fx) for each type of cousin mating was calculated and compared to that expected for autosomal genes (F). The effect of genealogical structure on the Fx/F ratio was compared to different cultural populations worldwide. Preferentiality and avoidance of close consanguinity along with specific types of pedigrees are discussed on the basis of premarital migration and sociocultural rules still deeply rooted in certain human groups. By admitting that the observed Fx coefficient is usually higher than F in most human populations some remarks have been made in terms of population genetic risk.
Cloutier, D; Kanashiro, M; Ciampi, A Y; Schoen, D J
Selective logging may impact patterns of genetic diversity within populations of harvested forest tree species by increasing distances separating conspecific trees, and modifying physical and biotic features of the forest habitat. We measured levels of gene diversity, inbreeding, pollen dispersal and spatial genetic structure (SGS) of an Amazonian insect-pollinated Carapa guianensis population before and after commercial selective logging. Similar levels of gene diversity and allelic richness were found before and after logging in both the adult and the seed generations. Pre- and post-harvest outcrossing rates were high, and not significantly different from one another. We found no significant levels of biparental inbreeding either before or after logging. Low levels of pollen pool differentiation were found, and the pre- vs. post-harvest difference was not significant. Pollen dispersal distance estimates averaged between 75 m and 265 m before logging, and between 76 m and 268 m after logging, depending on the value of tree density and the dispersal model used. There were weak and similar levels of differentiation of allele frequencies in the adults and in the pollen pool, before and after logging occurred, as well as weak and similar pre- and post-harvest levels of SGS among adult trees. The large neighbourhood sizes estimated suggest high historical levels of gene flow. Overall our results indicate that there is no clear short-term genetic impact of selective logging on this population of C. guianensis.
Henryon, M; Berg, P; Sørensen, A C
We reasoned that mating animals by minimising the covariance between ancestral contributions (MCAC mating) will generate less inbreeding and at least as much genetic gain as minimum-coancestry mating in breeding schemes where the animals are truncation-selected. We tested this hypothesis by stoch...
Fareed, Mohd; Kaisar Ahmad, Mir; Azeem Anwar, Malik; Afzal, Mohammad
The aim of our study was to understand the relationship between consanguineous marriages and reproductive outcomes. A total of 999 families were recruited from five Muslim populations of Jammu region. Family pedigrees were drawn to access the family history and inbreeding status in terms of coefficient of inbreeding (F). Fertility, mortality, secondary sex ratio, selection intensity, and lethal equivalents were measured using standard methods. The significant differences for gross fertility was found to be higher among inbred groups as compared to the unrelated families (P consanguineous families of all populations in comparison with the non-consanguineous family groups. Moreover, the prenatal and postnatal child mortality rates (i.e., U5MR and U18MR) have presented a persuasive increase with an upsurge in the homozygosity level. The mortality rate was found to be maximum among families with the highest value of coefficient of inbreeding (F). The selection intensity (SI) also showed inflations among families with respect to their increasing inbreeding coefficients. The greater values of lethal equivalents per gamete (LEs/gamete) were observed for autosomal inheritance in comparison with sex-linked inheritance. Our conclusive assessment brings out the deleterious consequence of consanguineous marriages on reproductive outcomes.
Joseph, Paul N; Sasson, Daniel A; Allen, Pablo E; Somjee, Ummat; Miller, Christine W
Adverse conditions may be the norm rather than the exception in natural populations. Many populations experience poor nutrition on a seasonal basis. Further, brief interludes of inbreeding can be common as population density fluctuates and because of habitat fragmentation. Here, we investigated the effects of poor nutrition and inbreeding on traits that can be very important to reproductive success and fitness in males: testes mass, sperm concentration, and sperm viability. Our study species was Narnia femorata, a species introduced to north-central Florida in the 1950s. This species encounters regular, seasonal changes in diet that can have profound phenotypic effects on morphology and behavior. We generated inbred and outbred individuals through a single generation of full-sibling mating or outcrossing, respectively. All juveniles were provided a natural, high-quality diet of Opuntia humifusa cactus cladode with fruit until they reached adulthood. New adult males were put on a high- or low-quality diet for at least 21 days before measurements were taken. As expected, the low-quality diet led to significantly decreased testes mass in both inbred and outbred males, although there were surprisingly no detectable effects on sperm traits. We did not find evidence that inbreeding affected testes mass, sperm concentration, and sperm viability. Our results highlight the immediate and overwhelming effects of nutrition on testes mass, while suggesting that a single generation of inbreeding might not be detrimental for primary sexual traits in this particular population.
Murphy, T W; Berger, Y M; Holman, P W; Baldin, M; Burgett, R L; Thomas, D L
For the past 2 decades, the Spooner Agriculture Research Station (ARS) of the University of Wisconsin-Madison operated the only dairy sheep research flock in North America. The objectives of the present study were to 1) obtain estimates of genetic parameters for lactation and reproductive traits in dairy ewes, 2) estimate the amount of genetic change in these traits over time, and 3) quantify the level of inbreeding in this flock over the last 20 yr. Multiple-trait repeatability models (MTRM) were used to analyze ewe traits through their first 6 parities. The first MTRM jointly analyzed milk (180-d-adjusted milk yield [180d MY]), fat (180-d-adjusted fat yield [180d FY]), and protein (180-d-adjusted protein yield [180d PY]) yields adjusted to 180 d of lactation; number of lambs born per ewe lambing (NLB); and lactation average test-day somatic cell score (LSCS). A second MTRM analyzed 180d MY, NLB, LSCS, and percentage milk fat (%F) and percentage milk protein (%P). The 3 yield traits were moderately heritable (0.26 to 0.32) and strongly genetically correlated (0.91 to 0.96). Percentage milk fat and %P were highly heritable (0.53 and 0.61, respectively) and moderately genetically correlated (0.61). Milk yield adjusted to 180 d was negatively genetically correlated with %F and %P (-0.31 and -0.34, respectively). Ewe prolificacy was not significantly ( > 0.67) genetically correlated with yield traits, %P, or LSCS but lowly negatively correlated with %F (-0.26). Lactation somatic cell score was unfavorably genetically correlated with yield traits (0.28 to 0.39) but not significantly ( > 0.09) correlated with %F, %P, and NLB. Within-trait multiple-trait models through the first 4 parities revealed that 180d MY, 180d FY, 180d PY, %F, and %P were strongly genetically correlated across parity (0.67 to 1.00). However, the genetic correlations across parity for NLB and LSCS were somewhat lower (0.51 to 0.96). Regressing predicted breeding values for 180d MY, without and with
Márcio Costa Rodrigues
Full Text Available The objective of this work was to investigate heterosis and its components in 16 white grain maize populations presenting high quality protein. These populations were divided according to grain type in order to establish different heterosis groups. The crosses were carried out according to a partial diallel cross design among flint and dent populations. Seven agronomic traits were evaluated in three environments while four leaf diseases and incidence of corn stunt were evaluated in one. Least square procedure was applied to the normal equation X'Xbeta = X'Y, to estimate the model effects and their respective sum of squares. Among the heterosis components, in diallel analysis, significance for average heterosis in grain yield, number of days to female flowering and to all evaluated diseases was detected. Specific heterosis was significant for days to female flowering and resistance to Puccinia polysora. Results concerned to grain yield trait indicate that populations with superior performance in dent group, no matter what flint population group is used in crosses, tend to generate superior intervarietal hybrids. In decreasing order of preference, the dent type populations CMS 476, ZQP/B 103 and ZQP/B 101 and the flint type CMS 461, CMS 460, ZQP/B 104 and ZQP/B 102 are recommended to form composites.O objetivo deste trabalho foi investigar a heterose e seus componentes em 16 populações de milho de grãos brancos, de alta qualidade protéica. Estas populações foram divididas de acordo com o tipo de grão, para estabelecer grupos heteróticos diferentes. Os cruzamentos foram realizados entre populações dentadas e duras, seguindo o esquema dialélico parcial. Sete caracteres agronômicos foram avaliados em três locais, e quatro doenças foliares e a incidência de enfezamento, em um. O procedimento de quadrados mínimos foi aplicado à equação normal X'Xbeta = X'Y, para estimar os efeitos do modelo e suas respectivas somas de quadrados
Brown, Jacqueline A.; Russell, Samantha; Rasor, Kaitlin
Depression is among the most common mental disorders in the United States. Its diagnosis is often related to impairment of functioning across several domains, including how an individual thinks, feels, and participates in daily activities. Although depression has a relatively high prevalence among adults, the rate is alarmingly higher among…
... professionals for help. With support and treatment, new mothers with depression can go on to be healthy, happy parents. ... or two, talk to your doctor. A new mother who feels like giving up, who feels that life is not ... depression can last for several months or even longer ...
Carson, Richard C; Hollon, Steven D; Shelton, Richard C
Depressive realism suggests that depressed individuals make more accurate judgments of control than their nondepressed counterparts. However, most studies demonstrating this phenomenon were conducted in nonclinical samples. In this study, psychiatric patients who met criteria for major depressive disorder underestimated control in a contingent situation and were consistently more negative in their judgments than were nondepressed controls. Depressed patients were less likely than their nondepressed counterparts to overestimate control in a noncontingent situation, but largely because they perceived receiving less reinforcement. Depressed patients were no more likely to use the appropriate logical heuristic to generate their judgments of control than their nondepressed counterparts and each appeared to rely on different primitive heuristics. Depressed patients were consistently more negative than their nondepressed counterparts and when they did appear to be more "accurate" in their judgments of control (as in the noncontingent situation) it was largely because they applied the wrong heuristic to less accurate information. These findings do not support the notion of depressive realism and suggest that depressed patients distort their judgments in a characteristically negative fashion. 2009 Elsevier Ltd. All rights reserved.
... You are here Home » Depression In The Workplace Depression In The Workplace Clinical depression has become one ... will die by suicide vi . Employees' Attitudes Towards Depression Often times a depressed employee will not seek ...
Background: In three academic articles, this PhD thesis investigates maternal postpartum depression (PPD) as a risk factor for the infant-mother attachment and infant development. Previous studies have been contradictory with respect to the question of whether PPD can have long term effects...... on offspring. This may be due to not differing between when PPD is only occurring in the postpartum period and when effects are also due to ongoing or recurrent depression. However, it may also be due to viewing maternal depression as a unitary construct, and not considering underlying maternal psychological...... difficulties which may moderate potential adverse effects. The present thesis investigates two potential maternal moderators of risk:. Comorbid personality disorder and adult attachment insecurity. Moreover, the question of early environmental effects of PPD versus effects of later or ongoing depression...
Chetviverikova, E P; Iashina, S G; Shabaeva, E V; Egorova, E F; Iashina, A V
The effect of deep freezing of seeds at -196 degrees C (-320.8 degrees Fahrenheit) and inbreeding on the morphological characteristics of the evening-primrose biennal (Oenothera biennis L.), such as the size of plant parts and the amount of fruits, cauline nodes, and generative and vegetative shoots was investigated. The variation coefficients for these characteristics after treatment with low temperatures and inbreeding were calculated. It was shown that the characteristics of plant size show a low and a middle level of variability in the control group. The variation curves for these characteristics are similar to normal distribution curves. After stresses they slightly change or remain invariant. Large adventive shoots show a high level of variability. The distribution of the results in this case significantly differs from the normal. The branching of plants changes after both stress factors: the amount of all kinds of shoots decreases by half or even more.
Paty Castilleja Sánchez
Full Text Available Seed production, quality, germination and seedling establishment are indicators of reproductive success in conifers. Monitoring of these parameters is essential to determine the viability of populations for the purposes of conservation. We analyze cone and seed traits as indicators of reproductive success in the endangered Rzedowski´s pine (Pinus rzedowskii (Madrigal et Caballero and near-threatened veitchii pine (Pinus ayacahuite var. veitchii (Shaw in west-central Michoacán, Mexico. These traits were systematically quantified and their variation assessed using Generalized Linear Mixed Models (GLMMs. We found that the reproductive success of Rzedowski’s pine seems to be critical, presenting low seed efficiency (17.10%, germination (5.0% and seedling establishment (27.7%, with high levels of inbreeding (0.79. In contrast, veitchii pine presents moderate seed efficiency (54.9%, high germination (71.5% and seedling establishment (84%–97% and low inbreeding (0.33. Reproductive indicators differed significantly among zones and populations for each species, where fragment sizes mainly affected seed production and efficiency. This result indicates that fragmentation has played a more important role in the reproductive success of Rzedowski’s pine than in veitchii pine, perhaps by limiting pollen flow among zones and populations and producing higher levels of inbreeding and lower seed efficiency in the former species. We propose a conservation strategy for these important pine species in order to increase their long-term genetic viability.
Maria Elisa Ayres Guidetti Zagatto Paterniani
heterosis Thirty-six single-crosses resulting from partial diallel and the 12 parental lines were evaluated in Campinas, State of São Paulo, in randomized block design, with tree replicates and two commercial checks. The following traits were evaluated: plant and ear height, ear weight and grain weight. Individual variance analysis of hybrids were performed, and the averages were compared by Tukey test (P<0.05. General combining ability of the lines was obtained according to Geraldi e Miranda Filho. Correlations among matrices were estimated through Mantel statistics, considering heterosis, yield and specific combining ability with genetic divergence assessed by AFLP and SSR. The hybrid PM624 x IP398 exhibited outstanding yield capacity and the lines VER266 and L105 showed positive GCA for grain yield. Estimate heterosis ranged from -559 to 6.320 kg ha-1. No significant correlation was observed between heterosis, specific combination ability or grain yield with genetic distance assessed by AFLP and SSR. Therefore, no prediction of hybrids performance could be made on the basis of the genetic divergence of the parent lines.
Montoya S. Camilo
Full Text Available En la presente investigación se revisaron 4948 datos referentes a lactancias de vacas en razas B taurus y B indicus, los cuales se obtuvieron entre los años 1986 y 1994 en las Ganaderías La Unión y La K, localizadas en los municipios Plato y Santa Ana en el departamento de Magdalena; San Fernando Pinillos y Magangué en el departamento de Bolívar; y Playones de Sucre y Buenavista en el departamento de Sucre. Para determinar la influencia de los diferentes efectos tanto genéticos como no genéticos sobre las características a estudiar, se utilizó el programa de mínimos cuadrados de Harvey (1988. Los efectos tenidos en cuenta en los modelos para las características leche vendible, días de lactancia e intervalo entre partos fueron: El grupo genético materno, la época y año de parto, número de parto, y hato. Como cavariables se tuvieron en cuenta el peso al destete, la producción de leche duración de la lactancia y el intervalo entre partos según el modelo a estudiar. De los factores 110 genéticos la gran mayoría dieron efecto significativo a los niveles del (P~0.05; no presentaron significancia la época para la duració1l de la lactancia y el grupo genético para el intervalo entre partos; y las covariables intervalo entre partos para la producción de leche y producción de leche en el modelo para el intervalo entre partos. La estimación de la heterosis se hizo una vez realizados los contrastes ortogonales entre los grupos genéticos para las características en las cuales el grupo racial presentó significancia en los ANAVAS. La heterosis obtenida para la producción de leche teniendo como base el promedio de las raza Criolla y el promedio entre el Criollo y el Cebú fue respectivamente: ½ Taurus-1/2 Criollo (17.95% y 22.5%; ½ Taurus - ½ Cebú (9% y 14%; Trihíbrido (7.7% y 11. 7%; ¼ Taurus- ¾ Cebú (5% y 9%; ½ Cebú- ½ Criollo (1.05% y 4.8%; y el ¾ Cebú- ½ Criollo (-7.88% y -4.46%; todas altamente
Birth control necessary to limit family size in tribal couples with aberrant heterosis of G-6-PD deficiency and sickle cell disorders in India: an urgency of creating awareness and imparting genetic counseling.
Balgir, R S
(i) To study the outcome of ignorance and lack of awareness about sickle cell disease and G-6-PD deficiency among Dhelki Kharia tribal families of Orissa, and (ii) to study the reproductive output in relation to clinical genetics and patho-physiological implications. A random genetic study of screening for hemoglobinopathies and G-6-PD deficiency among Dhelki Kharia tribal community in Sundargarh district of Orissa was carried out for intervention during the year 2000-2004. A total of 81 Dhelki Kharia families were screened and six families with double heterozygosity for above genetic anomalies were encountered. About 2-3 ml. intravenous blood samples were collected in EDTA by disposable syringes and needles after taking informed consent from each individual in the presence of a doctor and community leaders and sent to laboratory at Bhubaneswar for hematological investigations. Analysis was carried out following the standard procedures after cross checking for quality control. There were 12 (about 52%) children out of 23 who were either suffering from sickle cell trait or disease in concurrence with G-6-PD deficiency in hemizygous/heterozygous/homozygous condition in Dhelki Kharia tribal community of Orissa. There were on an average 3.83 number of surviving (range 2-6) children per mother in families of G-6-PD deficiency and sickle cell disorders. The average number of children (3.83) born (range 2-6 children) per mother to carrier/affected mother was much higher than the average for India (2.73). It is very difficult to maintain the normal health of an affected child with aberrant anomalies due to exorbitant cost of treatment, frequent transfusions and huge involvement of economy. One of the implications of aberrant heterosis is its adverse affects on routine individual physiology and hard activities. It is suggested to limit the family size in carrier couples to avoid aberrant heterosis of hereditary hemolytic disorders in their offsprings.
Vallejo Cabrera Franco Alirio
Full Text Available Se realizó el análisis de la heterosis y de la habilidad combinatoria entre 21 cultivares de tomate, para el carácter producción por planta y sus componentes a partir de un cruzamiento dialélico (6 progenitores, 15 híbridos F1, sin incluir los recíprocos: utilizando el método experimental 2, modelo I propuesto por Griffing (1956. Se encontraron diferencias altamente significativas para los efectos de hcg y de hce para todos los caracteres a excepción del carácter producción de frutos de primera (frutos de más de 180 g. Los híbridos Motelle x Ángela I 5100, Motelle x Zambao y Licapal 21 x Zambao presentaron altos efectos de h c e para el carácter producción por planta. Los anteriores efectos asociados con altas heterobeltiosis hacen que estos híbridos sean promisorios para una posterior comercialización.An analysis of heterosis and combining ability of traits related with per plant production was carried out using a diallele crossing between different tomate cultivars, Lycopersicon esculentum Mill (six parent and 15 F1 hybrids from as possible crossing in one direction, according to the methodology proposed by Griffing (1956, selecting experimental method 2, and model 1. In the genetic variation of all traits related to per plant production, except in first class fruit trait, the general combining ability (gen non addite action effects participate jointly and in highly significant manner. Hybrids Motelle x Angela I 5100, Motelle x Zambao y Licapal21 x Zambao, exhibited high s c a effects for the trait per plant production. Former effects related to high heterobeltyosis make these hybrids promising for later marketing.
