WorldWideScience

Sample records for mole-rat heterocephalus glaber

  1. Structural Features of the Telomerase RNA Gene in the Naked Mole Rat Heterocephalus glaber

    Science.gov (United States)

    Evfratov, S. A.; Smekalova, E. M.; Golovin, A. V.; Logvina, N. A.; Zvereva, M. I.; Dontsova, O. A.

    2014-01-01

    Telomere length, an important feature of life span control, is dependent on the activity of telomerase (a key enzyme of the telomere-length-maintaining system). Telomerase RNA is a component of telomerase and, thus, is crucial for its activity. The structures of telomerase RNA genes and their promoter regions were compared for the long-living naked mole rat and different organisms. Two rare polymorphisms in Heterocephalus glaber telomerase RNA (hgTER) were identified: A→G in the first loop of pseudoknot P2b-p3 (an equivalent of 111nt in hTR) and G→A in the scaRNA domain CR7-p8b (an equivalent of 421nt in hTR). Analysis of TER promoter regions allowed us to identify two new transcription factor binding sites. The first one is the ETS family site, which was found to be a conserved element for all the analyzed TER promoters. The second site is unique for the promoter region of TER of the naked mole rat and is a binding site for the SOX17 transcription factor. The absence of one Sp1 site in the TER promoter region of the naked small rat is an additional specific feature of the promoter area of hgTER. Such variation in the hgTER transcription regulation region and hgTER itself could provide increased telomerase activity in stem cells and an extended lifespan to H. glaber. PMID:25093110

  2. Cutaneous and periodontal inputs to the cerebellum of the naked mole-rat (Heterocephalus glaber

    Directory of Open Access Journals (Sweden)

    Diana K Sarko

    2013-11-01

    Full Text Available The naked mole-rat (Heterocephalus glaber is a small fossorial rodent with specialized dentition that is reflected by the large cortical area dedicated to representation of the prominent incisors. Due to naked mole-rats’ behavioral reliance on the incisors for digging and for manipulating objects, as well as their ability to move the lower incisors independently, we hypothesized that expanded somatosensory representations of the incisors would be present within the cerebellum in order to accommodate a greater degree of proprioceptive, cutaneous, and periodontal input. Multiunit electrophysiological recordings targeting the ansiform lobule were used to investigate tactile inputs from receptive fields on the entire body with a focus on the incisors. Similar to other rodents, a fractured somatotopy appeared to be present with discrete representations of the same receptive fields repeated within each folium of the cerebellum. These findings confirm the presence of somatosensory inputs to a large area of the naked mole-rat cerebellum with particularly extensive representations of the lower incisors and mystacial vibrissae. We speculate that these extensive inputs facilitate processing of tactile cues as part of a sensorimotor integration network that optimizes how sensory stimuli are acquired through active exploration and in turn adjusts motor outputs (such as independent movement of the lower incisors. These results highlight the diverse sensory specializations and corresponding brain organizational schemes that have evolved in different mammals to facilitate exploration of and interaction with their environment.

  3. Peripheral administration of oxytocin increases social affiliation in the naked mole-rat (Heterocephalus glaber).

    Science.gov (United States)

    Mooney, Skyler J; Douglas, Natasha R; Holmes, Melissa M

    2014-04-01

    The neuropeptide oxytocin regulates a wide variety of social behaviors across diverse species. However, the types of behaviors that are influenced by this hormone are constrained by the species in question and the social organization that a particular species exhibits. Therefore, the present experiments investigated behaviors regulated by oxytocin in a eusocial mammalian species by using the naked mole-rat (Heterocephalus glaber). In Experiment 1, adult non-breeding mole-rats were given intraperitoneal injections of either oxytocin (1mg/kg or 10mg/kg) or saline on alternate days. Animals were then returned to their colony and behavior was recorded for minutes 15-30 post-injection. Both doses of oxytocin increased huddling behavior during this time period. In Experiment 2, animals received intraperitoneal injections of either oxytocin (1mg/kg), an oxytocin-receptor antagonist (0.1mg/kg), a cocktail of oxytocin and the antagonist, or saline across 4 testing days in a counterbalanced design. Animals were placed in either a 2-chamber arena with a familiar conspecific or in a small chamber with 1week old pups from their home colony and behaviors were recorded for minutes 15-30 post-injection. Oxytocin increased investigation of, and time spent in close proximity to, a familiar conspecific; these effects were blocked by the oxytocin antagonist. No effects were seen on pup-directed behavior. These data suggest that oxytocin is capable of modulating affiliative-like behavior in this eusocial species.

  4. Expression pattern of cadherins in the naked mole rat (Heterocephalus glaber) suggests innate cortical diversification of the cerebrum.

    Science.gov (United States)

    Matsunaga, Eiji; Nambu, Sanae; Iriki, Atsushi; Okanoya, Kazuo

    2011-06-15

    The cerebral cortex is an indispensable region for higher cognitive function that is remarkably diverse among mammalian species. Although previous research has shown that the cortical area map in the mammalian cerebral cortex is formed by innate and activity-dependent mechanisms, it remains unknown how these mechanisms contribute to the evolution and diversification of the functional cortical areas in various species. The naked mole rat (Heterocephalus glaber) is a subterranean, eusocial rodent. Physiological and anatomical studies have revealed that the visual system is regressed and the somatosensory system is enlarged. To examine whether species differences in cortical area development are caused by intrinsic factors or environmental factors, we performed comparative gene expression analysis of neonatal naked mole rat and mouse brains. The expression domain of cadherin-6, a somatosensory marker, was expanded caudally and shifted dorsally in the cortex, whereas the expression domain of cadherin-8, a visual marker, was reduced caudally in the neonatal naked mole rat cortex. The expression domain of cadherin-8 was also reduced in other visual areas, such as the lateral geniculate nucleus and superior colliculus. Immunohistochemical analysis of thalamocortical fibers further suggested that somatosensory input did not affect cortical gene expression in the neonatal naked mole rat brain. These results suggest that the development of the somatosensory system and the regression of the visual system in the naked mole rat cortex are due to intrinsic genetic mechanisms as well as sensory input-dependent mechanisms. Intrinsic genetic mechanisms thus appear to contribute to species diversity in cortical area formation. Copyright © 2011 Wiley-Liss, Inc.

  5. Selective inflammatory pain insensitivity in the African naked mole-rat (Heterocephalus glaber.

    Directory of Open Access Journals (Sweden)

    Thomas J Park

    2008-01-01

    Full Text Available In all mammals, tissue inflammation leads to pain and behavioral sensitization to thermal and mechanical stimuli called hyperalgesia. We studied pain mechanisms in the African naked mole-rat, an unusual rodent species that lacks pain-related neuropeptides (e.g., substance P in cutaneous sensory fibers. Naked mole-rats show a unique and remarkable lack of pain-related behaviors to two potent algogens, acid and capsaicin. Furthermore, when exposed to inflammatory insults or known mediators, naked mole-rats do not display thermal hyperalgesia. In contrast, naked mole-rats do display nocifensive behaviors in the formalin test and show mechanical hyperalgesia after inflammation. Using electrophysiology, we showed that primary afferent nociceptors in naked mole-rats are insensitive to acid stimuli, consistent with the animal's lack of acid-induced behavior. Acid transduction by sensory neurons is observed in birds, amphibians, and fish, which suggests that this tranduction mechanism has been selectively disabled in the naked mole-rat in the course of its evolution. In contrast, nociceptors do respond vigorously to capsaicin, and we also show that sensory neurons express a transient receptor potential vanilloid channel-1 ion channel that is capsaicin sensitive. Nevertheless, the activation of capsaicin-sensitive sensory neurons in naked mole-rats does not produce pain-related behavior. We show that capsaicin-sensitive nociceptors in the naked mole-rat are functionally connected to superficial dorsal horn neurons as in mice. However, the same nociceptors are also functionally connected to deep dorsal horn neurons, a connectivity that is rare in mice. The pain biology of the naked mole-rat is unique among mammals, thus the study of pain mechanisms in this unusual species can provide major insights into what constitutes "normal" mammalian nociception.

  6. Novel husbandry techniques support survival of naked mole rat (Heterocephalus glaber) pups.

    Science.gov (United States)

    Ke, Zhonghe; Vaidya, Amita; Ascher, Jill; Seluanov, Andrei; Gorbunova, Vera

    2014-01-01

    The naked mole rat (NMR) is a small eusocial rodent. Because of its remarkable longevity (maximal lifespan, 32 y) and resistance to cancer, the NMR has emerged as a valuable model for aging and cancer research. However, breeding NMR can be difficult. Here, we report the successful introduction and acceptance of pups into a foreign colony with existing pups of different ages. Among the 7 NMR colonies in our satellite facility, one had a consistently poor record of pup viability, with nearly 100% preweaning mortality in multiple litters born over the course of 2 y. The queen of this colony gave birth to 18 pups in January 2013; by 2 d after parturition, it was evident that the pups were not receiving sufficient nourishment. To salvage the litter, the most vigorous pups were cross-fostered to another queen that had recently given birth. On postparturition day 1 (PD1), two pups from the poorly nourished donor litter were bathed with warm water, rolled in recipient colony bedding, and transferred to the recipient colony, which included 8 PD14 pups. The new pups were accepted by the recipient queen, who continued to produce milk in response to suckling by the donor pups well past the weaning of her own litter. This case report provides evidence of successful cross-fostering of NMR pups despite age differences between donor pups and those in the recipient litter; this technique may prove beneficial to researchers struggling with NMR breeding issues.

  7. Investigation of the presence and antinociceptive function of muscarinic acetylcholine receptors in the African naked mole-rat (Heterocephalus glaber)

    DEFF Research Database (Denmark)

    Jørgensen, Kristine B.; Krogh-Jensen, Karen; Pickering, Darryl S;

    2016-01-01

    musculus) using basic local alignment search tool (BLAST). The presence and function of M1 and M4 was investigated in vivo, using the formalin test with the muscarinic receptor agonists xanomeline and VU0152100. Spinal cord tissue from the naked mole-rat was used for receptor saturation binding studies...... with [3H]-N-methylscopolamine. The BLAST test revealed 95 % protein sequence homology showing the naked mole-rat to have the genetic potential to express all five muscarinic acetylcholine receptor subtypes. A significant reduction in pain behavior was demonstrated after administration of 8.4 mg...

  8. The effects of oxotremorine, epibatidine, atropine, mecamylamine and naloxone in the tail-flick, hot-plate, and formalin tests in the naked mole-rat (Heterocephalus glaber)

    DEFF Research Database (Denmark)

    Dulu, Thomas D; Kanui, Titus I; Towett, Philemon K

    2014-01-01

    -plate, and the formalin tests. The effects of co-administration of the muscarinic receptor antagonist atropine, the nicotinic receptor antagonist mecamylamine, and the opioid receptor antagonist naloxone were also investigated. Oxotremorine and epibatidine induced a significant, dose-dependent antinociceptive effect...... in the tail-flick, hot-plate, and formalin tests, respectively. The effects of oxotremorine and epibatidine were blocked by atropine and mecamylamine, respectively. In all three nociceptive tests, naloxone in combination with oxotremorine or epibatidine enhanced the antinociceptive effects of the drugs....... The present study demonstrated that stimulation of muscarinic and nicotinic receptors produces antinociceptive effects in the naked-mole rat. The reversal effect of atropine and mecamylamine suggests that this effect is mediated by cholinergic receptors. As naloxone increases the antinociceptive effects...

  9. Genome sequencing reveals insights into physiology and longevity of the naked mole rat

    DEFF Research Database (Denmark)

    Kim, Eun Bae; Fang, Xiaodong; Fushan, Alexey A

    2011-01-01

    The naked mole rat (Heterocephalus glaber) is a strictly subterranean, extraordinarily long-lived eusocial mammal. Although it is the size of a mouse, its maximum lifespan exceeds 30 years, making this animal the longest-living rodent. Naked mole rats show negligible senescence, no age......-related increase in mortality, and high fecundity until death. In addition to delayed ageing, they are resistant to both spontaneous cancer and experimentally induced tumorigenesis. Naked mole rats pose a challenge to the theories that link ageing, cancer and redox homeostasis. Although characterized...... by significant oxidative stress, the naked mole rat proteome does not show age-related susceptibility to oxidative damage or increased ubiquitination. Naked mole rats naturally reside in large colonies with a single breeding female, the 'queen', who suppresses the sexual maturity of her subordinates. They also...

  10. High-molecular-mass hyaluronan mediates the cancer resistance of the naked mole rat.

    Science.gov (United States)

    Tian, Xiao; Azpurua, Jorge; Hine, Christopher; Vaidya, Amita; Myakishev-Rempel, Max; Ablaeva, Julia; Mao, Zhiyong; Nevo, Eviatar; Gorbunova, Vera; Seluanov, Andrei

    2013-07-18

    The naked mole rat (Heterocephalus glaber) displays exceptional longevity, with a maximum lifespan exceeding 30 years. This is the longest reported lifespan for a rodent species and is especially striking considering the small body mass of the naked mole rat. In comparison, a similarly sized house mouse has a maximum lifespan of 4 years. In addition to their longevity, naked mole rats show an unusual resistance to cancer. Multi-year observations of large naked mole-rat colonies did not detect a single incidence of cancer. Here we identify a mechanism responsible for the naked mole rat's cancer resistance. We found that naked mole-rat fibroblasts secrete extremely high-molecular-mass hyaluronan (HA), which is over five times larger than human or mouse HA. This high-molecular-mass HA accumulates abundantly in naked mole-rat tissues owing to the decreased activity of HA-degrading enzymes and a unique sequence of hyaluronan synthase 2 (HAS2). Furthermore, the naked mole-rat cells are more sensitive to HA signalling, as they have a higher affinity to HA compared with mouse or human cells. Perturbation of the signalling pathways sufficient for malignant transformation of mouse fibroblasts fails to transform naked mole-rat cells. However, once high-molecular-mass HA is removed by either knocking down HAS2 or overexpressing the HA-degrading enzyme, HYAL2, naked mole-rat cells become susceptible to malignant transformation and readily form tumours in mice. We speculate that naked mole rats have evolved a higher concentration of HA in the skin to provide skin elasticity needed for life in underground tunnels. This trait may have then been co-opted to provide cancer resistance and longevity to this species.

  11. The Naked Mole Rat Genome Resource: facilitating analyses of cancer and longevity-related adaptations

    Science.gov (United States)

    Keane, Michael; Craig, Thomas; Alföldi, Jessica; Berlin, Aaron M.; Johnson, Jeremy; Seluanov, Andrei; Gorbunova, Vera; Di Palma, Federica; Lindblad-Toh, Kerstin; Church, George M.; de Magalhães, João Pedro

    2014-01-01

    Motivation: The naked mole rat (Heterocephalus glaber) is an exceptionally long-lived and cancer-resistant rodent native to East Africa. Although its genome was previously sequenced, here we report a new assembly sequenced by us with substantially higher N50 values for scaffolds and contigs. Results: We analyzed the annotation of this new improved assembly and identified candidate genomic adaptations which may have contributed to the evolution of the naked mole rat’s extraordinary traits, including in regions of p53, and the hyaluronan receptors CD44 and HMMR (RHAMM). Furthermore, we developed a freely available web portal, the Naked Mole Rat Genome Resource (http://www.naked-mole-rat.org), featuring the data and results of our analysis, to assist researchers interested in the genome and genes of the naked mole rat, and also to facilitate further studies on this fascinating species. Availability and implementation: The Naked Mole Rat Genome Resource is freely available online at http://www.naked-mole-rat.org. This resource is open source and the source code is available at https://github.com/maglab/naked-mole-rat-portal. Contact: jp@senescence.info PMID:25172923

  12. RNA sequencing reveals differential expression of mitochondrial and oxidation reduction genes in the long-lived naked mole-rat when compared to mice.

    Directory of Open Access Journals (Sweden)

    Chuanfei Yu

    Full Text Available The naked mole-rat (Heterocephalus glaber is a long-lived, cancer resistant rodent and there is a great interest in identifying the adaptations responsible for these and other of its unique traits. We employed RNA sequencing to compare liver gene expression profiles between naked mole-rats and wild-derived mice. Our results indicate that genes associated with oxidoreduction and mitochondria were expressed at higher relative levels in naked mole-rats. The largest effect is nearly 300-fold higher expression of epithelial cell adhesion molecule (Epcam, a tumour-associated protein. Also of interest are the protease inhibitor, alpha2-macroglobulin (A2m, and the mitochondrial complex II subunit Sdhc, both ageing-related genes found strongly over-expressed in the naked mole-rat. These results hint at possible candidates for specifying species differences in ageing and cancer, and in particular suggest complex alterations in mitochondrial and oxidation reduction pathways in the naked mole-rat. Our differential gene expression analysis obviated the need for a reference naked mole-rat genome by employing a combination of Illumina/Solexa and 454 platforms for transcriptome sequencing and assembling transcriptome contigs of the non-sequenced species. Overall, our work provides new research foci and methods for studying the naked mole-rat's fascinating characteristics.

  13. Naked mole-rat has increased translational fidelity compared with the mouse, as well as a unique 28S ribosomal RNA cleavage

    Science.gov (United States)

    Azpurua, Jorge; Ke, Zhonghe; Chen, Iris X.; Zhang, Quanwei; Ermolenko, Dmitri N.; Zhang, Zhengdong D.; Gorbunova, Vera; Seluanov, Andrei

    2013-01-01

    The naked mole-rat (Heterocephalus glaber) is a subterranean eusocial rodent with a markedly long lifespan and resistance to tumorigenesis. Multiple data implicate modulation of protein translation in longevity. Here we report that 28S ribosomal RNA (rRNA) of the naked mole-rat is processed into two smaller fragments of unequal size. The two breakpoints are located in the 28S rRNA divergent region 6 and excise a fragment of 263 nt. The excised fragment is unique to the naked mole-rat rRNA and does not show homology to other genomic regions. Because this hidden break site could alter ribosome structure, we investigated whether translation rate and amino acid incorporation fidelity were altered. We report that naked mole-rat fibroblasts have significantly increased translational fidelity despite having comparable translation rates with mouse fibroblasts. Although we cannot directly test whether the unique 28S rRNA structure contributes to the increased fidelity of translation, we speculate that it may change the folding or dynamics of the large ribosomal subunit, altering the rate of GTP hydrolysis and/or interaction of the large subunit with tRNA during accommodation, thus affecting the fidelity of protein synthesis. In summary, our results show that naked mole-rat cells produce fewer aberrant proteins, supporting the hypothesis that the more stable proteome of the naked mole-rat contributes to its longevity. PMID:24082110

  14. Absence of histamine-induced itch in the African naked mole-rat and "rescue" by Substance P

    Directory of Open Access Journals (Sweden)

    Lewin Gary R

    2010-05-01

    Full Text Available Abstract Recent research has proposed a pathway in which sensory neurons expressing the capsaicin activated ion channel TRPV1 are required for histamine-induced itch and subsequent scratching behavior. We examined histamine-induced itch in the African naked mole-rat (Heterocephalus glaber and found that although naked mole-rats display innate scratching behavior, histamine was unable to evoke increased scratching as is observed in most mouse strains. Using calcium imaging, we examined the histamine sensitivity of naked mole-rat dorsal root ganglia (DRG neurons and identified a population of small diameter neurons activated by histamine, the majority of which are also capsaicin-sensitive. This suggested that naked mole-rat sensory neurons are activated by histamine, but that spinal dorsal horn processing of sensory information is not the same as in other rodents. We have previously shown that naked mole-rats naturally lack substance P (SP in cutaneous C-fibers, but that the neurokinin-1 receptor is expressed in the superficial spinal cord. This led us to investigate if SP deficiency plays a role in the lack of histamine-induced scratching in this species. After intrathecal administration of SP into the spinal cord we observed robust scratching behavior in response to histamine injection. Our data therefore support a model in which TRPV1-expressing sensory neurons are important for histamine-induced itch. In addition, we demonstrate a requirement for active, SP-induced post-synaptic drive to enable histamine sensitive afferents to drive itch-related behavior in the naked mole-rat. These results illustrate that it is altered dorsal horn connectivity of nociceptors that underlies the lack of itch and pain-related behavior in the naked mole-rat.

  15. Cancer resistance in the blind mole rat is mediated by concerted necrotic cell death mechanism.

    Science.gov (United States)

    Gorbunova, Vera; Hine, Christopher; Tian, Xiao; Ablaeva, Julia; Gudkov, Andrei V; Nevo, Eviatar; Seluanov, Andrei

    2012-11-20

    Blind mole rats Spalax (BMR) are small subterranean rodents common in the Middle East. BMR is distinguished by its adaptations to life underground, remarkable longevity (with a maximum documented lifespan of 21 y), and resistance to cancer. Spontaneous tumors have never been observed in spalacids. To understand the mechanisms responsible for this resistance, we examined the growth of BMR fibroblasts in vitro of the species Spalax judaei and Spalax golani. BMR cells proliferated actively for 7-20 population doublings, after which the cells began secreting IFN-β, and the cultures underwent massive necrotic cell death within 3 d. The necrotic cell death phenomenon was independent of culture conditions or telomere shortening. Interestingly, this cell behavior was distinct from that observed in another long-lived and cancer-resistant African mole rat, Heterocephalus glaber, the naked mole rat in which cells display hypersensitivity to contact inhibition. Sequestration of p53 and Rb proteins using SV40 large T antigen completely rescued necrotic cell death. Our results suggest that cancer resistance of BMR is conferred by massive necrotic response to overproliferation mediated by p53 and Rb pathways, and triggered by the release of IFN-β. Thus, we have identified a unique mechanism that contributes to cancer resistance of this subterranean mammal extremely adapted to life underground.

  16. Specific Paucity of Unmyelinated C-Fibers in Cutaneous Peripheral Nerves of the African Naked-Mole Rat: Comparative Analysis Using Six Species of Bathyergidae

    Science.gov (United States)

    Smith, Ewan S; Purfürst, Bettina; Grigoryan, Tamara; Park, Thomas J; Bennett, Nigel C; Lewin, Gary R

    2012-01-01

    In mammalian peripheral nerves, unmyelinated C-fibers usually outnumber myelinated A-fibers. By using transmission electron microscopy, we recently showed that the saphenous nerve of the naked mole-rat (Heterocephalus glaber) has a C-fiber deficit manifested as a substantially lower C:A-fiber ratio compared with other mammals. Here we determined the uniqueness of this C-fiber deficit by performing a quantitative anatomical analysis of several peripheral nerves in five further members of the Bathyergidae mole-rat family: silvery (Heliophobius argenteocinereus), giant (Fukomys mechowii), Damaraland (Fukomys damarensis), Mashona (Fukomys darlingi), and Natal (Cryptomys hottentotus natalensis) mole-rats. In the largely cutaneous saphenous and sural nerves, the naked mole-rat had the lowest C:A-fiber ratio (∼1.5:1 compared with ∼3:1), whereas, in nerves innervating both skin and muscle (common peroneal and tibial) or just muscle (lateral/medial gastrocnemius), this pattern was mostly absent. We asked whether lack of hair follicles alone accounts for the C-fiber paucity by using as a model a mouse that loses virtually all its hair as a consequence of conditional deletion of the β-catenin gene in the skin. These β-catenin loss-of function mice (β-cat LOF mice) displayed only a mild decrease in C:A-fiber ratio compared with wild-type mice (4.42 compared with 3.81). We suggest that the selective cutaneous C-fiber deficit in the cutaneous nerves of naked mole-rats is unlikely to be due primarily to lack of skin hair follicles. Possible mechanisms contributing to this unique peripheral nerve anatomy are discussed. J. Comp. Neurol. 520:2785–2803, 2012. © 2012 Wiley Periodicals, Inc. PMID:22528859

  17. INK4 locus of the tumor-resistant rodent, the naked mole rat, expresses a functional p15/p16 hybrid isoform.

    Science.gov (United States)

    Tian, Xiao; Azpurua, Jorge; Ke, Zhonghe; Augereau, Adeline; Zhang, Zhengdong D; Vijg, Jan; Gladyshev, Vadim N; Gorbunova, Vera; Seluanov, Andrei

    2015-01-27

    The naked mole rat (Heterocephalus glaber) is a long-lived and tumor-resistant rodent. Tumor resistance in the naked mole rat is mediated by the extracellular matrix component hyaluronan of very high molecular weight (HMW-HA). HMW-HA triggers hypersensitivity of naked mole rat cells to contact inhibition, which is associated with induction of the INK4 (inhibitors of cyclin dependent kinase 4) locus leading to cell-cycle arrest. The INK4a/b locus is among the most frequently mutated in human cancer. This locus encodes three distinct tumor suppressors: p15(INK4b), p16(INK4a), and ARF (alternate reading frame). Although p15(INK4b) has its own ORF, p16(INK4a) and ARF share common second and third exons with alternative reading frames. Here, we show that, in the naked mole rat, the INK4a/b locus encodes an additional product that consists of p15(INK4b) exon 1 joined to p16(INK4a) exons 2 and 3. We have named this isoform pALT(INK4a/b) (for alternative splicing). We show that pALT(INK4a/b) is present in both cultured cells and naked mole rat tissues but is absent in human and mouse cells. Additionally, we demonstrate that pALT(INK4a/b) expression is induced during early contact inhibition and upon a variety of stresses such as UV, gamma irradiation-induced senescence, loss of substrate attachment, and expression of oncogenes. When overexpressed in naked mole rat or human cells, pALT(INK4a/b) has stronger ability to induce cell-cycle arrest than either p15(INK4b) or p16(INK4a). We hypothesize that the presence of the fourth product, pALT(INK4a/b) of the INK4a/b locus in the naked mole rat, contributes to the increased resistance to tumorigenesis of this species.