Moshe, Hagar; Gal, Ram; Barnea-Ygael, Noam; Gulevsky, Tatiana; Alyagon, Uri; Zangen, Abraham
Approximately one third of all major depression patients fail to respond to conventional pharmacological antidepressants, and brain stimulation methods pose a promising alternative for this population. Recently, based on repeated multifactorial selective inbreeding of rats for depressive-like behaviors, we introduced a novel animal model for MDD. Rats from this Depressive Rat Line (DRL) exhibit inherent depressive-like behaviors, which are correlated with lower levels of brain-derived neurotrophic factor (BDNF) in specific brain regions. In addition, DRL rats do not respond to antidepressant medication but respond to electroconvulsive treatment, and they can thus be utilized to test the effectiveness of brain stimulation on hereditary, medication-resistant depressive-like behaviors. To test the effect of sub-convulsive electrical stimulation (SCES) of the prelimbic cortex, using TMS-like temporal pattern of stimulation, on depressive-like behaviors and regional BDNF levels in DRL rats. SCES sessions were administered daily for 10 days through chronically implanted electrodes. Temporal stimulation parameters were similar to those used in TMS for major depression in human patients. Depressive-like behaviors were assayed after treatment, followed by brain extraction and regional BDNF measurements. SCES normalized both the depressive-like behaviors and the reduced BDNF levels observed in DRL rats. Correlation analyses suggest that changes in specific behaviors are mediated, at least in part, by BDNF expression in reward-related brain regions. Brain stimulation is effective in a drug-resistant, inherited animal model for depression. BDNF alterations in specific regions may mediate different antidepressant effects. Copyright © 2016 Elsevier Inc. All rights reserved.
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Ingram, Colleen M; Troendle, Nicholas J; Gill, Clare A; Braude, Stanton; Honeycutt, Rodney L
The role of genetic relatedness in the evolution of eusociality has been the topic of much debate, especially when contrasting eusocial insects with vertebrates displaying reproductive altruism. The naked mole-rat, Heterocephalus glaber, was the first described eusocial mammal. Although this discovery was based on an ecological constraints model of eusocial evolution, early genetic studies reported high levels of relatedness in naked mole-rats, providing a compelling argument that low dispersal rates and consanguineous mating (inbreeding as a mating system) are the driving forces for the evolution of this eusocial species. One caveat to accepting this long-held view is that the original genetic studies were based on limited sampling from the species' geographic distribution. A growing body of evidence supports a contrary view, with the original samples not representative of the species-rather reflecting a single founder event, establishing a small population south of the Athi River. Our study is the first to address these competing hypotheses by examining patterns of molecular variation in colonies sampled from north and south of the Athi and Tana rivers, which based on our results, serve to isolate genetically distinct populations of naked mole-rats. Although colonies south of the Athi River share a single mtDNA haplotype and are fixed at most microsatellite loci, populations north of the Athi River are considerably more variable. Our findings support the position that the low variation observed in naked mole-rat populations south of the Athi River reflects a founder event, rather than a consequence of this species' unusual mating system. © 2015 John Wiley & Sons Ltd.
Marina S Ascunce
Full Text Available Understanding the evolution of parasites is important to both basic and applied evolutionary biology. Knowledge of the genetic structure of parasite populations is critical for our ability to predict how an infection can spread through a host population and for the design of effective control methods. However, very little is known about the genetic structure of most human parasites, including the human louse (Pediculus humanus. This species is composed of two ecotypes: the head louse (Pediculus humanus capitis De Geer, and the clothing (body louse (Pediculus humanus humanus Linnaeus. Hundreds of millions of head louse infestations affect children every year, and this number is on the rise, in part because of increased resistance to insecticides. Clothing lice affect mostly homeless and refugee-camp populations and although they are less prevalent than head lice, the medical consequences are more severe because they vector deadly bacterial pathogens. In this study we present the first assessment of the genetic structure of human louse populations by analyzing the nuclear genetic variation at 15 newly developed microsatellite loci in 93 human lice from 11 sites in four world regions. Both ecotypes showed heterozygote deficits relative to Hardy-Weinberg equilibrium and high inbreeding values, an expected pattern given their parasitic life history. Bayesian clustering analyses assigned lice to four distinct genetic clusters that were geographically structured. The low levels of gene flow among louse populations suggested that the evolution of insecticide resistance in lice would most likely be affected by local selection pressures, underscoring the importance of tailoring control strategies to population-specific genetic makeup and evolutionary history. Our panel of microsatellite markers provides powerful data to investigate not only ecological and evolutionary processes in lice, but also those in their human hosts because of the long
Nielsen, L.R.; Siegismund, Hans Redlef; Hansen, T.
Abstract A previous study showed that some individuals of the tetraploid Galápagos endemic Scalesia affinis were able to produce offspring after selfing. The present study compares the fitness of self-pollinated offspring with the fitness of cross-pollinated offspring. Germination success, seedl...
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Gutzmann, H; Qazi, A
Depression and cognitive disorders, including dementia and mild cognitive impairment, are common disorders in old age. Depression is frequent in dementia, causing distress, reducing the quality of life, exacerbating cognitive and functional impairment and increasing caregiver stress. Even mild levels of depression can significantly add to the functional impairment of dementia patients and the severity of psychopathological and neurological impairments increases with increasing severity of depression. Depressive symptoms may be both a risk factor for, as well as a prodrome of dementia. Major depressive syndrome of Alzheimer's disease may be among the most common mood disorders of older adults. Treating depression is therefore a key clinical priority to improve the quality of life both of people with dementia as well as their carergivers. Nonpharmacological approaches and watchful waiting should be attempted first in patients who present with mild to moderate depression and dementia. In cases of severe depression or depression not able to be managed through nonpharmacological means, antidepressant therapy should be considered.
Juliana G de Lalla
Full Text Available O objetivo do trabalho foi estimar o efeito da capacidade geral (CGC e específica (CEC de combinação e a heterose de linhagens e populações de pepino japonês, empregando-se um topcross. Foram obtidos 16 híbridos experimentais a partir de duas populações testadoras (geração F2 de Yoshinari, T Y, e de Natsusuzumi, T N e oito linhagens S5 obtidas a partir do híbrido comercial Hokuho. Também foi avaliado o híbrido F1 Hokuho, totalizando 27 tratamentos. O delineamento experimental utilizado foi em blocos casualizados, com quatro repetições e cada parcela foi constituída de quatro plantas. Foram avaliadas as massas totais e comerciais, número de frutos total e comercial, porcentagem de frutos comerciais e massa média de frutos comerciais. A população de Yoshinari (T Y apresentou, em média, melhor capacidade de se combinar com as linhagens de Hokuho. A linhagem L7 apresentou os maiores valores positivos da estimativa da CGC para a maioria das características avaliadas. Os híbridos H1Y e H1N, que apresentavam a linhagem L1 como parental, foram os que apresentaram maiores valores para a estimativa da CEC com as populações testadoras para a maioria das características avaliadas, enquanto os que tinham a linhagem L5 como parental (H5Y e H5N apresentaram os menores valores. A população F2 proveniente do híbrido Yoshinari apresentou, em geral, maior potencial de originar linhagens superiores para cruzamentos com linhagens de Hokuho, a fim de se obter híbridos com maior potencial produtivo. A heterose foi positiva para a grande maioria das características avaliadas.The objective of this work was to estimate general (GCA and specific combining ability (SCA and heterosis of lines and populations of Japanese cucumber using a topcross. We obtained 16 experimental hybrids crossing two test populations (Yoshinari, T Y, and Natsusuzumi, T N, F2 population and eight S5 lines obtained from Hokuho commercial hybrid. The Hokuho hybrid F1
Fernández, E N; Legarra, A; Martínez, R; Sánchez, J P; Baselga, M
Inbreeding generates covariances between additive and dominance effects (breeding values and dominance deviations). In this work, we developed and applied models for estimation of dominance and additive genetic variances and their covariance, a model that we call "full dominance," from pedigree and phenotypic data. Estimates with this model such as presented here are very scarce both in livestock and in wild genetics. First, we estimated pedigree-based condensed probabilities of identity using recursion. Second, we developed an equivalent linear model in which variance components can be estimated using closed-form algorithms such as REML or Gibbs sampling and existing software. Third, we present a new method to refer the estimated variance components to meaningful parameters in a particular population, i.e., final partially inbred generations as opposed to outbred base populations. We applied these developments to three closed rabbit lines (A, V and H) selected for number of weaned at the Polytechnic University of Valencia. Pedigree and phenotypes are complete and span 43, 39 and 14 generations, respectively. Estimates of broad-sense heritability are 0.07, 0.07 and 0.05 at the base versus 0.07, 0.07 and 0.09 in the final generations. Narrow-sense heritability estimates are 0.06, 0.06 and 0.02 at the base versus 0.04, 0.04 and 0.01 at the final generations. There is also a reduction in the genotypic variance due to the negative additive-dominance correlation. Thus, the contribution of dominance variation is fairly large and increases with inbreeding and (over)compensates for the loss in additive variation. In addition, estimates of the additive-dominance correlation are -0.37, -0.31 and 0.00, in agreement with the few published estimates and theoretical considerations. © 2017 Blackwell Verlag GmbH.
Vinberg, Maj; Levinsen, Mette Frandsen; Kessing, Lars Vedel
Depression is considered resistant when two treatment attempts with antidepressants from different classes fail to produce significant clinical improvement. In cases of treatment-resistant depression, it is recommended to reevaluate the diagnosis, clarify comorbidity, substance abuse and lack of ...
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Everyone has down days and times when they feel sad. But depression is more than feeling sad or having a bad day. You may have depression if you feel sad every day (or most days) for at least two weeks.
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The suicide of Robert Enke,the goalkeeper of the Germany national football team who had battled depression for years,stunned the country and cast depression into the national spotlight as a disturbing disease.
Buntrock, Claudia; Berking, Matthias; Smit, Filip
-based guided self-help intervention (ie, cognitive-behavioral therapy and problem-solving therapy assisted by supervised graduate students or health care professionals) in addition to usual care or to usual care supplemented with Web-based psycho-education (enhanced usual care). Depression-free years (DFYs......BACKGROUND: Psychological interventions for the prevention of depression might be a cost-effective way to reduce the burden associated with depressive disorders. OBJECTIVE: To evaluate the cost-effectiveness of a Web-based guided self-help intervention to prevent major depressive disorder (MDD......) in people with subthreshold depression (sD). METHODS: A pragmatic randomized controlled trial was conducted with follow-up at 12 months. Participants were recruited from the general population via a large statutory health insurance company and an open access website. Participants were randomized to a Web...
Henn, Fritz [East Patchogue, NY
Methods for treatment of depression-related mood disorders in mammals, particularly humans are disclosed. The methods of the invention include administration of compounds capable of enhancing glutamate transporter activity in the brain of mammals suffering from depression. ATP-sensitive K.sup.+ channel openers and .beta.-lactam antibiotics are used to enhance glutamate transport and to treat depression-related mood disorders and depressive symptoms.
Thomson, Michael; Sharma, Verinder
Postpartum depression is a prevalent disorder affecting many women of reproductive age. Despite increasing public awareness, it is frequently underdiagnosed and undertreated leading to significant maternal morbidity and adverse child outcomes. When identified, postpartum depression is usually treated as major depressive disorder. Many studies have identified the postpartum as a period of high risk for first presentations and relapses of bipolar disorder. Areas covered: This article reviews the acute and prophylactic treatment of postpartum major depressive disorder, bipolar depression and major depressive disorder with mixed features. The safety of antidepressant and mood stabilizing medications in pregnancy and breastfeeding will also be reviewed. Expert commentary: Differentiating postpartum major depressive disorder and postpartum bipolar depression can be difficult given their clinical similarities but accurate identification is vital for initiating proper treatment. Antidepressants are the mainstay of drug treatment for postpartum major depressive disorder, yet randomized controlled trials have shown conflicting results. A paucity of evidence exists for the effectiveness of antidepressant prophylaxis in the prevention of recurrences of major depressive disorder. Mood stabilizing medications reduce the risk of postpartum bipolar depression relapse but no randomized controlled trials have examined their use in the acute or prophylactic treatment of postpartum bipolar depression.
Østergaard, Søren Dinesen; Meyers, B S; Flint, A J
Psychotic depression (PD) is a highly debilitating condition, which needs intensive monitoring. However, there is no established rating scale for evaluating the severity of PD. The aim of this analysis was to assess the psychometric properties of established depression rating scales and a number...... of new composite rating scales, covering both depressive and psychotic symptoms, in relation to PD....
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Everyone feels blue now and then. It's a part of life. But if your feelings last more than few days and interfere with your normal daily activities, you may be suffering from depression. On this page: Symptoms of depression Who gets depressed and why?
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Heterosis and direct effects for Charolais-sired calf weight and growth, cow weight and weight change, and ratios of cow and calf weights and weight changes across warm season lactation in Romosinuano, Angus, and F cows in Arkansas.
Riley, D G; Burke, J M; Chase, C C; Coleman, S W
The use of Brahman in cow-calf production offers some adaptation to the harsh characteristics of endophyte-infected tall fescue. Criollo breeds, such as the Romosinuano, may have similar adaptation. The objectives were to estimate genetic effects in Romosinuano, Angus, and crossbred cows for their weights, weights of their calves, and ratios (calf weight:cow weight and cow weight change:calf weight gain) across lactation and to assess the influence of forage on traits and estimates. Cows ( = 91) were bred to Charolais bulls after their second parity. Calves ( = 214) were born from 2006 to 2009. Cows and calves were weighed in early (April and June), mid- (July), and late lactation (August and October). Animal was a random effect in analyses of calf data; sire was random in analyses of cow records and ratios. Fixed effects investigated included calf age, calf sex, cow age-year combinations, sire breed of cow, dam breed of cow, and interactions. Subsequent analyses evaluated the effect of forage grazed: endophyte-free or endophyte-infected tall fescue. Estimates of maternal heterosis for calf weight ranged from 9.3 ± 4.3 to 15.4 ± 5.7 kg from mid-lactation through weaning ( cow) were -6.8 ± 3.0 and -8.9 ± 4.2 kg for weights recorded in April and June. Calf weights and weight gains from birth were greater ( cows grazing endophyte-free tall fescue except in mid-summer. Cow weight change from April to each time was negative for Angus cows and lower ( Cows grazing endophyte-free tall fescue were heavier ( cows had the lowest ( cow weight change:calf weight gain, indicating an energy-deficit condition. Cows grazing endophyte-free tall fescue had more negative ( cow weight, 7.9 ± 3.0 to 15.8 ± 5.0 kg for cow weight change, and 0.07 ± 0.03 to 0.27 ± 0.1 for cow weight change:calf weight gain. Direct Romosinuano effects ranged from 14.8 ± 4.2 to 49.8 ± 7.7 kg for cow weight change and 0.2 ± 0.04 to 0.51 ± 0.14 for cow weight change:calf weight gain. The adaptive
Full Text Available Depression is the most frequent psychological complication of haemodialysis (HD patients (pts and has been associated with impaired Quality of Life (QoL. The aim of our study was to investigate the prevalence of depression in HD pts in relation to sociodemographic factors and the relationship between depression and QoL.200 pts from Clinic for haemodialysis in Sarajevo, B&H were participating in the study. Mean age was S7,26±13,78 years and mean HD duration was 64’26±58,18 months. From the test material we applied BDI and SF-36.51% of our pts have shown depression (BDI>11 in various degrees (30%-mild depression, 8,5%-moderate depression and 12,5%-severe depression. As we could expect, the most emphasized symptoms of depression were somatic symptoms. 55,5% of pts have shown QoL lower then average. Sociodemographic data such as gender, marital status and HD duration did not influence significantly on pt’s QoL and occurrence of depression (p>0,05. As the age of the pts increased, level of depression increased too and QoL significantly decreased (p<0,05. Employed pts have shown significantly better QoL and lower level of depression in relation to unemployed pts (p<0,05. As the educational level of pts increased, QoL increased too and level of depression significantly decreased (p<0,05. Pts in 1st HD shift were significantly more depressed and have significantly worse mental health in compare to pts in 3rd HD shift (p<0,05. Our results showed a high prevalence of depressive symptoms among the study group that was linked to trend of poor QoL.
Rahim, Twana; Rashid, Roshe
This study exclusively aimed to clinically assess which symptom pattern discriminates primary depression from depression-secondary to-schizophrenia. A total of 98 patients with primary depression and 71 patients with secondary-to-schizophrenia depression were assessed for identifying the clinical phenomena of depression. Diagnosis of schizophrenia was confirmed by Mini International Neuropsychiatric Interview. Each participant was, however, assessed by Patient Health Questionnaire-9 as well as Calgary Depression Scale for Schizophrenia (CDSS) for possible concurrent depressive symptoms. Depressed mood, loss of interest, reduced energy and pathological guilt were more common in primary depression, whereas sleep disturbance and guilty ideas of reference were more amounting towards the diagnosis of depression secondary-to-schizophrenia. It is clinically hard to differentiate primary from secondary-to-schizophrenia depression, especially in the absence of obvious psychotic symptoms. However, the classical symptoms of depression like subjective depressed mood, anhedonia, reduced energy and pathological guilt are more prominent in the primary depression.
Jacka, Felice N; Berk, Michael
Unhealthy lifestyle behaviour is driving an increase in the burden of chronic non-communicable diseases worldwide. Recent evidence suggests that poor diet and a lack of exercise contribute to the genesis and course of depression. While studies examining dietary improvement as a treatment strategy in depression are lacking, epidemiological evidence clearly points to diet quality being of importance to the risk of depression. Exercise has been shown to be an effective treatment strategy for depression, but this is not reflected in treatment guidelines, and increased physical activity is not routinely encouraged when managing depression in clinical practice. Recommendations regarding dietary improvement, increases in physical activity and smoking cessation should be routinely given to patients with depression. Specialised and detailed advice may not be necessary. Recommendations should focus on following national guidelines for healthy eating and physical activity.
Wahl, Inka; Löwe, Bernd; Bjørner, Jakob
OBJECTIVES: To provide a standardized metric for the assessment of depression severity to enable comparability among results of established depression measures. STUDY DESIGN AND SETTING: A common metric for 11 depression questionnaires was developed applying item response theory (IRT) methods. Data...... of 33,844 adults were used for secondary analysis including routine assessments of 23,817 in- and outpatients with mental and/or medical conditions (46% with depressive disorders) and a general population sample of 10,027 randomly selected participants from three representative German household surveys....... RESULTS: A standardized metric for depression severity was defined by 143 items, and scores were normed to a general population mean of 50 (standard deviation = 10) for easy interpretability. It covers the entire range of depression severity assessed by established instruments. The metric allows...
Wålinder, J; Rutzt, W
Based on the experiences of the Gotland Study that education of general practitioners about depressive illness resulted in a statistically significant reduction in the number of female suicides, leaving the rate of male suicides almost unaffected, we propose the concept of a male depressive syndrome. This syndrome comprises a low stress tolerance, an acting-out behavior, a low impulse control, substance abuse and a hereditary loading of depressive illness, alcoholism and suicide. This notion is supported by data from The Amish study as well as the concept of van Praag of a stress-precipitated, cortisol-induced, serotonin-related and anxiety-driven depressive illness most often seen in males. In order to identify depressed males, the Gotland Male Depression Scale has been developed. Some preliminary data using the scale in a group of alcohol-dependant patients are presented.