  18. Adaptations to a Subterranean Environment and Longevity Revealed by the Analysis of Mole Rat Genomes

    Directory of Open Access Journals (Sweden)

    Xiaodong Fang

    2014-09-01

    Full Text Available Subterranean mammals spend their lives in dark, unventilated environments that are rich in carbon dioxide and ammonia and low in oxygen. Many of these animals are also long-lived and exhibit reduced aging-associated diseases, such as neurodegenerative disorders and cancer. We sequenced the genome of the Damaraland mole rat (DMR, Fukomys damarensis and improved the genome assembly of the naked mole rat (NMR, Heterocephalus glaber. Comparative genome analyses, along with the transcriptomes of related subterranean rodents, revealed candidate molecular adaptations for subterranean life and longevity, including a divergent insulin peptide, expression of oxygen-carrying globins in the brain, prevention of high CO2-induced pain perception, and enhanced ammonia detoxification. Juxtaposition of the genomes of DMR and other more conventional animals with the genome of NMR revealed several truly exceptional NMR features: unusual thermogenesis, an aberrant melatonin system, pain insensitivity, and unique processing of 28S rRNA. Together, these genomes and transcriptomes extend our understanding of subterranean adaptations, stress resistance, and longevity.

  19. The colonic groove or furrow: a comparative morphological study of six species of African mole-rats (Rodentia, Bathyergidae).

    Science.gov (United States)

    Kotzé, S H; van der Merwe, E L; Ndou, R; O'Riain, M J; Bennett, N C

    2009-08-01

    Herbivorous mammals such as nutrias, guinea pigs, chinchillas, and mole-rats have a longitudinal mucosal colonic groove (furrow) in their ascending colon, which is thought to play a role in the colonic separation mechanism (CSM). It is not known whether this groove is structurally modified to adapt to this function in mole-rat species. The morphology of this groove was studied in 32 mol-rats, four species, one of which consisted of three subspecies, endemic to southern Africa and two species found in eastern Africa. The macroscopic morphology of the groove was documented, and samples for histological examination were taken. The groove was wide at its origin at the cecocolic junction and was lined on either side by a row of papillae with the opposing papillae slightly offset in arrangement. The papillated groove gradually decreased in size toward the distal part of the ascending colon where it disappeared. This pattern was similar in all species except in Heterocephalus glaber, where the papillae were absent and the groove was lined by two longitudinal ridges. A histological examination of cross sections revealed that the mucosa covering the inner and outer walls of the groove was rich in mucous-secreting goblet cells. The walls of the groove contained smooth muscle extending from the inner circular smooth muscle layer at the base to the tips of the papillae in all species examined as well as arteries, lymphatic vessels, and prominent sinusoid-like veins. The groove could be demonstrated both macroscopically and histologically in three Bathyergus suillus fetuses of varying sizes. The sinusoid-like veins present in all grooves, regardless of macroscopic shape, suggest that they have a role in the functioning of the groove. (c) 2009 Wiley-Liss, Inc.

  20. A distinct role of the queen in coordinated workload and soil distribution in eusocial naked mole-rats.

    Directory of Open Access Journals (Sweden)

    Nobuyuki Kutsukake

    Full Text Available We investigated how group members achieve collective decision-making, by considering individual intrinsic behavioural rules and behavioural mechanisms for maintaining social integration. Using a simulated burrow environment, we investigated the behavioural rules of coordinated workload for soil distribution in a eusocial mammal, the naked mole-rat (Heterocephalus glaber. We tested two predictions regarding a distinct role of the queen, a socially dominant individual in the caste system: the presence of a queen would increase the workload of other caste individuals, and the cues by a queen would affect the soil distribution. In experiment 1, we placed four individuals of various castes from the same colony into an experimental burrow. Workers exhibited the highest frequency of workload compared to other castes. The presence of a queen activated the workload by other individuals. Individuals showed a consistent workload in a particular direction so as to bias the soil distribution. These results suggest that individuals have a consensus on soil distribution and that the queen plays a distinct role. In experiment 2, we placed the odour of a queen in one of four cells and observed its effect on other individuals' workload and soil distribution. Relative to other cells, individuals frequently dug in the queen cell so the amount of soil in the queen cell decreased. These results suggest that queen odour is an important cue in coordinated workload and soil distribution in this species.

  1. The Insulin-Like Growth Factor System in the Long-Lived Naked Mole-Rat

    Science.gov (United States)

    Brohus, Malene; Gorbunova, Vera; Faulkes, Chris G.; Overgaard, Michael T.; Conover, Cheryl A.

    2015-01-01

    Naked mole-rats (Heterocephalus glaber) (NMRs) are the longest living rodents known. They show negligible senescence, and are resistant to cancers and certain damaging effects associated with aging. The insulin-like growth factors (IGFs) have pluripotent actions, influencing growth processes in virtually every system of the body. They are established contributors to the aging process, confirmed by the demonstration that decreased IGF signaling results in life-extending effects in a variety of species. The IGFs are likewise involved in progression of cancers by mediating survival signals in malignant cells. This report presents a full characterization of the IGF system in the NMR: ligands, receptors, IGF binding proteins (IGFBPs), and IGFBP proteases. A particular emphasis was placed on the IGFBP protease, pregnancy-associated plasma protein-A (PAPP-A), shown to be an important lifespan modulator in mice. Comparisons of IGF-related genes in the NMR with human and murine sequences indicated no major differences in essential parts of the IGF system, including PAPP-A. The protease was shown to possess an intact active site despite the report of a contradictory genome sequence. Furthermore, PAPP-A was expressed and translated in NMRs cells and retained IGF-dependent proteolytic activity towards IGFBP-4 and IGF-independent activity towards IGFBP-5. However, experimental data suggest differential regulatory mechanisms for PAPP-A expression in NMRs than those described in humans and mice. This overall description of the IGF system in the NMR represents an initial step towards elucidating the complex molecular mechanisms underlying longevity, and how these animals have evolved to ensure a delayed and healthy aging process. PMID:26694858

  2. The Insulin-Like Growth Factor System in the Long-Lived Naked Mole-Rat.

    Directory of Open Access Journals (Sweden)

    Malene Brohus

    Full Text Available Naked mole-rats (Heterocephalus glaber (NMRs are the longest living rodents known. They show negligible senescence, and are resistant to cancers and certain damaging effects associated with aging. The insulin-like growth factors (IGFs have pluripotent actions, influencing growth processes in virtually every system of the body. They are established contributors to the aging process, confirmed by the demonstration that decreased IGF signaling results in life-extending effects in a variety of species. The IGFs are likewise involved in progression of cancers by mediating survival signals in malignant cells. This report presents a full characterization of the IGF system in the NMR: ligands, receptors, IGF binding proteins (IGFBPs, and IGFBP proteases. A particular emphasis was placed on the IGFBP protease, pregnancy-associated plasma protein-A (PAPP-A, shown to be an important lifespan modulator in mice. Comparisons of IGF-related genes in the NMR with human and murine sequences indicated no major differences in essential parts of the IGF system, including PAPP-A. The protease was shown to possess an intact active site despite the report of a contradictory genome sequence. Furthermore, PAPP-A was expressed and translated in NMRs cells and retained IGF-dependent proteolytic activity towards IGFBP-4 and IGF-independent activity towards IGFBP-5. However, experimental data suggest differential regulatory mechanisms for PAPP-A expression in NMRs than those described in humans and mice. This overall description of the IGF system in the NMR represents an initial step towards elucidating the complex molecular mechanisms underlying longevity, and how these animals have evolved to ensure a delayed and healthy aging process.

  3. Immunohistochemical characterization of the chemosensory pulmonary neuroepithelial bodies in the naked mole-rat reveals a unique adaptive phenotype.

    Directory of Open Access Journals (Sweden)

    Jie Pan

    Full Text Available The pulmonary neuroepithelial bodies (NEBs constitute polymodal airway chemosensors for monitoring and signaling ambient gas concentrations (pO2, pCO2/H+ via complex innervation to the brain stem controlling breathing. NEBs produce the bioactive amine, serotonin (5-HT, and a variety of peptides with multiple effects on lung physiology and other organ systems. NEBs in mammals appear prominent and numerous during fetal and neonatal periods, and decline in the post-natal period suggesting an important role during perinatal adaptation. The naked mole-rat (NMR, Heterocephalus glaber, has adapted to the extreme environmental conditions of living in subterranean burrows in large colonies (up to 300 colony mates. The crowded, unventilated burrows are environments of severe hypoxia and hypercapnia. However, NMRs adjust readily to above ground conditions. The chemosensory NEBs of this species were characterized and compared to those of the conventional Wistar rat (WR to identify similarities and differences that could explain the NMR's adaptability to environments. A multilabel immunohistochemical analysis combined with confocal microscopy revealed that the expression patterns of amine, peptide, neuroendocrine, innervation markers and chemosensor component proteins in NEBs of NMR were similar to that of WR. However, we found the following differences: 1 NEBs in both neonatal and adult NMR lungs were significantly larger and more numerous as compared to WR; 2 NEBs in NMR had a more variable compact cell organization and exhibited significant differences in the expression of adhesion proteins; 3 NMR NEBs showed a significantly greater ratio of 5-HT positive cells with an abundance of 5-HT; 4 NEBs in NMR expressed the proliferating cell nuclear antigen (PCNA and the neurogenic gene (MASH1 indicating active proliferation and a state of persistent differentiation. Taken together our findings suggest that NEBs in lungs of NMR are in a hyperactive, functional

  4. Life in Burrows Channelled the Morphological Evolution of the Skull in Rodents: the Case of African Mole-Rats (Bathyergidae, Rodentia)

    OpenAIRE

    2015-01-01

    International audience; African mole-rats are fossorial rodents that consist of five chisel-tooth digging genera (Heterocephalus, Heliophobius, Georychus, Fukomys, and Cryptomys) and one scratch digger (Bathyergus). They are characterized by striking physiological, morphological, and behavioral adaptations intimately related to their subterranean life. The influence of their mode of life in shaping the cranial morphology has yet to be evaluated in comparison to other Ctenohystrica, especially...

  5. Lack of sexual dimorphism in femora of the eusocial and hypogonadic naked mole-rat: a novel animal model for the study of delayed puberty on the skeletal system.

    Science.gov (United States)

    Pinto, M; Jepsen, K J; Terranova, C J; Buffenstein, R

    2010-01-01

    Sex steroid hormones are major determinants of bone morphology and quality and are responsible for sexually dimorphic skeletal traits. Hypogonadism results in suboptimal skeletal development and may lead to an increased risk of bone fracture later in life. The etiology of delayed puberty and/or hypothalamic amenorrhea is poorly understood, and experimental animal models addressing this issue are predominantly based upon short-term experimental induction of hormonal suppression via gonadotropin releasing hormone antagonists (GnRH-a). This acute change in hormone profile does not necessarily emulate the natural progression of hypogonadic bone disorders. We propose a novel animal model with which to explore the effects of chronic hypogonadism on bone quality, the naked mole-rat (NMR; Heterocephalus glaber). This mouse-size rodent may remain reproductively suppressed throughout its life, if it remains as a subordinate within the eusocial mole-rat colony. NMRs live in large colonies with a single dominant breeding female. She, primarily by using aggressive social contact, naturally suppresses the hypothalamic gonadotropic axis of subordinate NMRs and thereby their reproductive expression. However, should an NMR be separated from the dominant breeder, within less than a week reproductive hormones may become elevated and the animal attains breeding status. We questioned if sexual suppression of subordinates impact upon the development and maintenance of the femora and lead to a sexually indistinct monomorphic skeleton. Femora were obtained from male and female NMRs that were either non-breeders (subordinate) or breeders at the time of sacrifice. Diaphyseal cross-sectional morphology, metaphyseal trabecular micro-architecture and tissue mineral density of the femur were measured using microcomputed tomography and diaphyseal mechanical properties were assessed by four-point bending tests to failure. Subordinates were sexually monomorphic and showed no significant

  6. High molecular weight hyaluronan mediates the cancer resistance of the naked mole-rat

    Science.gov (United States)

    Tian, Xiao; Azpurua, Jorge; Hine, Christopher; Vaidya, Amita; Myakishev-Rempel, Max; Ablaeva, Julia; Mao, Zhiyong; Nevo, Eviatar; Gorbunova, Vera; Seluanov, Andrei

    2013-01-01

    The naked mole-rat displays exceptional longevity, with a maximum lifespan exceeding 30 years1–3. This is the longest reported lifespan for a rodent species and is especially striking considering the small body mass of the naked mole-rat. In comparison, a similarly sized house mouse has a maximum lifespan of 4 years4,5. In addition to their longevity, naked mole-rats show an unusual resistance to cancer. Multi-year observations of large naked mole-rat colonies did not detect a single incidence of cancer2,6. Here we identify a mechanism responsible for the naked mole-rat’s cancer resistance. We found that naked mole-rat fibroblasts secrete extremely high molecular weight hyaluronan (HA), which is over five times larger than human or mouse HA. This high molecular weight HA accumulates abundantly in naked mole rat tissues due to the decreased activity of HA-degrading enzymes and a unique sequence of hyaluronan synthase 2 (HAS2). Furthermore, the naked mole-rat cells are more sensitive to HA signaling, as the naked mole rat cells have a higher affinity to HA than the mouse or human cells. Perturbation of the signaling pathways sufficient for malignant transformation of mouse fibroblasts fails to transform naked mole-rat cells. However, once high molecular weight HA is removed by either knocking down HAS2 or overexpressing the HA-degrading enzyme, Hyal2, naked mole-rat cells become susceptible to malignant transformation and readily form tumors in mice. We speculate that naked mole-rats have evolved a higher concentration of HA in the skin to provide skin elasticity needed for life in underground tunnels. This trait may have then been co-opted to provide cancer resistance and longevity to this species. PMID:23783513

  7. Trading new neurons for status: Adult hippocampal neurogenesis in eusocial Damaraland mole-rats.

    Science.gov (United States)

    Oosthuizen, M K; Amrein, I

    2016-06-02

    Diversity in social structures, from solitary to eusocial, is a prominent feature of subterranean African mole-rat species. Damaraland mole-rats are eusocial, they live in colonies that are characterized by a reproductive division of labor and a subdivision into castes based on physiology and behavior. Damaraland mole-rats are exceptionally long lived and reproductive animals show delayed aging compared to non-reproductive animals. In the present study, we described the hippocampal architecture and the rate of hippocampal neurogenesis of wild-derived, adult Damaraland mole-rats in relation to sex, relative age and social status or caste. Overall, Damaraland mole-rats were found to have a small hippocampus and low rates of neurogenesis. We found no correlation between neurogenesis and sex or relative age. Social status or caste was the most prominent modulator of neurogenesis. An inverse relationship between neurogenesis and social status was apparent, with queens displaying the lowest neurogenesis while the worker mole-rats had the most. As there is no natural progression from one caste to another, social status within a colony was relatively stable and is reflected in the level of neurogenesis. Our results correspond to those found in the naked mole-rat, and may reflect an evolutionary and environmentally conserved trait within social mole-rat species.

  8. Possible incipient sympatric ecological speciation in blind mole rats (Spalax)

    Science.gov (United States)

    Hadid, Yarin; Tzur, Shay; Pavlíček, Tomáš; Šumbera, Radim; Šklíba, Jan; Lövy, Matěj; Fragman-Sapir, Ori; Beiles, Avigdor; Arieli, Ran; Raz, Shmuel; Nevo, Eviatar

    2013-01-01

    Sympatric speciation has been controversial since it was first proposed as a mode of speciation. Subterranean blind mole rats (Spalacidae) are considered to speciate allopatrically or peripatrically. Here, we report a possible incipient sympatric adaptive ecological speciation in Spalax galili (2n = 52). The study microsite (0.04 km2) is sharply subdivided geologically, edaphically, and ecologically into abutting barrier-free ecologies divergent in rock, soil, and vegetation types. The Pleistocene Alma basalt abuts the Cretaceous Senonian Kerem Ben Zimra chalk. Only 28% of 112 plant species were shared between the soils. We examined mitochondrial DNA in the control region and ATP6 in 28 mole rats from basalt and in 14 from chalk habitats. We also sequenced the complete mtDNA (16,423 bp) of four animals, two from each soil type. Remarkably, the frequency of all major haplotype clusters (HC) was highly soil-biased. HCI and HCII are chalk biased. HC-III was abundant in basalt (36%) but absent in chalk; HC-IV was prevalent in basalt (46.5%) but was low (20%) in chalk. Up to 40% of the mtDNA diversity was edaphically dependent, suggesting constrained gene flow. We identified a homologous recombinant mtDNA in the basalt/chalk studied area. Phenotypically significant divergences differentiate the two populations, inhabiting different soils, in adaptive oxygen consumption and in the amount of outside-nest activity. This identification of a possible incipient sympatric adaptive ecological speciation caused by natural selection indirectly refutes the allopatric alternative. Sympatric ecological speciation may be more prevalent in nature because of abundant and sharply abutting divergent ecologies. PMID:23359700

  9. Assessment of naked mole-rat distribution and threats in Eastern Ethiopia

    Institute of Scientific and Technical Information of China (English)

    Mengistu Wale; Abeje Kassie; Tesfu Fekensa

    2016-01-01

    Objective:To identify the distribution, threats and community attitudes towards naked mole-rat in Eastern Ethiopia. Methods: Data were collected through direct observation and interview andChi-square at 95% confidence interval was used for significance test. Results:Naked mole-rat was identified in Fafan, City/Shinele,Eastern Hararghe Zone and Dire Dawa Administrative. The main threats of naked mole-rat identified were agricultural expansion, human killing and lack of awareness. Froma total of 100 respondents, 92% of them considered naked mole-rat as pest as a result that 46% of them participated in direct killing. Literacy rate significantly affects thewillingness to participate in the conservation of naked mole-rat (χ2 = 7.478,df = 1,P Conclusions:Naked mole-rat is fairly common in many of the study sites. However, rapid shift from nomadic life style to cultivation of crops and lacks of awareness were the main threats of naked mole-rat. Therefore, since there is no conservation action currently, further comprehensive study is required to design conservation plan for this species.

  10. Eye development in the Cape dune mole rat.

    Science.gov (United States)

    Nikitina, Natalya V; Kidson, Susan H

    2014-03-01

    Studies on mammalian species with naturally reduced eyes can provide valuable insights into the evolutionary developmental mechanisms underlying the reduction of the eye structures. Because few naturally microphthalmic animals have been studied and eye reduction must have evolved independently in many of the modern groups, novel evolutionary developmental models for eye research have to be sought. Here, we present a first report on embryonic eye development in the Cape dune mole rat, Bathyergus suillus. The eyes of these animals contain all the internal structures characteristic of the normal eye but exhibit abnormalities in the anterior chamber structures. The lens is small but develops normally and exhibits a normal expression of α- and γ-crystallins. One of the interesting features of these animals is an extremely enlarged and highly pigmented ciliary body. In order to understand the molecular basis of this unusual feature, the expression pattern of an early marker of the ciliary zone, Ptmb4, was investigated in this animal. Surprisingly, in situ hybridization results revealed that Ptmb4 expression was absent from the ciliary body zone of the developing Bathyergus eye.

  11. Hypersensitivity to contact inhibition provides a clue to cancer resistance of naked mole-rat

    Science.gov (United States)

    Seluanov, Andrei; Hine, Christopher; Azpurua, Jorge; Feigenson, Marina; Bozzella, Michael; Mao, Zhiyong; Catania, Kenneth C.; Gorbunova, Vera

    2009-01-01

    The naked mole-rat is the longest living rodent with a maximum lifespan exceeding 28 years. In addition to its longevity, naked mole-rats have an extraordinary resistance to cancer as tumors have never been observed in these rodents. Furthermore, we show that a combination of activated Ras and SV40 LT fails to induce robust anchorage-independent growth in naked mole-rat cells, while it readily transforms mouse fibroblasts. The mechanisms responsible for the cancer resistance of naked mole-rats were unknown. Here we show that naked mole-rat fibroblasts display hypersensitivity to contact inhibition, a phenomenon we termed “early contact inhibition.” Contact inhibition is a key anticancer mechanism that arrests cell division when cells reach a high density. In cell culture, naked mole-rat fibroblasts arrest at a much lower density than those from a mouse. We demonstrate that early contact inhibition requires the activity of p53 and pRb tumor suppressor pathways. Inactivation of both p53 and pRb attenuates early contact inhibition. Contact inhibition in human and mouse is triggered by the induction of p27Kip1. In contrast, early contact inhibition in naked mole-rat is associated with the induction of p16Ink4a. Furthermore, we show that the roles of p16Ink4a and p27Kip1 in the control of contact inhibition became temporally separated in this species: the early contact inhibition is controlled by p16Ink4a, and regular contact inhibition is controlled by p27Kip1. We propose that the additional layer of protection conferred by two-tiered contact inhibition contributes to the remarkable tumor resistance of the naked mole-rat. PMID:19858485

  12. High Autophagy in the Naked Mole Rat may Play a Significant Role in Maintaining Good Health

    Directory of Open Access Journals (Sweden)

    Shanmin Zhao

    2014-02-01

    Full Text Available Background/Aims: The maximum lifespan of the naked mole rat is over 28.3 years, which exceeds that of any other rodent species, suggesting that age-related changes in its body composition and functionality are either attenuated or delayed in this extraordinarily long-lived species. However, the mechanisms underlying the aging process in this species are poorly understood. In this study, we investigated whether long-lived naked mole rats display more autophagic activity than short-lived mice. Methods: Hepatic stellate cells isolated from naked mole rats were treated with 50 nM rapamycin or 20 mM 3-methyladenine (3-MA for 12 or 24 h. Expression of the autophagy marker proteins LC3-II and beclin 1 was measured with western blotting and immunohistochemistry. The induction of apoptosis was analyzed by flow cytometry. Results: Our results demonstrate that one-day-old naked mole rats have higher levels of autophagy than one-day-old short-lived C57BL/6 mice, and that both adult naked mole rats (eight months old and adult C57BL/6 mice (eight weeks old have high basal levels of autophagy, which may be an important mechanism inhibiting aging and reducing the risk of age-related diseases. Conclusion: Here, we report that autophagy facilitated the survival of hepatic stellate cells from the naked mole rat, and that treatment with 3-MA or rapamycin increased the ratio of apoptotic cells to normal hepatic stellate cells.