Davidsen, Annette Sofie; Fosgerau, Christina Fogtmann
of depression is insufficient and a collaborative care (CC) model between general practice and psychiatry has been proposed to overcome this. However, for successful implementation, a CC model demands shared agreement about the concept of depression and the diagnostic process in the two sectors. We aimed......The diagnosis of depression is defined by psychiatrists, and guidelines for treatment of patients with depression are created in psychiatry. However, most patients with depression are treated exclusively in general practice. Psychiatrists point out that general practitioners' (GPs') treatment...... to explore how depression is understood by GPs and clinical psychiatrists. We carried out qualitative in-depth interviews with 11 psychiatrists and 12 GPs. Analysis was made by Interpretative Phenomenological Analysis. We found that the two groups of physicians differed considerably in their views...
Dorval, Bill; Smith, Gregor W.
Interwar macroeconomic history is a natural place to look for evidence on the correlations between (a) deflation and depression and (b) unexpected deflation and depression. We apply time-series methods to measure unexpected deflation or inflation for 26 countries from 1922 to 1939. The results suggest much variation across countries in the degree to which the ongoing deflation of the 1930s was unexpected. There is a significant, positive correlation between deflation and depression for the en...
This thesis is theoretical and it engage in problems of the depression, in particular depression in old age. It divide in four chapters. In first chapter mentioned a characteristic deppresion. Here is a description, what is the depression and that exit some questionnaires, what make find, whether is a man it distress. Further here is mentioned it occurrence, history, mythes, causes, symptoms, types, treatment and consequences. In second chapter talk about age and growing old and their concomi...
Nedley, Neil; Ramirez, Francisco E.
Depression is often diagnosed using the Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM-5) criteria. We propose how certain lifestyle choices and non-modifiable factors can predict the development of depression. We identified 10 cause categories (hits or ?blows? to the brain) and theorize that four or more active hits could trigger a depression episode. Methods. A sample of 4271 participants from our community-based program (70% female; ages 17-94 years) was assessed ...
In this thesis, I examine the complex experiences of what we call depression in everyday life, the multifaceted and ambiguous experiences of getting a depression diagnosis, and the in-depth processes involved in learning to live under the description of depression. The thesis is based......-and-for-all-dealt-with matters but rather messy and complicated processes, that involve several actors and multiple relations to the diagnosis. The thesis furthermore challenges the dominant diagnostic understanding depression as a neurobiological, and individual disorder in present-day diagnostic cultures, by arguing...
Primary headaches--mainly tension-type headache and migraine--affect a significant portion of the population. Depression is also highly prevalent. The co-existence of a primary headache and depression in the same patient therefore might be a coincidence due to the high prevalence of these conditions, but there might be a causal relationship between them, or headaches and depression might have a common background. This review of the literature summarizes the features of the relationship between primary headaches and depression. Depression is more prevalent in headache patients than in the headache-free population. Prospective epidemiological studies suggest a common genetic, biochemical or environmental background behind primary headaches and depression. This theory is supported by the role of the same neurotransmitter systems (mostly serotonin and dopamine) in headaches as well as in depression. Comorbid depression is associated with female gender, higher age, and higher frequency of headaches. Most depression inventories--questionnaires used to screen for the severity of depressive symptoms--contain transdiagnostic items, therefore their use in their original form is limited in organic diseases: due to the somatic items they might overestimate the severity of depression. When examining a headache patient special attention should be paid to the recognition of comorbid depression. The diagnosis of suspected mood disorder could be supported by using simple screening methods, such as the original or the abbreviated versions of standard depression inventories, but the final diagnosis of major depression needs psychiatric evaluation. Quality of life of the headache patient is affected not only by the characteristics of pain (frequency, duration, severity) but also by the disability caused by headache and the associating mood disorder. Recognizing coexisting mood disorder and disability helps to make the best treatment choice for the acute and preventive treatment of
Undine E. Lang
Full Text Available Several nutrition, food and dietary compounds have been suggested to be involved in the onset and maintenance of depressive disorders and in the severity of depressive symptoms. Nutritional compounds might modulate depression associated biomarkers and parallel the development of depression, obesity and diabetes. In this context, recent studies revealed new mediators of both energy homeostasis and mood changes (i.e. IGF-1, NPY, BDNF, ghrelin, leptin, CCK, GLP-1, AGE, glucose metabolism and microbiota acting in gut brain circuits. In this context several healthy foods such as olive oil, fish, fruits, vegetables, nuts, legumes, poultry, dairy and unprocessed meat have been inversely associated with depression risk and even have been postulated to improve depressive symptoms. In contrast, unhealthy western dietary patterns including the consumption of sweetened beverage, refined food, fried food, processed meat, refined grain, and high fat diary, biscuits, snacking and pastries have been shown to be associated with an increased risk of depression in longitudinal studies. However, it is always difficult to conclude a real prospective causal relationship from these mostly retrospective studies as depressed individuals might also change their eating habits secondarily to their depression. Additionally specific selected nutritional compounds, e.g. calcium, chromium, folate, PUFAs, vitamin D, B12, zinc, magnesium and D-serine have been postulated to be used as ad-on strategies in antidepressant treatment. In this context, dietary and lifestyle interventions may be a desirable, effective, pragmatical and non-stigmatizing prevention and treatment strategy for depression. At last, several medications (pioglitazone, metformin, exenatide, atorvastatin, gram-negative antibiotics, which have traditionally been used to treat metabolic disorders showed a certain potential to treat depression in first randomized controlled clinical trials.
Lang, Undine E; Beglinger, Christoph; Schweinfurth, Nina; Walter, Marc; Borgwardt, Stefan
Several nutrition, food and dietary compounds have been suggested to be involved in the onset and maintenance of depressive disorders and in the severity of depressive symptoms. Nutritional compounds might modulate depression associated biomarkers and parallel the development of depression, obesity and diabetes. In this context, recent studies revealed new mediators of both energy homeostasis and mood changes (i.e. IGF-1, NPY, BDNF, ghrelin, leptin, CCK, GLP-1, AGE, glucose metabolism and microbiota) acting in gut brain circuits. In this context several healthy foods such as olive oil, fish, fruits, vegetables, nuts, legumes, poultry, dairy and unprocessed meat have been inversely associated with depression risk and even have been postulated to improve depressive symptoms. In contrast, unhealthy western dietary patterns including the consumption of sweetened beverage, refined food, fried food, processed meat, refined grain, and high fat diary, biscuits, snacking and pastries have been shown to be associated with an increased risk of depression in longitudinal studies. However, it is always difficult to conclude a real prospective causal relationship from these mostly retrospective studies as depressed individuals might also change their eating habits secondarily to their depression. Additionally specific selected nutritional compounds, e.g. calcium, chromium, folate, PUFAs, vitamin D, B12, zinc, magnesium and D-serine have been postulated to be used as ad-on strategies in antidepressant treatment. In this context, dietary and lifestyle interventions may be a desirable, effective, pragmatical and non-stigmatizing prevention and treatment strategy for depression. At last, several medications (pioglitazone, metformin, exenatide, atorvastatin, gram-negative antibiotics), which have traditionally been used to treat metabolic disorders showed a certain potential to treat depression in first randomized controlled clinical trials. © 2015 The Author(s) Published by S
Full Text Available ... few days. It is a serious illness that affects many people. Symptoms can vary, but many depressed ... suffer from depression trying to learn why it affects some people but not others. Treatments for depression ...
Full Text Available ... 3 items) Institute Announcements (24 items) Symptoms and Treatment of Depression February 1, 2010 People with depression ... why it affects some people but not others. Treatments for depression do work. One type of effective ...
Kleinke, Chris L.
College students (N=396), chronic pain patients (N=319), and schizophrenic veterans (N=43) completed the Depression Coping Questionnaire (DCQ) and the Beck Depression Inventory (BDI). Factor analysis of the DCQ identified eleven coping responses: social support, problem solving, self-blame/escape, aggression, indulgence, activities, medication,…
Occurring in about 12 percent of postpartum women, postpartum depression has been focus of considerable research. Variables that have been correlated with postpartum depression range from biological causes, to lack of social support, to relationship with husband, to attributional styles, to psychodynamic explanations. There is need for more…
Full Text Available Androgens have various effects on human body and mood. Testosterone, a hormone mainly secreted from testes and adrenals, is one of the most potent androgens. Multiple studies have found that testosterone plays a role in regulating sexual activity, libido, social behaviors, aggression, cognitive functions, sleep control and well-being in men and women. Testosterone deficiency in hypogonadic or elderly men leads to neuropsychiatric problems, such as fatigue, loss of libido, irritability, insomnia and depressive mood. Testosterone replacement therapy consistently reverses these sequel in men. On the other hand, hyperandrogenic states in women are related to aggression and antisocial behavior, which might lead to depressive mood. Low testosterone levels may also result in depression among oophorectomized women. Because of such effects, a relationship between testosterone and depression has long been an issue of speculation, but yet very few studies have addressed this relation. Along with clinical studies, experimental and epidemiological studies show that testosterone is related to depression in men and women. But studies of testosterone concentrations in depression have yielded inconsistent results reporting low as well as high testosterone levels associated with depression. In this article, the physiological and psychological effects of testosterone and evidence regarding its relationship to depressive disorders and possible gender differences have been reviewed.
Although studies have shown the prevalence of depression in nursing homes to be high, under-recognition of depression in these facilities is widespread. Use of screening tests to enhance detection of depressive symptoms has been recommended. This paper aims to provoke discussion about optimal management of depression in nursing homes. The utility of the Cornell Scale for Depression in Dementia (CSDD) is considered. CSDD data relating to residents assessed in 2008-2009 were collected from three Sydney nursing homes. CSDD scores were available from 162 residents, though raters stated they were unable to score participants on at least one item in 47 cases. Scores of 13 or more were recorded for 23% of residents in these facilities, but in most of these cases little was documented in case files to show that the results had been discussed by staff, or that they led to interventions, or that follow-up testing was arranged. Results of CSDD testing should prompt care staff (including doctors) to consider causation of depression in cases where residents are identified as possibly depressed. In particular, there needs to be discussion of how to help residents to cope with disability, losses, and feelings of powerlessness. Research is needed, examining factors that might predict response to antidepressants, and what else helps. Accreditation of nursing homes could be made to depend partly on evidence that staff regularly search for, and (if found) ensure appropriate responses to, depression.
The association between depression and sleep disturbances is perhaps as old as makind. In view of the longstanding experience with this association it is amazing that only some 20 years ago, a few depressed patients attracted attention to the fact that Total Sleep Deprivation (TSD) had
Pedersen, Niels C; Brucker, Lynn; Tessier, Natalie Green; Liu, Hongwei; Penedo, Maria Cecilia T; Hughes, Shayne; Oberbauer, Anita; Sacks, Ben
Sebaceous adenitis (SA) and Addison's disease (AD) increased rapidly in incidence among Standard Poodles after the mid-twentieth century. Previous attempts to identify specific genetic causes using genome wide association studies and interrogation of the dog leukocyte antigen (DLA) region have been non-productive. However, such studies led us to hypothesize that positive selection for desired phenotypic traits that arose in the mid-twentieth century led to intense inbreeding and the inadvertent amplification of AD and SA associated traits. This hypothesis was tested with genetic studies of 761 Standard, Miniature, and Miniature/Standard Poodle crosses from the USA, Canada and Europe, coupled with extensive pedigree analysis of thousands more dogs. Genome-wide diversity across the world-wide population was measured using a panel of 33 short tandem repeat (STR) loci. Allele frequency data were also used to determine the internal relatedness of individual dogs within the population as a whole. Assays based on linkage between STR genomic loci and DLA genes were used to identify class I and II haplotypes and disease associations. Genetic diversity statistics based on genomic STR markers indicated that Standard Poodles from North America and Europe were closely related and reasonably diverse across the breed. However, genetic diversity statistics, internal relatedness, principal coordinate analysis, and DLA haplotype frequencies showed a marked imbalance with 30 % of the diversity in 70 % of the dogs. Standard Poodles with SA and AD were strongly linked to this inbred population, with dogs suffering with SA being the most inbred. No single strong association was found between STR defined DLA class I or II haplotypes and SA or AD in the breed as a whole, although certain haplotypes present in a minority of the population appeared to confer moderate degrees of risk or protection against either or both diseases. Dogs possessing minor DLA class I haplotypes were half as
Full Text Available Abstract Selection programmes are mainly concerned with increasing genetic gain. However, short-term progress should not be obtained at the expense of the within-population genetic variability. Different prediction models for the evolution within a small population of the genetic mean of a selected trait, its genetic variance and its inbreeding have been developed but have mainly been validated through Monte Carlo simulation studies. The purpose of this study was to compare theoretical predictions to experimental results. Two deterministic methods were considered, both grounded on a polygenic additive model. Differences between theoretical predictions and experimental results arise from differences between the true and the assumed genetic model, and from mathematical simplifications applied in the prediction methods. Two sets of experimental lines of chickens were used in this study: the Dutch lines undergoing true truncation mass selection, the other lines (French undergoing mass selection with a restriction on the representation of the different families. This study confirmed, on an experimental basis, that modelling is an efficient approach to make useful predictions of the evolution of selected populations although the basic assumptions considered in the models (polygenic additive model, normality of the distribution, base population at the equilibrium, etc. are not met in reality. The two deterministic methods compared yielded results that were close to those observed in real data, especially when the selection scheme followed the rules of strict mass selection: for instance, both predictions overestimated the genetic gain in the French experiment, whereas both predictions were close to the observed values in the Dutch experiment.
Vanthournout, Bram; Greve, Michelle; Bruun, Anne; Bechsgaard, Jesper; Overgaard, Johannes; Bilde, Trine
Group living carries a price: it inherently entails increased competition for resources and reproduction, and may also be associated with mating among relatives, which carries costs of inbreeding. Nonetheless, group living and sociality is found in many animals, and understanding the direct and indirect benefits of cooperation that override the inherent costs remains a challenge in evolutionary ecology. Individuals in groups may benefit from more efficient management of energy or water reserves, for example in the form of reduced water or heat loss from groups of animals huddling, or through reduced energy demands afforded by shared participation in tasks. We investigated the putative benefits of group living in the permanently social spider Stegodyphus dumicola by comparing the effect of group size on standard metabolic rate, lipid/protein content as a body condition measure, feeding efficiency, per capita web investment, and weight/water loss and survival during desiccation. Because energetic expenditure is temperature sensitive, some assays were performed under varying temperature conditions. We found that feeding efficiency increased with group size, and the rate of weight loss was higher in solitary individuals than in animals in groups of various sizes during desiccation. Interestingly, this was not translated into differences in survival or in standard metabolic rate. We did not detect any group size effects for other parameters, and group size effects did not co-vary with experimental temperature in a predictive manner. Both feeding efficiency and mass loss during desiccation are relevant ecological factors as the former results in lowered predator exposure time, and the latter benefits social spiders which occupy arid, hot environments. PMID:26869936
Full Text Available Group living carries a price: it inherently entails increased competition for resources and reproduction, and may also be associated with mating among relatives, which carries costs of inbreeding. Nonetheless, group living and sociality is found in many animals, and understanding the direct and indirect benefits of cooperation that override the inherent costs remains a challenge in evolutionary ecology. Individuals in groups may benefit from more efficient management of energy or water reserves, for example in the form of reduced water or heat loss from groups of animals huddling, or through reduced energy demands afforded by shared participation in tasks. We investigated the putative benefits of group living in the permanently social spider Stegodyphus dumicola by comparing the effect of group size on standard metabolic rate, lipid/protein content as a body condition measure, feeding efficiency, per capita web investment and weight/water loss and survival during desiccation. Because energetic expenditure is temperature sensitive, some assays were performed under varying temperature conditions. We found that feeding efficiency increased with group size, and the rate of weight loss was higher in solitary individuals than in animals in groups of various sizes during desiccation. Interestingly, this was not translated into differences in survival or in standard metabolic rate. We did not detect any group size effects for other parameters, and group size effects did not co-vary with experimental temperature in a predictive manner. Both feeding efficiency and mass loss during desiccation are relevant ecological factors as the former results in lowered predator exposure time, and the latter benefits social spiders which occupy arid, hot environments.
Howell, Cate; Marshall, Charlotte; Opolski, Melissa; Newbury, Wendy
Depression is a potentially recurring or chronic disorder. The provision of evidence based treatment and effective practice organisation is central to chronic disease management, and these principles can be applied to managing depression. This article outlines the principles of chronic disease management, including the use of management plans and a team care approach, and their application to the management of depression. Treatment approaches that systematically assist patients in managing their chronic disease are more effective than those based on acute care. Depression treatment guidelines are available, as well as primary care initiatives which facilitate comprehensive and long term mental health care, including relapse prevention strategies. A number of risk factors for depression relapse have been identified, and research has recommended that novel intensive relapse prevention programs need to be developed.
Østergaard, S D; Meyers, B S; Flint, A J
OBJECTIVE: Psychotic depression (PD) is a highly debilitating condition, which needs intensive monitoring. However, there is no established rating scale for evaluating the severity of PD. The aim of this analysis was to assess the psychometric properties of established depression rating scales...... and a number of new composite rating scales, covering both depressive and psychotic symptoms, in relation to PD. METHOD: The psychometric properties of the rating scales were evaluated based on data from the Study of Pharmacotherapy of Psychotic Depression. RESULTS: A rating scale consisting of the 6-item......'s correlation coefficient between change in HAMD-BPRS11 and Clinical Global Impression - Improvement (CGI-I) scores = -0.74--0.78) and unidimensionality (Loevinger's coefficient of homogeneity = 0.41) in the evaluation of PD. The HAM-D6 fulfilled the same criteria, whereas the full 17-item Hamilton Depression...
Larsen, Karen Kjær
whether the mental burden of MI is so heavy that it increases the risk of suicide. Although post-MI depression is common and burdensome, the condition remains under-recognised and under-treated. The development of new strategies to improve the quality of care for people with post-MI depression requires...... between post-MI depression and new cardiovascular events or death, taking potential mediators into account (Paper III); 4. To examine the association between MI and suicide (Paper IV). Two different study designs were employed: a population-based cohort study using data obtained from registers......Myocardial infarction (MI) is a severe life event that is accompanied by an increased risk of depression. Mounting evidence suggests that post-MI depression is associated with adverse outcomes, but the underlying mechanisms of this association remain unclear, and no previous studies have examined...