  13. Is evolution of blind mole rats determined by climate oscillations?

    Directory of Open Access Journals (Sweden)

    Yarin Hadid

    Full Text Available The concept of climate variability facilitating adaptive radiation supported by the "Court Jester" hypothesis is disputed by the "Red Queen" one, but the prevalence of one or the other might be scale-dependent. We report on a detailed, comprehensive phylo-geographic study on the ∼4 kb mtDNA sequence in underground blind mole rats of the family Spalacidae (or subfamily Spalacinae from the East Mediterranean steppes. Our study aimed at testing the presence of periodicities in branching patterns on a constructed phylogenetic tree and at searching for congruence between branching events, tectonic history and paleoclimates. In contrast to the strong support for the majority of the branching events on the tree, the absence of support in a few instances indicates that network-like evolution could exist in spalacids. In our tree, robust support was given, in concordance with paleontological data, for the separation of spalacids from muroid rodents during the first half of the Miocene when open, grass-dominated habitats were established. Marine barriers formed between Anatolia and the Balkans could have facilitated the separation of the lineage "Spalax" from the lineage "Nannospalax" and of the clade "leucodon" from the clade "xanthodon". The separation of the clade "ehrenbergi" occurred during the late stages of the tectonically induced uplift of the Anatolian high plateaus and mountains, whereas the separation of the clade "vasvarii" took place when the rapidly uplifting Taurus mountain range prevented the Mediterranean rainfalls from reaching the Central Anatolian Plateau. The separation of Spalax antiquus and S. graecus occurred when the southeastern Carpathians were uplifted. Despite the role played by tectonic events, branching events that show periodicity corresponding to 400-kyr and 100-kyr eccentricity bands illuminate the important role of orbital fluctuations on adaptive radiation in spalacids. At the given scale, our results supports the

  14. Extended Longevity of Reproductives Appears to be Common in Fukomys Mole-Rats (Rodentia, Bathyergidae)

    Science.gov (United States)

    Dammann, Philip; Šumbera, Radim; Maßmann, Christina; Scherag, André; Burda, Hynek

    2011-01-01

    African mole-rats (Bathyergidae, Rodentia) contain several social, cooperatively breeding species with low extrinsic mortality and unusually high longevity. All social bathyergids live in multigenerational families where reproduction is skewed towards a few breeding individuals. Most of their offspring remain as reproductively inactive “helpers” in their natal families, often for several years. This “reproductive subdivision” of mole-rat societies might be of interest for ageing research, as in at least one social bathyergid (Ansell's mole-rats Fukomys anselli), breeders have been shown to age significantly slower than non-breeders. These animals thus provide excellent conditions for studying the epigenetics of senescence by comparing divergent longevities within the same genotypes without the inescapable short-comings of inter-species comparisons. It has been claimed that many if not all social mole-rat species may have evolved similar ageing patterns, too. However, this remains unclear on account of the scarcity of reliable datasets on the subject. We therefore analyzed a 20-year breeding record of Giant mole-rats Fukomys mechowii, another social bathyergid species. We found that breeders indeed lived significantly longer than helpers (ca. 1.5–2.2fold depending on the sex), irrespective of social rank or other potentially confounding factors. Considering the phylogenetic positions of F. mechowii and F. anselli and unpublished data on a third Fukomys-species (F. damarensis) showing essentially the same pattern, it seems probable that the reversal of the classic trade-off between somatic maintenance and sexual reproduction is characteristic of the whole genus and hence of the vast majority of social mole-rats. PMID:21533255

  15. Extended longevity of reproductives appears to be common in Fukomys mole-rats (Rodentia, Bathyergidae.

    Directory of Open Access Journals (Sweden)

    Philip Dammann

    Full Text Available African mole-rats (Bathyergidae, Rodentia contain several social, cooperatively breeding species with low extrinsic mortality and unusually high longevity. All social bathyergids live in multigenerational families where reproduction is skewed towards a few breeding individuals. Most of their offspring remain as reproductively inactive "helpers" in their natal families, often for several years. This "reproductive subdivision" of mole-rat societies might be of interest for ageing research, as in at least one social bathyergid (Ansell's mole-rats Fukomys anselli, breeders have been shown to age significantly slower than non-breeders. These animals thus provide excellent conditions for studying the epigenetics of senescence by comparing divergent longevities within the same genotypes without the inescapable short-comings of inter-species comparisons. It has been claimed that many if not all social mole-rat species may have evolved similar ageing patterns, too. However, this remains unclear on account of the scarcity of reliable datasets on the subject. We therefore analyzed a 20-year breeding record of Giant mole-rats Fukomys mechowii, another social bathyergid species. We found that breeders indeed lived significantly longer than helpers (ca. 1.5-2.2fold depending on the sex, irrespective of social rank or other potentially confounding factors. Considering the phylogenetic positions of F. mechowii and F. anselli and unpublished data on a third Fukomys-species (F. damarensis showing essentially the same pattern, it seems probable that the reversal of the classic trade-off between somatic maintenance and sexual reproduction is characteristic of the whole genus and hence of the vast majority of social mole-rats.

  16. The eye of the African mole-rat Cryptomys anselli : to see or not to see?

    NARCIS (Netherlands)

    Cernuda-Cernuda, R; Garcia-Fernandez, JM; Gordijn, MCM; Bovee-Geurts, PHM; DeGrip, WJ; de Grip, W.J.

    2003-01-01

    In an attempt to clarify its possible physiological role, we studied the eye of the Zambian mole rat Cryptomys anselli by light, electron and confocal microscopy using conventional staining as well as immunolabelling with rod and cone cell markers. The small eyes of Cryptomys are located superficial

  17. Family Wide Molecular Adaptations to Underground Life in African Mole-Rats Revealed by Phylogenomic Analysis.

    Science.gov (United States)

    Davies, Kalina T J; Bennett, Nigel C; Tsagkogeorga, Georgia; Rossiter, Stephen J; Faulkes, Christopher G

    2015-12-01

    During their evolutionary radiation, mammals have colonized diverse habitats. Arguably the subterranean niche is the most inhospitable of these, characterized by reduced oxygen, elevated carbon dioxide, absence of light, scarcity of food, and a substrate that is energetically costly to burrow through. Of all lineages to have transitioned to a subterranean niche, African mole-rats are one of the most successful. Much of their ecological success can be attributed to a diet of plant storage organs, which has allowed them to colonize climatically varied habitats across sub-Saharan Africa, and has probably contributed to the evolution of their diverse social systems. Yet despite their many remarkable phenotypic specializations, little is known about molecular adaptations underlying these traits. To address this, we sequenced the transcriptomes of seven mole-rat taxa, including three solitary species, and combined new sequences with existing genomic data sets. Alignments of more than 13,000 protein-coding genes encompassed, for the first time, all six genera and the full spectrum of ecological and social variation in the clade. We detected positive selection within the mole-rat clade and along ancestral branches in approximately 700 genes including loci associated with tumorigenesis, aging, morphological development, and sociality. By combining these results with gene ontology annotation and protein-protein networks, we identified several clusters of functionally related genes. This family wide analysis of molecular evolution in mole-rats has identified a suite of positively selected genes, deepening our understanding of the extreme phenotypic traits exhibited by this group.

  18. Comparative analysis of genome maintenance genes in naked mole rat, mouse, and human

    NARCIS (Netherlands)

    S.L. Macrae (Sheila L.); Q. Zhang (Quanwei); C. Lemetre (Christophe); I. Seim (Inge); R.B. Calder (Robert B.); J.H.J. Hoeijmakers (Jan); Y. Suh (Yousin); V.N. Gladyshev (Vadim N.); A. Seluanov (Andrei); V. Gorbunova (Vera); J. Vijg (Jan); Z.D. Zhang (Zhengdong D.)

    2015-01-01

    textabstractGenome maintenance (GM) is an essential defense system against aging and cancer, as both are characterized by increased genome instability. Here, we compared the copy number variation and mutation rate of 518 GM-associated genes in the naked mole rat (NMR), mouse, and human genomes. GM g

  19. Blunted behavioral and c Fos responses to acidic fumes in the African naked mole-rat.

    Directory of Open Access Journals (Sweden)

    Pamela Colleen LaVinka

    Full Text Available Acidosis in the skin triggers activation of pain pathways and behaviors indicative of pain in vertebrates. The exception is the naked mole-rat, the only known vertebrate to show physiological and behavioral insensitivity to acid pain in the skin. The goal of the present study was to determine behavioral and physiological responses of this species to airborne acidic fumes, which would be expected to affect the trigeminal pain pathway in other species. Behaviorally, naked mole-rats did not avoid fumes from moderately high concentrations of acetic acid (10 and 20%, and c Fos labeling showed no increase in activity in the trigeminal nuclei and nucleus tractus solitarius. In contrast, these concentrations triggered behavioral aversion and increased Fos activity in other laboratory rodents. For a very high concentration of acetic acid (50%, naked mole-rats showed significant avoidance behavior and increased Fos labeling in the nucleus tractus solitarius caudal region, which receives vagal chemosensory information. However, there was no increase in trigeminal labeling, and in fact, activity significantly decreased. This pattern is opposite of that associated with another irritant, ammonia fumes, which elicited an increase in trigeminal but not nucleus tractus solitarius Fos labeling, and no behavioral avoidance. Behavioral avoidance of acidic fumes, but no increased labeling in the trigeminal pain nucleus is consistent with the notion of adaptations to blunt acid pain, which would be advantageous for naked mole-rats as they normally live under chronically high levels of acidosis-inducing CO(2.

  20. Effects of ultraviolet radiation on mole rats kidney: A histopathologic and ultrastructural study

    Directory of Open Access Journals (Sweden)

    Hüseyin Türker

    2014-04-01

    Full Text Available The purpose of this study was to realize the ultrastructural effects of ultraviolet radiation on the kidney tissue cells of mole rats (Spalax leucodon. The mole rats of 180–200 g body weight were divided into the control and radiation-trial groups. The control group was not given any radiation. The other groups were irradiated with artificially produced UVC radiation for 14, 28 and 60 days. The kidney tissue samples were prepared at the end of experiments and analyzed by the light and electron microscope. Several effects were observed in the kidney tissues cells analyzed in accordance with the dose magnitude of radiation. These results clearly show the detrimental effects of UVC radiation on kidney tissue cells in exposure periods dependent on radiation dose and exposure time.

  1. Seasonal changes in burrow geometry of the common mole rat (Rodentia: Bathyergidae)

    Science.gov (United States)

    Thomas, H. G.; Scantlebury, M.; Swanepoel, D.; Bateman, P. W.; Bennett, N. C.

    2013-11-01

    Sociality in mole rats has been suggested to have evolved as a response to the widely dispersed food resources and the limited burrowing opportunities that result from sporadic rainfall events. In the most arid regions, individual foraging efficiency is reduced, and energetic constraints increase. In this study, we investigate seasonal differences in burrow architecture of the social Cryptomys hottentotus hottentotus in a mesic region. We describe burrow geometry in response to seasonal weather conditions for two seasons (wet and dry). Interactions occurred between seasons and colony size for the size of the burrow systems, but not the shape of the burrow systems. The fractal dimension values of the burrow systems did not differ between seasons. Thus, the burrow complexity was dependent upon the number of mole rats present in the social group.

  2. Hypofunctional TrkA Accounts for the Absence of Pain Sensitization in the African Naked Mole-Rat

    Directory of Open Access Journals (Sweden)

    Damir Omerbašić

    2016-10-01

    Full Text Available The naked mole-rat is a subterranean rodent lacking several pain behaviors found in humans, rats, and mice. For example, nerve growth factor (NGF, an important mediator of pain sensitization, fails to produce thermal hyperalgesia in naked mole-rats. The sensitization of capsaicin-sensitive TRPV1 ion channels is necessary for NGF-induced hyperalgesia, but naked mole-rats have fully functional TRPV1 channels. We show that exposing isolated naked mole-rat nociceptors to NGF does not sensitize TRPV1. However, the naked mole-rat NGF receptor TrkA displays a reduced ability to engage signal transduction pathways that sensitize TRPV1. Between one- and three-amino-acid substitutions in the kinase domain of the naked mole-rat TrkA are sufficient to render the receptor hypofunctional, and this is associated with the absence of heat hyperalgesia. Our data suggest that evolution has selected for a TrkA variant that abolishes a robust nociceptive behavior in this species but is still compatible with species fitness.

  3. Genetic signatures for enhanced olfaction in the African mole-rats.

    Directory of Open Access Journals (Sweden)

    Sofia Stathopoulos

    Full Text Available The Olfactory Receptor (OR superfamily, the largest in the vertebrate genome, is responsible for vertebrate olfaction and is traditionally subdivided into 17 OR families. Recent studies characterising whole-OR subgenomes revealed a 'birth and death' model of evolution for a range of species, however little is known about fine-scale evolutionary dynamics within single-OR families. This study reports the first assessment of fine-scale OR evolution and variation in African mole-rats (Bathyergidae, a family of subterranean rodents endemic to sub-Saharan Africa. Because of the selective pressures of life underground, enhanced olfaction is proposed to be fundamental to the evolutionary success of the Bathyergidae, resulting in a highly diversified OR gene-repertoire. Using a PCR-sequencing approach, we analysed variation in the OR7 family across 14 extant bathyergid species, which revealed enhanced levels of functional polymorphisms concentrated across the receptors' ligand-binding region. We propose that mole-rats are able to recognise a broad range of odorants and that this diversity is reflected throughout their OR7 gene repertoire. Using both classic tests and tree-based methods to test for signals of selection, we investigate evolutionary forces across the mole-rat OR7 gene tree. Four well-supported clades emerged in the OR phylogeny, with varying signals of selection; from neutrality to positive and purifying selection. Bathyergid life-history traits and environmental niche-specialisation are explored as possible drivers of adaptive OR evolution, emerging as non-exclusive contributors to the positive selection observed at OR7 genes. Our results reveal unexpected complexity of evolutionary mechanisms acting within a single OR family, providing insightful perspectives into OR evolutionary dynamics.

  4. Multidimensional MRI-CT atlas of the naked mole-rat brain

    Directory of Open Access Journals (Sweden)

    Fumiko eSeki

    2013-12-01

    Full Text Available Naked mole-rats have a variety of distinctive features such as the organisation of a hierarchical society (known as eusociality, extraordinary longevity, and cancer resistance; thus, it would be worthwhile investigating these animals in detail. One important task is the preparation of a brain atlas database that provide comprehensive information containing multidimensional data with various image contrasts, which can be achievable using a magnetic resonance imaging (MRI. Advanced MRI techniques such as diffusion tensor imaging (DTI, which generates high contrast images of fibre structures, can characterise unique morphological properties in addition to conventional MRI. To obtain high spatial resolution images, MR histology, DTI, and X-ray computed tomography (CT were performed on the fixed adult brain. Skull and brain structures were segmented as well as reconstructed in stereotaxic coordinates. Data were also acquired for the neonatal brain to allow developmental changes to be observed. Moreover, in vivo imaging of naked mole-rats was established as an evaluation tool of live animals. The data obtained comprised three-dimensional (3D images with high tissue contrast as well as stereotaxic coordinates. Developmental differences in the visual system were highlighted in particular by DTI. Although it was difficult to delineate optic nerves in the mature adult brain, parts of them could be distinguished in the immature neonatal brain. From observation of cortical thickness, possibility of high somatosensory system development replaced to the visual system was indicated. 3D visualisation of brain structures in the atlas as well as the establishment of in vivo imaging would promote neuroimaging researches towards detection of novel characteristics of eusocial naked mole-rats.

  5. Mechanisms regulating proteostasis are involved in sympatric speciation of the blind mole rat, Spalax galili.

    Science.gov (United States)

    Rodriguez, Karl A; Li, Kexin; Nevo, Eviatar; Buffenstein, Rochelle

    2016-01-01

    Genome-wide analysis demonstrates extensive genomic adaptive complexes involved in sympatric speciation between blind mole rats (Spalax galili) in abutting populations living in basalt and chalk soils. Among the gene ontology (GO) enrichment, musculature and metabolism stood out in basalt dwellers while nutrition and neurogenetics were highlighted in chalk residents. Measurements of mechanisms regulating protein homeostasis inspired by these GO terms suggest that at the proteomic level there is also a habitat/soil-type driven divergence with the basalt residents exhibiting higher proteasome activity whereas elevated levels of markers of autophagy are evident in the chalk inhabitants.

  6. Comparative analysis of genome maintenance genes in naked mole rat, mouse, and human

    Science.gov (United States)

    MacRae, Sheila L; Zhang, Quanwei; Lemetre, Christophe; Seim, Inge; Calder, Robert B; Hoeijmakers, Jan; Suh, Yousin; Gladyshev, Vadim N; Seluanov, Andrei; Gorbunova, Vera; Vijg, Jan; Zhang, Zhengdong D

    2015-01-01

    Genome maintenance (GM) is an essential defense system against aging and cancer, as both are characterized by increased genome instability. Here, we compared the copy number variation and mutation rate of 518 GM-associated genes in the naked mole rat (NMR), mouse, and human genomes. GM genes appeared to be strongly conserved, with copy number variation in only four genes. Interestingly, we found NMR to have a higher copy number of CEBPG, a regulator of DNA repair, and TINF2, a protector of telomere integrity. NMR, as well as human, was also found to have a lower rate of germline nucleotide substitution than the mouse. Together, the data suggest that the long-lived NMR, as well as human, has more robust GM than mouse and identifies new targets for the analysis of the exceptional longevity of the NMR. PMID:25645816

  7. Transcriptome, genetic editing, and microRNA divergence substantiate sympatric speciation of blind mole rat, Spalax.

    Science.gov (United States)

    Li, Kexin; Wang, Liuyang; Knisbacher, Binyamin A; Xu, Qinqin; Levanon, Erez Y; Wang, Huihua; Frenkel-Morgenstern, Milana; Tagore, Satabdi; Fang, Xiaodong; Bazak, Lily; Buchumenski, Ilana; Zhao, Yang; Lövy, Matěj; Li, Xiangfeng; Han, Lijuan; Frenkel, Zeev; Beiles, Avigdor; Cao, Yi Bin; Wang, Zhen Long; Nevo, Eviatar

    2016-07-05

    Incipient sympatric speciation in blind mole rat, Spalax galili, in Israel, caused by sharp ecological divergence of abutting chalk-basalt ecologies, has been proposed previously based on mitochondrial and whole-genome nuclear DNA. Here, we present new evidence, including transcriptome, DNA editing, microRNA, and codon usage, substantiating earlier evidence for adaptive divergence in the abutting chalk and basalt populations. Genetic divergence, based on the previous and new evidence, is ongoing despite restricted gene flow between the two populations. The principal component analysis, neighbor-joining tree, and genetic structure analysis of the transcriptome clearly show the clustered divergent two mole rat populations. Gene-expression level analysis indicates that the population transcriptome divergence is displayed not only by soil divergence but also by sex. Gene ontology enrichment of the differentially expressed genes from the two abutting soil populations highlights reproductive isolation. Alternative splicing variation of the two abutting soil populations displays two distinct splicing patterns. L-shaped FST distribution indicates that the two populations have undergone divergence with gene flow. Transcriptome divergent genes highlight neurogenetics and nutrition characterizing the chalk population, and energetics, metabolism, musculature, and sensory perception characterizing the abutting basalt population. Remarkably, microRNAs also display divergence between the two populations. The GC content is significantly higher in chalk than in basalt, and stress-response genes mostly prefer nonoptimal codons. The multiple lines of evidence of ecological-genomic and genetic divergence highlight that natural selection overrules the gene flow between the two abutting populations, substantiating the sharp ecological chalk-basalt divergence driving sympatric speciation.

  8. Lipid profile and serum characteristics of the blind subterranean mole rat, Spalax.

    Directory of Open Access Journals (Sweden)

    Nicola J Nasser

    Full Text Available BACKGROUND: Spalax (blind subterranean mole rat, is a mammal adapted to live in fluctuating oxygen levels, and can survive severe hypoxia and hypercapnia. The adaptive evolution of Spalax to underground life resulted in structural and molecular-genetic differences comparing to above-ground mammals. These differences include higher myocardial maximal oxygen consumption, increased lung diffusion capacity, increased blood vessels density, and unique expression patterns of cancer and angiogenesis related genes such as heparanase, vascular endothelial growth factor, and P53. METHODOLOGY/PRINCIPAL FINDINGS: Here we elucidate the main characteristics of Spalax lipid profile, as well as its main antioxidant and serum parameters. Compared to human, Spalax possesses lower total-cholesterol, low density lipoproteins (LDL and triglycerides levels, and higher levels of high density lipoproteins (HDL. Apolipoprotein A-I and apolipoprotein B-100 were significantly lower in Spalax compared to human. Paraoxonase (PON 1 arylesterase activity, was higher in Spalax compared to both human and mouse serum levels. Analysis of serum chemistry of Spalax revealed special features in this mammal. CONCLUSIONS/SIGNIFICANCE: Spalax possesses a unique lipid profile with high HDL and low LDL lipoproteins. The antioxidant serum content in the mole rat is higher than that of human and mouse. Serum C reactive protein (CRP levels are significantly lower in Spalax compared to that of human or mouse, reflecting low levels of inflammation. These differences between Spalax, human and mouse are due to several factors including the intensive activity life-style that Spalax pursue underground, dietary components, and evolutionary genetic adaptations. Unfolding the genetic basis of these differences will probably result in unique treatments for a variety of human diseases such as dyslipedemias, inflammation and cancer.

  9. Functional neurokinin and NMDA receptor activity in an animal naturally lacking substance P: the naked mole-rat.

    Directory of Open Access Journals (Sweden)

    Antje Brand

    Full Text Available Naked mole-rats are extremely unusual among mammals in that their cutaneous C-fibers lack the neuropeptide Substance P (SP. In other mammals, SP plays an important role in nociception: it is released from C-fibers onto spinal neurons where it facilitates NMDA receptor activity and causes sensitization that can last for minutes, hours or days. In the present study, we tested the effects of intrathecal application of: 1 SP, 2 an SP antagonist (GR-82334, and 3 an NMDA antagonist (APV on heat-evoked foot withdrawal. In the naked mole-rat, at a high enough concentration, application of SP caused a large, immediate, and long-lasting sensitization of foot withdrawal latency that was transiently reversed by application of either antagonist. However, neither SP nor NMDA antagonists had an effect when administered alone to naïve animals. In contrast, both antagonists induced an increase in basal withdrawal latency in mice. These results indicate that spinal neurons in naked mole-rats have functional SP and NMDA receptors, but that these receptors do not participate in heat-evoked foot withdrawal unless SP is experimentally introduced. We propose that the natural lack of SP in naked mole-rat C-fibers may have resulted during adaptation to living in a chronically high carbon dioxide, high ammonia environment that, in other mammals, would stimulate C-fibers and evoke nocifensive behavior.

  10. Adaptive methylation regulation of p53 pathway in sympatric speciation of blind mole rats, Spalax.

    Science.gov (United States)

    Zhao, Yang; Tang, Jia-Wei; Yang, Zhi; Cao, Yi-Bin; Ren, Ji-Long; Ben-Abu, Yuval; Li, Kexin; Chen, Xue-Qun; Du, Ji-Zeng; Nevo, Eviatar

    2016-02-23

    Epigenetic modifications play significant roles in adaptive evolution. The tumor suppressor p53, well known for controlling cell fate and maintaining genomic stability, is much less known as a master gene in environmental adaptation involving methylation modifications. The blind subterranean mole rat Spalax eherenbergi superspecies in Israel consists of four species that speciated peripatrically. Remarkably, the northern Galilee species Spalax galili (2n = 52) underwent adaptive ecological sympatric speciation, caused by the sharply divergent chalk and basalt ecologies. This was demonstrated by mitochondrial and nuclear genomic evidence. Here we show that the expression patterns of the p53 regulatory pathway diversified between the abutting sympatric populations of S. galili in sharply divergent chalk-basalt ecologies. We identified higher methylation on several sites of the p53 promoter in the population living in chalk soil (chalk population). Site mutagenesis showed that methylation on these sites linked to the transcriptional repression of p53 involving Cut-Like Homeobox 1 (Cux1), paired box 4 (Pax 4), Pax 6, and activator protein 1 (AP-1). Diverse expression levels of p53 between the incipiently sympatrically speciating chalk-basalt abutting populations of S. galili selectively affected cell-cycle arrest but not apoptosis. We hypothesize that methylation modification of p53 has adaptively shifted in supervising its target genes during sympatric speciation of S. galili to cope with the contrasting environmental stresses of the abutting divergent chalk-basalt ecologies.

  11. Macroscopic anatomy of the lower respiratory system in mole rats (Spalax leucodon).

    Science.gov (United States)

    İlgun, R; Yoldas, A; Kuru, N; Özkan, Z E

    2014-12-01

    The morphologic and morphometric features of the lower respiratory system in mole rats were examined. It was seen that the low respiratory system of this species leading a special life under highly hypoxic/hypercapnic conditions underground is structurally similar to other mammals living on land in terms of the parts examined; trachea was formed by 29.5 ± 4 oval-formed cartilaginous tracheals arranged backwards and became gradually more stenotic diameter from cranial to the caudal of the neck. The trachea was separated in two principal bronchus at the fourth thoracal intercostal spatium level. The angle between the two main principal bronchi was 60.5 ± 2.35°. The lung constituted 1.29 ± 0.03% of the body weight and the right lung was heavier than the left lung. Fissura inter-lobaris was deep and separated the lung lobes wholly, and the right lung was separated in four lobes, whereas the left lung was not separated into the lobes. Also, the medial lobe of the left lung was the lightest lobe.

  12. Functional characteristics of the naked mole rat μ-opioid receptor.

    Directory of Open Access Journals (Sweden)

    Melanie Busch-Dienstfertig

    Full Text Available While humans and most animals respond to µ-opioid receptor (MOR agonists with analgesia and decreased aggression, in the naked mole rat (NMR opioids induce hyperalgesia and severe aggression. Single nucleotide polymorphisms in the human mu-opioid receptor gene (OPRM1 can underlie altered behavioral responses to opioids. Therefore, we hypothesized that the primary structure of the NMR MOR may differ from other species. Sequencing of the NMR oprm1 revealed strong homology to other mammals, but exposed three unique amino acids that might affect receptor-ligand interactions. The NMR and rat oprm1 sequences were cloned into mammalian expression vectors and transfected into HEK293 cells. Radioligand binding and 3'-5'-cyclic adenosine monophosphate (cAMP enzyme immunoassays were used to compare opioid binding and opioid-mediated cAMP inhibition. At normalized opioid receptor protein levels we detected significantly lower [3H]DAMGO binding to NMR compared to rat MOR, but no significant difference in DAMGO-induced cAMP inhibition. Strong DAMGO-induced MOR internalization was detectable using radioligand binding and confocal imaging in HEK293 cells expressing rat or NMR receptor, while morphine showed weak or no effects. In summary, we found minor functional differences between rat and NMR MOR suggesting that other differences e.g. in anatomical distribution of MOR underlie the NMR's extreme reaction to opioids.

  13. Effects of laboratory housing on exploratory behaviour, novelty discrimination and spatial reference memory in a subterranean, solitary rodent, the Cape mole-rat (Georychus capensis)

    OpenAIRE

    Oosthuizen, Maria Kathleen; Scheibler, Anne-Gita; Bennett, Nigel Charles; Amrein, Irmgard

    2013-01-01

    A large number of laboratory and field based studies are being carried out on mole-rats, both in our research group and others. Several studies have highlighted the development of adverse behaviours in laboratory animals and have emphasised the importance of enrichment for captive animals. Hence we were interested in evaluating how laboratory housing would affect behavioural performance in mole-rats. We investigated exploratory behaviour, the ability to discriminate between novel and familiar...

  14. Local and regional scale genetic variation in the Cape dune mole-rat, Bathyergus suillus.

    Science.gov (United States)

    Visser, Jacobus H; Bennett, Nigel C; Jansen van Vuuren, Bettine

    2014-01-01

    The distribution of genetic variation is determined through the interaction of life history, morphology and habitat specificity of a species in conjunction with landscape structure. While numerous studies have investigated this interplay of factors in species inhabiting aquatic, riverine, terrestrial, arboreal and saxicolous systems, the fossorial system has remained largely unexplored. In this study we attempt to elucidate the impacts of a subterranean lifestyle coupled with a heterogeneous landscape on genetic partitioning by using a subterranean mammal species, the Cape dune mole-rat (Bathyergus suillus), as our model. Bathyergus suillus is one of a few mammal species endemic to the Cape Floristic Region (CFR) of the Western Cape of South Africa. Its distribution is fragmented by rivers and mountains; both geographic phenomena that may act as geographical barriers to gene-flow. Using two mitochondrial fragments (cytochrome b and control region) as well as nine microsatellite loci, we determined the phylogeographic structure and gene-flow patterns at two different spatial scales (local and regional). Furthermore, we investigated genetic differentiation between populations and applied Bayesian clustering and assignment approaches to our data. Nearly every population formed a genetically unique entity with significant genetic structure evident across geographic barriers such as rivers (Berg, Verlorenvlei, Breede and Gourits Rivers), mountains (Piketberg and Hottentots Holland Mountains) and with geographic distance at both spatial scales. Surprisingly, B. suillus was found to be paraphyletic with respect to its sister species, B. janetta-a result largely overlooked by previous studies on these taxa. A systematic revision of the genus Bathyergus is therefore necessary. This study provides a valuable insight into how the biology, life-history and habitat specificity of animals inhabiting a fossorial system may act in concert with the structure of the surrounding

  15. Teasing apart socially-induced infertility in non-reproductive female Damaraland mole-rats, Fukomys damarensis (Rodentia: Bathyergidae).

    Science.gov (United States)

    Bennett, Nigel C

    2011-12-01

    The Damaraland mole-rat is a subterranean mammal exhibiting extreme reproductive skew with a single reproductive female in each colony responsible for procreation. Non-reproductive female colony members are physiologically suppressed while in the colony, exhibiting reduced concentrations of plasma luteinizing hormone (LH) and a decreased response of the pituitary, as measured by the release of bioactive LH, to an exogenous dose of gonadotrophin releasing hormone (GnRH). Removal of the reproductive female from the colony results in an elevation of LH and an enhanced response of the pituitary to a GnRH challenge in non-reproductive females comparable to reproductive females, implying control of reproduction in these individuals by the reproductive female. The Damaraland mole-rat is an ideal model for investigating the physiological and behavioral mechanisms that regulate the hypothalamo-pituitary-gonadal axis. In contrast, we know less about the control of reproduction at the level of the hypothalamus. The immunohistochemistry of the GnRH system of both reproductive and non-reproductive female Damaraland mole-rats has revealed no significant differences with respect to morphology, distribution or numbers of immunoreactive GnRH perikarya. We examined whether the endogenous opioid peptide beta-endorphin was responsible for the inhibition of the release of the GnRH from the neurons indirectly by measuring LH concentrations in these non-reproductive females following single, hourly and 8 hourly injections of the opioid antagonist naloxone. The results imply that the endogenous opioid peptide, beta-endorphin, is not responsible for the inhibition of GnRH release from the perikarya in non-reproductive females. Preliminary data examining the circulating levels of cortisol also do not support a role for circulating glucocorticoids. The possible role of kisspeptin is discussed.

  16. Gis-approach for variability assessment of soil electric conductivity under pedoturbation activity of mole rat (Spalax microphthalmus

    Directory of Open Access Journals (Sweden)

    T. М. Konovalova

    2010-06-01

    Full Text Available The results of the investigation of the impact of the mole rat’s activity on soil electric conductivity have been presented. GIS-technology have been shown to be effective for assessment of the pedoturbation activity effect on the soil surface heterogeneity formation. Method of the one-dimension spatial coordinated array transformation into matrix form has been proposed for following multidimension statistic analysis application. The quantity estimation of the mole rats role in formation of the habitat nanorelief-level diversity has been obtained by means of indexes of the landscape complexity and diversity.

  17. Transcriptome sequencing of the blind subterranean mole rat, Spalax galili: Utility and potential for the discovery of novel evolutionary patterns

    KAUST Repository

    Malik, Assaf

    2011-08-12

    The blind subterranean mole rat (Spalax ehrenbergi superspecies) is a model animal for survival under extreme environments due to its ability to live in underground habitats under severe hypoxic stress and darkness. Here we report the transcriptome sequencing of Spalax galili, a chromosomal type of S. ehrenbergi. cDNA pools from muscle and brain tissues isolated from animals exposed to hypoxic and normoxic conditions were sequenced using Sanger, GS FLX, and GS FLX Titanium technologies. Assembly of the sequences yielded over 51,000 isotigs with homology to ~12,000 mouse, rat or human genes. Based on these results, it was possible to detect large numbers of splice variants, SNPs, and novel transcribed regions. In addition, multiple differential expression patterns were detected between tissues and treatments. The results presented here will serve as a valuable resource for future studies aimed at identifying genes and gene regions evolved during the adaptive radiation associated with underground life of the blind mole rat. 2011 Malik et al.

  18. Transcriptome sequencing of the blind subterranean mole rat, Spalax galili: utility and potential for the discovery of novel evolutionary patterns.

    Directory of Open Access Journals (Sweden)

    Assaf Malik

    Full Text Available The blind subterranean mole rat (Spalax ehrenbergi superspecies is a model animal for survival under extreme environments due to its ability to live in underground habitats under severe hypoxic stress and darkness. Here we report the transcriptome sequencing of Spalax galili, a chromosomal type of S. ehrenbergi. cDNA pools from muscle and brain tissues isolated from animals exposed to hypoxic and normoxic conditions were sequenced using Sanger, GS FLX, and GS FLX Titanium technologies. Assembly of the sequences yielded over 51,000 isotigs with homology to ∼12,000 mouse, rat or human genes. Based on these results, it was possible to detect large numbers of splice variants, SNPs, and novel transcribed regions. In addition, multiple differential expression patterns were detected between tissues and treatments. The results presented here will serve as a valuable resource for future studies aimed at identifying genes and gene regions evolved during the adaptive radiation associated with underground life of the blind mole rat.

  19. Spatial and temporal activity patterns of the free-living giant mole-rat (Fukomys mechowii, the largest social bathyergid.

    Directory of Open Access Journals (Sweden)

    Matěj Lövy

    Full Text Available Despite the considerable attention devoted to the biology of social species of African mole-rats (Bathyergidae, Rodentia, knowledge is lacking about their behaviour under natural conditions. We studied activity of the largest social bathyergid, the giant mole-rat Fukomys mechowii, in its natural habitat in Zambia using radio-telemetry. We radio-tracked six individuals during three continuous 72-h sessions. Five of these individuals, including a breeding male, belonged to a single family group; the remaining female was probably a solitary disperser. The non-breeders of the family were active (i.e. outside the nest 5.8 hours per 24h-day with the activity split into 6.5 short bouts. The activity was more concentrated in the night hours, when the animals also travelled longer distances from the nest. The breeding male spent only 3.2 hours per day outside the nest, utilizing less than 20% of the whole family home range. The dispersing female displayed a much different activity pattern than the family members. Her 8.0 hours of outside-nest activity per day were split into 4.6 bouts which were twice as long as in the family non-breeders. Her activity peak in the late afternoon coincided with the temperature maximum in the depth of 10 cm (roughly the depth of the foraging tunnels. Our results suggest that the breeding individuals (at least males contribute very little to the work of the family group. Nevertheless, the amount of an individual's activity and its daily pattern are probably flexible in this species and can be modified in response to actual environmental and social conditions.

  20. Size variation in Tachyoryctes splendens (East African mole-rat) and its implications for late Quaternary temperature change in equatorial East Africa

    Science.gov (United States)

    Faith, J. Tyler; Patterson, David B.; Blegen, Nick; O'Neill, Chris J.; Marean, Curtis W.; Peppe, Daniel J.; Tryon, Christian A.

    2016-05-01

    This study develops a new proxy for Quaternary temperature change in tropical Africa through analysis of size variation in East African mole-rat (Tachyoryctes splendens). In modern mole-rats, mandibular alveolar length is unrelated to annual precipitation, precipitation seasonality, temperature seasonality, or primary productivity. However, it is inversely correlated with mean annual temperature, in agreement with Bergmann's rule. This relationship is observed at temperatures below ˜17.3 °C, but not at higher temperatures. We apply these observations to late Quaternary mole-rats from Wakondo (˜100 ka) and Kisaaka (˜50 ka) in the Lake Victoria region and Enkapune ya Muto (EYM; ˜7.2-3.2 ka) in Kenya's central rift. The Lake Victoria mole-rats are larger than expected for populations from warm climates typical of the area today, implying cooler temperatures in the past. The magnitude of temperature decline needed to drive the size shift is substantial (˜4-6 °C), similar in magnitude to the degree of change between the Last Glacial Maximum and Holocene, but is consistent with regional temperature records and with scenarios linking equatorial African temperature to northern hemisphere summer insolation. Size changes through time at EYM indicate that rising temperatures during the middle Holocene accompanied and potentially contributed to a decline in Lake Naivasha and expansion of grassland vegetation.

  1. Non-image Forming Light Detection by Melanopsin, Rhodopsin, and Long-Middlewave (L/W) Cone Opsin in the Subterranean Blind Mole Rat, Spalax Ehrenbergi

    DEFF Research Database (Denmark)

    Esquiva, Gema; Avivi, Aaron; Hannibal, Jens

    2016-01-01

    The blind mole rat, Spalax ehrenbergi, can, despite severely degenerated eyes covered by fur, entrain to the daily light/dark cycle and adapt to seasonal changes due to an intact circadian timing system. The present study demonstrates that the Spalax retina contains a photoreceptor layer, an outer...

  2. Effects of laboratory housing on exploratory behaviour, novelty discrimination and spatial reference memory in a subterranean, solitary rodent, the Cape mole-rat (Georychus capensis).

    Science.gov (United States)

    Oosthuizen, Maria Kathleen; Scheibler, Anne-Gita; Bennett, Nigel Charles; Amrein, Irmgard

    2013-01-01

    A large number of laboratory and field based studies are being carried out on mole-rats, both in our research group and others. Several studies have highlighted the development of adverse behaviours in laboratory animals and have emphasised the importance of enrichment for captive animals. Hence we were interested in evaluating how laboratory housing would affect behavioural performance in mole-rats. We investigated exploratory behaviour, the ability to discriminate between novel and familiar environments and reference memory in the solitary Cape mole-rat (Georychus capensis). Our data showed that both wild and captive animals readily explore open spaces and tunnels. Wild animals were however more active than their captive counterparts. In the Y maze two trial discrimination task, wild animals failed to discriminate between novel and familiar environments, while laboratory housed mole-rats showed preferential spatial discrimination in terms of the length of time spent in the novel arm. The performance of the laboratory and wild animals were similar when tested for reference memory in the Y maze, both groups showed a significant improvement compared to the first day, from the 3rd day onwards. Wild animals made more mistakes whereas laboratory animals were slower in completing the task. The difference in performance between wild and laboratory animals in the Y-maze may be as a result of the lower activity of the laboratory animals. Laboratory maintained Cape mole-rats show classic behaviours resulting from a lack of stimulation such as reduced activity and increased aggression. However, they do display an improved novelty discrimination compared to the wild animals. Slower locomotion rate of the laboratory animals may increase the integration time of stimuli, hence result in a more thorough inspection of the surroundings. Unlike the captive animals, wild animals show flexibility in their responses to unpredictable events, which is an important requirement under

  3. Dental peculiarities in the silvery mole-rat: an original model for studying the evolutionary and biological origins of continuous dental generation in mammals

    Directory of Open Access Journals (Sweden)

    Helder Gomes Rodrigues

    2015-09-01

    Full Text Available Unravelling the evolutionary and developmental mechanisms that have impacted the mammalian dentition, since more than 200 Ma, is an intricate issue. Interestingly, a few mammal species, including the silvery mole-rat Heliophobius argenteocinereus, are able to replace their dentition by the addition of supernumerary molars at the back of jaw migrating then toward the front. The aim here was to demonstrate the potential interest of further studying this rodent in order to better understand the origins of continuous dental replacement in mammals, which could also provide interesting data concerning the evolution of limited dental generation occurring in first mammals. In the present study, we described the main stages of the dental eruptive sequence in the silvery mole-rat and the associated characteristics of horizontal replacement using X-ray microtomography. This was coupled to the investigation of other African mole-rats which have no dental replacement. This method permitted to establish evidence that the initial development of the dentition in Heliophobius is comparable to what it is observed in most of African mole-rats. This rodent first has premolars, but then identical additional molars, a mechanism convergent to manatees and the pygmy rock-wallaby. Evidence of continuous replacement and strong dental dynamics were also illustrated in Heliophobius, and stressed the need to deeply investigate these aspects for evolutionary, functional and developmental purposes. We also noticed that two groups of extinct non-mammalian synapsids convergently acquired this dental mechanism, but in a way differing from extant mammals. The discussion on the diverse evolutionary origins of horizontal dental replacement put emphasis on the necessity of focusing on biological parameters potentially involved in both continuous and limited developments of teeth in mammals. In that context, the silvery mole-rat could appear as the most appropriate candidate to do so.

  4. Circadian genes in a blind subterranean mammal II: Conservation and uniqueness of the three Period homologs in the blind subterranean mole rat, Spalax ehrenbergi superspecies

    OpenAIRE

    Avivi, A; Oster, H; A Joel; BEILES, A.; Albrecht, U; Nevo, E.

    2002-01-01

    We demonstrated that a subterranean, visually blind mammal has a functional set of three Per genes that are important components of the circadian clockwork in mammals. The mole rat superspecies Spalax ehrenbergi is a blind subterranean animal that lives its entire life underground in darkness. It has degenerated eyes, but the retina and highly hypertrophic harderian gland are involved in photoperiodic perception. All three Per genes oscillate with a periodicity of 24 h in the suprachiasmatic ...

  5. Low sulfide levels and a high degree of cystathionine β-synthase (CBS) activation by S-adenosylmethionine (SAM) in the long-lived naked mole-rat.

    Science.gov (United States)

    Dziegelewska, Maja; Holtze, Susanne; Vole, Christiane; Wachter, Ulrich; Menzel, Uwe; Morhart, Michaela; Groth, Marco; Szafranski, Karol; Sahm, Arne; Sponholz, Christoph; Dammann, Philip; Huse, Klaus; Hildebrandt, Thomas; Platzer, Matthias

    2016-08-01

    Hydrogen sulfide (H2S) is a gaseous signalling molecule involved in many physiological and pathological processes. There is increasing evidence that H2S is implicated in aging and lifespan control in the diet-induced longevity models. However, blood sulfide concentration of naturally long-lived species is not known. Here we measured blood sulfide in the long-lived naked mole-rat and five other mammalian species considerably differing in lifespan and found a negative correlation between blood sulfide and maximum longevity residual. In addition, we show that the naked mole-rat cystathionine β-synthase (CBS), an enzyme whose activity in the liver significantly contributes to systemic sulfide levels, has lower activity in the liver and is activated to a higher degree by S-adenosylmethionine compared to other species. These results add complexity to the understanding of the role of H2S in aging and call for detailed research on naked mole-rat transsulfuration. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  6. Low sulfide levels and a high degree of cystathionine β-synthase (CBS activation by S-adenosylmethionine (SAM in the long-lived naked mole-rat

    Directory of Open Access Journals (Sweden)

    Maja Dziegelewska

    2016-08-01

    Full Text Available Hydrogen sulfide (H2S is a gaseous signalling molecule involved in many physiological and pathological processes. There is increasing evidence that H2S is implicated in aging and lifespan control in the diet-induced longevity models. However, blood sulfide concentration of naturally long-lived species is not known. Here we measured blood sulfide in the long-lived naked mole-rat and five other mammalian species considerably differing in lifespan and found a negative correlation between blood sulfide and maximum longevity residual. In addition, we show that the naked mole-rat cystathionine β-synthase (CBS, an enzyme whose activity in the liver significantly contributes to systemic sulfide levels, has lower activity in the liver and is activated to a higher degree by S-adenosylmethionine compared to other species. These results add complexity to the understanding of the role of H2S in aging and call for detailed research on naked mole-rat transsulfuration.

  7. Application prospects of naked mole rats in biomedical research%裸鼹鼠在生物医学研究中的应用前景

    Institute of Scientific and Technical Information of China (English)

    崔淑芳

    2016-01-01

    裸鼹鼠是一种奇特的动物,具有寿命长、抗肿瘤、耐缺氧、新陈代谢率低、痛觉缺失、触觉灵敏、视觉功能低下、骨骼再生能力强等诸多特点。本文在概述裸鼹鼠上述生物学特点的基础上,结合当前肿瘤、衰老、低氧适应以及疼痛等领域研究趋势,对裸鼹鼠在生物医学研究中的应用前景进行分析与展望。%Naked mole rats are unique animals with long lifetime, anti-tumor properties, hypoxia tolerance, low metabolic rate, analgesia, tactile sensitiveness, poor eyesight and strong bone regeneration ability. Based on the basic bio-logical characteristics of naked mole rats, and the current research trends in the field of cancer, aging, hypoxia tolerance, as well as algesia, this review focuses on the application prospects of naked mole rats in biomedical research.

  8. Non-Breeding Eusocial Mole-Rats Produce Viable Sperm--Spermiogram and Functional Testicular Morphology of Fukomys anselli.