Taleb, M; Rouillon, F; Hegerl, U; Hamdani, N; Gorwood, Ph
Depressive disorders represent a major public health concern, regarding their high frequency and their important cost. Depression impair the quality of life more than any other disease, sometimes leading to suicidal ideas or behavior. Indeed, 50% of patients with severe major depression commit suicide. Numerous studies showed that depressive disorders are frequently not recognised, and regularly untreated. In France, where at least 3 millions of inhabitants are concerned, 38% of depressed patients are not using any health system. When they are asking for care, the majority of depressed patients visit their general practitioner (51%), whereas less than 10% visit a psychiatrist. Even when the diagnostic is correct, the treatment prescribed is not systematically relevant. The treatment is, for example, frequently proposed for a too short period, and sometimes the prescribed product does not have proven antidepressive efficacy. Furthermore, as incorrect informations are frequently given to patients, and as there is a general biased judgement about psychotropic drugs in the general population, the compliance is usually poor for antidepressive treatment. Therefore, only a small minority of depressed patients benefits from an adequate care. Public health information methodological asserts. To improve this situation, delivering simple and clear-cut recommendations cannot be considered as sufficiently effective, and public health interventions are required. Different programs improving the recognition of depressive disorders have already been tested in some countries with encouraging results. These programs are based on information campaigns given to the public, and the training of general practitioners about the management of depressive disorders. The "Defeat Depression" campaign in Great-Britain and the "National Depression Screening Day" in the United-States of America may represent informative examples. Restricting these programs to general practitioners only is
Jorm Anthony F
Full Text Available Abstract Background To investigate and compare the predictors of personal and perceived stigma associated with depression. Method Three samples were surveyed to investigate the predictors: a national sample of 1,001 Australian adults; a local community sample of 5,572 residents of the Australian Capital Territory and Queanbeyan aged 18 to 50 years; and a psychologically distressed subset (n = 487 of the latter sample. Personal and Perceived Stigma were measured using the two subscales of the Depression Stigma Scale. Potential predictors included demographic variables (age, gender, education, country of birth, remoteness of residence, psychological distress, awareness of Australia's national depression initiative beyondblue, depression literacy and level of exposure to depression. Not all predictors were used for all samples. Results Personal stigma was consistently higher among men, those with less education and those born overseas. It was also associated with greater current psychological distress, lower prior contact with depression, not having heard of a national awareness raising initiative, and lower depression literacy. These findings differed from those for perceived stigma except for psychological distress which was associated with both higher personal and higher perceived stigma. Remoteness of residence was not associated with either type of stigma. Conclusion The findings highlight the importance of treating the concepts of personal and perceived stigma separately in designing measures of stigma, in interpreting the pattern of findings in studies of the predictors of stigma, and in designing, interpreting the impact of and disseminating interventions for stigma.
Elderon, Larkin; Whooley, Mary A
Approximately one out of every five patients with cardiovascular disease (CVD) suffers from major depressive disorder (MDD). Both MDD and depressive symptoms are risk factors for CVD incidence, severity and outcomes. Great progress has been made in understanding potential mediators between MDD and CVD, particularly focusing on health behaviors. Investigators have also made considerable strides in the diagnosis and treatment of depression among patients with CVD. At the same time, many research questions remain. In what settings is depression screening most effective for patients with CVD? What is the optimal screening frequency? Which therapies are safe and effective? How can we better integrate the care of mental health conditions with that of CVD? How do we motivate depressed patients to change health behaviors? What technological tools can we use to improve care for depression? Gaining a more thorough understanding of the links between MDD and heart disease, and how best to diagnose and treat depression among these patients, has the potential to substantially reduce morbidity and mortality from CVD. Published by Elsevier Inc.
... Topic En español Get Your Teen Screened for Depression Browse Sections The Basics Overview What Is Depression? ... 1 of 9 sections The Basics: What Is Depression? What is depression? Teen depression can be a ...
Vinberg, Maj; Levinsen, Mette Frandsen; Kessing, Lars Vedel
Depression is considered resistant when two treatment attempts with antidepressants from different classes fail to produce significant clinical improvement. In cases of treatment-resistant depression, it is recommended to reevaluate the diagnosis, clarify comorbidity, substance abuse and lack...... of compliance. Regarding treatment, evidence is sparse, but switching to a different antidepressant, and combination or augmentation with another agent, admission and treatment with ECT are the options. The choice of treatment must be based on the characteristics of the depression, the severity of treatment...
Haaga, D A; Beck, A T
Beck's cognitive theory of depression has provided a successful description of depressive thinking, with one major exception. The hypothesis that depressed people show biased negative thinking seems contradicted by research indicating that Ss scoring 9 or above on the Beck Depression Inventory were more accurate than their nondepressed counterparts in judging contingencies between their responses and outcomes, seemingly showing "depressive realism". Depressive realism research has attracted attention in numerous areas of psychology, along with critical commentary focused on such issues as whether realism is limited to mild depressive states, whether laboratory tasks are sufficient to document realism, and whether realism is a general characteristic of either depressed or nondepressed people. We analyze the main critiques and show how debates about depressive realism can be heuristic for refinement of cognitive theory of depression.
Esser, Sally R.; Vitaliano, Peter P.
Reviews recent literature on the relationships among dementia, depression, and social support, emphasizing the diagnostic differentiation of dementia and depression, and the role of these three entities in elderly with cognitive impairment. Discusses dementia-like symptoms arising in depression and the coexistence of dementia and depression.…
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... on your own, talk to your doctor or mental health professional. Depression treatment may be unsuccessful until you address your substance use. Manage stress. Relationship issues, financial problems, an unhappy work life and many other issues can all contribute ...
Jan 2, 1971 ... ... repressed, internalized, tumed against the self and causes the patient to suffer. ... depression, and suicide) and analysed the Szondi profiles obtained upon a first ... causes resentment and loss of dependency and esteem."".
... editorial staff Categories: Emotional Well-Being, Family Health, Men, Mental Health, Prevention and Wellness, Seniors, WomenTags: adult, antidepressants, dementia, depression, Disorientation, elderly, older adults, Psychiatric and Psychologic, senior ...
Katon, Wayne; Russo, Joan; Gavin, Amelia
To examine sociodemographic factors, pregnancy-associated psychosocial stress and depression, health risk behaviors, prepregnancy medical and psychiatric illness, pregnancy-related illnesses, and birth outcomes as risk factors for post-partum depression (PPD). A prospective cohort study screened women at 4 and 8 months of pregnancy and used hierarchical logistic regression analyses to examine predictors of PPD. The study sample include 1,423 pregnant women at a university-based high risk obstetrics clinic. A score of ≥10 on the Patient Health Questionnaire-9 (PHQ-9) indicated clinically significant depressive symptoms. Compared with women without significant postpartum depressive symptoms, women with PPD were significantly younger (pdepressive symptoms (pdepression case finding for pregnant women.
Bubl, E.; Tebartz Van Elst, L.; Ebert, D.
Background. Reduced dopaminergic transmission has been implicated in the pathophysiology of major depression. Furthermore, dopaminergic neurotransmission plays an important role in the physiology of visual contrast sensitivity (CS). To test the hypothesis that altered dopaminergic neurotransmissi...
Christiansen, Sofie Laage; Bouzinova, Elena
Data demonstrate that abnormal regulation of the circadian system can result in cardiovascular disease, metabolic syndrome, obesity, immune dysfunction, increased risk for cancer, reproductive complications, etc. It is highly individual among depressed patients and may be expressed as a phase...... in the brain and liver: expression of Per2 is sensitive to stress and changes in Bmal1 mostly associated with depressive behavior. The Per1 expression is sustainable in maintaining the circadian rhythm. A normalization of the expression patterns is likely to be essential for the recovery from the pathological...... state. Depression is a high prevalent disorder. The number of incidents is rising due to changes in lifestyle. The symptomatology is inconsistent and it is difficult to agree on one hypothesis. The disturbances of the 24 h circadian rhythm may be a factor in the development of major depressive disorder...
Wium-Andersen, Marie Kim; Ørsted, David Dynnes; Rode, Line
BACKGROUND: Depression has been cross-sectionally associated with short telomeres as a measure of biological age. However, the direction and nature of the association is currently unclear. AIMS: We examined whether short telomere length is associated with depression cross-sectionally as well...... as prospectively and genetically. METHOD: Telomere length and three polymorphisms, TERT, TERC and OBFC1, were measured in 67 306 individuals aged 20-100 years from the Danish general population and associated with register-based attendance at hospital for depression and purchase of antidepressant medication....... RESULTS: Attendance at hospital for depression was associated with short telomere length cross-sectionally, but not prospectively. Further, purchase of antidepressant medication was not associated with short telomere length cross-sectionally or prospectively. Mean follow-up was 7.6 years (range 0...
Full Text Available The treatment guideline draws on several international guidelines: (iPractice Guidelines of the American Psychiatric Association (APAfor the Treatment of Patients with Major Depressive Disorder, SecondEdition;(ii Clinical Guidelines for the Treatment of DepressiveDisorders by the Canadian Psychiatric Association and the CanadianNetwork for Mood and Anxiety Treatments (CANMAT;(iiiNational Institute for Clinical Excellence (NICE guidelines;(iv RoyalAustralian and New Zealand College of Psychiatrists Clinical PracticeGuidelines Team for Depression (RANZCAP;(v Texas MedicationAlgorithm Project (TMAP Guidelines;(vi World Federation ofSocieties of Biological Psychiatry (WFSBP Treatment Guideline forUnipolar Depressive Disorder;and (vii British Association forPsychopharmacology Guidelines.[7
Möller-Leimkühler, Anne Maria; Yücel, Mete
Scientific evidence for a male-typed depression ("male depression") is still limited, but mainly supports this concept with respect to single externalizing symptoms or symptom clusters. In particular, studies on non-clinical populations including males and females are lacking. The present study aims at assessing general well-being, the risk and the symptoms of male depression dependent on biological sex and gender-role orientation on instrumental (masculine) and expressive (feminine) personality traits in an unselected community sample of males and females. Students (518 males, 500 females) of the Ludwig-Maximilians-University of Munich, Germany, were asked to participate in a "stress study" and complete the following self-report questionnaires: the WHO-5 Well-being Index [Bech, P., 1998. Quality of Life in the Psychiatric Patient. Mosby-Wolfe, London], the Gotland Scale for Male Depression [Walinder, J., Rutz, W., 2001. Male depression and suicide. International Clinical Psychopharmacology 16 (suppl 2), 21-24] and the German Extended Personal Attribute Questionnaire [Runge, T.E., Frey, D., Gollwitzer, P.M., et al., 1981. Masculine (instrumental) and feminine (expressive) traits. A comparison between students in the United States and West Germany. Journal of Cross-Cultural Psychology 12, 142-162]. General well-being of the students was significantly lower compared to population norms. Contrary to expectations, female students had a greater risk of male depression than male students (28.9% vs. 22.4%; p<0.05). Overall, prototypic depressive symptoms as well as externalizing symptoms were more pronounced in females. In the subgroup of those at risk for male depression, biological sex and kind of symptoms were unrelated. Principal component analyses revealed a similar symptom structure for males and females. Low scores on masculinity/instrumentality significantly predicted higher risk of male depression, independent of biological sex. The study sample is not
Social media has recently emerged as a premier method to disseminate information online. Through these online networks, tens of millions of individuals communicate their thoughts, personal experiences, and social ideals. We therefore explore the potential of social media to predict, even prior to onset, Major Depressive Disorder (MDD) in online personas. We employ a crowdsourced method to compile a list of Twitter users who profess to being diagnosed with depression. Using up to a year of pri...
Van Assche, E; De Backer, J; Vermote, R
Music therapy is a predominantly non-verbal psychotherapy based on music improvisation, embedded in a therapeutic relationship. This is the reason why music therapy is also used to treat depression. To examine the efficacy of music therapy and to report on the results of recent research into the value of music therapy as a treatment for depression. We reviewed the literature on recent research into music therapy and depression, reporting on the methods used and the results achieved, and we assessed the current position of music therapy for depression in the context of evidence-based scientific research. A wide variety of research methods was used to investigate the effects of using music therapy as a psychotherapy. Most studies focused usually on the added value that music therapy brings to the standard form of psychiatric treatment, when administered with or without psychopharmacological support. Music therapy produced particularly significant and favourable results when used to treat patients with depression. Current research into music therapy and depression points to a significant and persistent reduction in patients' symptoms and to improvements in their quality of life. However, further research is needed with regard to the best methods of illustrating the effects of music therapy.
Long, Kathleen M.
Noting that adolescents who commit suicide are often clinically depressed, this paper examines various approaches in the treatment of depression. Major treatment models of adult depression, which can be directly applied to the treatment of the depressed adolescent, are described. Major treatment models and selected research studies are reviewed in…
Leonardo Yovany Álvarez Ramírez
Full Text Available The present study has the intention of establishing the identification that a group of depressed male subjects does with the narrative prototype of depression compared to a group of depressed female subjects. The sample was made of 65 depressive subjects and 65non depressive subjects for every group according to the genderwith ages between 16 and 40 years. The participants were derived from different centers of psychological attention of the city of Bucaramanga. An additional inclusion criterion was not applied except reading comprehension, which facilitates them the handling of the applied psychological instruments. The study followed a transverse correlational design. The procedure included the application ofthe SCID structured interview, the Hamilton test and the narrative prototype of depression of Gonçalves. The Ji squared statistic wasapplied to confirm the hypotheses of identification with the narrative prototype of depression in the depressive subjects and the opposite in those not depressed in every group according to the gender by means of a study of cases and controls. The findings demonstrate that the male and female group of depressed subjects, in comparison, identify with the narrative prototype of depression, while those not depressed don’t. It is concluded that both, depressed males and females of the study identify with the narrative prototype of depression unless in top grades in the second group.
Charpentier, M; Setchell, J M; Prugnolle, F; Knapp, L A; Wickings, E J; Peignot, P; Hossaert-McKey, M
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.
Anees, M.; Barki, H.; Masood, M.
To measure the frequency of depression and its risk factors in patients under going hemodialysis. It is a cross-sectional prospective study conducted at Hemodialysis unit of Shalamar Hospital and Shaikh Zayed Hospital, Lahore from 1/sup st/ January 2006 to 30/sup th/ April 2006. All patients getting regular hemodialysis for more than three months were included. Beck's Depression Inventory- II (BDI-II; adapted in Urdu) was administered on all the patients who were able to read or understand it. Blood sample were drawn at the same time for routine hematological, biochemical parameters and viral markers (Anti HCV and HbsAg). Diagnosis was made as per Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM IV) for correlation of psychological variables with clinical, hematological and biochemical parameters. Eighty nine patients were enrolled which included fifty two (58.4%) were male and seventy seven (86.5%) were married. Major causes of renal failure were diabetes, hypertension and chronic glomerulonephrotis. Duration of dialysis was from 03 to 49 months with mean of 19.64 +- 11.7 months. Severity of depression was categorized in to mild, moderate and severe on the basis of BDI score. Majority of the patients fifty (56.1%) were moderately to severely depressed and there was no gender difference in the prevalence of depression. Majority of patients undergoing hemodialysis were depressed. Major risk factors for depression were marital status, illiteracy, number of children, socioeconomic factors, gender, hypertension and hypoalbuminemia. Patients with anemia, hyponatremia and hyperkalemia had suicidal tendency. Patients with hepatitis C and disturbed liver function have strong correlation with psychological parameters. (author)
Kessing, L V
depression, dysthymia, and subsyndromal states; the association between stressful life events and depression appears to diminish with the number of depressive episodes. Finally, recent genetic findings are congruent with a model indicating that the majority of depressions develop in the interplay between...... genes and stressful experiences, whereas 'reactive' depressions and 'endogenous' depressions apparently exist at a lower prevalence. CONCLUSION: Further longitudinal, analytical, and genetic epidemiologic studies are needed to reveal which conditions are mild and transient, and which may be precursors......OBJECTIVE: There is a general clinical impression that depression differs qualitatively from non-depressive conditions, and that it can be identified as a categorical entity. In contrast, epidemiological studies support the view that depression is dynamic in nature and develops on a continuous...
Bouvet de la Maisonneuve, O
The indication for psychoanalysis in severe depression is not clear. And yet, demands for this type of intervention are increasing, despite the absence of any form of consensus on the subject. Freud considered depression as a failure of analytical efforts and, based on this observation, revised his theory, in particular to include the notions of narcissism and the death drive. Many analysts have been reluctant to follow his teachings on this last point and provide depressed patients with analytical-type therapies aimed at restoring narcissism. Melanie Klein pushed Freud's ideas about depression even further and brought such therapies back to the heart of analytical practice. Jacques Lacan took the debate to another level by proposing an overhaul of the principles on which analysis has been based. Today, while following certain precautionary rules, true psychoanalyses can be proposed to patients with severe depression, whether of the bipolar, recurring or even neurotic type that can reach this level of severity. Copyright 2009 L'Encéphale. Published by Elsevier Masson SAS.. All rights reserved.
Videbech, Poul Bror Hemming; Deleuran, Anette
AIM OF DATABASE: The purpose of the Danish Depression Database (DDD) is to monitor and facilitate the improvement of the quality of the treatment of depression in Denmark. Furthermore, the DDD has been designed to facilitate research. STUDY POPULATION: Inpatients as well as outpatients...... with depression, aged above 18 years, and treated in the public psychiatric hospital system were enrolled. MAIN VARIABLES: Variables include whether the patient has been thoroughly somatically examined and has been interviewed about the psychopathology by a specialist in psychiatry. The Hamilton score as well...... as an evaluation of the risk of suicide are measured before and after treatment. Whether psychiatric aftercare has been scheduled for inpatients and the rate of rehospitalization are also registered. DESCRIPTIVE DATA: The database was launched in 2011. Every year since then ~5,500 inpatients and 7,500 outpatients...
McKendree-Smith, N; Scogin, F
This study examined the theory of depressive realism, which posits that depressed people often are more accurate in perceptions and judgments than nondepressed people. Two possible qualifications to this theory were examined: (1) severity of depression moderates the effect, and (2) length of processing time will impact the presence of bias in depressed people, that is, negative bias will develop over time. College students were presented with a bogus personality profile that actually consisted of items previously rated as neutral in desirability. Participants rated these profiles for desirability initially and then again three days later. Results indicated a significant effect of depression severity on desirability rating. Nondepressed and mildly depressed students found their profiles to be more positive than the moderately/severely depressed students, with both groups having scores in the positive range. However, those participants who were moderately/severely depressed showed a negative bias in their ratings. No support was found for the effect of different times of interpretation.
Full Text Available Abstract Background Given that the prevalence of antenatal and postnatal depression is high, with estimates around 13%, and the consequences serious, efforts have been made to identify risk factors to assist in prevention, identification and treatment. Most risk factors associated with postnatal depression have been well researched, whereas predictors of antenatal depression have been less researched. Risk factors associated with early parenting stress have not been widely researched, despite the strong link with depression. The aim of this study was to further elucidate which of some previously identified risk factors are most predictive of three outcome measures: antenatal depression, postnatal depression and parenting stress and to examine the relationship between them. Methods Primipara and multiparae women were recruited antenatally from two major hoitals as part of the beyondblue National Postnatal Depression Program 1. In this subsidiary study, 367 women completed an additional large battery of validated questionnaires to identify risk factors in the antenatal period at 26–32 weeks gestation. A subsample of these women (N = 161 also completed questionnaires at 10–12 weeks postnatally. Depression level was measured by the Beck Depression Inventory (BDI. Results Regression analyses identified significant risk factors for the three outcome measures. (1. Significant predictors for antenatal depression: low self-esteem, antenatal anxiety, low social support, negative cognitive style, major life events, low income and history of abuse. (2. Significant predictors for postnatal depression: antenatal depression and a history of depression while also controlling for concurrent parenting stress, which was a significant variable. Antenatal depression was identified as a mediator between seven of the risk factors and postnatal depression. (3. Postnatal depression was the only significant predictor for parenting stress and also acted as a mediator
Leigh, Bronwyn; Milgrom, Jeannette
Given that the prevalence of antenatal and postnatal depression is high, with estimates around 13%, and the consequences serious, efforts have been made to identify risk factors to assist in prevention, identification and treatment. Most risk factors associated with postnatal depression have been well researched, whereas predictors of antenatal depression have been less researched. Risk factors associated with early parenting stress have not been widely researched, despite the strong link with depression. The aim of this study was to further elucidate which of some previously identified risk factors are most predictive of three outcome measures: antenatal depression, postnatal depression and parenting stress and to examine the relationship between them. Primipara and multiparae women were recruited antenatally from two major hoitals as part of the beyondblue National Postnatal Depression Program 1. In this subsidiary study, 367 women completed an additional large battery of validated questionnaires to identify risk factors in the antenatal period at 26-32 weeks gestation. A subsample of these women (N = 161) also completed questionnaires at 10-12 weeks postnatally. Depression level was measured by the Beck Depression Inventory (BDI). Regression analyses identified significant risk factors for the three outcome measures. (1). Significant predictors for antenatal depression: low self-esteem, antenatal anxiety, low social support, negative cognitive style, major life events, low income and history of abuse. (2). Significant predictors for postnatal depression: antenatal depression and a history of depression while also controlling for concurrent parenting stress, which was a significant variable. Antenatal depression was identified as a mediator between seven of the risk factors and postnatal depression. (3). Postnatal depression was the only significant predictor for parenting stress and also acted as a mediator for other risk factors. Risk factor profiles for
Smith, Caroline A; Armour, Mike; Lee, Myeong Soo; Wang, Li-Qiong; Hay, Phillipa J
Depression is recognised as a major public health problem that has a substantial impact on individuals and on society. People with depression may consider using complementary therapies such as acupuncture, and an increasing body of research has been undertaken to assess the effectiveness of acupuncture for treatment of individuals with depression. This is the second update of this review. To examine the effectiveness and adverse effects of acupuncture for treatment of individuals with depression.To determine:• Whether acupuncture is more effective than treatment as usual/no treatment/wait list control for treating and improving quality of life for individuals with depression.• Whether acupuncture is more effective than control acupuncture for treating and improving quality of life for individuals with depression.• Whether acupuncture is more effective than pharmacological therapies for treating and improving quality of life for individuals with depression.• Whether acupuncture plus pharmacological therapy is more effective than pharmacological therapy alone for treating and improving quality of life for individuals with depression.• Whether acupuncture is more effective than psychological therapies for treating and improving quality of life for individuals with depression.• Adverse effects of acupuncture compared with treatment as usual/no treatment/wait list control, control acupuncture, pharmacological therapies, and psychological therapies for treatment of individuals with depression. We searched the following databases to June 2016: Cochrane Common Mental Disorders Group Controlled Trials Register (CCMD-CTR), Korean Studies Information Service System (KISS), DBPIA (Korean article database website), Korea Institute of Science and Technology Information, Research Information Service System (RISS), Korea Med, Korean Medical Database (KM base), and Oriental Medicine Advanced Searching Integrated System (OASIS), as well as several Korean medical journals
Aalbers, Sonja; Fusar-Poli, Laura; Freeman, Ruth E; Spreen, Marinus; Ket, Johannes Cf; Vink, Annemiek C; Maratos, Anna; Crawford, Mike; Chen, Xi-Jing; Gold, Christian
Depression is a highly prevalent mood disorder that is characterised by persistent low mood, diminished interest, and loss of pleasure. Music therapy may be helpful in modulating moods and emotions. An update of the 2008 Cochrane review was needed to improve knowledge on effects of music therapy for depression. 1. To assess effects of music therapy for depression in people of any age compared with treatment as usual (TAU) and psychological, pharmacological, and/or other therapies.2. To compare effects of different forms of music therapy for people of any age with a diagnosis of depression. We searched the following databases: the Cochrane Common Mental Disorders Controlled Trials Register (CCMD-CTR; from inception to 6 May 2016); the Cochrane Central Register of Controlled Trials (CENTRAL; to 17 June 2016); Thomson Reuters/Web of Science (to 21 June 2016); Ebsco/PsycInfo, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase, and PubMed (to 5 July 2016); the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP), ClinicalTrials.gov, the National Guideline Clearing House, and OpenGrey (to 6 September 2016); and the Digital Access to Research Theses (DART)-Europe E-theses Portal, Open Access Theses and Dissertations, and ProQuest Dissertations and Theses Database (to 7 September 2016). We checked reference lists of retrieved articles and relevant systematic reviews and contacted trialists and subject experts for additional information when needed. We updated this search in August 2017 and placed potentially relevant studies in the "Awaiting classification" section; we will incorporate these into the next version of this review as appropriate. All randomised controlled trials (RCTs) and controlled clinical trials (CCTs) comparing music therapy versus treatment as usual (TAU), psychological therapies, pharmacological therapies, other therapies, or different forms of music therapy for reducing depression. Two review
Full Text Available ... Information Health Information Home Mental Health Information Statistics Consumer Health Publications Help for Mental Illnesses Clinical Trials ... Symptoms and Treatment of Depression February 1, 2010 People with depression discuss how they got help. & ...
Full Text Available ... Disorder (3 items) Depression (32 items) Eating Disorders (9 items) Panic Disorder (1 item) Post-Traumatic Stress ... Disorder (3 items) Depression (32 items) Eating Disorders (9 items) Panic Disorder (1 item) Post-Traumatic Stress ...
Full Text Available ... reason for me to do anything for myself. NARRATOR : Depression is more than just a feeling of ... at all. I gained a lot of weight. NARRATOR : A person with depression can feel irritable and ...
Full Text Available ... Hyperactivity Disorder (ADHD) (3 items) Autism (13 items) Bipolar Disorder (2 items) Borderline Personality Disorder (3 items) Depression ( ... Hyperactivity Disorder (ADHD) (3 items) Autism (13 items) Bipolar Disorder (2 items) Borderline Personality Disorder (3 items) Depression ( ...
Depression and Bipolar Support Alliance Crisis Hotline Information Coping with a Crisis Suicide Prevention Information Psychiatric Hospitalization ... sign-up Education info, training, events Mood Disorders Depression Bipolar Disorder Anxiety Screening Center Co-occurring Illnesses/ ...
Kraus, Mary Ann; Redman, E. Scott
Postpartum depression is conceptualized as a predictable developmental, family crisis, which occurs when the natural difficulties of childbirth are benignly mishandled. Tactics are illustrated for interdicting maladaptive interpersonal spirals, including normalizing conflicting complaints; reframing depression as positive but costly; regulating…
Full Text Available ... Autism (13 items) Bipolar Disorder (2 items) Borderline Personality Disorder (3 items) Depression (32 items) Eating Disorders (9 ... Autism (13 items) Bipolar Disorder (2 items) Borderline Personality Disorder (3 items) Depression (32 items) Eating Disorders (9 ...
Full Text Available ... Symptoms and Treatment of Depression February 1, 2010 People with depression discuss how they got help. & ... I felt like I was such an awful person that there was no real reason for me ...
Full Text Available ... suffer from depression trying to learn why it affects some people but not others. Treatments for depression do work. One type of effective psychotherapy is called cognitive ...
Full Text Available ... for depression do work. One type of effective psychotherapy is called cognitive behavioral therapy or CBT. CBT ... For many people, a combination of medication and psychotherapy may be the best choice. Depression can be ...
Full Text Available ... a serious illness that affects many people. Symptoms can vary, but many depressed people lose interest in ... lot of weight. NARRATOR : A person with depression can feel irritable and restless, and have sleep problems. ...
Full Text Available ... Autism (13 items) Bipolar Disorder (2 items) Borderline Personality Disorder (3 items) Depression (32 items) Eating Disorders ( ... Autism (13 items) Bipolar Disorder (2 items) Borderline Personality Disorder (3 items) Depression (32 items) Eating Disorders ( ...
Full Text Available ... items) Training (1 item) Other Treatments (15 items) Alzheimer’s Disease (2 items) Coping with Traumatic Events (3 items) Institute Announcements (24 items) Symptoms and Treatment of Depression February 1, 2010 People with depression discuss how ...
Joergensen, Terese Sara Hoej; Maartensson, Solvej; Ibfelt, Else Helene
PURPOSE: Depression is common following acute coronary syndrome, and thus, it is important to provide knowledge to improve prevention and detection of depression in this patient group. The objectives of this study were to examine: (1) whether indicators of stressors and coping resources were risk...... factors for developing depression early and later after an acute coronary syndrome and (2) whether prior depression modified these associations. METHODS: The study was a register-based cohort study, which includes 87,118 patients with a first time diagnosis of acute coronary syndrome during the period...... 2001-2009 in Denmark. Cox regression models were used to analyse hazard ratios (HRs) for depression. RESULTS: 1.5 and 9.5 % develop early (≤30 days) and later (31 days-2 years) depression after the acute coronary syndrome. Among all patients with depression, 69.2 % had first onset depression, while 30...
Full Text Available ... Borderline Personality Disorder (3 items) Depression (32 items) Eating Disorders (9 items) Panic Disorder (1 item) Post- ... Borderline Personality Disorder (3 items) Depression (32 items) Eating Disorders (9 items) Panic Disorder (1 item) Post- ...
Krieger, Tobias; Altenstein, David; Baettig, Isabelle; Doerig, Nadja; Holtforth, Martin Grosse
Self-compassion involves being kind to oneself when challenged with personal weaknesses or hardship and has been claimed to be associated with resilience in various areas. So far, there are only a handful of studies that investigate self-compassion and its relation to clinical depression. Therefore, the principal goals of the present study were (a) to compare self-compassion in clinically depressed patients and never-depressed subjects, (b) to investigate self-compassion and its relation to cognitive-behavioral avoidance and rumination in depressed outpatients, and (c) to investigate rumination and avoidance as mediators of the relationship between self-compassion and depressive symptoms. One hundred and forty-two depressed outpatients and 120 never-depressed individuals from a community sample completed a self-report measure of self-compassion along with other measures. Results indicate that depressed patients showed lower levels of self-compassion than never-depressed individuals, even when controlled for depressive symptoms. In depressed outpatients, self-compassion was negatively related to depressive symptoms, symptom-focused rumination, as well as cognitive and behavioral avoidance. Additionally, symptom-focused rumination and cognitive and behavioral avoidance mediated the relationship between self-compassion and depressive symptoms. These findings extend previous research on self-compassion, its relation to depression, as well as processes mediating this relationship, and highlight the importance of self-compassion in clinically depressed patients. Since depressed patients seem to have difficulties adopting a self-compassionate attitude, psychotherapists are well advised to explore and address how depressed patients treat themselves. Copyright © 2013. Published by Elsevier Ltd.
Most persons with emotional disorders are evaluated and treated by primary health ... the full clinical picture has emerged, and in most of their patients the .... Depression is common in attention deficit disorder where hyperactivity ... tncyclic antidepressants, SSRls ; selective serotonin re-uptake inhibitors; SNRls ; serotonin ...
Depression is one of the most prevalent and debilitating diseases. In recent years there has been increased awareness of sex- and gender-specific issues in depression. This narrative review presents and discusses differences in prevalence, symptom profile, age at onset and course, comorbidity, biological and psychosocial factors, the impact of sexual stereotyping, help-seeking, emotion regulation and doctor-patient communication. Typically, women are diagnosed with depression twice as often as men, and their disease follows a more chronic course. Comorbid anxiety is more prevalent in women, whereas comorbid alcohol abuse is a major concern in men. Sucide rates for men are between three and five times higher compared with women. Although there are different symptom profiles in men and women, it is difficult to define a gender-specific symptom profile. Socially mediated gender roles have a significant impact on psychosocial factors associated with risk, sickness behavior and coping strategies. In general, too little attention has been paid to the definition and handling of depression and the gender-related requirements it makes on the healthcare system.
Simon, Robin W.; Lively, Kathryn
A social problem that has preoccupied sociologists of gender and mental health is the higher rate of depression found among women. Although a number of hypotheses about this health disparity between men and women have been advanced, none consider the importance of subjectively experienced anger. Drawing on theoretical and empirical insights from…
Full Text Available Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL is a hereditary neurological disease accompanied by recurrent ischemic events, characterized by the presence of psychiatric disorders. The aim of this study was to examine the occurrence of depression and its severity among patients with CADASIL. Sixteen patients with diffuse white matter changes on MRI and clinical signs suggesting CADASIL were included in the study. Definitive diagnosis of CADASIL was obtained by electron microscopic analysis of skin biopsies. Testing of the patients’ affective status was primarily devoted to detecting depression. Electron microscopic examinations of all skin biopsies revealed numerous granular osmiophilic material (GOM deposits embedded into the basal lamina around altered or degenerated vascular smooth muscle cells (VSMCs. Clinical symptoms of depression were present in a great number of examined CADASIL patients. The frequency of depression was higher than previously reported. Psychiatric disturbances might also represent the onset of CADASIL, especially in young patients, and should be evaluated by differential diagnosis. [Projekat Ministarstva nauke Republike Srbije, br. 41002
Aalbers, Sonja; Fusar-Poli, Laura; Freeman, Ruth E.; Spreen, Marinus; Ket, Johannes C.F.; Vink, Annemiek C.; Maratos, Anna; Crawford, Mike; Chen, Xi Jing; Gold, Christian
Background: Depression is a highly prevalent mood disorder that is characterised by persistent low mood, diminished interest, and loss of pleasure. Music therapy may be helpful in modulating moods and emotions. An update of the 2008 Cochrane review was needed to improve knowledge on effects of music
Blanco, Fernando; Matute, Helena; Vadillo, Miguel A.
Depressive realism consists of the lower personal control over uncontrollable events perceived by depressed as compared to nondepressed individuals. In this article, we propose that the realism of depressed individuals is caused not by an increased accuracy in perception, but by their more comprehensive exposure to the actual environmental…
Murray, Lynne, Ed.; Cooper, Peter J., Ed.
Only recently has the research on postpartum depression dealt with the disorder's effects on child development. This book explores the impact of postpartum depression on mother-infant interaction and child development, its treatment, and postpartum psychosis. The chapters are: (1) "The Nature of Postpartum Depressive Disorders" (Michael…
Depression is defined as a "whole-body" illness, involving the body, mood, and thoughts. Three of the most prevalent types of depressive disorders are described: major depression, dysthymia, and bipolar disorders (formerly called manic-depressive illness). Eleven symptoms of depression and 10 symptoms of mania are listed. Causes of depression are…
Atkins, David C.; Dimidjian, Sona; Bedics, Jamie D.; Christensen, Andrew
The association between depression and relationship distress as well as the impact of treatment for the one on the other was examined across 2 treatment-seeking samples: individuals seeking treatment for depression (N = 120) and couples seeking marital therapy (N = 134 couples). Although there was a baseline association between depression and…
Alexander S. Bobrov
Full Text Available Based on the current study, the clinical characteristics of unipolar depression in the clinical picture of schizophrenia with the paroxysmal type of disease course are presented. Given the concomitant depression with phobic symptoms, the following clinical variants are marked: depression with generalized social phobia and/or anthropophobia and depression with generalized pathological body sensations and hypochondriacal phobias. In other words, we are talking about a necessity to allocate a special type of schizophrenia with affective structure episodes and comorbid neurosis-like symptoms. Information on the basic treatment strategy of schizophrenia with depressive structure episodes and comorbid neurosis-like symptoms in everyday psychiatric practice is also provided.
Hobzova, Milada; Prasko, Jan; Vanek, Jakub; Ociskova, Marie; Genzor, Samuel; Holubova, Michaela; Grambal, Ales; Latalova, Klara
Obstructive sleep apnea (OSA), is described as intermittent interruptions or reductions in airflow which are initiated by an incomplete or complete collapse of the upper airways despite respiratory effort. When left untreated, OSA is connected with comorbid conditions, such as cardiovascular and metabolic illnesses. The PubMed database was used to examine papers published until April 2017 using the subsequent terms: "obstructive sleep apnea" or "obstructive sleep apnoea" and "depression" in successive combination with "CPAP (continuous positive airway pressure)", "therapy", "pharmacotherapy", "psychotherapy", "cognitive behavioral therapy" or "quality of life". After assessment for the suitability, 126 articles were chosen. The numerous evidence of a connection between OSA and depressive symptoms, as well as depressive disorder, were found. This connection may be directly or indirectly linked due to the participation of some OSA mediators consequences such as obesity, hypertension, and the decreased quality of life. Patients with the comorbid major depression and OSA reported more severe and longer episodes of depression. Nevertheless, the information on the effect of the treatment of OSA using CPAP on the depressive symptoms was limited. Still, the current state of the art suggests that this treatment decreases the severity of the comorbid depressive symptoms. It is important to evaluate the symptoms of depression in the patients with OSA. On the other side, a psychiatrist should not just treat the depression, as it is also important to screen individuals at high risk of OSA when assessing patients for depressive disorder, especially those with depression resistant to treatment.
Full Text Available Introduction: Depression is one of the Common psychological disorders. From the cognitive point of view, the unhealthy attitudes increase the severity of the depression. The aim of this study was to investigate depression and unhealthy attitudes in coronary patients hospitalized at Tabriz Shahid Madani Heart Center. Methods: One hundred twenty eight hospitalized patients having myocardial Infarctions were studied regarding unhealthy attitudes, severity of depression and demographic data. Results: The study showed a significant relation between unhealthy attitudes, BDI (Beck Depression Inventory and severe depression. Moreover, a significant relation existed between gender and depression (P=0.0001. In addition, the level of education increased the intensity of unhealthy attitudes (P=0.0001. Several researches in both outside and inside Iran support the idea. Conclusion: Based on present study and more other investigations, it can be suggested to provide the necessary elements and parameters such as antidepressant medication, psychologists, complementary treatment for coping with negative mood and its unwanted consequences.
Gade, Anders; Kristoffersen, Marius; Kessing, Lars Vedel
not been consistent. METHOD: We examined neuroticism, extraversion and perceived stress in 88 fully remitted depressed patients with a mean age of 60 years and with a history of hospitalization for major depressive disorder. Patients were divided into those with onset after and those with onset before 50......BACKGROUND: The personality trait of neuroticism is strongly related to depression, but depression is etiologically heterogeneous. Late-onset depression (LOD) may be more closely related to vascular factors, and previous studies of neuroticism in LOD versus early-onset depression (EOD) have...... age of onset and neuroticism was confirmed in analyses based on age of depression onset as a continuous variable. CONCLUSION: Neuroticism may be an etiological factor in EOD but not or less so in LOD. This finding contributes to the growing evidence for etiological differences between early- and late...