    Directory of Open Access Journals (Sweden)

    Angelica Garcia Montero

    Full Text Available Ansell's mole-rats (Fukomys anselli are subterranean rodents living in families composed of about 20 members with a single breeding pair and their non-breeding offspring. Most of them remain with their parents for their lifetime and help to maintain and defend the natal burrow system, forage, and care for younger siblings. Since incest avoidance is based on individual recognition (and not on social suppression we expect that non-breeders produce viable sperm spontaneously. We compared the sperm of breeding and non-breeding males, obtained by electroejaculation and found no significant differences in sperm parameters between both groups. Here, we used electroejaculation to obtain semen for the first time in a subterranean mammal. Spermiogram analysis revealed no significant differences in sperm parameters between breeders and non-breeders. We found significantly larger testes (measured on autopsies and on living animals per ultrasonography of breeders compared to non-breeders (with body mass having a significant effect. There were no marked histological differences between breeding and non-breeding males, and the relative area occupied by Leydig cells and seminiferous tubules on histological sections, respectively, was not significantly different between both groups. The seminiferous epithelium and to a lesser degree the interstitial testicular tissue are characterized by lesions (vacuolar degenerations, however, this feature does not hinder fertilization even in advanced stages of life. The continuous production of viable sperm also in sexually abstinent non-breeders might be best understood in light of the mating and social system of Fukomys anselli, and the potential to found a new family following an unpredictable and rare encounter with an unfamiliar female ("provoked or induced dispersal". Apparently, the non-breeders do not reproduce because they do not copulate but not because they would be physiologically infertile. The significantly

  9. Non-Breeding Eusocial Mole-Rats Produce Viable Sperm—Spermiogram and Functional Testicular Morphology of Fukomys anselli

    Science.gov (United States)

    Garcia Montero, Angelica; Vole, Christiane; Burda, Hynek; Malkemper, Erich Pascal; Holtze, Susanne; Morhart, Michaela; Saragusty, Joseph; Hildebrandt, Thomas B.; Begall, Sabine

    2016-01-01

    Ansell’s mole-rats (Fukomys anselli) are subterranean rodents living in families composed of about 20 members with a single breeding pair and their non-breeding offspring. Most of them remain with their parents for their lifetime and help to maintain and defend the natal burrow system, forage, and care for younger siblings. Since incest avoidance is based on individual recognition (and not on social suppression) we expect that non-breeders produce viable sperm spontaneously. We compared the sperm of breeding and non-breeding males, obtained by electroejaculation and found no significant differences in sperm parameters between both groups. Here, we used electroejaculation to obtain semen for the first time in a subterranean mammal. Spermiogram analysis revealed no significant differences in sperm parameters between breeders and non-breeders. We found significantly larger testes (measured on autopsies and on living animals per ultrasonography) of breeders compared to non-breeders (with body mass having a significant effect). There were no marked histological differences between breeding and non-breeding males, and the relative area occupied by Leydig cells and seminiferous tubules on histological sections, respectively, was not significantly different between both groups. The seminiferous epithelium and to a lesser degree the interstitial testicular tissue are characterized by lesions (vacuolar degenerations), however, this feature does not hinder fertilization even in advanced stages of life. The continuous production of viable sperm also in sexually abstinent non-breeders might be best understood in light of the mating and social system of Fukomys anselli, and the potential to found a new family following an unpredictable and rare encounter with an unfamiliar female (“provoked or induced dispersal”). Apparently, the non-breeders do not reproduce because they do not copulate but not because they would be physiologically infertile. The significantly increased

  10. Non-Breeding Eusocial Mole-Rats Produce Viable Sperm--Spermiogram and Functional Testicular Morphology of Fukomys anselli.

    Science.gov (United States)

    Garcia Montero, Angelica; Vole, Christiane; Burda, Hynek; Malkemper, Erich Pascal; Holtze, Susanne; Morhart, Michaela; Saragusty, Joseph; Hildebrandt, Thomas B; Begall, Sabine

    2016-01-01

    Ansell's mole-rats (Fukomys anselli) are subterranean rodents living in families composed of about 20 members with a single breeding pair and their non-breeding offspring. Most of them remain with their parents for their lifetime and help to maintain and defend the natal burrow system, forage, and care for younger siblings. Since incest avoidance is based on individual recognition (and not on social suppression) we expect that non-breeders produce viable sperm spontaneously. We compared the sperm of breeding and non-breeding males, obtained by electroejaculation and found no significant differences in sperm parameters between both groups. Here, we used electroejaculation to obtain semen for the first time in a subterranean mammal. Spermiogram analysis revealed no significant differences in sperm parameters between breeders and non-breeders. We found significantly larger testes (measured on autopsies and on living animals per ultrasonography) of breeders compared to non-breeders (with body mass having a significant effect). There were no marked histological differences between breeding and non-breeding males, and the relative area occupied by Leydig cells and seminiferous tubules on histological sections, respectively, was not significantly different between both groups. The seminiferous epithelium and to a lesser degree the interstitial testicular tissue are characterized by lesions (vacuolar degenerations), however, this feature does not hinder fertilization even in advanced stages of life. The continuous production of viable sperm also in sexually abstinent non-breeders might be best understood in light of the mating and social system of Fukomys anselli, and the potential to found a new family following an unpredictable and rare encounter with an unfamiliar female ("provoked or induced dispersal"). Apparently, the non-breeders do not reproduce because they do not copulate but not because they would be physiologically infertile. The significantly increased testes

  11. Relic populations of Fukomys mole-rats in Tanzania: description of two new species F. livingstoni sp. nov. and F. hanangensis sp. nov.

    Directory of Open Access Journals (Sweden)

    Chris G. Faulkes

    2017-04-01

    Full Text Available Previous studies of African mole-rats of the genera Heliophobius and Fukomys (Bathyergidae in the regions of East and south central Africa have revealed a diversity of species and vicariant populations, with patterns of distribution having been influenced by the geological process of rifting and changing patterns of drainage of major river systems. This has resulted in most of the extant members of the genus Fukomys being distributed west of the main Rift Valley. However, a small number of isolated populations are known to occur east of the African Rift Valley in Tanzania, where Heliophobius is the most common bathyergid rodent. We conducted morphological, craniometric and phylogenetic analysis of mitochondrial cytochrome b (cyt b sequences of two allopatric populations of Tanzanian mole-rats (genus Fukomys at Ujiji and around Mount Hanang, in comparison with both geographically adjacent and more distant populations of Fukomys. Our results reveal two distinct evolutionary lineages, forming clades that constitute previously unnamed species. Here, we formally describe and designate these new species F. livingstoni and F. hanangensis respectively. Molecular clock-based estimates of divergence times, together with maximum likelihood inference of biogeographic range evolution, offers strong support for the hypothesis that vicariance in the Western Rift Valley and the drainage patterns of major river systems has subdivided populations of mole-rats. More recent climatic changes and tectonic activity in the “Mbeya triple junction” and Rungwe volcanic province between Lakes Rukwa and Nyasa have played a role in further isolation of these extra-limital populations of Fukomys in Tanzania.

  12. Neuroanatomical investigation of the gonadotrophin-releasing hormone 1 system in the seasonally breeding Cape dune mole-rat, Bathyergus suillus.

    Science.gov (United States)

    Hart, Leanne; Bennett, Nigel C; Kalamatianos, Theodosis; Oosthuizen, Maria K; Jarvis, Jennifer U M; O'Riain, M Justin; Coen, Clive W

    2008-10-22

    The gonadotrophin-releasing hormone 1 (GnRH1) system has been investigated immunohistochemically in Cape dune mole-rats (Bathyergus suillus), subterranean rodents that normally display severe aggression towards conspecifics. These animals breed seasonally and show a reduced mean plasma level of luteinising hormone during the non-breeding season. GnRH1-immunoreactive (ir) cell bodies and processes are found in the septal/preoptic area and the mediobasal hypothalamus; the cell bodies are found in equal measure in these two regions. Dense aggregations of GnRH1-ir fibres are present in the organum vasculosum of the lamina terminalis and the external zone of the median eminence. The total number of detectable GnRH1-ir cell bodies does not differ between the sexes or within the sexes between breeding and non-breeding seasons. Similarly there is no difference in the distribution of detectable GnRH1-ir cell bodies in male and female mole-rats in and out of the breeding season. Although the average size of GnRH1-ir cell bodies does not differ between the seasons in males, their size in females is significantly smaller in the non-breeding season. Whether this reduced size reflects reduced GnRH1 synthesis remains to be determined.

  13. Reproduction is associated with a tissue-dependent reduction of oxidative stress in eusocial female Damaraland mole-rats (Fukomys damarensis.

    Directory of Open Access Journals (Sweden)

    Christina M Schmidt

    Full Text Available Oxidative stress has been implicated as both a physiological cost of reproduction and a driving force on an animal's lifespan. Since increased reproductive effort is generally linked with a reduction in survival, it has been proposed that oxidative stress may influence this relationship. Support for this hypothesis is inconsistent, but this may, in part, be due to the type of tissues that have been analyzed. In Damaraland mole-rats the sole reproducing female in the colony is also the longest lived. Therefore, if oxidative stress does impact the trade-off between reproduction and survival in general, this species may possess some form of enhanced defense. We assessed this relationship by comparing markers of oxidative damage (malondialdehyde, MDA; protein carbonyls, PC and antioxidants (total antioxidant capacity, TAC; superoxide dismutase, SOD in various tissues including plasma, erythrocytes, heart, liver, kidney and skeletal muscle between wild-caught reproductive and non-reproductive female Damaraland mole-rats. Reproductive females exhibited significantly lower levels of PC across all tissues, and lower levels of MDA in heart, kidney and liver relative to non-reproductive females. Levels of TAC and SOD did not differ significantly according to reproductive state. The reduction in oxidative damage in breeding females may be attributable to the unusual social structure of this species, as similar relationships have been observed between reproductive and non-reproductive eusocial insects.

  14. How attractive is the girl next door? An assessment of spatial mate acquisition and paternity in the solitary Cape dune mole-rat, Bathyergus suillus.

    Directory of Open Access Journals (Sweden)

    Timothy C Bray

    Full Text Available Behavioural observations of reproduction and mate choice in wild fossorial rodents are extremely limited and consequently indirect methods are typically used to infer mating strategies. We use a combination of morphological, reproductive, spatial, and genetic data to investigate the reproductive strategy of a solitary endemic species, the Cape dune mole-rat Bathyergus suillus. These data provide the first account on the population dynamics of this species. Marked sexual dimorphism was apparent with males being both significantly larger and heavier than females. Of all females sampled 36% had previously reproduced and 12% were pregnant at the time of capture. Post-partum sex ratio was found to be significantly skewed in favour of females. The paternity of fifteen litters (n = 37 was calculated, with sires assigned to progeny using both categorical and full probability methods, and including a distance function. The maximum distance between progeny and a putative sire was determined as 2149 m with males moving between sub-populations. We suggest that above-ground movement should not be ignored in the consideration of mate acquisition behaviour of subterranean mammals. Estimated levels of multiple paternity were shown to be potentially as high as 26%, as determined using sibship and sire assignment methods. Such high levels of multiple paternity have not been found in other solitary mole-rat species. The data therefore suggest polyandry with no evidence as yet for polygyny.

  15. Relations between social status and the gonadotrophin-releasing hormone system in females of two cooperatively breeding species of African mole-rats, Cryptomys hottentotus hottentotus and Cryptomys hottentotus pretoriae: neuroanatomical and neuroendocrinological studies.

    Science.gov (United States)

    Du Toit, Lydia; Bennett, Nigel C; Katz, Arieh A; Kalló, Imre; Coen, Clive W

    2006-01-10

    In common (Cryptomys hottentotus hottentotus) and highveld (Cryptomys hottentotus pretoriae) mole-rats, reproduction is subject to two forms of regulation in addition to incest avoidance. These are the only social bathyergids known to restrict breeding to a particular season; furthermore, subordinate members of their colonies show suppressed reproduction throughout the year. Females from both species were assessed and compared for social and seasonal effects on the gonadotrophin-releasing hormone (GnRH) system. GnRH-immunoreactive (ir) structures were visualized immunohistochemically; GnRH content was determined by radioimmunoassay. In both species, GnRH-ir cell bodies and processes are loosely distributed along the septopreopticoinfundibular continuum, with dense fiber aggregations in the region of the organum vasculosum of the lamina terminalis and median eminence. The two species differ in the rostrocaudal distribution of their GnRH-ir cell bodies. In highveld mole-rats, most of these cells are in the septal/preoptic area; in common mole-rats, more than half of them are in the mediobasal hypothalamus. Compared with common mole-rats, highveld mole-rats have a greater total number of GnRH-ir cell bodies, higher GnRH content, and more intense GnRH immunoreactivity in the median eminence. Within highveld colonies, the nonreproductive females have larger GnRH-ir cell bodies, more intense GnRH immunoreactivity in the median eminence, and higher GnRH content than the reproductive females; these findings suggest inhibited release of GnRH in the nonreproductive, subordinate females. In contrast, in common mole-rat females, neither status nor season appears to affect the investigated parameters of the GnRH system; this suggests a predominantly behavioral basis to their suppressed reproduction.

  16. Circadian genes in a blind subterranean mammal II: conservation and uniqueness of the three Period homologs in the blind subterranean mole rat, Spalax ehrenbergi superspecies.

    Science.gov (United States)

    Avivi, Aaron; Oster, Henrik; Joel, Alma; Beiles, Avigdor; Albrecht, Urs; Nevo, Eviatar

    2002-09-03

    We demonstrated that a subterranean, visually blind mammal has a functional set of three Per genes that are important components of the circadian clockwork in mammals. The mole rat superspecies Spalax ehrenbergi is a blind subterranean animal that lives its entire life underground in darkness. It has degenerated eyes, but the retina and highly hypertrophic harderian gland are involved in photoperiodic perception. All three Per genes oscillate with a periodicity of 24 h in the suprachiasmatic nuclei, eye, and harderian gland and are expressed in peripheral organs. This oscillation is maintained under constant conditions. The light inducibility of sPer1 and sPer2, which are similar in structure to those of other mammals, indicates the role of these genes in clock resetting. However, sPer3 is unique in mammals and has two truncated isoforms, and its expressional analysis leaves its function unresolved. Per's expression analysis in the harderian gland suggests an important participation of this organ in the stabilization and resetting mechanism of the central pacemaker in the suprachiasmatic nuclei and in unique adaptation to life underground.

  17. Taxonomic confusion of two tramp ant species: Iridomyrmex anceps and Ochetellus glaber are really species complexes

    Institute of Scientific and Technical Information of China (English)

    Benjamin D. HOFFMANN; Alan N. ANDERSEN; Xiang ZHANG

    2011-01-01

    Many invasive invertebrates belong to unresolved species complexes,and have a history of misidentification and inappropriate management.Here we detail confusion surrounding the taxonomy and identification of two dolichoderine ant species,Iridomyrmex anceps Roger and Ochetellus glaber Mayr,which are commonly cited in the literature as having been spread widely by human commerce.We provide morphometric data and images strongly suggesting that these two “species” are instead complexes of species that are likely native to many regions where they are purportedly introduced.We take particular interest in the status of species referred to as I.anceps and O.glaber in China,as this is the most northerly distribution of both genera.We conclude by suggesting that many identifications of both species are likely to be unreliable,and we recommend against any management action aimed at controlling these species under the assumption that they are exotic [Current Zoology 57 (5):662-667,2011].

  18. Analysis of Alpha-2 Macroglobulin from the Long-Lived and Cancer-Resistant Naked Mole-Rat and Human Plasma.

    Directory of Open Access Journals (Sweden)

    René Thieme

    Full Text Available The naked mole-rat (NMR is a long-lived and cancer resistant species. Identification of potential anti-cancer and age related mechanisms is of great interest and makes this species eminent to investigate anti-cancer strategies and understand aging mechanisms. Since it is known that the NMR expresses higher liver mRNA-levels of alpha 2-macroglobulin than mice, nothing is known about its structure, functionality or expression level in the NMR compared to the human A2M.Here we show a comprehensive analysis of NMR- and human plasma-A2M, showing a different prediction in glycosylation of NMR-A2M, which results in a higher molecular weight compared to human A2M. Additionally, we found a higher concentration of A2M (8.3±0.44 mg/mL vs. and 4.4±0.20 mg/mL and a lower total plasma protein content (38.7±1.79 mg/mL vs. 61.7±3.20 mg/mL in NMR compared to human. NMR-A2M can be transformed by methylamine and trypsin resulting in a conformational change similar to human A2M. NMR-A2M is detectable by a polyclonal antibody against human A2M. Determination of tryptic and anti-tryptic activity of NMR and human plasma revealed a higher anti-tryptic activity of the NMR plasma. On the other hand, less proteolytic activity was found in NMR plasma compared to human plasma.We found transformed NMR-A2M binding to its specific receptor LRP1. We could demonstrate lower protein expression of LRP1 in the NMR liver tissue compared to human but higher expression of A2M. This was accompanied by a higher EpCAM protein expression as central adhesion molecule in cancer progression. NMR-plasma was capable to increase the adhesion in human fibroblast in vitro most probably by increasing CD29 protein expression. This is the first report, demonstrating similarities as well as distinct differences between A2M in NMR and human plasma. This might be directly linked to the intriguing phenotype of the NMR and suggests that A2M might probably play an important role in anti-cancer and the

  19. Analysis of Alpha-2 Macroglobulin from the Long-Lived and Cancer-Resistant Naked Mole-Rat and Human Plasma.

    Science.gov (United States)

    Thieme, René; Kurz, Susanne; Kolb, Marlen; Debebe, Tewodros; Holtze, Susanne; Morhart, Michaela; Huse, Klaus; Szafranski, Karol; Platzer, Matthias; Hildebrandt, Thomas B; Birkenmeier, Gerd

    2015-01-01

    The naked mole-rat (NMR) is a long-lived and cancer resistant species. Identification of potential anti-cancer and age related mechanisms is of great interest and makes this species eminent to investigate anti-cancer strategies and understand aging mechanisms. Since it is known that the NMR expresses higher liver mRNA-levels of alpha 2-macroglobulin than mice, nothing is known about its structure, functionality or expression level in the NMR compared to the human A2M. Here we show a comprehensive analysis of NMR- and human plasma-A2M, showing a different prediction in glycosylation of NMR-A2M, which results in a higher molecular weight compared to human A2M. Additionally, we found a higher concentration of A2M (8.3±0.44 mg/mL vs. and 4.4±0.20 mg/mL) and a lower total plasma protein content (38.7±1.79 mg/mL vs. 61.7±3.20 mg/mL) in NMR compared to human. NMR-A2M can be transformed by methylamine and trypsin resulting in a conformational change similar to human A2M. NMR-A2M is detectable by a polyclonal antibody against human A2M. Determination of tryptic and anti-tryptic activity of NMR and human plasma revealed a higher anti-tryptic activity of the NMR plasma. On the other hand, less proteolytic activity was found in NMR plasma compared to human plasma. We found transformed NMR-A2M binding to its specific receptor LRP1. We could demonstrate lower protein expression of LRP1 in the NMR liver tissue compared to human but higher expression of A2M. This was accompanied by a higher EpCAM protein expression as central adhesion molecule in cancer progression. NMR-plasma was capable to increase the adhesion in human fibroblast in vitro most probably by increasing CD29 protein expression. This is the first report, demonstrating similarities as well as distinct differences between A2M in NMR and human plasma. This might be directly linked to the intriguing phenotype of the NMR and suggests that A2M might probably play an important role in anti-cancer and the anti

  20. Repeated functional convergent effects of NaV1.7 on acid insensitivity in hibernating mammals.

    Science.gov (United States)

    Liu, Zhen; Wang, Wei; Zhang, Tong-Zuo; Li, Gong-Hua; He, Kai; Huang, Jing-Fei; Jiang, Xue-Long; Murphy, Robert W; Shi, Peng

    2014-02-07

    Hibernating mammals need to be insensitive to acid in order to cope with conditions of high CO2; however, the molecular basis of acid tolerance remains largely unknown. The African naked mole-rat (Heterocephalus glaber) and hibernating mammals share similar environments and physiological features. In the naked mole-rat, acid insensitivity has been shown to be conferred by the functional motif of the sodium ion channel NaV1.7. There is now an opportunity to evaluate acid insensitivity in other taxa. In this study, we tested for functional convergence of NaV1.7 in 71 species of mammals, including 22 species that hibernate. Our analyses revealed a functional convergence of amino acid sequences, which occurred at least six times independently in mammals that hibernate. Evolutionary analyses determined that the convergence results from both parallel and divergent evolution of residues in the functional motif. Our findings not only identify the functional molecules responsible for acid insensitivity in hibernating mammals, but also open new avenues to elucidate the molecular underpinnings of acid insensitivity in mammals.

  1. Non-image Forming Light Detection by Melanopsin, Rhodopsin, and Long-Middlewave (L/W) Cone Opsin in the Subterranean Blind Mole Rat, Spalax Ehrenbergi: Immunohistochemical Characterization, Distribution, and Connectivity.

    Science.gov (United States)

    Esquiva, Gema; Avivi, Aaron; Hannibal, Jens

    2016-01-01

    The blind mole rat, Spalax ehrenbergi, can, despite severely degenerated eyes covered by fur, entrain to the daily light/dark cycle and adapt to seasonal changes due to an intact circadian timing system. The present study demonstrates that the Spalax retina contains a photoreceptor layer, an outer nuclear layer (ONL), an outer plexiform layer (OPL), an inner nuclear layer (INL), an inner plexiform layer (IPL), and a ganglion cell layer (GCL). By immunohistochemistry, the number of melanopsin (mRGCs) and non-melanopsin bearing retinal ganglion cells was analyzed in detail. Using the ganglion cell marker RNA-binding protein with multiple splicing (RBPMS) it was shown that the Spalax eye contains 890 ± 62 RGCs. Of these, 87% (752 ± 40) contain melanopsin (cell density 788 melanopsin RGCs/mm(2)). The remaining RGCs were shown to co-store Brn3a and calretinin. The melanopsin cells were located mainly in the GCL with projections forming two dendritic plexuses located in the inner part of the IPL and in the OPL. Few melanopsin dendrites were also found in the ONL. The Spalax retina is rich in rhodopsin and long/middle wave (L/M) cone opsin bearing photoreceptor cells. By using Ctbp2 as a marker for ribbon synapses, both rods and L/M cone ribbons containing pedicles in the OPL were found in close apposition with melanopsin dendrites in the outer plexus suggesting direct synaptic contact. A subset of cone bipolar cells and all photoreceptor cells contain recoverin while a subset of bipolar and amacrine cells contain calretinin. The calretinin expressing amacrine cells seemed to form synaptic contacts with rhodopsin containing photoreceptor cells in the OPL and contacts with melanopsin cell bodies and dendrites in the IPL. The study demonstrates the complex retinal circuitry used by the Spalax to detect light, and provides evidence for both melanopsin and non-melanopsin projecting pathways to the brain.

  2. Molecular evolution of the hyaluronan synthase 2 gene in mammals: implications for adaptations to the subterranean niche and cancer resistance.