Wollersheim, J P
Depression is a highly prevalent disorder that causes much personal distress and difficulties in functioning at home and in the workplace. In the workplace, as elsewhere, depression can manifest as a variation in normal mood, as a symptom, as a disorder, or as a disease. Occupational health professionals are more concerned with clinical depression, a term used to signify any type of depression that causes significant personal distress and/or problems in functioning. Clinical depression is manifest in the workplace and adversely affects the employee's work satisfaction and performance. For most types of depression, women are at a higher risk than men. A number of events and variables related to women and depression were reviewed. Although the effects of some of these events, such as menopause, can be manifest in the workplace, they are not associated with an increased incidence of clinical depression. Other events, such as victimization (e.g., childhood sexual abuse or battering by an intimate partner), are associated with higher risks of depression in women. Women derive substantial satisfaction from interpersonal relationships but also are at greater risk for depression when strains and conflicts in these relationships occur. In the workplace women who have no difficulty in arranging for child care and whose spouses share in the care of children show lower rates of depression. When marriages are unhappy, women are three times as likely as men to be depressed. These findings speak to the importance of relationships to women. In the workplace, when women are depressed, problems with relationships are likely to be involved. Clinically depressed women are not difficult to identify in work settings. Dejected mood and loss of interest in usual activities are noticeable, along with numerous other symptoms that accompany depression. The effective treatment of depression depends on careful diagnosis and assessment. Both drug therapy and the more structured psychotherapies
Carroll, Linda J.; Cassidy, J. David; Côté, Pierre
Depression is common in whiplash-associated disorders (WAD). Our objectives were to identify factors associated with depressive symptomatology occurring in the initial stages of WAD, and to identify factors predicting the course of depressive symptoms. A population-based cohort of adults sustaining traffic-related WAD was followed at 6 weeks, 3, 6, 9, and 12 months. Baseline measures (assessed a median of 11 days post-crash) included demographic and collision-related factors, prior health, and initial post-crash pain and symptoms. Depressive symptomatology was assessed at baseline and at each follow-up using the Centre for Epidemiological Studies Depression Scale (CES-D). We included only those who participated at all follow-ups (n = 3,452; 59% of eligible participants). Using logistic regression, we identified factors associated with initial (post-crash) depression. Using multinomial regression, we identified baseline factors predicting course of depression. Courses of depression were no depression; initial depression that resolves, recurs or persists, and later onset depression. Factors associated with initial depression included greater neck and low back pain severity, greater percentage of body in pain, numbness/tingling in arms/hand, dizziness, vision problems, post-crash anxiety, fracture, prior mental health problems, and poorer general health. Predictors of persistent depression included older age, greater initial neck and low back pain, post-crash dizziness, vision and hearing problems, numbness/tingling in arms/hands, anxiety, prior mental health problems, and poorer general health. Recognition of these underlying risk factors may assist health care providers to predict the course of psychological reactions and to provide effective interventions. PMID:20127261
Charles, Julian; Fazeli, Mandana
Major depressive disorder (MDD) in children (5-12 years of age) is a confronting and serious psychiatric illness. MDD has significant ramifications for the psychosocial development of the child, yet it remains under-recognised and undertreated. General practice is where these children and their parents will first present. The aim of this article is to provide general practitioners (GPs) with a framework for considering MDD in a child and recommendations for treatment. Children with MDD have the same core features as adolescents and adults, taking into account the child's capacities for cognition and language, and developmental stage. Earlier onset of illness is associated with poorer outcomes and greater psychiatric morbidity persisting into adulthood. MDD is more common than anticipated, and should be considered for any child presenting with depressive symptoms and/or impaired psychosocial functioning. Despite limited evidence, numerous interventions exist that will, ideally, significantly affect the child's developmental trajectory. GPs are in an important position to initiate these interventions.
Kessing, Lars Vedel; Hansen, Hanne Vibe; Demyttenaere, Koen
of the patients (40-80%) had erroneous views as to the effect of antidepressants. Older patients (over 40 years of age) consistently had a more negative view of the doctor-patient relationship, more erroneous ideas concerning the effect of antidepressants and a more negative view of antidepressants in general....... Moreover, their partners agreed on these negative views. Women had a more negative view of the doctor-patient relationship than men, and patients with a depressive disorder had a more negative view of antidepressants than patients with bipolar disorder. The number of psychiatric hospitalizations......BACKGROUND: There is increasing evidence that attitudes and beliefs are important in predicting adherence to treatment and medication in depressive and bipolar disorders. However, these attitudes have received little study in patients whose disorders were sufficiently severe to require...
Kessler, Ronald C.
Data are reviewed on the societal costs of major depressive disorder (MDD). Early-onset MDD is found to predict difficulties in subsequent role transitions, including low educational attainment, high risk of teen child-bearing, marital disruption, and unstable employment. Among people with specific social and productive roles, MDD is found to predict significant decrements in role functioning (e.g., low marital quality, low work performance, low earnings). MDD is also associated with elevated...
Maller, Jerome J; Thomson, Richard H S; Rosenfeld, Jeffrey V; Anderson, Rodney; Daskalakis, Zafiris J; Fitzgerald, Paul B
There are reports of differences in occipital lobe asymmetry within psychiatric populations when compared with healthy control subjects. Anecdotal evidence and enlarged lateral ventricles suggests that there may also be a different pattern of curvature whereby one occipital lobe wraps around the other, termed 'occipital bending'. We investigated the prevalence of occipital bending in 51 patients with major depressive disorder (males mean age = 41.96 ± 14.00 years, females mean age = 40.71 ± 12.41 years) and 48 age- and sex-matched healthy control subjects (males mean age = 40.29 ± 10.23 years, females mean age = 42.47 ± 14.25 years) and found the prevalence to be three times higher among patients with major depressive disorder (18/51, 35.3%) when compared with control subjects (6/48, 12.5%). The results suggest that occipital bending is more common among patients with major depressive disorder than healthy subjects, and that occipital asymmetry and occipital bending are separate phenomena. Incomplete neural pruning may lead to the cranial space available for brain growth being restricted, or ventricular enlargement may exacerbate the natural occipital curvature patterns, subsequently causing the brain to become squashed and forced to 'wrap' around the other occipital lobe. Although the clinical implications of these results are unclear, they provide an impetus for further research into the relevance of occipital bending in major depression disorder. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: email@example.com.
Recently, according to the increase in physical and psychological fatigue due to overwork and/or emotional labor, burnout has been received broad attention and widely infiltrated the popular culture. Despite an extended concept of burnout, however, the distinction between burnout and depression remains inconclusive. Furthermore, in spite of a rapid increase in research dedicated physical and biological aspects in addition to symptomatic and psychosocial ones of burnout, a clear difference bet...
A different approach for using genomic information in genetic improvement is proposed. Past research in population genetics and animal breeding combined with information on sequence variants suggest the possibility that selection might be able to capture a portion of inbreeding and heterosis effect...
Full Text Available It is not enough to consider treatment and care depression in the oncology that is the most common psychiatric illness in cancer patient affects of cancer treatment and the patient`s quality of life negatively, which is determined through researches in the field. With development of psycho-oncology it has been demonstrated to establish an important link between the cancer patient`s treatment as well as psycho-social support for the patient and psychiatric treatment and care for the if it is needed. With this connection between them it has been proposed to use of bio-psycho-social-model in cancer patient to improve their care. To achieve this goal, it is expected from medical personnel to realize patients psychosocial need und if he/she has a psychiatric disorders or syndromes. For the medical personnel that work in oncology services, it is inevitable to organize in order to raise the awareness of depression in the cancer patients. In the present study, it is focused on raising the awareness of depression in cancer patient for the medical personnel. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2014; 6(2.000: 186-198
Background It is not clear whether the severity of depressive episodes changes during the course of depressive disorder. Aims To investigate whether the severity of depressive episodes increases during the course of illness. Method Using a Danish nationwide case register, all psychiatric inpatients...... and out-patients with a main ICD-10 diagnosis of a single mild, moderate or severe depressive episode at the end of first contact were identified. Patients included in the study were from the period 1994-2003. Results A total of 19 392 patients received a diagnosis of a single depressive episode at first...... contact. The prevalence of severe depressive episodes increased from 25.5% at the first episode to 50.0% at the 15th episode and the prevalence of psychotic episodes increased from 8.7% at the first episode to 25.0% at the 15th episode. The same pattern was found regardless of gender, age at first contact...
Kessing, Lars Vedel
BACKGROUND: It is not clear whether the severity of depressive episodes changes during the course of depressive disorder. AIMS: To investigate whether the severity of depressive episodes increases during the course of illness. METHOD: Using a Danish nationwide case register, all psychiatric in......-patients and out-patients with a main ICD-10 diagnosis of a single mild, moderate or severe depressive episode at the end of first contact were identified. Patients included in the study were from the period 1994-2003. RESULTS: A total of 19 392 patients received a diagnosis of a single depressive episode at first...... contact. The prevalence of severe depressive episodes increased from 25.5% at the first episode to 50.0% at the 15th episode and the prevalence of psychotic episodes increased from 8.7% at the first episode to 25.0% at the 15th episode. The same pattern was found regardless of gender, age at first contact...
Frantzen, Mikkel Krause; Bjering, Jens Christian Borrebye
The article sets out by investigating how depression is represented in Lars von Trier´s disaster movie Melancholia with the specific intent to detach mental illness from classic, somewhat romantic notions of metaphoric and epistemological connections between psychopathology and deeper “truths......” about the world. Employing what one could call a symptomatological view on the depression of the main protagonist Justine, the article concludes that her depression should be seen as a temporal disorder in the sense that she lacks the ability to project and plan a future. From here, the article turns...... to Eve Kosofsky Sedgwick´s concept of a “reparative praxis” as a possible ethico-practical way out of the depressive situation, arguing that such a reparative praxis is exactly what ends up pulling Justine out of her depression and enabling her to act. In a concluding step, the article relates depression...
Wesselhöft, Rikke Thaarup
Major depressive disorder (MDD) is a frequent and painful mental disorder considered among the five leading causes of disability in Western countries by the World Health Organization. MDD occurs at all ages, but childhood onset MDD has a more severe course with longer depressive episodes, more suicidality, and more frequent hospitalization, than later onset MDD. Childhood seems to be a window of opportunity for prevention of mental disorders, and subsequently prevention of MDD onset in childhood is recommended. Feasible prevention targets either individuals who present early signs of a given disorder but have not reached diagnostic threshold (indicated prevention) or individuals who are at increased risk for a disorder due to risk factor exposure (selective prevention). Indicated prevention is rational also for depressive disorders, because subthreshold depression (SD) in adults is found to be a precursor to MDD. The purpose of this thesis was to provide information necessary for the prevention of MDD onset in childhood. First, we examined whether the literature supports that SD is a MDD precursor also in children (systematic review). Second, we explored the risk that gender might constitute for pre-pubertal and post-pubertal onset MDD (register study). Third, we estimated the prevalence of SD and MDD in a large-scale pre-pubertal sample, and compared the clinical features of SD and MDD and potential risk factors (population-based study). The systematic review of the literature showed that SD in children and adolescents presents analogous comorbidity and symptom patterns (including self-harm symptoms). It also supports that SD is a precursor to MDD in children and adolescents causing poor outcomes like psychopathology, functional impairment and high use of health service. In the register study of Danish children and adolescents, we found a higher incidence of clinical MDD for girls after puberty compared to boys. Before puberty however, we demonstrated that boys
Blanco, Fernando; Matute, Helena; Vadillo, Miguel A.
Depressive realism consists of the lower personal control over uncontrollable events perceived by depressed as compared to nondepressed individuals. In this article, we propose that the realism of depressed individuals is caused not by an increased accuracy in perception, but by their more comprehensive exposure to the actual environmental contingencies, which in turn is due to their more passive pattern of responding. To test this hypothesis, dysphoric and nondysphoric participants were e...
Full Text Available Nádia Nara Rolim Lima,1 Vânia Barbosa do Nascimento,1 Sionara Melo Figueiredo de Carvalho,1 Luiz Carlos de Abreu,1,3 Modesto Leite Rolim Neto,2 Aline Quental Brasil,2 Francisco Telésforo Celestino Junior,2 Gislene Farias de Oliveira,2 Alberto Olavo Advíncula Reis3 1Programa de Pós-graduação em Ciências da Saúde, Faculdade de Medicina do ABC, Santo André, São Paulo, Brazil; 2Departamento de Medicina. Universidade Federal do Ceará, UFC, Barbalha, Ceará, Brazil; 3Departamento de Saúde Materno Infantil, Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo, Brazil Abstract: As an important public health issue, childhood depression deserves special attention, considering the serious and lasting consequences of the disease to child development. Taking this into consideration, the present study was based on the following question: what practical contributions to clinicians and researchers does the current literature on childhood depression have to offer? The objective of the present study was to conduct a systematic review of articles regarding childhood depression. To accomplish this purpose, a systematic review of articles on childhood depression, published from January 1, 2010 to November 24, 2012, on MEDLINE and SciELO databases was carried out. Search terms were “depression” (medical subject headings [MeSH], “child” (MeSH, and "childhood depression" (keyword. Of the 180 retrieved studies, 25 met the eligibility criteria. Retrieved studies covered a wide range of aspects regarding childhood depression, such as diagnosis, treatment, prevention and prognosis. Recent scientific literature regarding childhood depression converge to, directly or indirectly, highlight the negative impacts of depressive disorders to the children's quality of life. Unfortunately, the retrieved studies show that childhood depression commonly grows in a background of vulnerability and poverty, where individual and familiar needs
Full Text Available Jean-Pierre Lépine1, Mike Briley21Hôpital Lariboisière Fernand Widal, Assistance Publique Hôpitaux de Paris Unité INSERM 705 CNRS UMR 8206, Université Paris Diderot, Paris, France; 2NeuroBiz Consulting and Communication, Castres, FranceAbstract: Recent epidemiological surveys conducted in general populations have found that the lifetime prevalence of depression is in the range of 10% to 15%. Mood disorders, as defined by the World Mental Health and the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, have a 12-month prevalence which varies from 3% in Japan to over 9% in the US. A recent American survey found the prevalence of current depression to be 9% and the rate of current major depression to be 3.4%. All studies of depressive disorders have stressed the importance of the mortality and morbidity associated with depression. The mortality risk for suicide in depressed patients is more than 20-fold greater than in the general population. Recent studies have also shown the importance of depression as a risk factor for cardiovascular death. The risk of cardiac mortality after an initial myocardial infarction is greater in patients with depression and related to the severity of the depressive episode. Greater severity of depressive symptoms has been found to be associated with significantly higher risk of all-cause mortality including cardiovascular death and stroke. In addition to mortality, functional impairment and disability associated with depression have been consistently reported. Depression increases the risk of decreased workplace productivity and absenteeism resulting in lowered income or unemployment. Absenteeism and presenteeism (being physically present at work but functioning suboptimally have been estimated to result in a loss of $36.6 billion per year in the US. Worldwide projections by the World Health Organization for the year 2030 identify unipolar major depression as the leading cause of disease burden
Spence, S A; Taylor, D G; Hirsch, S R
Secondary causes of depression are legion, and must always be considered in patients presenting with features atypical of primary idiopathic depressive disorder. The case described is that of a middle-aged woman presenting initially with a major depressive disorder who was subsequently found to have a craniopharyngioma, leading to a revised diagnosis of mood disorder due to the tumour. Some features of the presentation might have led to earlier diagnosis had their localizing significance been recognized. Diencephalic lesions should always be considered in patients presenting with the hypersomnic-hyperphagic variant of depressive disorder. Images Figure 1 PMID:8544149
Full Text Available In this study we review recent research literature focused on relationship between unemployment and depression, and theories emphasizing the mechanisms by which unemployment may contribute to increased levels of depression. Our research investigated depressive symptomatology and its predictors among unemployed people (N = 453 varying in length of unemployment. Results showed that self - mastery, self - esteem, financial strain, gender, intensity of job - seek behavior and length on unemployment were significant predictors of depressive symptoms. Results are discussed in light of current theories of unemployment and mental health and recommendations are made for practice.
Full Text Available This mixed-methods study aimed to explore the initial process of engagement with an online support group (OSG for depression. Fifteen British National Health Service patients experiencing depression who had not previously used an OSG for depression were offered facilitated access to an existing peer-to-peer OSG for 10 weeks. Pre- and post-measures of depression, social support, and self-stigma were taken in addition to a weekly measure of OSG usage. A follow-up qualitative interview was conducted with a subsample of nine participants. Depression and self-stigma reduced over the 10-week period, but perceived social support did not change. There was no evidence of adverse outcomes. Perceived benefits of OSG participation included connection to others, normalization of depression, and stigma reduction. However, engagement with the OSG was generally low. Barriers included concerns over causing harm to others or being harmed oneself, feeling different from others in the group, and fears of being judged by others. OSGs may potentially reduce depressive symptoms and perceived self-stigma. However, considerable barriers may hinder people with depression from engaging with OSGs. Further work is needed to determine who will benefit most from participating in OSGs for depression and how best to facilitate engagement.
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Wurtman, Richard J
A relationship between genetic makeup and susceptibility to major depressive disorder (MDD) has long been suspected on the basis of family and twin studies. A metaanalysis of reports on the basis of twin studies has estimated MDD's degree of heritability to be 0.33 (confidence interval, 0.26-0.39). Among families exhibiting an increased prevalence of MDD, risk of developing the illness was enhanced in members exposed to a highly stressful environment. Aberrant genes can predispose to depression in a number of ways, for example, by diminishing production of growth factors that act during brain development. An aberrant gene could also increase or decrease a neurotransmitter's release into synapses, its actions, or its duration of activity. The gene products of greatest interest at present are those involved in the synthesis and actions of serotonin; among them, the serotonin-uptake protein localized within the terminals and dendrites of serotonin-releasing neurons. It has been found that the Vmax of platelet serotonin uptake is low in some patients with MDD; also, Vmax is highly correlated in twins. Antidepressant drugs such as the selective serotonin reuptake inhibitors act on this uptake protein. The specific genetic locus causing serotonin uptake to be lower in some patients with major depression involves a polymorphic region (5-HTTLPR) in the promoter region of the gene for the uptake protein. The gene itself exists as several alleles, the short "S" allele and the long "L" allele. The S variant is associated with less, and the L variant with more, of the uptake protein. The effect of stressful life events on depressive symptoms in young adults was found to be significantly stronger among SS or SL subjects than among LL subjects. Neuroimaging studies showed that people with the SS or SL alleles exhibited a greater activation of the amygdala in response to fearful stimuli than those with LL. It has been reported recently that mutations in the gene that controls
Sowa, Claudia J.; Lustman, Patrick J.
Administered the Life Stress Questionnaire, the Beck Depression Inventory, and the Automatic Thought Questionnaire to 140 students. Results showed significant sex differences. Men reported more stressful life change, but women rated the impact of stressors more severely and had higher depression. Men exhibited greater distortions in cognitive…
Koopman, Margreet; El Aidy, Sahar; Daniels, Judith
Purpose of reviewAccording to the WHO reports, around 350 million people worldwide suffer from depression. Despite its high prevalence, the complex interaction of multiple mechanisms underlying depression still needs to be elucidated.Recent findingsOver the course of the last few years, several
de Winter, Remco F. P.; Zwinderman, Koos H.; Goekoop, Jaap G.
Anxious-retarded depression is a two-dimensionally defined subcategory of depression based on high scores for both anxiety and retardation. The anxious-retarded subcategory is related to melancholia as defined by DSM-IV. Patients with this diagnosis exhibit elevated plasma arginine vasopressin (AVP)
Full Text Available Narcolepsy main symptoms include excessive daytime sleepiness and cataplexy. Its chronic course is accompanied by psychosocial impairment added to the difficulties and side effects of stimulants and tricyclics long term use. Depressive complaints are occasionally reported. The aim of this paper was to evaluate objectively the possibility of depression in a sample of 12 narcoleptics (7F;5 M, with mean age of 53 years (12 years SD, using the Beck Depression Inventory (BDI and the Hamilton Rating Scale for Depression (HAM-D. The results showed absence of depressive disorder in 75.0% of the cases according to BDI (or 58.3% according to HAM-D. The remaining patients had mild depression (only one patient presented major depression. The findings showed no correlation between narcolepsy and major depression.Narcolepsia é um distúrbio do sono caracterizado por sonolência diurna excessiva e ataques de cataplexia. Sendo crônico, traz uma série de dificuldades psicossociais às quais se aliam aquelas geradas pelos efeitos colaterais dos estimulantes e tricíclicos utilizados. Queixas depressivas são encontradas ocasionalmente. Esta pesquisa buscou verificar objetivamente a ocorrência de depressão em narcolépticos. Foi avaliado um grupo de 12 pacientes narcolépticos (7F; 5M com média de idade de 53 anos (DP 12 usando-se como instrumentos o Inventário de Beck para Depressão (BDI e a Escala Hamilton de Depressão (HAM-D. Os resultados demonstraram ausência de distúrbio depressivo em 75.0% dos pacientes avaliados pelo BDI e em 58.3% pela HAM-D. Os demais escores evidenciaram depressão leve ou disforia; depressão maior foi encontrada em apenas um caso. Tais achados não sugerem correlação entre narcolepsia e depressão.
Medeiros, Gustavo C; Seger, Liliana; Grant, Jon E; Tavares, Hermano
It is estimated that between 1.7 and 2.6 million people have had intermittent explosive disorder (IED) during their life in the United States alone. Co-occurring psychiatric disorders are very common in IED, being major depressive disorder arguably the most common. The objective of this study was to examine the clinical correlates of IED and depressive manifestations in 74 treatment-seeking subjects. After controlling for confounders, there were associations between major depressive disorder and severity of depressive symptoms, and (a) higher assault scores, (b) more severe hostile behavior and (c) worse social adjustment. Management of depressive symptoms may be an important for IED treatment. Copyright © 2018 Elsevier B.V. All rights reserved.
Fernanda Cristina Breda
Full Text Available Objetivou-se, com este trabalho, avaliar o comportamento do coeficiente de endogamia e do limite de seleção considerando população-base selecionada. Utilizou-se o programa GENESYS para a simulação do genoma constituído de uma única característica quantitativa com valor de herdabilidade igual a 0,40, população-base, população inicial e populações sob seleção. Foram consideradas três gerações distintas como gerações bases, gerações zero (G0PB, três (G3PB e sete (G7PB. As populações foram selecionadas a partir dos valores genéticos obtidos pelo melhor preditor linear não-viesado (BLUP e com base no desempenho individual, sendo considerados: a dois tamanhos efetivos de população (Ne1 = 38,09 e Ne2 = 88,88 e b dois sistemas de acasalamentos dos reprodutores selecionados (reprodutores acasalados aleatoriamente - RAA e exclusão de irmãos completos - EIC. Os parâmetros avaliados foram: coeficiente médio de endogamia, percentagem de locos fixados favoravelmente e limite de seleção. A não-utilização da população-base verdadeira (G0PB subestimou os coeficientes de endogamia. As populações que utilizaram as gerações três e sete como base apresentaram as mesmas taxas de fixação de alelos favoráveis e os mesmos valores do limite de seleção das populações que consideraram a G0PB.Objective was to evaluate the behavior average inbreeding coefficient associated to the selection limit considering selected population as base population. GENESYS program was used for simulation of the genome (one trait of h² = 0.40, base population, initial population and populations under selection. Three different generations were considered as base generations, zero (G0PB, three (G3PB and seven (G7PB. Populations were selected based on best linear unbiased predictor (BLUP and on individual phenotype in which were considered: a two effective population sizes (Ne1 = 38.09 and Ne2 = 88.88 and b two mating systems (random mating
Full Text Available There is a lack of research in health psychology on the subjective experience of adolescents with mental health disorders. The aim of this study was to explore the experience of depression and the journey into therapy of young people (YP diagnosed with depression. Semi-structured interviews were carried out with six YP (5 female, aged 15–19. Interviews were analyzed using Interpretative Phenomenological Analysis. The following four key themes were identified: “Suffering is experienced as overwhelming,” “An experience of loneliness and isolation,” “Struggling to understand the suffering,” and “Therapy as a last resort.” Reasons for a delay in accessing treatment were not knowing what is “normal,” the feeling that they have to deal with it by themselves, and/or the lack of a caring adult who supports the YP in getting help. The findings suggest the ongoing importance of reducing stigma and promoting mental health education for YP as well as parents, school staff, and health professionals.
Full Text Available Our laboratory reported that male mice with cardiomyocyte-selective knockout of the prostaglandin E2 EP4 receptor sub-type (EP4 KO exhibit reduced cardiac function. Gene array on left ventricles (LV showed increased fractalkine, a chemokine implicated in heart failure. We therefore hypothesized that fractalkine is regulated by PGE2 and contributes to depressed contractility via alterations in intracellular calcium.Fractalkine was measured in LV of 28-32 week old male EP4 KO and wild type controls (WT by ELISA and the effect of PGE2 on fractalkine secretion was measured in cultured neonatal cardiomyocytes and fibroblasts. The effect of fractalkine on contractility and intracellular calcium was determined in Fura-2 AM-loaded, electrical field-paced cardiomyocytes. Cardiomyocytes (AVM from male C57Bl/6 mice were treated with fractalkine and responses measured under basal conditions and after isoproterenol (Iso stimulation.LV fractalkine was increased in EP4 KO mice but surprisingly, PGE2 regulated fractalkine secretion only in fibroblasts. Fractalkine treatment of AVM decreased both the speed of contraction and relaxation under basal conditions and after Iso stimulation. Despite reducing contractility after Iso stimulation, fractalkine increased the Ca(2+ transient amplitude but decreased phosphorylation of cardiac troponin I, suggesting direct effects on the contractile machinery.Fractalkine depresses myocyte contractility by mechanisms downstream of intracellular calcium.
Pfost, Karen S.; And Others
Notes that women are particularly vulnerable to depression during the postpartum period. Distinguishes postpartum depression from normal postpartum adjustment, postpartum blues, and postpartum psychosis. Describes biological, psychodynamic, and diathesis-stress perspectives on postpartum depression. Encourages counselors to fashion individualized…
Counselling students with depressive tendencies for better educational and ... score of 20 and above on Beck Depression Inventory and still functioning in a normal ... such as no age barrier for depression, stress and hassles of life emanating ...
... For Consumers Consumer Information by Audience For Women Depression--Medicines To Help You Share Tweet Linkedin Pin ... medicines for depression. Important Warnings about Medicines for Depression Children and teens who take antidepressants may be ...
Alzheimer's or depression: Could it be both? Alzheimer's and depression have some similar symptoms. Proper treatment improves quality of life. By Mayo Clinic Staff Early Alzheimer's disease and depression share many ...
Full Text Available ... Borderline Personality Disorder (3 items) Depression (32 items) Eating Disorders (9 items) Panic Disorder (1 item) Post-Traumatic ... Borderline Personality Disorder (3 items) Depression (32 items) Eating Disorders (9 items) Panic Disorder (1 item) Post-Traumatic ...
Hale, WWH; Jansen, JHC; Bouhuys, AL; vandenHoofdakker, RH
Within the framework of interactional theories on depression, the question is raised whether depression relapse can be predicted by observable behavior of remitted patients and their interviewer during an interaction (i.e. discharge interview). Thirty-four patients were interviewed at hospital
Full Text Available Manual of Mental Disorders (DSM-IV, postpartum depression may include any nonpsychotic depressive disorder during the first four weeks of postpartum, according to research criteria during the first year after birth. The exact cause of postpartum depression is not yet known, and most researchers believe that postpartum depression is a bio-psycho-social problem. So far, the biological aspect of the disease is explained by changing the levels of estrogen and progesterone during pregnancy, and by decrease of hormone levels after birth. Psychological correlates are often associated with low selfesteem, pessimism as a personality trait, bad strategies of coping with stress, mood swings and emotional reactions. The social aspect of the disease is associated with the existential conditions of pregnant woman, support of partners and education level. This paper will include issues like hereditary causes and possible psychological factors of postpartum depression prevention. Nowadays, it is estimated that on average 15% of women, regardless of the pregnancy outcome, are suffering from postpartum depression. However, this information includes only those women who were diagnosed with postpartum depression and who themselves reported about it. Almost every woman receives basic care during pregnancy to prevent complications in the physiological level. This paper has shown possible psychological factors of postpartum depression prevention, the impact of optimism, self-esteem and coping skills.
Żuchowicz, Paulina; Jasionowska, Justyna; Gałecki, Piotr; Talarowska, Monika
Contemporary research studies regarding autobiographical memory (AM) indicate that its deficits have a significant impact on the development of mental disorders. We find particularly many reports regarding the comorbidity of AM deficits and depressive disorders. The characteristic feature of AM in the people suffering from depressive disorders is the presence of overgeneral autobiographical memory (OGM), i.e. the reminiscences which contain a summary of many emotion-laden situations, yet without significant detail. This type of reminiscences is observed in the patients with depressive disorders and the ones susceptible to the disease but not experiencing presently an episode of depression, as well as the ones being in the phase of disease remission. In recent years, the interest in the significance of negative thinking processes, such as ruminations, as risk factors in the development of depression has been growing. It is emphasized that they are significantly associated with the occurrence of OGM. Research shows that people suffering from OGM and characterised by a rumination-based style of processing experience a greater number of depressive episodes. There are also research studies which confirm that the activities aimed at reducing the number of ruminations influence an improvement of the detail level of reminiscences. These data may serve as valuable therapeutic advice in depression disorders. The aim of the paper is to present results of contemporary research regarding mutual interrelations between autobiographical memory dysfunctions and the occurrence of symptoms of depression and its course.
Full Text Available ... to recovery. Depression treatment can take time to work, so don't give up. Read more about depression on this Web page. If the symptoms fit, get help ... Mental Health Information Summaries of Scientific Meetings Information about NIMH ...
Full Text Available ... few days. It is a serious illness that affects many people. Symptoms can vary, but many depressed people lose interest in ... I did have depression. NARRATOR : Medications called antidepressants can ... to figuring out exactly how these medications work, who benefits from them the ...
Full Text Available ... to recovery. Depression treatment can take time to work, so don't give up. Read more about depression on this Web page. If the symptoms fit, get help now. ... of Scientific Meetings Information about NIMH RePORTER : Research Portfolio Online ...
Full Text Available ... Depression (32 items) Eating Disorders (9 items) Panic Disorder (1 item) Post-Traumatic Stress Disorder (7 items) Schizophrenia (3 items) Social Phobia ( ... Depression (32 items) Eating Disorders (9 items) Panic Disorder (1 item) Post-Traumatic Stress Disorder (7 items) Schizophrenia (3 items) Social Phobia ( ...
Barbara L Parry
Full Text Available Barbara L ParryDepartment of Psychiatry, University of California, San Diego, USAAbstract: Only recently has the perimenopause become recognized as a time when women are at risk for new onset and recurrence of major depression. Untreated depression at this time not only exacerbates the course of a depressive illness, but also puts women at increased risk for sleep disorders, cardiovascular disease, diabetes, and osteoporosis. Although antidepressant medication is the mainstay of treatment, adjunctive therapy, especially with estrogen replacement, may be indicated in refractory cases, and may speed the onset of antidepressant action. Many, but not all, studies, report that progesterone antagonizes the beneficial effects of estrogen. Although some antidepressants improve vasomotor symptoms, in general they are not as effective as estrogen alone for relieving these symptoms. Estrogen alone, however, does not generally result in remission of major depression in most (but not all studies, but may provide benefit to some women with less severe symptoms if administered in therapeutic ranges. The selective serotonin reuptake inhibitors (SSRIs in addition to estrogen are usually more beneficial in improving mood than SSRIs or estrogen treatment alone for major depression, whereas the selective norepinephrine and serotonin reuptake inhibitors do not require the addition of estrogen to exert their antidepressant effects in menopausal depression. In addition to attention to general health, hormonal status, and antidepressant treatment, the optimal management of perimenopausal depression also requires attention to the individual woman’s psychosocial and spiritual well being.Keywords: menopause, depression, management
Strelow, Brittany; Fellows, Nicole; Fink, Stephanie R; OʼLaughlin, Danielle J; Radke, Gladys; Stevens, Joy; Tweedy, Johanna M
Postpartum depression, which affects 10% to 20% of women in the United States, can significantly harm the health and quality of life for mother, child, and family. This article reviews the risk factors, pathophysiology, clinical manifestations, diagnosis, and treatment of postpartum depression with specific focus on women of advanced maternal age.
Full Text Available ... items) Autism (13 items) Bipolar Disorder (2 items) Borderline Personality Disorder (3 items) Depression (32 items) Eating Disorders (9 ... items) Autism (13 items) Bipolar Disorder (2 items) Borderline Personality Disorder (3 items) Depression (32 items) Eating Disorders (9 ...
Caldwell, Jean; O'Driscoll, Timothy G.
Economists and historians have struggled for almost 80 years to account for the American Great Depression, which began in 1929 and lasted until the early years of World War II. In this article, the authors discuss three major schools of thought on the causes of the Great Depression and the long failure of the American economy to return to full…
Full Text Available ... Disorder (2 items) Borderline Personality Disorder (3 items) Depression (32 items) Eating Disorders (9 items) Panic Disorder (1 item) Post-Traumatic ... Disorder (2 items) Borderline Personality Disorder (3 items) Depression (32 items) Eating Disorders (9 items) Panic Disorder (1 item) Post-Traumatic ...
Full Text Available ... alone. NARRATOR : If you have depression, telling friends, family, or someone you trust, and finding a doctor or therapist are the first steps on the road to recovery. Depression treatment can take time to work, so don't give up. Read more about ...
Full Text Available ... why. Scientists at the National Institute of Mental Health are studying brain images of people who suffer from depression trying to learn why it affects some people but not others. Treatments for depression do work. One type of effective psychotherapy is called cognitive ...
Full Text Available ... depression do work. One type of effective psychotherapy is called cognitive behavioral therapy or CBT. CBT can help you change ways of thinking and behaving that may be damaging or contribute to depression. RODOLFO : I had one really good therapist and through her I think I started ...
Full Text Available ... Funded Science on EurekAlert EEG signals accurately predict autism as early as 3 months of age Researchers identify 44 genomic variants associated with depression Brain activity can predict success of depression treatment More News From the Field... Contact Us The ...
Kragh, Mette; Videbech, Poul
Patients admitted with depression are highly tormented and many are suicidal. Standard treatment does not offer full effect until after several weeks. Wake therapy is a method that may reduce depressive symptoms within days. In this paper, the literature regarding wake therapy is reviewed...
Full Text Available O presente trabalho teve o objetivo de estimar os parâmetros genético, fenotípico e de ambiente e do nível de endogamia em bovinos da raça Santa Gertrudis. As características estudadas foram peso ao nascer (PN, peso aos 120 dias de idade (P120, peso à desmama (PD, peso a um ano de idade (PANO e peso ao sobreano (PSANO. Foram utilizados dados de produção de 12.737 animais e dados de pedigree de 17.184 animais de 10 gerações anteriores aos animais com dados de produção, num total de 29.921 animais. As análises genéticas foram feitas por meio de metodologia de modelos mistos sob modelo animal. A média da endogamia observada não foi elevada (0,0395. As estimativas de herdabilidade para essa população podem ser consideradas de média a baixa magnitude, o que sugere que processos seletivos terão eficiência apenas a longo prazo. As estimativas de herdabilidade dos efeitos genéticos direto foram: PN = 0,16; P120 = 0,06; PD = 0,13; PANO = 0,12; PSANO = 0,12.The present study was carried out in order to estimate genetic, phenotypic and environmental parameters, and inbreeding levels of Santa Gertrudis cattle in Brazil. The traits analyzed were birth weight (PN, 120-day weight (P120, weaning weight (PD, one-year weight (PANO and 18-month weight (PSANO. A total of 12,737 weight records and pedigree informations of 17,184 animals from 10 generations prior to animals with records (total of 29,921 animals in pedigree were used. Mixed model methodology under animal model was used in the genetic analyses. Average inbreeding level was not high (0.0395. Heritability estimates for all traits varied from moderate to low (PN = 0.16; P120 = 0.06; PD = 0.13; PANO = 0.12; PSANO = 0.12.
Byers, Amy L.; Yaffe, Kristine
Depression is highly common throughout the life course and dementia is common in late life. The literature suggests an association between depression and dementia, and growing evidence implies that timing of depression may be important to defining the nature of the association. In particular, earlier-life depression or depressive symptoms consistently have been shown to be associated with a 2-fold or greater increase in risk of dementia. In contrast, studies of late-life depression have been ...
Sharifa Z. Williams
Full Text Available Many large provider networks are investing heavily in preventing disease within the communities that they serve. We explore the potential benefits and challenges associated with tackling depression at the community level using a unique dataset designed for one such provider network. The economic costs of having depression (increased medical care use, lower quality of life, and decreased workplace productivity are among the highest of any disease. Depression often goes undiagnosed, yet many believe that depression can be treated or prevented altogether. We explore the prevalence, distribution, economic burden, and the psychosocial and economic factors associated with undiagnosed depression in a lower-income neighborhood in northern Manhattan. Even using state-of-the art data to “diagnose” the risk factors within a community, it can be challenging for provider networks to act against such risk factors.
Becker, Madeleine; Weinberger, Tal; Chandy, Ann; Schmukler, Sarah
Depression is a common complication of pregnancy and the postpartum period. There are multiple risk factors for peripartum mood disorders, most important of which is a prior history of depression. Both depression and antidepressant medications confer risk upon the infant. Maternal depression has been associated with preterm birth, low birth weight, fetal growth restriction, and postnatal cognitive and emotional complications. Antidepressant exposure has been associated with preterm birth, reductions in birth weight, persistent pulmonary hypertension, and postnatal adaptation syndrome (PNAS) as well as a possible connection with autism spectrum disorder. Paroxetine has been associated with cardiac malformations. Most antidepressant medications are excreted in low levels in breast milk and are generally compatible with breastfeeding. The use of antidepressants during pregnancy and postpartum must be weighed against the risk of untreated depression in the mother.