    Science.gov (United States)

    Faulkes, Christopher G; Davies, Kalina T J; Rossiter, Stephen J; Bennett, Nigel C

    2015-05-01

    The naked mole-rat (NMR) Heterocephalus glaber is a unique and fascinating mammal exhibiting many unusual adaptations to a subterranean lifestyle. The recent discovery of their resistance to cancer and exceptional longevity has opened up new and important avenues of research. Part of this resistance to cancer has been attributed to the fact that NMRs produce a modified form of hyaluronan--a key constituent of the extracellular matrix--that is thought to confer increased elasticity of the skin as an adaptation for living in narrow tunnels. This so-called high molecular mass hyaluronan (HMM-HA) stems from two apparently unique substitutions in the hyaluronan synthase 2 enzyme (HAS2). To test whether other subterranean mammals with similar selection pressures also show molecular adaptation in their HAS2 gene, we sequenced the HAS2 gene for 11 subterranean mammals and closely related species, and combined these with data from 57 other mammals. Comparative screening revealed that one of the two putatively important HAS2 substitutions in the NMR predicted to have a significant effect on hyaluronan synthase function was uniquely shared by all African mole-rats. Interestingly, we also identified multiple other amino acid substitutions in key domains of the HAS2 molecule, although the biological consequences of these for hyaluronan synthesis remain to be determined. Despite these results, we found evidence of strong purifying selection acting on the HAS2 gene across all mammals, and the NMR remains unique in its particular HAS2 sequence. Our results indicate that more work is needed to determine whether the apparent cancer resistance seen in NMR is shared by other members of the African mole-rat clade. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  3. Ecology of mole rats Tachyoryctes splendens and its impact on farmlands at Angacha, central Ethiopia%长毛速掘鼠的生态学以及对埃塞俄比亚中部Angacha地区农田的影响

    Institute of Scientific and Technical Information of China (English)

    Abebe KOKISO; Afework BEKELE

    2008-01-01

    Studies on the distribution, abundance and impact of mole rat Tachyoryctes splendens in farmlands at Angacha, Ethiopia, were carried out from August 2005 to April 2006 covering both wet and dry seasons. Direct total count was carried out from fresh mounds to estimate the abundance and distribution of mole rats. Stomach content analysis was carried out to determine the food contents of mole rats at four sites representing "Dega" (cool) and "Woina-dega" (warm) temperate climatic zones. Total count by digging and using local trap catches depicted that "Dega" climatic zone sites, Lemi-suticho and Serera-bokata, harbored more mole rat population, 12 and 15 individuals /ha, respectively than "Woina-dega"climatic zone sites, Angacha-01 (7/ha) and Kerekicho (10/ha). 31 individuals consisting of 22 adults and nine juveniles, were captured. Male to female sex ratito nearby crop fields. Drainage, fertility of soil and availability of food resources were the main factors that reduced the length of burrow systems (11.3-18.6m). There was no significant difference in the length and depth of foraging tunnel, bolthole, and nest between males and females. Loss on enset plantation Ensete ventricosum is about 12% for the whole district. Such loss can greatly affect the economy of people where there is a large family size. Mole rats are the major rodent pests on enset and potatoes though their effect on other crops is minor. It is crucial to devise a proper control method to minimize the impact on economically important food enset.%于2005年8月-2006年4月研究了埃塞俄比亚Angacha地区农田中的长毛速掘鼠的分布、多度以及影响.通过直接计数地面的新隆起来估计速掘鼠的分布和多度,通过分析胃容物确定了四个地区(分别代表了"凉爽"和"温暖"的温带气候区)速掘鼠的食物成分.通过挖洞和鼠夹捕捉发现,两个凉爽区域内速掘鼠的数量分别为12只/ha和15只/ha,而温暖区域内的数量分别为7

  4. Structural and functional differences of the reproductive system in fertile and infertile male naked mole rats%雄性裸鼹鼠可育个体与不可育个体生殖系统结构与功能差异初探

    Institute of Scientific and Technical Information of China (English)

    余琛琳; 林丽芳; 袁子彦; 赵善民; 汤球; 孙伟; 蔡丽萍; 徐晨; 崔淑芳

    2016-01-01

    目的:观察和分析雄性裸鼹鼠中可育个体和不可育个体生殖系统结构和功能的差异,初步探索雄性不可育个体不能繁育后代的原因。方法雄性裸鼹鼠可育个体和不可育个体各5只,先采集一侧睾丸和附睾组织,称重后换算脏器系数;再采集另一侧睾丸组织,用中性甲醛溶液进行固定后制备组织切片;取另一侧附睾用作精子计数、精子活动度的测定;采集血清测定血清中黄体生成素( LH)和睾酮( T)浓度。结果与可育个体组相比较,不可育个体组的睾丸重量下降(P<0.05),附睾重量显著下降(P<0.01),且睾丸系数和附睾系数均显著下降(P<0.01);精子数量显著减少(P<0.01),精子活动度也显著减弱(P<0.01);血清黄体生成素和睾酮水平均显著降低(P<0.01);睾丸组织切片观察显示,不可育个体各级生精细胞严重脱落,排列混乱无序,支持细胞和间质细胞均有减少。结论雄性裸鼹鼠不可育个体生殖系统存在睾丸和附睾萎缩、生精功能下降和性激素分泌减少等现象。%Objective The aim of this study was to observe and analyze the differences of reproductive system in fertile and infertile male naked mole rats. Methods Five fertile and 5 infertile 2-5-year old male naked mole rats were used in this study. The testis and epididymis on one side were collected, weighted, and measured to get their viscera coeffi-cient. The other side testicle was collected and fixed in neutral formalin solution for histological examination. The other side epididymis was used to examine the sperm count and sperm activity. Serum of the naked mole rats was collected to measure the level of luteinizing hormone ( LH) and testosterone ( T) . Results Compared with the fertile group, the testis weight of infertile group was significantly decreased (P<0. 05), their epididymis weight, testicular coefficient and the

  5. Evolutionary adaptation of the sensitivity of connexin26 hemichannels to CO2.

    Science.gov (United States)

    de Wolf, Elizabeth; Cook, Jonathan; Dale, Nicholas

    2017-02-08

    CO2 readily combines with H2O to form [Formula: see text] and H(+) Because an increase of only 100 nM in the concentration of H(+) (a decrease of 0.1 unit of pH) in blood can prove fatal, the regulated excretion of CO2 during breathing is an essential life-preserving process. In rodents and humans, this vital process is mediated in part via the direct sensing of CO2 via connexin26 (Cx26). CO2 binds to hemichannels of Cx26 causing them to open and allow release of the neurotransmitter ATP. If Cx26 were to be a universal and important CO2 sensor across all homeothermic animals, then a simple hypothesis would posit that it should exhibit evolutionary adaptation in animals with different homeostatic set points for the regulation of partial pressure of arterial CO2 (PaCO2). In humans and rats, PaCO2 is regulated around a set point of 40 mmHg. By contrast, birds are able to maintain cerebral blood flow and breathing at much lower levels of PaCO2 Fossorial mammals, such as the mole rat, live exclusively underground in burrows that are both hypoxic and hypercapnic and can thrive under very hypercapnic conditions. We have therefore compared the CO2 sensitivity of Cx26 from human, chicken, rat and mole rat (Heterocephalus glaber). We find that both the affinity and cooperativity of CO2 binding to Cx26 have been subjected to evolutionary adaption in a manner consistent with the homeostatic requirements of these four species. This is analogous to the evolutionary adaptation of haemoglobin to the needs of O2 transport across the animal kingdom and supports the hypothesis that Cx26 is an important and universal CO2 sensor in homeotherms.

  6. Oxidative Stress in Aging: Advances in Proteomic Approaches

    Directory of Open Access Journals (Sweden)

    Daniel Ortuño-Sahagún

    2014-01-01

    Full Text Available Aging is a gradual, complex process in which cells, tissues, organs, and the whole organism itself deteriorate in a progressive and irreversible manner that, in the majority of cases, implies pathological conditions that affect the individual’s Quality of Life (QOL. Although extensive research efforts in recent years have been made, the anticipation of aging and prophylactic or treatment strategies continue to experience major limitations. In this review, the focus is essentially on the compilation of the advances generated by cellular expression profile analysis through proteomics studies (two-dimensional [2D] electrophoresis and mass spectrometry [MS], which are currently used as an integral approach to study the aging process. Additionally, the relevance of the oxidative stress factors is discussed. Emphasis is placed on postmitotic tissues, such as neuronal, muscular, and red blood cells, which appear to be those most frequently studied with respect to aging. Additionally, models for the study of aging are discussed in a number of organisms, such as Caenorhabditis elegans, senescence-accelerated probe-8 mice (SAMP8, naked mole-rat (Heterocephalus glaber, and the beagle canine. Proteomic studies in specific tissues and organisms have revealed the extensive involvement of reactive oxygen species (ROS and oxidative stress in aging.

  7. Determinants of rodent longevity in the chaperone-protein degradation network.

    Science.gov (United States)

    Rodriguez, Karl A; Valentine, Joseph M; Kramer, David A; Gelfond, Jonathan A; Kristan, Deborah M; Nevo, Eviatar; Buffenstein, Rochelle

    2016-05-01

    Proteostasis is an integral component of healthy aging, ensuring maintenance of protein structural and functional integrity with concomitant impact upon health span and longevity. In most metazoans, increasing age is accompanied by a decline in protein quality control resulting in the accrual of damaged, self-aggregating cytotoxic proteins. A notable exception to this trend is observed in the longest-lived rodent, the naked mole-rat (NMR, Heterocephalus glaber) which maintains proteostasis and proteasome-mediated degradation and autophagy during aging. We hypothesized that high levels of the proteolytic degradation may enable better maintenance of proteostasis during aging contributing to enhanced species maximum lifespan potential (MLSP). We test this by examining proteasome activity, proteasome-related HSPs, the heat-shock factor 1 (HSF1) transcription factor, and several markers of autophagy in the liver and quadriceps muscles of eight rodent species with divergent MLSP. All subterranean-dwelling species had higher levels of proteasome activity and autophagy, possibly linked to having to dig in soils rich in heavy metals and where underground atmospheres have reduced oxygen availability. Even after correcting for phylogenetic relatedness, a significant (p rodents.

  8. Growth curve of Balloniscus glaber Araujo & Zardo (Crustacea, Isopoda, Oniscidea from Parque Estadual de Itapuã, Rio Grande do Sul, Brazil Curva de crescimento de Balloniscus glaber Araujo & Zardo (Crustacea, Isopoda, Oniscidea no Parque Estadual de Itapuã, Rio Grande do Sul, Brasil

    Directory of Open Access Journals (Sweden)

    Helena Meinhardt

    2007-12-01

    Full Text Available Based on field data, this study presents the growth curve of Balloniscus glaber Araujo & Zardo, 1995, a terrestrial isopod species found in Parque Estadual de Itapuã (PEI, Rio Grande do Sul, Brazil. Specimens were monthly sampled, from May 2004 to April 2005, at PEI. Captured individuals were sexed, their cephalothorax width was measured, and the growth curve was described according to von Bertalanffy's model. Male and female growth curves are described by the equations: Wt = 2.256[1-e-0.00394(t+91.128] and Wt = 2.588[1-e-0.00301(t+101], respectively. Curves show differential growth between males and females, with females reaching higher W¥, and a slower growth rate than males. Based on theses curves, life span was estimated.Esse estudo, baseado em dados de campo, esse estudo apresenta a curva de crescimento de Balloniscus glaber Araujo & Zardo, 1995, um isópodo terrestre encontrado no Parque Estadual de Itapuã (PEI, Rio Grande do Sul. Os espécimes foram coletados mensalmente, de maio de 2004 a abril de 2005, no PEI. Os indivíduos capturados foram sexados e tiveram o cefalotórax mensurado e a curva de crescimento descrita a partir do modelo de von Bertalanffy. As curvas de crescimento para machos e para fêmeas são descritas pelas equações: Lt = 2,256[1-e-0,00394(t+91,128] e Lt = 2,588[1-e-0,00301(t+101], respectivamente. As curvas apresentam crescimento diferencial entre machos e fêmeas, com fêmeas atingindo maior L' mas com uma taxa de crescimento menor do que os machos. Com base na curva foi estimada a longevidade dos animais.

  9. Naked Mole Rat Longevity — Possible Mechanism Identified —

    Science.gov (United States)

    University of Rochester researchers, who previously discovered a mechanism that may contribute to the species’ resistance to tumor formation, have announced that ribosome function may help account for the rats’ longevity.

  10. Effect of the incubation of the phosphorus with the soil on growth and vesicular arbuscular micorrhizal infection in Lotus glaber and L. corniculatus

    OpenAIRE

    1999-01-01

    Se investigó el efecto de la incubación de distintas dosis de fósforo (P) con un suelo Natraquol Típico, sobre el crecimiento y la absorción de P en Lotus glaber Mill. (syn. L. tenuis Waldst et. Kit.). y Lotus. corniculatus L., y su relación con la infección de micorrizas vesiculo-arbusculares (VAM). Un primer grupo de muestras de suelo fue fertilizado con KH2PO4 (0-400 µgP/g suelo) y luego incubado a 30 °C durante 34 días. El segundo grupo (control) se incubó en las mismas condiciones, pero ...

  11. Predation and dispersal of Lithocarpus glaber seeds by rodents in Tiantong National Forest Park, Zhejiang Province%浙江天童国家森林公园鼠类对石栎种子的捕食和传播

    Institute of Scientific and Technical Information of China (English)

    张天澍; 李恺; 蔡永立; 杨坤; 胡星明; 彭士明; 陈立侨

    2006-01-01

    研究了浙江天童国家森林公园鼠类对石栎(Lithocarpus glaber)(常绿阔叶林重要伴生种)种子的捕食和传播.共设置了带1、带2、带3(常绿阔叶林中)、带4(马尾松林中)和带5(灌丛中)5条样带及2种种子的布置方式(有无掩盖和有无标签).结果表明,社鼠(Niviwnter confucianus)和针毛鼠(Niviventer fulvescens)是石栎种子潜在的捕食和传播者.损失种子可以分为3类:即Ⅰ类种子被吃,标签连着种子的残余部分;Ⅱ类种子被搬走,仅标签留在原地;Ⅲ类是标签和种子均消失.实验观察前期,种子损失量较大,随后逐渐降低;种子的日消失率在整个实验期间具有明显的波动,带2的日均消失率最高,为1.03%,带5的日均消失率最低(0.32%).3种种子命运所占比例在5个样带中存在差异,与不同样带的植被组成密切相关.有掩盖和无掩盖放置方式之间存在显著差异(P<0.05),前者的日消失率明显低于后者,而有无标签之间则无显著性差异(P>0.05).种子被鼠类搬运的最远距离为6.7 m.

  12. Oxygen-Binding Characteristics of Hemoglobins from Hypoxia and Hypercapnia Tolerant African Mole Rats

    DEFF Research Database (Denmark)

    Weber, Roy E.; Jarvis, Jennifer U. M; Fago, Angela

    2016-01-01

    to cancer, and the capability of tolerating more extreme levels of hypoxia (O2 tensions lower than on Mount Everest) and hypercapnia (10% CO2 concentrations) than other mammals. With the view of identifying possible cellular and molecular mechanisms that mitigate the constraints on the exchange and internal...

  13. Transcriptome, genetic editing, and microRNA divergence substantiate sympatric speciation of blind mole rat, Spalax

    National Research Council Canada - National Science Library

    Li, Kexin; Wang, Liuyang; Knisbacher, Binyamin A; Xu, Qinqin; Levanon, Erez Y; Wang, Huihua; Frenkel-Morgenstern, Milana; Tagore, Satabdi; Fang, Xiaodong; Bazak, Lily; Buchumenski, Ilana; Zhao, Yang; Lövy, Matěj; Li, Xiangfeng; Han, Lijuan; Frenkel, Zeev; Beiles, Avigdor; Cao, Yi Bin; Wang, Zhen Long; Nevo, Eviatar

    2016-01-01

    ... on mitochondrial and whole-genome nuclear DNA. Here, we present new evidence, including transcriptome, DNA editing, microRNA, and codon usage, substantiating earlier evidence for adaptive divergence in the abutting chalk and basalt populations...

  14. The reproductive biology of the giant Zambian mole-rat, Cryptomys ...

    African Journals Online (AJOL)

    1994-09-29

    Sep 29, 1994 ... pare growth patterns in the particular Cryptomys species. (Table I). ... 2 thrusts per second) reaching a peak. prior to ejaculation. ... tation period of approximately 111 days (Figure 1). In a sec- ... rest of the time they sleep.

  15. 3d soil structure within the mound of mole rats (Spalax microphthalmus

    Directory of Open Access Journals (Sweden)

    T. М. Konovalova

    2011-10-01

    Full Text Available The pedoturbation activity of the soil-dwelling mammals results in the complicated spatial soil structure with combined mechanically stable dense soil and the soil mass of low density. Such organization of the soil body has useful combination of the soil properties. The prolonged effect of the mammals’ pedoturbation activity is positive for different constituents of an ecosystem: soil animals, microorganisms and plants.

  16. Sympatric speciation revealed by genome-wide divergence in the blind mole rat Spalax.

    Science.gov (United States)

    Li, Kexin; Hong, Wei; Jiao, Hengwu; Wang, Guo-Dong; Rodriguez, Karl A; Buffenstein, Rochelle; Zhao, Yang; Nevo, Eviatar; Zhao, Huabin

    2015-09-22

    Sympatric speciation (SS), i.e., speciation within a freely breeding population or in contiguous populations, was first proposed by Darwin [Darwin C (1859) On the Origins of Species by Means of Natural Selection] and is still controversial despite theoretical support [Gavrilets S (2004) Fitness Landscapes and the Origin of Species (MPB-41)] and mounting empirical evidence. Speciation of subterranean mammals generally, including the genus Spalax, was considered hitherto allopatric, whereby new species arise primarily through geographic isolation. Here we show in Spalax a case of genome-wide divergence analysis in mammals, demonstrating that SS in continuous populations, with gene flow, encompasses multiple widespread genomic adaptive complexes, associated with the sharply divergent ecologies. The two abutting soil populations of S. galili in northern Israel habituate the ancestral Senonian chalk population and abutting derivative Plio-Pleistocene basalt population. Population divergence originated ∼0.2-0.4 Mya based on both nuclear and mitochondrial genome analyses. Population structure analysis displayed two distinctly divergent clusters of chalk and basalt populations. Natural selection has acted on 300+ genes across the genome, diverging Spalax chalk and basalt soil populations. Gene ontology enrichment analysis highlights strong but differential soil population adaptive complexes: in basalt, sensory perception, musculature, metabolism, and energetics, and in chalk, nutrition and neurogenetics are outstanding. Population differentiation of chemoreceptor genes suggests intersoil population's mate and habitat choice substantiating SS. Importantly, distinctions in protein degradation may also contribute to SS. Natural selection and natural genetic engineering [Shapiro JA (2011) Evolution: A View From the 21st Century] overrule gene flow, evolving divergent ecological adaptive complexes. Sharp ecological divergences abound in nature; therefore, SS appears to be an important mode of speciation as first envisaged by Darwin [Darwin C (1859) On the Origins of Species by Means of Natural Selection].

  17. Influence of spatial environment on maze learning in an African mole-rat

    CSIR Research Space (South Africa)

    Du Toit, L

    2012-05-01

    Full Text Available of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Private Bag 3, Johannesburg, Wits 2050, South Africa e-mail: martin.whiting@mq.edu.au Present Address: L. du Toit, Obesity Research and Management, University of Alberta...

  18. The King of Denmark and the Naked Mole Rat: Teaching Critical Thinking for Social Justice

    Science.gov (United States)

    McLaughlin, Danielle

    2012-01-01

    Asking hard questions is just that--hard. But if we are truly committed to teaching for social justice, we need to encourage our children to find as many points of view as they can, and to ask questions we may never be able to answer, knowing that education for citizenship lies in the process of thinking critically about the many sides of a…

  19. Spatial variability of soil electrical conductivity under the mole rats (Spalax microphthalmus digging activity at the different scales

    Directory of Open Access Journals (Sweden)

    A. V. Zhukov

    2012-07-01

    Full Text Available The soil mounds emerged owing to the mole rats’ digging activity have been shown to be characterised by less electrical conductivity than surrounded soil. This effect is due to the changes of the mounds bulk’s density and moisture. The effect of the mole rats’ digging activity on the soil electrical conductivity has been found not to be restricted by the geometrical border of the mounds. The mounds are surrounded by 1–1.5 m halo of increased soil electrical conductivity. The halo size is increased with the aging of the mound and with the compacting of their aggregation.

  20. Comparative Efficacy of Bromadiolone, Cholecalciferol and Zinc Phosphide Against Short -Tailed Mole Rat Nesokia indica in Captivity

    OpenAIRE

    PERVEZ, Amjad; AHMAD, Syed M.; Waqar, S; RIZVI, A.

    1998-01-01

    We conducted no-choice and paired choice feeding trials with individually caged Nesokia indica to evaluate the efficacy of Bromadiolone, Cholecalciferol and Zinc phosphide baits. Under no-choice test (1 day and 3 day) male rats consumed less bromadiolone bait. However, sex-wise difference was observed non-significant. Under choice feeding test, difference between bromadiolone bait intake and sex was observed non-significant. Under cholecalciferol bait, treated bait was consumed more than ...

  1. Regulation of Gene Expression by DNA Methylation and RNA Editing in Animals

    DEFF Research Database (Denmark)

    Li, Qiye

    The central dogma of molecular biology assumes the faithful transmission of genetic information from DNA to RNA to protein. However, epigenetic modifications such as DNA methylation can strongly affect the flow of genetic information without changing the underlying DNA sequences. In addition......, there has been growing interest in exploring the modifications occurring at the RNA level, which can impact the fate and function of mRNA. One fascinating type of such modifications is RNA editing, which alters specific nucleotides in transcribed RNA and thus can produce transcripts that are not encoded...... (Heterocephalus glaber), a eusocial mammal living in cooperative colonies. Finally, I introduce a software package that I developed that is specifically designed for the genome-wide identification of RNA-editing sites in animals, with the ultimate aim of promoting the evolutionary and functional study of RNA...

  2. Subterranean sympatry: An investigation into diet using stable isotope analysis

    CSIR Research Space (South Africa)

    Robb, GN

    2012-11-01

    Full Text Available mole-rat (Georychus capensis) and the Cape dune mole-rat (Bathyergus suillus) were examined using stable isotope analysis. Blood, fur and claw samples were collected from 70 mole-rats, in addition to several potential food items, to assess food...

  3. The mitochondrial free radical theory of aging: a critical view.

    Science.gov (United States)

    Sanz, Alberto; Stefanatos, Rhoda K A

    2008-03-01

    The Mitochondrial Free Radical Theory of Aging (MFRTA) proposes that mitochondrial free radicals, produced as by-products during normal metabolism, cause oxidative damage. According to MFRTA, the accumulation of this oxidative damage is the main driving force in the aging process. Although widely accepted, this theory remains unproven, because the evidence supporting it is largely correlative. For example, long-lived animals produce fewer free radicals and have lower oxidative damage levels in their tissues. However, this does not prove that free radical generation determines life span. In fact, the longest-living rodent -Heterocephalus glaber- produces high levels of free radicals and has significant oxidative damage levels in proteins, lipids and DNA. At its most orthodox MFRTA proposes that these free radicals damage mitochondrial DNA (mtDNA) and in turn provoke mutations that alter mitochondrial function (e.g. ATP production). According to this, oxidative damage to mtDNA negatively correlates with maximum life span in mammals. However, in contrast to MFRTA predictions, high levels of oxidative damage in mtDNA do not decrease longevity in mice. Moreover, mice with alterations in polymerase gamma (the mitochondrial DNA polymerase) accumulate 500 times higher levels of point mutations in mtDNA without suffering from accelerated aging. Dietary restriction (DR) is the only non-genetic treatment that clearly increases mean and maximum life span. According to MFRTA caloric restricted animals produce fewer mitochondrial reactive oxygen species (mtROS). However, DR alters more than free radical production (e.g. it decreases insulin signalling) and therefore the increase in longevity cannot be exclusively attributed to a decrease in mtROS generation. Thus, moderate exercise produces similar changes in free radical production and oxidative damage without increasing maximum life span. In summary, available data concerning the role of free radicals in longevity control are

  4. Interspeciifc associations of dominant species in a Lithocarpus glaber-Cyclobalanopsis glauca forest community in subtropical China%中亚热带石栎-青冈群落优势种种间关联研究

    Institute of Scientific and Technical Information of China (English)

    赵丽娟; 项文化

    2014-01-01

    应用方差比率法、χ2检验、Pearson相关系数和Spearman秩相关系数检验等数量分析方法对大山冲石栎-青冈群落的10个优势种组成的45个种对间的关联性进行定量研究。多物种总体关联性检验结果显示10个优势种总体种间呈较显著的正关联,该群落结构较为稳定;χ2检验结合V值(种对间联结指数)显示26个种对正关联,19个种对负关联,正负关联比为1.372;Spearman秩相关系数检验灵敏度较Pearson相关系数高,其中29个种对正相关,16个种对负相关,正负关联比为1.813。45个种对中有63%的种对联结关系未达到显著水平,说明种对间存在较强的独立性,群落种间联结相对松散,这可能与该群落处于稳定的亚顶级阶段有关。根据基于秩相关系数绘制的星座图和χ2检验将10个种群被分为3个生态种组。%We selected 10 dominant species (45 species-pairs) according to important values and quantitatively researched interspeciifc associations and correlations by using variance ratio analysis,χ2 test, Pearson correlation coefifcient and Spearman rank correlation coefifcient test. Signiifcantly positive correlations existed among the 10 dominant species, which suggested that the community structure was stable. The interspeciifc correlations showed that 26 species-pairs were positive associations, while 19 species-pairs had negative associations, and the ratio of positive and negative correlations were 1.372 based on χ2-test and V values (species-pairs correlation index). The Spearman correlation coefifcient test was more sensitive than Pearson correlation coefifcient test, and Spearman correlation coefifcient test reflected there were 29 pairs were positive correlations, 16 pairs had negative correlations with the positive/negative correlation coefifcient ratio 1.813. It was not signiifcant association for 63%of species pairs and showed that they were relatively loose and independent, which may be related to the community was close to climax community. According toχ2-test and constellation diagram of Spearman rank correlation coefifcient network, the 10 species were divided into three ecological species groups.