Koopman, Margreet; El Aidy, Sahar
According to the WHO reports, around 350 million people worldwide suffer from depression. Despite its high prevalence, the complex interaction of multiple mechanisms underlying depression still needs to be elucidated. Over the course of the last few years, several neurobiological alterations have been linked to the development and maintenance of depression. One basic process that seems to link many of these findings is inflammation. Chronic inflammation has been associated with both biological factors such as excessive neurotransmitter concentrations as well as psychological processes such as adult stress reactivity and a history of childhood trauma. As a balanced microbial community, modulated by diet, is a key regulator of the host physiology, it seems likely that gut microbiota plays a role in depression. The review summarizes the existent literature on this emerging research field and provides a comprehensive overview of the multifaceted links between the microbiota, diet, and depression. Several pathways linking early life trauma, pharmacological treatment effects, and nutrition to the microbiome in depression are described aiming to foster the psychotherapeutic treatment of depressed patients by interventions targeting the microbiota.
Payk, T R
Depressions are the most common psychiatric diseases. For treatment, plant extracts have been used for thousands of years: examples are extracts from the (sleeping) poppy (opium), deadly nightshade (Atropa belladonna), Indian hemp (hashish), henbane (hyoscyamine), thorn apple (scopolamine), and St. John's wort (hypericum oil). In addition, psychotherapeutic measures, like playing music, dancing, playing theatre, and also the temple sleep, were used. In the 19th century, the introduction of brome (1826), codeine (1832), chloral hydrate (1869), and paraldehyde (1882), as well as the barbiturates (at the turn of the century) introduced significant improvements in pharmacotherapy. The modern thymoleptica therapy started in 1957 with the introduction of imipramine. Now about 40 active antidepressants are marketed. New drug developments should be characterized mainly by an improvement in tolerance.
Chua, P.; O`Keefe, G.J.; Egan, G.F.; Berlangieri, S.U.; Tochon-Danguy, H.J.; Mckay, W.J.; Morris, P.L.P.; Burrows, G.D. [Austin Hospital, Melbourne, VIC (Australia). Dept of Psychiatry and Centre for PET
Full text: Studies of regional cerebral glucose metabolism (rCMRGlu) using positron emission tomography (PET) in patients with affective disorders have consistently demonstrated reduced metabolism in the frontal regions. Different quantitative and semi-quantitative rCMRGlu regions of interest (ROI) comparisons, e.g. absolute metabolic rates, ratios of dorsolateral prefrontal cortex (DLPFC) to ipsilateral hemisphere cortex, have been reported. These studies suffered from the use of a standard brain atlas to define ROls, whereas in this case study, the individual``s magnetic resonance imaging (MRI) scan was registered with the PET scan to enable accurate neuroanatomical ROI definition for the subject. The patient is a 36-year-old female with a six-week history of major depression (HAM-D = 34, MMSE = 28). A quantitative FDG PET study and an MRI scan were performed. Six MRI-guided ROls (DLPFC, PFC, whole hemisphere) were defined. The average rCMRGlu in the DLPFC (left = 28.8 + 5.8 mol/100g/min; right = 25.6 7.0 mol/100g/min) were slightly reduced compared to the ipsilateral hemispherical rate (left = 30.4 6.8 mol/100g/min; right = 29.5 7.2 mol/100g/min). The ratios of DLPFC to ipsilateral hemispheric rate were close to unity (left = 0.95 0.29; right 0.87 0.32). The right to left DLPFC ratio did not show any significant asymmetry (0.91 0.30). These results do not correlate with earlier published results reporting decreased left DLPFC rates compared to right DLPFC, although our results will need to be replicated with a group of depressed patients. Registration of PET and MRI studies is necessary in ROI-based quantitative FDG PET studies to allow for the normal anatomical variation among individuals, and thus is essential for accurate comparison of rCMRGlu between individuals.
Chua, P.; O'Keefe, G.J.; Egan, G.F.; Berlangieri, S.U.; Tochon-Danguy, H.J.; Mckay, W.J.; Morris, P.L.P.; Burrows, G.D.
Full text: Studies of regional cerebral glucose metabolism (rCMRGlu) using positron emission tomography (PET) in patients with affective disorders have consistently demonstrated reduced metabolism in the frontal regions. Different quantitative and semi-quantitative rCMRGlu regions of interest (ROI) comparisons, e.g. absolute metabolic rates, ratios of dorsolateral prefrontal cortex (DLPFC) to ipsilateral hemisphere cortex, have been reported. These studies suffered from the use of a standard brain atlas to define ROls, whereas in this case study, the individual''s magnetic resonance imaging (MRI) scan was registered with the PET scan to enable accurate neuroanatomical ROI definition for the subject. The patient is a 36-year-old female with a six-week history of major depression (HAM-D = 34, MMSE = 28). A quantitative FDG PET study and an MRI scan were performed. Six MRI-guided ROls (DLPFC, PFC, whole hemisphere) were defined. The average rCMRGlu in the DLPFC (left = 28.8 + 5.8 mol/100g/min; right = 25.6 7.0 mol/100g/min) were slightly reduced compared to the ipsilateral hemispherical rate (left = 30.4 6.8 mol/100g/min; right = 29.5 7.2 mol/100g/min). The ratios of DLPFC to ipsilateral hemispheric rate were close to unity (left = 0.95 0.29; right 0.87 0.32). The right to left DLPFC ratio did not show any significant asymmetry (0.91 0.30). These results do not correlate with earlier published results reporting decreased left DLPFC rates compared to right DLPFC, although our results will need to be replicated with a group of depressed patients. Registration of PET and MRI studies is necessary in ROI-based quantitative FDG PET studies to allow for the normal anatomical variation among individuals, and thus is essential for accurate comparison of rCMRGlu between individuals
Phillips, Leah A.; Carroll, Linda J.; Cassidy, J. David; Côté, Pierre
Depression is common in whiplash-associated disorders (WAD). Our objectives were to identify factors associated with depressive symptomatology occurring in the initial stages of WAD, and to identify factors predicting the course of depressive symptoms. A population-based cohort of adults sustaining traffic-related WAD was followed at 6 weeks, 3, 6, 9, and 12 months. Baseline measures (assessed a median of 11 days post-crash) included demographic and collision-related factors, prior health, an...
the cost of dispersal is high and inbreeding depression low. However, inbreeding ..... cluded by the unexpected fatalities and the logistics of having to separately house .... is likely that sparring was simply a means of incorporating the foreign ...
Meller, William; Welle, Nicole; Sutley, Kristen; Thurber, Steven
Patients who underwent liver transplantation and experienced clinical depression have heretofore evinced lower survival rates when compared to nondepressed counterparts. To investigate the hypothesis that transplant patients who seek and obtain medical treatment for depression would circumvent the prior reduced survival findings. A total of 765 patients with liver transplants were scrutinized for complications following transplantation. Further, 104 patients experienced posttransplant depression as manifested by diagnosis and treatment by medical personnel. Survival analyses were conducted comparing hazard and survival curves for these selected individuals and the remainder of transplant patients. Contrary to prior data and consistent with the aforementioned hypothesis, median survival durations, survival curves, and hazard functions (controlling for age and prolonged posttransplant survival for the depressed patients were better. The improved survival for the depressed patients may simply be related to an amelioration of depressed symptoms via antidepressant medications. However, this interpretation would only be congruent with reduced hazard, not elevated survival, beyond the norm (median) for other transplant participants. Assuming the reliability and generalization of our findings, perhaps a reasonable and compelling interpretation is that combined with the effectiveness of antidepressant medications, the seeking and receiving treatment for depression is a type of proxy measure of a more global pattern of adherence to recommended posttransplant medical regimens. Copyright © 2017 The Academy of Psychosomatic Medicine. Published by Elsevier Inc. All rights reserved.
Full Text Available Background: Overweight is an increasing problem worldwide. Data from 2008 show that, in Portugal, 60% of the adult population was overweight and 25% was obese. The relation between mood disorders and obesity is well known and about 2/3 of those who search for bariatric surgery have a psychiatric diagnosis, being depression the most common. Aims: We reviewed the relation between depression and obesity before and after bariatric surgery and evaluated its impact in the pharmacokinetics of antidepressant medication and nutrients that influence depressive symptomatology. Methods: We conducted a non-systematic review of the literature published in English between 1988 and 2015, through research in MEDLINE with the keywords absorption, bioavailability, bariatric surgery, obesity, depression, antidepressants. Results: Depression and obesity potentiates each other in a bidirectional way and the strength of this association is modulated by gender, physical activity, diet and antidepressant medication usage. Bariatric surgery leads to changes in the pharmacokinetics of antidepressant medication and nutrients that have a regulatory role on mood symptomatology. Discussion and Conclusions: Available data show we need to pay special attention to obese depressive patients proposed for bariatric surgery. The existence of depressive symptoms leads to a greater risk of not losing weight after a bariatric surgery but, in the opposite direction, bariatric surgery leads to a lower bioavailability of antidepressant medication.
Delsalle, P; Schuster, J-P; von Gunten, A; Limosin, F
The use of psychostimulants in the treatment of depressive disorders is receiving renewed interest. Recent publications suggest a particular interest of psychostimulants in the treatment of depression in the elderly. The aim of this article is to review the literature on the role of psychostimulants in the treatment of depression in older adults. The literature review focused on efficacy and tolerability studies of psychostimulants in the treatment of depression for the elderly that were published between 1980 and 2016. The only inclusion criterion applied was an average age of the sample studied greater than or equal to 60 years. Overall, 12 trials were selected: 3 controlled trials and 9 uncontrolled trials. Of the 3 controlled trials, one compared parallel groups and the other two were cross-tests. Among the psychostimulants, methylphenidate was the most studied molecule. The trials demonstrate an efficacy of this molecule in particular as an add-on therapy in old-age depression but for the most part with a level of proof that remains insufficient. The small size of the samples and the methodological limitations of the studies obviate the possibility of extracting definitive conclusions concerning the place of psychostimulants in the treatment of depression in the elderly. Further studies are required in particular in the treatment of resistant depressive episodes. Copyright © 2017 L'Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.
Full Text Available This study was undertaken to determine the extent and nature of depressive symptoms exhibited by black South African children during hospitalisation for orthopaedic procedures. Social factors associated with the risk for depression, in response to hospitalisation, were also examined. Pre- and post-test assessments were conducted on a sample of 30 children aged between 6 and 12 years. The assessment entailed a structured interview, together with the following psychometric instruments: A Global Mood Scale, a Depressive Symptoms Checklist, a Hospital Fears Rating Scale and a Self Report Depression Rating Scale. A large proportion of the children were rated by ward sisters as showing high levels of depressive symptomatology two weeks after admission to hospital. As expected, discrepancies were found between adult and child self-ratings of depression. The results of this study indicate that hospitalisation for orthopaedic child patients is associated with the development of depressive symptomatology. It is suggested that emphasis be placed on the development of supportive programmes and procedures aimed at maximising children's coping responses to hospitalisation, particularly for children who find themselves Isolated from their communities and families, as a result of both centralised health services and poor socio-economic conditions.
O’Connor, Erin E.; Langer, David A.; Tompson, Martha C.
Maternal depression is a well-documented risk factor for youth depression, and taking into account its severity and chronicity may provide important insight into the degree of risk conferred. This study explored the degree to which the severity/chronicity of maternal depression history explained variance in youth internalizing and externalizing symptoms above and beyond current maternal depressive symptoms among 171 youth (58% male) ages 8 to 12 over a span of three years. Severity and chronicity of past maternal depression and current maternal depressive symptoms were examined as predictors of parent-reported youth internalizing and externalizing symptomatology, as well as youth self-reported depressive symptoms. Severity and chronicity of past maternal depression did not account for additional variance in youth internalizing and externalizing symptoms at Time 1 beyond what was accounted for by maternal depressive symptoms at Time 1. Longitudinal growth curve modeling indicated that prior severity/chronicity of maternal depression predicted levels of youth internalizing and externalizing symptoms at each time point when controlling for current maternal depressive symptoms at each time point. Chronicity of maternal depression, apart from severity, also predicted rate of change in youth externalizing symptoms over time. These findings highlight the importance of screening and assessing for current maternal depressive symptoms, as well as the nature of past depressive episodes. Possible mechanisms underlying the association between severity/chronicity of maternal depression and youth outcomes, such as residual effects from depressive history on mother–child interactions, are discussed. PMID:27401880
Sobocki, Patrik; Jönsson, Bengt; Angst, Jules; Rehnberg, Clas
Depression is one of the most disabling diseases, and causes a significant burden both to the individual and to society. WHO data suggests that depression causes 6% of the burden of all diseases in Europe in terms of disability adjusted life years (DALYs). Yet, the knowledge of the economic impact of depression has been relatively little researched in Europe. The present study aims at estimating the total cost of depression in Europe based on published epidemiologic and economic evidence. A model was developed to combine epidemiological and economic data on depression in Europe to estimate the cost. The model was populated with data collected from extensive literature reviews of the epidemiology and economic burden of depression in Europe. The cost data was calculated as annual cost per patient, and epidemiologic data was reported as 12-month prevalence estimates. National and international statistics for the model were retrieved from the OECD and Eurostat databases. The aggregated annual cost estimates were presented in Euro for 2004. In 28 countries with a population of 466 million, at least 21 million were affected by depression. The total annual cost of depression in Europe was estimated at Euro 118 billion in 2004, which corresponds to a cost of Euro 253 per inhabitant. Direct costs alone totalled dollar 42 billion, comprised of outpatient care (Euro 22 billion), drug cost (Euro 9 billion) and hospitalization (Euro 10 billion). Indirect costs due to morbidity and mortality were estimated at Euro 76 billion. This makes depression the most costly brain disorder in Europe, accounting for 33% of the total cost. The cost of depression corresponds to 1% of the total economy of Europe (GDP). Our cost results are in good agreement with previous research findings. The cost estimates in the present study are based on model simulations for countries where no data was available. The predictability of our model is limited to the accuracy of the input data employed. As
Siegle, Greg J.
An exciting review in this issue (Forgeard et al., 2011) highlights a number of emerging themes in contemporary translational research in this area. A primary challenge for the next generation of researchers reading this work will be how to carry out the grand charges levied by Forgeard et al., on the ground, i.e., to lay the foundations for moving the emerging basic science of depression into the Depression Clinic of Tomorrow. Addressing these challenges could suggest changes in the nature of the basic science, and questions that are being asked, and employed approaches in contemporary depression research. Preconditions for clinical adoption discussed in the review include 1) beginning to hold neuroscience-based measures of features of depression to the same standards held for other depression measures in the clinic, 2) attending to how the proposed methods might actually end up being feasibly imported into the clinic, and 3) what interventions targeted at mechanisms of depression might look like in the next decade. PMID:24634570
Chamberlain, Jude; Huprich, Steven K
The Depressive Personality Disorder Inventory (DPDI; Huprich, Margrett, Barthelemy, & Fine, 1996; see Appendix) was created to assess Depressive Personality Disorder in clinical and nonclinical samples. Since its creation, the DPDI has been used in multiple studies, and the psychometric properties of the measure have generally supported its reliability, convergent validity, and construct validity; however, evidence for the measure's discriminant validity has been mixed. Specifically, the DPDI tends to correlate highly with measures of current depressive symptoms, which limits its efficacy in differentiating current depressive symptoms from a depressive personality structure. A principal components analysis of 362 individuals who completed both the DPDI and Beck Depression Inventory (BDI-II; Beck, Steer, & Brown, 1996) found that 49% of the variance was accounted for in two components. Seven items from the DPDI loaded more strongly on the first component composed of many BDI-II items. These items were removed in order to create a measure believed to assess DPD without the confounding influence of current depressive symptomology. Principal components analysis of the revised measure yielded three components, accounting for 46% of the variance. The revised DPDI was used to calculate convergent, discriminant, and construct validity coefficients from measures used in former studies. Virtually no improvement in the validity coefficients was observed. It is concluded that assessing DPD via self-report is limited in its utility.
Kálmán, Janos; Kálmán, Sára
Chronobiological problems are always present as aetiological or pathoplastic conditions almost in all psychiatric disorders and considered as the greatest contributors to the mood and sleep disorders associated problems. The present review summarise the recent advances in the chronobiology research from the point of the clinician with particular emphasis on the psychobiology and pharmacotherapy of the depression. Human behaviour builds up from different length of circadian, ultradian and seasonal rhytms, strictly controlled by a hierarchical organisation of sub-cellullar, cellular, neuro-humoral and neuro-immunological clock systems. These internal clock systems are orchestrated at molecular level by certain clock genes and on the other hand--at neuro-humoral level--by the effect of the sleep hormone, melatonine, produced by the neurons of the suprachiasmatic nucleus (SCN). Beside the biological factors, social interactions are also considered as important regulators of the biological clock systems. The pacemaker centers of the SCN receive efferents from the serotoninergic raphe nuclei in order to regulate stress responses and neuroimmunological functions. The direction and the level of the chronobiological desynchronisation could be totally divergent in the case of the different affective disorders. Different chronobiological interventions are required therefore in the case of the advanced and delayed sleep disorders. Sleeping disorders are considered as the most recognised signs of the chronobiological desynchronisation in depression, but these symptoms are only the tip of the iceberg, since other chronobiological symptoms could be present due to the hidden physiological abnormalities. The serum melatonine profile is considered to be characteristic to age, gender and certain neuropsychiatric disorders. The natural and synthetic agonist of the melatonine receptors could be used as chronobiotics. The recently marketed agomelatine with a highly selective receptor
Ottesen, Johnny T.
Depression is a very common disease. Approximately 10% of people in the Western world experience severe depression during their lifetime and many more experience a mild form of depression. It is commonly believed that depression is caused by malfunctions in the biological system constituted...... by statistical hypothesis testing....
Bos, Elisabeth Henriëtte
Depression is serious disease, also because of its recurrent nature. Many people who have become depressed once, will become depressed more often. Moreover, the risk of depression seems to increase with every further episode. These observations underline the importance of gaining a better
Pearson, Quinn M.
The menopausal transition is associated with both first onset of depression and recurrent depression. Risk factors include vasomotor symptoms, a history of premenstrual dysphoria, postpartum depression, major depression, and sleep disturbances. Hormone replacement therapy, complementary and alternative medicine approaches, and counseling…
Monroe, Scott M.; Harkness, Kate L.
Theory and research on major depression have increasingly assumed a recurrent and chronic disease model. Yet not all people who become depressed suffer recurrences, suggesting that depression is also an acute, time-limited condition. However, few if any risk indicators are available to forecast which of the initially depressed will or will not…
Full Text Available ... depression can feel irritable and restless, and have sleep problems. RODOLFO : Sometimes I would sleep only 3 hours a night or cause I couldn't sleep for weeks. And then but most of the ...
Full Text Available ... NIMH continues to study the genetic, biological and environmental factors that influence depression so ... the Field NIMH-Funded Science on EurekAlert EEG signals accurately predict autism as ...
Full Text Available ... NIMH continues to study the genetic, biological and environmental factors that influence depression so that new and ... to NIMH Email Updates Type email address... Privacy Notice Policies FOIA Accessibility Topic Finder Publicaciones en Español ...
Full Text Available ... Home Mental Health Information Statistics Consumer Health Publications Help for Mental Illnesses Clinical Trials Outreach Outreach Home ... 2010 People with depression discuss how they got help.   Watch on YouTube. Transcript RODOLFO : ...
Full Text Available ... most, and how to make better, more effective ones. For many people, a combination of medication and psychotherapy may be the best choice. Depression can be successfully treated in many ...