  5. Animal remains of the Neolithic Ritual Burial Complex near Krum Village (Haskovo Region, SE Bulgaria

    Directory of Open Access Journals (Sweden)

    Zlatozar Boev

    2014-10-01

    Full Text Available From a total of 389 highly fragmented animal bone and tooth finds, dated ca. 6500-6300 B.P. have been identified 7 taxa: Lesser mole rat, Eurasian beaver, Cattle, Sheep, Goat, Pig, and Donkey.

  6. Light perception in two strictly subterranean rodents: life in the dark or blue?

    Directory of Open Access Journals (Sweden)

    Ondrej Kott

    Full Text Available BACKGROUND: The African mole-rats (Bathyergidae, Rodentia are strictly subterranean, congenitally microphthalmic rodents that are hardly ever exposed to environmental light. Because of the lack of an overt behavioural reaction to light, they have long been considered to be blind. However, recent anatomical studies have suggested retention of basic visual capabilities. In this study, we employed behavioural tests to find out if two mole-rat species are able to discriminate between light and dark, if they are able to discriminate colours and, finally, if the presence of light in burrows provokes plugging behaviour, which is assumed to have a primarily anti-predatory function. METHODOLOGY/PRINCIPAL FINDING: We used a binary choice test to show that the silvery mole-rat Heliophobius argenteocinereus and the giant mole-rat Fukomys mechowii exhibit a clear photoavoidance response to full-spectrum ("white", blue and green-yellow light, but no significant reaction to ultraviolet or red light during nest building. The mole-rats thus retain dark/light discrimination capabilities and a capacity to perceive short to medium-wavelength light in the photopic range of intensities. These findings further suggest that the mole-rat S opsin has its absorption maximum in the violet/blue part of the spectrum. The assay did not yield conclusive evidence regarding colour discrimination. To test the putative role of vision in bathyergid anti-predatory behaviour, we examined the reaction of mole-rats to the incidence of light in an artificial burrow system. The presence of light in the burrow effectively induced plugging of the illuminated tunnel. CONCLUSION/SIGNIFICANCE: Our findings suggest that the photopic vision is conserved and that low acuity residual vision plays an important role in predator avoidance and tunnel maintenance in the African mole-rats.

  7. Comparative genetics of longevity and cancer: insights from long-lived rodents

    Science.gov (United States)

    Gorbunova, Vera; Seluanov, Andrei; Zhang, Zhengdong; Gladyshev, Vadim N.; Vijg, Jan

    2015-01-01

    Mammals have evolved a dramatic diversity of aging rates. Within the single order of Rodentia maximum lifespans differ from four years in mice to 32 years in naked mole rats. Cancer rates also differ significantly, from cancer-prone mice to virtually cancer-proof naked and blind mole rats. Recent progress in rodent comparative biology, in combination with the emergence of whole genome sequence information, has opened opportunities for the discovery of genetic factors controlling longevity and cancer susceptibility. PMID:24981598

  8. Two new species of the Coleopterous genus Acanthocerus

    NARCIS (Netherlands)

    Westwood, J.O.

    1883-01-01

    Ovali-rotundatus, convexus, glaber, niger, rude punctatus, punctis ovalibus, setas breves luteas emittentibus, capite punctatissimo; pronoti margine postico valde rotundato; lateribus valde deflexis, rotundatis; scutello sulco transverso basali, apice acuto; elytris stria gracillima suturæ proxima;

  9. First record of the genus Zaglyptus Förster (Hymenoptera: Ichneumonidae: Pimplinae) from Vietnam, with description of one new species.

    Science.gov (United States)

    Pham, Nhi Thi; Broad, Gavin R; Wägele, Wolfgang J

    2013-01-01

    The ichneumonid wasp genus Zaglyptus Förster, 1868 is reported for the first time from Vietnam, with three species found in the country. One new species, Zaglyptus guptai sp. nov., is described based on material collected in Chu Yang Sin NP, Dak Lak Province. Two other species, Z. glaber Gupta and Z. nigrolineatus, Gupta are recorded as new for the country. In addition, the subspecies Z glaber singaporensis Gupta is synonymised with the nominate subspecies.

  10. DNA repair in species with extreme lifespan differences

    Science.gov (United States)

    MacRae, Sheila L.; Croken, Matthew McKnight; Calder, R.B.; Aliper, Alexander; Milholland, Brandon; White, Ryan R.; Zhavoronkov, Alexander; Gladyshev, Vadim N.; Seluanov, Andrei; Gorbunova, Vera; Zhang, Zhengdong D.; Vijg, Jan

    2015-01-01

    Differences in DNA repair capacity have been hypothesized to underlie the great range of maximum lifespans among mammals. However, measurements of individual DNA repair activities in cells and animals have not substantiated such a relationship because utilization of repair pathways among animals—depending on habitats, anatomical characteristics, and life styles—varies greatly between mammalian species. Recent advances in high-throughput genomics, in combination with increased knowledge of the genetic pathways involved in genome maintenance, now enable a comprehensive comparison of DNA repair transcriptomes in animal species with extreme lifespan differences. Here we compare transcriptomes of liver, an organ with high oxidative metabolism and abundant spontaneous DNA damage, from humans, naked mole rats, and mice, with maximum lifespans of ∼120, 30, and 3 years, respectively, with a focus on genes involved in DNA repair. The results show that the longer-lived species, human and naked mole rat, share higher expression of DNA repair genes, including core genes in several DNA repair pathways. A more systematic approach of signaling pathway analysis indicates statistically significant upregulation of several DNA repair signaling pathways in human and naked mole rat compared with mouse. The results of this present work indicate, for the first time, that DNA repair is upregulated in a major metabolic organ in long-lived humans and naked mole rats compared with short-lived mice. These results strongly suggest that DNA repair can be considered a genuine longevity assurance system. PMID:26729707

  11. On the nest of Cryptomys Hottentotus in the Kruger National Park.

    Directory of Open Access Journals (Sweden)

    M.Sc.(Rand, G. De Graaff

    1962-05-01

    Full Text Available This paper briefly describes the structure of a nest of the mole rat, Cryptomys hotfentotus. In the Pretoriuskop area this species uses the gifbol fBop/ione disticha, grass roots and the sekelbos (Dichrosfachys nyassana as the main material for nest construction. The presence of invertebrates in the nest (such as mites and beetles is mentioned.

  12. Subterranean sympatry: an investigation into diet using stable isotope analysis.

    Directory of Open Access Journals (Sweden)

    Gillian N Robb

    Full Text Available In the Western Cape three species of mole-rat occur in sympatry, however, little is known about differences in their dietary preferences. Dietary composition of the three species; the common mole-rat (Cryptomys hottentotus hottentotus, the Cape mole-rat (Georychus capensis and the Cape dune mole-rat (Bathyergus suillus were examined using stable isotope analysis. Blood, fur and claw samples were collected from 70 mole-rats, in addition to several potential food items, to assess food selection of the three species under natural conditions. Overall there was a significant difference in the isotopic composition (δ(13C and δ(15N between all three species and significant differences in their diet composition. There were also significant differences between tissues in all three species suggesting temporal variation in diet. The small size and colonial lifestyle of C. h. hottentotus allows it to feed almost 100% on bulbs, while the solitary and larger species G. capensis and B. suillus fed to a greater extent on other resources such as grasses and clover. B. suillus, the largest of the species, had the most generalized diet. However, overall all species relied most heavily upon geophytes and consumed the same species suggesting competition for resources could exist. We also showed a high level of individual variation in diet choices. This was most pronounced in B. suillus and G. capensis and less so in C. h. hottentotus. We demonstrate that stable isotope analysis can successfully be applied to examine dietary patterns in subterranean mammals and provide insights into foraging patterns and dietary variation at both the inter and intra population level.

  13. Molecular evolution of growth hormone and insulin-like growth factor 1 receptors in long-lived, small-bodied mammals.

    Science.gov (United States)

    Davies, Kalina T J; Tsagkogeorga, Georgia; Bennett, Nigel C; Dávalos, Liliana M; Faulkes, Christopher G; Rossiter, Stephen J

    2014-10-10

    Mammals typically display a robust positive relationship between lifespan and body size. Two groups that deviate markedly from this pattern are bats and African mole-rats, with members of both groups being extremely long-lived given their body size, with the maximum documented lifespan for many species exceeding 20 years. A recent genomics study of the exceptionally long-lived Brandt's bat, Myotis brandtii (41 years), suggested that its longevity and small body size may be at least partly attributed to key amino acid substitutions in the transmembrane domains of the receptors of growth hormone (GH) and insulin-like growth factor 1 (IGF1). However, whereas elevated longevity is likely to be common across all 19 bat families, the reported amino acid substitutions were only observed in two closely related bat families. To test the hypothesis that an altered GH/IGF1 axis relates to the longevity of African mole-rats and bats, we compared and analysed the homologous coding gene sequences in genomic and transcriptomic data from 26 bat species, five mole-rats and 38 outgroup species. Phylogenetic analyses of both genes recovered the majority of nodes in the currently accepted species tree with high support. Compared to other clades, such as primates and carnivores, the bats and rodents had longer branch lengths. The single 24 amino acid transmembrane domain of IGF1R was found to be more conserved across mammals compared to that of GHR. Within bats, considerable variation in the transmembrane domain of GHR was found, including a previously unreported deletion in Emballonuridae. The transmembrane domains of rodents were found to be more conserved, with mole-rats lacking uniquely conserved amino acid substitutions. Molecular evolutionary analyses showed that both genes were under purifying selection in bats and mole-rats. Our findings suggest that while the previously documented mutations may confer some additional lifespan to Myotis bats, other, as yet unknown, genetic

  14. A new Burmannia from Enggano (Sumatra)

    NARCIS (Netherlands)

    Jonker, F.P.

    1938-01-01

    Herba pusilla, saprophytiea, 10—13 cm alta. Radices ignotae. Caulis simplex, erectus, teres, glaber, succulentus. Folia 3—8, squamas simulantia, lanceolata vel ovato-lanceolata, glabra, acuta vel acuminata, 2—6 mm longa, uninervia, nervo prominente. Folia basalia rosulata nulla. Bracteae plm. 5 mm l

  15. Additional description of Vaccinium podocarpoideum%罗汉松叶乌饭补充记载

    Institute of Scientific and Technical Information of China (English)

    林亲众

    1999-01-01

    @@ 罗汉松叶乌饭 Vaccinium podocarpoideum Fang et Z. H. Pan in Act. Phytotax. Sin. 19: 107. 1981. Racemi ex axillis supeioribus orti, 2.5~3.5 cm longi, (5) 7-11-flori, rachidibus et pedicellis glabris, bracteae deciduae; pedicelli 5 mm longi. Calycis tubus glaber, lobis 5, deltoideis, 1.5~1.8 mm longis glabris; corolla alba campanulata, utrinque glabra, limbo 5-lobo, lobis ovato-deltoideis, 1~1.2 mm longis; Stamina 10, 5.5?~6 mm longa, filamentis 1 mm longis puberulis, antheris dorso minute bicalcaratis, apice 2-tubiformibus, tubuli thecis dupol longi (tubuli 3 mm longi, theci 1.5 mm longi), ouarium et stylus glaber, stylis 5.5 mm longis.

  16. Consideraciones taxonómicas en especies de Senecio de Argentina Taxonomic considerations on Argentine species of Senecio

    Directory of Open Access Journals (Sweden)

    Roberto D. Tortosa

    2010-12-01

    Full Text Available Se incluyen algunas especies de Senecio de Argentina, reconocidas hasta el presente como especies válidas, en la sinonimia de otras: S. francisci Phil. en S. polygaloides Phil.; S. gymnocaulos Phil. en S. kingii Hook. f.; S. molinae Phil. en S. glaber Less.; S. mustersii Speg. y su var. dentatus Cabrera en S. subumbellatus Phil. Senecio microcephalus Phil. y su var. angustifolius Cabrera son consideradas una variedad de S. subumbellatus y S. schreiteri Cabrera una variedad de S. leucostachys Baker. No se acepta la validez de las variedades Senecio gilliesii Hook. et Arn. var. dasycarpus Cabrera, S. glaber Less. var. pratensis (Phil. Cabrera, S. gnidioides Phil. var. gilvus (Phil. Cabrera, S. kingii Hook. f. var. paradoxus (Albov ex Kurtz Cabrera, S. leucomallus A. Gray var. incisus A. Gray, S. linariifolius Poepp. ex DC. var. heliophytoides (Phil. Reiche y var. subtomentosus Cabrera y de la forma S. perezii Cabrera fo. integerrimus Cabrera.

  17. Efficiency of producing anion and relative humidity of the indigenous woody plants in Jeju islands

    Science.gov (United States)

    Son, S.-G.; Kim, K.-J.; Kim, H.-J.; Kim, C.-M.; Byun, K.-O.

    2009-04-01

    This study is to evaluate the ability of interior plants to produce anion and relative humidity that can purify polluted indoor air. Four indigenous woody plants in Jeju islands such as Sarcandra glaber (Thunb.) Nakai, Illicium anisatum L, Cleyera japonica Thunb. and Ilex rotunda Thunb. were used. Sansevieria trifasciata cv. Laurentii was also used as a comparative plant. The amount of anion and increment of relative humidity produced by five species of indoor plants was assessed by anion measurement (ITC-201A)in a sealed acryl chamber (118Ã-118Ã-119.5cm). The highest amount of anion was 515 ea/cm3produced by I. rotunda. The amounts of anion were 293 ea/cm3, 273 ea/cm3, and 211 ea/cm3 in S. glaber, I. anisatum and C. japonica, respecively while it was 220 ea/cm3 in S. trifasciata. The increment of relative humidity was highest in I. anisatum as 27.4% while it was lowest in S. trifasciata as 14.0%. This result suggested that all four indigenous plants tested were more effective to purify the indoor polluted air than S. trifasciata. Key words: interior plant, S. glaber, I. anisatum, C. japonica, I. rotunda, indoor polluted air

  18. First record of Wolbachia in South American terrestrial isopods: prevalence and diversity in two species of Balloniscus (Crustacea, Oniscidea

    Directory of Open Access Journals (Sweden)

    Mauricio Pereira Almerão

    2012-01-01

    Full Text Available Wolbachia are endosymbiotic bacteria that commonly infect arthropods, inducing certain phenotypes in their hosts. So far, no endemic South American species of terrestrial isopods have been investigated for Wolbachia infection. In this work, populations from two species of Balloniscus (B. sellowii and B. glaber were studied through a diagnostic PCR assay. Fifteen new Wolbachia 16S rDNA sequences were detected. Wolbachia found in both species were generally specific to one population, and five populations hosted two different Wolbachia 16S rDNA sequences. Prevalence was higher in B. glaber than in B. sellowii, but uninfected populations could be found in both species. Wolbachia strains from B. sellowii had a higher genetic variation than those isolated from B. glaber. AMOVA analyses showed that most of the genetic variance was distributed among populations of each species rather than between species, and the phylogenetic analysis suggested that Wolbachia strains from Balloniscus cluster within Supergroup B, but do not form a single monophyletic clade, suggesting multiple infections for this group. Our results highlight the importance of studying Wolbachia prevalence and genetic diversity in Neotropical species and suggest that South American arthropods may harbor a great number of diverse strains, providing an interesting model to investigate the evolution of Wolbachia and its hosts.

  19. Long-lived cancer-resistant rodents as new model species for cancer research

    Directory of Open Access Journals (Sweden)

    Jorge eAzpurua

    2013-01-01

    Full Text Available Most rodents are small and short-lived, but several lineages have independently evolved long lifespans without a concomitant increase in body mass. Most notably, the two subterranean species naked mole rat (NMR and blind mole rat (BMR which have maximum lifespans of 32 and 21 years respectively. The longevity of these species has sparked interest in the tumor suppression strategies that may have also evolved, because for many rodent species (including mice, rats, guinea pigs, gerbils and hamsters tumors are major source of late-life mortality. Here, we review the recent literature on anticancer mechanisms in long-lived rodents. Both NMR and BMR seem to have developed tumor defenses that rely on extra-cellular signals. However, while the NMR relies on a form of contact inhibition to suppress growth, the BMR evolved a mechanism mediated by the release of interferon and rapid necrotic cell death. Although both organisms ultimately rely on canonical downstream tumor suppressors (pRB and p53 the studies reveal species can evolve different strategies to achieve tumor-resistance. Importantly, studies of these cancer-resistant rodents may benefit human health if such mechanisms can be activated in human cells.

  20. Sensitivity of primary fibroblasts in culture to atmospheric oxygen does not correlate with species lifespan

    Science.gov (United States)

    Patrick, Alison; Seluanov, Michael; Hwang, Chaewon; Tam, Jonathan; Khan, Tanya; Morgenstern, Ari; Wiener, Lauren; Vazquez, Juan M.; Zafar, Hiba; Wen, Robert; Muratkalyeva, Malika; Doerig, Katherine; Zagorulya, Maria; Cole, Lauren; Catalano, Sophia; Lobo Ladd, Aliny AB; Coppi, A. Augusto; Coşkun, Yüksel; Tian, Xiao; Ablaeva, Julia; Nevo, Eviatar; Gladyshev, Vadim N.; Zhang, Zhengdong D.; Vijg, Jan; Seluanov, Andrei; Gorbunova, Vera

    2016-01-01

    Differences in the way human and mouse fibroblasts experience senescence in culture had long puzzled researchers. While senescence of human cells is mediated by telomere shortening, Parrinello et al. demonstrated that senescence of mouse cells is caused by extreme oxygen sensitivity. It was hypothesized that the striking difference in oxygen sensitivity between mouse and human cells explains their different rates of aging. To test if this hypothesis is broadly applicable, we cultured cells from 16 rodent species with diverse lifespans in 3% and 21% oxygen and compared their growth rates. Unexpectedly, fibroblasts derived from laboratory mouse strains were the only cells demonstrating extreme sensitivity to oxygen. Cells from hamster, muskrat, woodchuck, capybara, blind mole rat, paca, squirrel, beaver, naked mole rat and wild-caught mice were mildly sensitive to oxygen, while cells from rat, gerbil, deer mouse, chipmunk, guinea pig and chinchilla showed no difference in the growth rate between 3% and 21% oxygen. We conclude that, although the growth of primary fibroblasts is generally improved by maintaining cells in 3% oxygen, the extreme oxygen sensitivity is a peculiarity of laboratory mouse strains, possibly related to their very long telomeres, and fibroblast oxygen sensitivity does not directly correlate with species' lifespan. PMID:27163160

  1. Biomimeitc Design of a Stubble-Cutting Disc Using Finite Element Analysis

    Institute of Scientific and Technical Information of China (English)

    Mo Li; Donghui Chen; Shujun Zhang; Jin Tong

    2013-01-01

    Mole rat (Scaptochirus moschatus),a soil-burrowing mammal,can efficiently dig soil using its fore claws.The profile curves of its claw toe provide excellent structure for digging.In this paper,a biomimetic stubble-cutting disc was designed by learning from the geometrical characteristics of the mole rat claw toes.To compare the structural strength and working efficiency of the biomimetic disc and the conventional stubble-cutting disc,three-dimensional (3D) models of the discs were built and numerical analyzed in ABAQUS.In the dynamic soil cutting model,soil was modeled as an elastic-plastic material with elastic parameters,including Young's modulus,Poisson's ratio and Drucker-Prager criterion,which were obtained from triaxial tests.A general contact algorithm was used to simulate the interaction between rotary disc and soil.In FEA models,for the combined action of normal and friction stresses,the stress on the biomimetic disc is 34.33% lower than that of the conventional disc.For only the normal stress,the stress on the biomimetic disc is 22.64% lower than that on the conventional one.The magnitude of soil stress in biomimetic disc cutting model is 6.87% higher than that in conventional disc.The FEA results indicate that the biomimetic disc performs better in structural strength and cutting efficiency.

  2. Spontaneous expression of magnetic compass orientation in an epigeic rodent: the bank vole, Clethrionomys glareolus

    Science.gov (United States)

    Oliveriusová, Ludmila; Němec, Pavel; Pavelková, Zuzana; Sedláček, František

    2014-07-01

    Magnetoreception has been convincingly demonstrated in only a few mammalian species. Among rodents, magnetic compass orientation has been documented in four species of subterranean mole rats and two epigeic (i.e. active above ground) species—the Siberian hamster and the C57BL/6J mouse. The mole rats use the magnetic field azimuth to determine compass heading; their directional preference is spontaneous and unimodal, and their magnetic compass is magnetite-mediated. By contrast, the primary component of orientation response is learned in the hamster and the mouse, but both species also exhibit a weak spontaneous bimodal preference in the natural magnetic field. To determine whether the magnetic compass of wild epigeic rodents features the same functional properties as that of laboratory rodents, we investigated magnetic compass orientation in the bank vole Clethrionomys glareolus (Cricetidae, Rodentia). The voles exhibited a robust spontaneous bimodal directional preference, i.e. built nests and slept preferentially along the north-south axis, and deflected their directional preference according to a shift in the direction of magnetic north, clearly indicating that they were deriving directional information from the magnetic field. Thus, bimodal, axially symmetrical directional choice seems to be a common feature shared by epigeic rodents. However, spontaneous directional preference in the bank vole appeared to be more pronounced than that reported in the hamster and the mouse. These findings suggest that bank voles are well suited for future studies investigating the adaptive significance and mechanisms of magnetic orientation in epigeic rodents.

  3. Stability analysis of a model gene network links aging, stress resistance, and negligible senescence.

    Science.gov (United States)

    Kogan, Valeria; Molodtsov, Ivan; Menshikov, Leonid I; Shmookler Reis, Robert J; Fedichev, Peter

    2015-08-28

    Several animal species are considered to exhibit what is called negligible senescence, i.e. they do not show signs of functional decline or any increase of mortality with age. Recent studies in naked mole rat and long-lived sea urchins showed that these species do not alter their gene-expression profiles with age as much as other organisms do. This is consistent with exceptional endurance of naked mole rat tissues to various genotoxic stresses. We conjectured, therefore, that the lifelong transcriptional stability of an organism may be a key determinant of longevity. We analyzed the stability of a simple genetic-network model and found that under most common circumstances, such a gene network is inherently unstable. Over a time it undergoes an exponential accumulation of gene-regulation deviations leading to death. However, should the repair systems be sufficiently effective, the gene network can stabilize so that gene damage remains constrained along with mortality of the organism. We investigate the relationship between stress-resistance and aging and suggest that the unstable regime may provide a mathematical basis for the Gompertz "law" of aging in many species. At the same time, this model accounts for the apparently age-independent mortality observed in some exceptionally long-lived animals.

  4. The role of host traits, season and group size on parasite burdens in a cooperative mammal.

    Directory of Open Access Journals (Sweden)

    Hermien Viljoen

    Full Text Available The distribution of parasites among hosts is often characterised by a high degree of heterogeneity with a small number of hosts harbouring the majority of parasites. Such patterns of aggregation have been linked to variation in host exposure and susceptibility as well as parasite traits and environmental factors. Host exposure and susceptibility may differ with sexes, reproductive effort and group size. Furthermore, environmental factors may affect both the host and parasite directly and contribute to temporal heterogeneities in parasite loads. We investigated the contributions of host and parasite traits as well as season on parasite loads in highveld mole-rats (Cryptomys hottentotus pretoriae. This cooperative breeder exhibits a reproductive division of labour and animals live in colonies of varying sizes that procreate seasonally. Mole-rats were parasitised by lice, mites, cestodes and nematodes with mites (Androlaelaps sp. and cestodes (Mathevotaenia sp. being the dominant ecto- and endoparasites, respectively. Sex and reproductive status contributed little to the observed parasite prevalence and abundances possibly as a result of the shared burrow system. Clear seasonal patterns of parasite prevalence and abundance emerged with peaks in summer for mites and in winter for cestodes. Group size correlated negatively with mite abundance while it had no effect on cestode burdens and group membership affected infestation with both parasites. We propose that the mode of transmission as well as social factors constrain parasite propagation generating parasite patterns deviating from those commonly predicted.

  5. Region-specific associations between sex, social status, and oxytocin receptor density in the brains of eusocial rodents.

    Science.gov (United States)

    Mooney, S J; Coen, C W; Holmes, M M; Beery, A K

    2015-09-10

    Naturally occurring variations in neuropeptide receptor distributions in the brain contribute to numerous mammalian social behaviors. In naked mole-rats, which live in large social groups and exhibit remarkable reproductive skew, colony-related social behaviors vary with reproductive status. Here we examined whether variation in social status is associated with variations in the location and/or density of oxytocin binding in this species. Autoradiography was performed to assess forebrain oxytocin receptor (OTR) densities in breeding and non-breeding naked mole-rats of both sexes. Overall, males exhibited higher OTR binding in the medial amygdala in comparison to females. While there were no main effects of reproductive status in any region, a sex difference in OTR binding in the nucleus accumbens was mediated by status. Specifically, breeding males tended to have more OTR binding than breeding females in the nucleus accumbens, while no sex difference was observed in subordinates. These effects suggest that oxytocin may act in a sex- and region-specific way that corresponds to reproductive status and associated social behaviors.

  6. Spatial and seasonal variations of leaf area index (LAI) in subtropical secondary forests related to floristic composition and stand characters

    Science.gov (United States)

    Zhu, Wenjuan; Xiang, Wenhua; Pan, Qiong; Zeng, Yelin; Ouyang, Shuai; Lei, Pifeng; Deng, Xiangwen; Fang, Xi; Peng, Changhui

    2016-07-01

    Leaf area index (LAI) is an important parameter related to carbon, water, and energy exchange between canopy and atmosphere and is widely applied in process models that simulate production and hydrological cycles in forest ecosystems. However, fine-scale spatial heterogeneity of LAI and its controlling factors have yet to be fully understood in Chinese subtropical forests. We used hemispherical photography to measure LAI values in three subtropical forests (Pinus massoniana-Lithocarpus glaber coniferous and evergreen broadleaved mixed forests, Choerospondias axillaris deciduous broadleaved forests, and L. glaber-Cyclobalanopsis glauca evergreen broadleaved forests) from April 2014 to January 2015. Spatial heterogeneity of LAI and its controlling factors were analysed using geostatistical methods and the generalised additive models (GAMs) respectively. Our results showed that LAI values differed greatly in the three forests and their seasonal variations were consistent with plant phenology. LAI values exhibited strong spatial autocorrelation for the three forests measured in January and for the L. glaber-C. glauca forest in April, July, and October. Obvious patch distribution pattern of LAI values occurred in three forests during the non-growing period and this pattern gradually dwindled in the growing season. Stem number, crown coverage, proportion of evergreen conifer species on basal area basis, proportion of deciduous species on basal area basis, and forest types affected the spatial variations in LAI values in January, while stem number and proportion of deciduous species on basal area basis affected the spatial variations in LAI values in July. Floristic composition, spatial heterogeneity, and seasonal variations should be considered for sampling strategy in indirect LAI measurement and application of LAI to simulate functional processes in subtropical forests.

  7. A checklist of the Kateretidae and Nitidulidae of Iran (Coleoptera: Cucujoidea).

    Science.gov (United States)

    Lasoń, Andrzej; Ghahari, Hassan

    2013-12-10

    The current knowledge of the geographic distribution of short-winged flower beetles and sap beetles (Kateretidae and Nitidulidae, respectively) from Iran is summarized. In total, 84 species of Nitidulidae (in 22 genera and 5 subfamilies: Epuraeinae, Carpophilinae, Cryptarchinae, Nitidulinae, Meligethinae) and 6 species of Kateretidae (in 4 genera: Brachyleptus Motschulsky, Brachypterolus Grouvelle, Brachypterus Kugelann, Kateretes Herbst) are listed. Brachyleptus discolor Reitter, Brachypterus glaber (Newman) (both Kateretidae), Epuraea distincta (Grimmer), Soronia oblonga (Brisout), Lamiogethes bidens (Brisout), Lamiogethes medvedevi (Kirejtshuk), Sagittogethes devillei (Grouvelle) and Xerogethes rotundicollis (Brisout) (Nitidulidae) are new records for Iran. 

  8. New data on programmed aging - slow phenoptosis.

    Science.gov (United States)

    Skulachev, M V; Skulachev, V P

    2014-10-01

    This review summarizes the latest data on biochemistry and physiology of living organisms. These data suggest that aging, i.e. coordinated age-dependent weakening of many vital functions leading to gradual increase in the probability of dying, is not common to all organisms. Some species have been described whose probability of death does not depend on age or even decreases with age, this being accompanied by constant or increasing fertility. In the case of the naked mole rat (a non-aging mammal), a mechanism has been identified that protects this animal from cancer and the most common age-related diseases. The high molecular weight polysaccharide hyaluronan, a linear polymer composed of multiple repeated disaccharide of glucuronic acid and glucosamine, plays the key role in this mechanism. Hyaluronan is accumulated in the intercellular spaces in the organs and tissues of the naked mole rat. This polysaccharide provides early contact inhibition of cell division (anti-cancer effect). In addition, hyaluronan prevents the development of certain types of apoptosis, in particular, those induced by reactive oxygen species (ROS) (geroprotective effect preventing ROS-induced decrease in cellularity in the organs and tissues of aging organisms). Extraordinary longevity of the naked mole rat (over 30 years, which is long for a rodent the size of a mouse) is connected to its eusocial lifestyle, when only the "queen" and its few "husbands" breed, while the huge army of non-breeding "subordinates" provide the "royal family" with protection from predators, food, and construction and maintenance of an underground labyrinth size of a football field. This way of life removes the pressure of natural selection from the "family" and makes aging - the program that is counterproductive for the individual but increases "evolvability" of its offspring - unnecessary. The example of the naked mole rat demonstrates the optional character of the aging program for the organism. Many facts

  9. Rodents for comparative aging studies: from mice to beavers.

    Science.gov (United States)

    Gorbunova, Vera; Bozzella, Michael J; Seluanov, Andrei

    2008-09-01

    After humans, mice are the best-studied mammalian species in terms of their biology and genetics. Gerontological research has used mice and rats extensively to generate short- and long-lived mutants, study caloric restriction and more. Mice and rats are valuable model organisms thanks to their small size, short lifespans and fast reproduction. However, when the goal is to further extend the already long human lifespan, studying fast aging species may not provide all the answers. Remarkably, in addition to the fast-aging species, the order Rodentia contains multiple long-lived species with lifespans exceeding 20 years (naked mole-rat, beavers, porcupines, and some squirrels). This diversity opens great opportunities for comparative aging studies. Here we discuss the evolution of lifespan in rodents, review the biology of slow-aging rodents, and show an example of how the use of a comparative approach revealed that telomerase activity coevolved with body mass in rodents.

  10. Organization of the Mammalian Ionome According to Organ Origin, Lineage Specialization, and Longevity

    Directory of Open Access Journals (Sweden)

    Siming Ma

    2015-11-01

    Full Text Available Trace elements are essential to all mammals, but their distribution and utilization across species and organs remains unclear. Here, we examined 18 elements in the brain, heart, kidney, and liver of 26 mammalian species and report the elemental composition of these organs, the patterns of utilization across the species, and their correlation with body mass and longevity. Across the organs, we observed distinct distribution patterns for abundant elements, transition metals, and toxic elements. Some elements showed lineage-specific patterns, including reduced selenium utilization in African mole rats, and positive correlation between the number of selenocysteine residues in selenoprotein P and the selenium levels in liver and kidney across mammals. Body mass was linked positively to zinc levels, whereas species lifespan correlated positively with cadmium and negatively with selenium. This study provides insights into the variation of mammalian ionome by organ physiology, lineage specialization, body mass, and longevity.

  11. Animal Communications Through Seismic Vibrations

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Peggy (University of Tulsa)

    2001-05-02

    Substrate vibration has been important to animals as a channel of communication for millions of years, but our literature on vibration in this context of biologically relevant information is only decades old. The jaw mechanism of the earliest land vertebrates allowed them to perceive substrate vibrations as their heads lay on the ground long before airborne sounds could be heard. Although the exact mechanism of vibration production and the precise nature of the wave produced are not always understood, recent development of affordable instrumentation to detect and measure vibrations has allowed researchers to answer increasingly sophisticated questions about how animals send and receive vibration signals. We now know that vibration provides information used in predator defense, prey detection, recruitment to food, mate choice, intrasexual competition, and maternal/brood social interactions in a variety of insect orders, spiders, crabs, scorpions, chameleons, frogs, golden moles, mole rats, kangaroos rats, wallabies, elephants and bison.

  12. [Morphological diversity in the postnatal skull development in representatives of two families of rodents (Spalacidae, Castoridae, Rodentia)].

    Science.gov (United States)

    Puzachenko, A Iu; Korablev, N P

    2014-01-01

    This is the first study to describe the results of measurement of three information parameters of morphological diversity (entropy, the measure of organization, and the Kullback-Leibler divergence) in the course of postnatal development of the skull in the populations of two rodent species (greater mole rat (Spalax microphthalmus Guld.) and Eurasian beaver (Castor fiber (L.)). The terms "morphosystem" and "morphological space" and its structure are introduced. Within the framework of the developed approach, "morphological diversity" is considered as a variable associated with the morphological space structure. Testing the hypothesis of the dominance of self-organization processes and an increase in the organization of the morphological diversity of the skull in the course ofontogeny showed its inconsistency. The morphosystem of the skull of the studied species undergoes transitions between more organized and less organized states, periodically approaching and departing from the "steady state." Such dynamics characterizes the morphosystem of the skull as a dynamic and nonlinear system.

  13. Ecological traits of two neotropical oniscideans (Crustacea: Isopoda)%新热带区两种潮虫的生态特征(甲壳纲:等足目)

    Institute of Scientific and Technical Information of China (English)

    Aline Ferreira QUADROS; Paula Beatriz ARAUJO

    2007-01-01

    Two terrestrial isopods,Atlantoscia floridana (Philosciidae) and Balloniscus glaber (Balloniscidae) that differ in size,morphology and behaviour were studied with respect to the influence of the environmental variation on their reproduction and population structure.Samples were taken at Parque Estadual de Itapu(a),Brazil from May 2004 to April 2005.Twelve cores of litter and soil were extracted each month,and hand-searched in the lab.All specimens were sexed and measured.Overall,2 540 individuals were captured.Atlantoscia floridana reproductive females were present throughout the year,while B.glaber showed a shorter reproductive period,from early spring to early autumn,and both species showed high numbers of reproductive females and mancas during spring.Mean density of A.floridana was 114 ind./m2 and 133 ind./m2 for B.glaber.The increased dryness observed in the summer of 2005 affected the populations differently,as it reduced population size of A.floridana while B.glaber population remained stable.It seems that the differences in morphology,more specifically body size and presence of pleopodal lungs,confer upon B.glaber a higher tolerance to desiccation.Moreover,B.glaber may rely on behavioral strategies,such as burrowing,to increase the survival of the young,and even the survival of the adults under stressful climatic conditions.It is postulated that the continuous reproduction,lower time to maturity and higher proportion of reproductive females of A.floridana are responses to its high juvenile mortality[Acta Zoologica Sinica 53(2):241-249,2007].%对体型大小不同的两种陆生等足类动物进行形态特征和行为特征研究,探讨环境变化对其繁殖特征和种群结构的影响.自2004年5月至2005年4月,在巴西Parque Estadual de Itapu(a)进行野外采样,其中每月采集12个凋落物和土壤样品,实验室手拣法收集等足类,共获得2 540只,同时进行个体性别鉴定与测量.结果表明,Atlantoscia floridana

  14. New Mesostigmata records and species from the Korean Peninsula*

    Directory of Open Access Journals (Sweden)

    Kontschán, Jenő

    2014-06-01

    Full Text Available A total of 20 Mesostigmata species are recorded from the Korean Peninsula, of which 15 (Asca nubes Ishikawa, 1969, Lasioseius tomokoae Ishikawa, 1969, Evimirus uropodinus (Berlese, 1903, Macrocheles glaber (Müller, 1860, Macrocheles punctatus Ishikawa, 1967, Pachylaelaps ishizuchiensis Ishikawa, 1977, Gamasiphis pulchellus (Berlese, 1887, Ololaelaps ussurinensis Bregetova & Koroleva, 1964, Gamasellus humosus Ishikawa, 1969, Gamasholaspis variabilis Petrova, 1967, Parholaspulus hiasmaticus Petrova, 1967, Podocinum tsushimanum Ishikawa, 1970, Neoparasitus scleoides Ishikawa, 1969, Veigaia ochracea Bregetova, 1961, Uropoda similihamulifera Hiramatsu, 1979 are presented as first occurrences from this peninsula. Asca aphidioides (Linnaeus, 1758 is already reported from the southern part of the peninsula, but we present the first occurrence in the Democratic People’s Republic of Korea. One species (Trachytes koreana Kontschán & Lim, sp. nov. is described and illustrated in this paper. Seventeen of the recovered species were collected in the Democratic People’s Republic of Korea; the others were collected in the area of Republic of Korea.

  15. Javanese species of the mite genus Macrocheles (Arachnida: Acari: Gamasina: Macrochelidae).

    Science.gov (United States)

    Hartini, Sri; Takaku, Gen

    2003-10-01

    Twelve mite species of the genus Macrocheles (Acari: Macrochelidae) were collected from the body surface of dung beetles in Java, Indonesia. Of these, three species, i.e., Macrocheles jabarensis, M. jonggolensis, and M. sukabumiensis, were described as new to science. Female of M. dispar was redescribed. Two species, i.e., M. baliensis and M. sukaramiensis, were recorded from Java for the first time. The occurrence of five species previously recorded from Java, i.e., M. hallidayi, M. kraepelini, M. limue, M. oigru, and M. merdarius, were reconfirmed. Taxonomic status of M. sp. aff. glaber was not settled in the present study, because we could not obtain the male and immatures which are indispensable for exact identification. In total 15 species of the genus Macrocheles, including 3 species already recorded but not collected in this research (M. crispa, M. krantzi, and M. subbadius), are known from Java up to date.

  16. Comparative morphology and molecular phylogeny of Apicoporus n. Gen.: a new genus of marine benthic dinoflagellates formerly classified within Amphidinium.

    Science.gov (United States)

    Sparmann, Sarah F; Leander, Brian S; Hoppenrath, Mona

    2008-07-01

    The composition of the dinoflagellate genus Amphidinium is currently polyphyletic and includes several species in need of re-evaluation using modern morphological and phylogenetic methods. We investigated a broad range of uncultured morphotypes extracted from marine sediments in the Eastern Pacific Ocean that were similar in morphology to Amphidinium glabrum Hoppenrath and Okolodkov. To determine the number of distinct species associated with this phenotypic diversity, we collected LM, SEM, TEM and small subunit ribosomal DNA sequence information from different morphotypes, including the previously described A. glabrum. Both comparative morphological and molecular phylogenetic data supported the establishment of a new genus, Apicoporus n. gen., including at least two species, A. glaber n. comb., and A. parvidiaboli n. sp. Apicoporus is characterized by having amphiesmal pores and an apical pore covered by a hook-like protrusion; neither of these characters has been observed in other athecate dinoflagellates. The posterior end of Apicoporus parvidiaboli possessed varying degrees of "horn formation", ranging from slight to prominent. By contrast, the posterior end of Apicoporus glaber was distinctively rounded and lacked evidence of horn formation. Although these species were previously interpreted to be obligate heterotrophs, TEM and epifluorescence microscopy demonstrated that some cells of both species had unusually small but otherwise typical dinoflagellate plastids. The number and density of plastids in any particular cell varied significantly in the genus, but the plastids were almost always concentrated at the posterior end of the cells or around the nucleus. The presence of cryptic photosynthetic plastids in these benthic species suggests that photosynthesis might be much more widespread in dinoflagellates than is currently assumed.

  17. Small mammal utilization by Middle Stone Age humans at Die Kelders Cave 1 and Pinnacle Point Site 5-6, Western Cape Province, South Africa.

    Science.gov (United States)

    Armstrong, Aaron

    2016-12-01

    Reported here are the results of a taphonomic analysis of the small mammals (between 0.75 kg and 4.5 kg adult body weight) and size 1 bovids (≤20 kg adult body weight) from the Middle Stone Age (MSA) sites of Die Kelders Cave 1 (DK1) and Pinnacle Point Site 5-6 (PP5-6), Western Cape Province, South Africa. This study provides a comprehensive taphonomic analysis of MSA small mammals with a focus on discerning the role of humans in their accumulation and the implications for human behavioral adaptations. Based on comparisons with control assemblages of known accumulation, it is evident that humans accumulated many of the Cape dune mole-rats, hares, and size 1 bovids at DK1. The patterning of cut-marked and burned mole-rat remains at DK1 provides evidence in the MSA for the systematic utilization of small mammals for their skins and as a protein source. Unlike DK1, small mammals and size 1 bovids constitute only a small portion of the PP5-6 mammals and they exhibit little evidence of human accumulation. Nocturnal and diurnal raptors accumulated most of the small fauna at PP5-6. The nominal presence of small mammals in the PP5-6 fauna is atypical of MSA sites in the Cape Floristic Region, where they are abundant and often constitute large portions of MSA archaeofaunas. DK1 humans maximized the environmental yield by exploiting low-quality resources, a strategy employed possibly in response to localized environmental conditions and to greater human population densities. In comparison, the MIS5-4 humans at PP5-6 did not exploit small mammals and instead focused on higher-quality resources like shellfish and large ungulates. Humans and predators accumulated few small mammals at PP5-6, suggesting that these taxa may have been less abundant near the site and/or that humans could afford to concentrate on high-quality resources, perhaps because of a higher-yield local environment. This study suggests that an adaptive response to the environmental conditions of MIS4 was

  18. Controlling for Phylogenetic Relatedness and Evolutionary Rates Improves the Discovery of Associations Between Species’ Phenotypic and Genomic Differences

    Science.gov (United States)

    Prudent, Xavier; Parra, Genis; Schwede, Peter; Roscito, Juliana G.; Hiller, Michael

    2016-01-01

    The growing number of sequenced genomes allows us now to address a key question in genetics and evolutionary biology: which genomic changes underlie particular phenotypic changes between species? Previously, we developed a computational framework called Forward Genomics that associates phenotypic to genomic differences by focusing on phenotypes that are independently lost in different lineages. However, our previous implementation had three main limitations. Here, we present two new Forward Genomics methods that overcome these limitations by (1) directly controlling for phylogenetic relatedness, (2) controlling for differences in evolutionary rates, and (3) computing a statistical significance. We demonstrate on large-scale simulated data and on real data that both new methods substantially improve the sensitivity to detect associations between phenotypic and genomic differences. We applied these new methods to detect genomic differences involved in the loss of vision in the blind mole rat and the cape golden mole, two independent subterranean mammals. Forward Genomics identified several genes that are enriched in functions related to eye development and the perception of light, as well as genes involved in the circadian rhythm. These new Forward Genomics methods represent a significant advance in our ability to discover the genomic basis underlying phenotypic differences between species. Source code: https://github.com/hillerlab/ForwardGenomics/ PMID:27222536

  19. Reproduction, aging and mortality rate in social subterranean mole voles (Ellobius talpinus Pall.).

    Science.gov (United States)

    Novikov, E; Kondratyuk, E; Petrovski, D; Titova, T; Zadubrovskaya, I; Zadubrovskiy, P; Moshkin, M

    2015-12-01

    Eusocial subterranean rodents of the Bathyergidae family have enormous longevity. The long lifespan of these species is associated with negligible senescence, that is, an absence of the signs of age-related deterioration in physical condition. The question arises as to whether these features are unique to eusocial Bathyergids or typical of other social subterranean rodents as well. In the present study, we analysed data from observations of a social subterranean Microtinae rodent, the northern mole vole (Ellobius talpinus Pall.), which, like mole-rats, has reproductive skew. Among the individuals captured in the wild and maintained in captivity, females that reproduced lived significantly longer than non-breeding females. We did not find any changes in muscle strength with age in any of the demographic groups studied. Faecal glucocorticoid concentrations before death were significantly higher in non-breeding females than in breeding females and males. Increased adrenocortical activity may be one mechanism responsible for the decreased lifespan of non-reproducing individuals of social subterranean rodents. We conclude that the patterns of aging, although different in some respects, are generally common for social subterranean rodents of different taxonomic groups.

  20. Hyaluronic Acid--an "Old" Molecule with "New" Functions: Biosynthesis and Depolymerization of Hyaluronic Acid in Bacteria and Vertebrate Tissues Including during Carcinogenesis.

    Science.gov (United States)

    Tsepilov, R N; Beloded, A V

    2015-09-01

    Hyaluronic acid is an evolutionarily ancient molecule commonly found in vertebrate tissues and capsules of some bacteria. Here we review modern data regarding structure, properties, and biological functions of hyaluronic acid in mammals and Streptococcus spp. bacteria. Various aspects of biogenesis and degradation of hyaluronic acid are discussed, biosynthesis and degradation metabolic pathways for glycosaminoglycan together with involved enzymes are described, and vertebrate and bacterial hyaluronan synthase genes are characterized. Special attention is given to the mechanisms underlying the biological action of hyaluronic acid as well as the interaction between polysaccharide and various proteins. In addition, all known signaling pathways involving hyaluronic acid are outlined. Impaired hyaluronic acid metabolism, changes in biopolymer molecular weight, hyaluronidase activity, and enzyme isoforms often accompany carcinogenesis. The interaction between cells and hyaluronic acid from extracellular matrix that may be important during malignant change is discussed. An expected role for high molecular weight hyaluronic acid in resistance of naked mole rat to oncologic diseases and the protective role of hyaluronic acid in bacteria are discussed.

  1. High-resolution imaging of selenium in kidneys: a localized selenium pool associated with glutathione peroxidase 3

    Energy Technology Data Exchange (ETDEWEB)

    Malinouski, M.; Kehr, S.; Finney, L.; Vogt, S.; Carlson, B.A.; Seravalli, J.; Jin, R.; Handy, D.E.; Park, T.J.; Loscalzo, J.; Hatfield, D.L.; Gladyshev, V.N. (Harvard-Med)

    2012-04-17

    Recent advances in quantitative methods and sensitive imaging techniques of trace elements provide opportunities to uncover and explain their biological roles. In particular, the distribution of selenium in tissues and cells under both physiological and pathological conditions remains unknown. In this work, we applied high-resolution synchrotron X-ray fluorescence microscopy (XFM) to map selenium distribution in mouse liver and kidney. Liver showed a uniform selenium distribution that was dependent on selenocysteine tRNA{sup [Ser]Sec} and dietary selenium. In contrast, kidney selenium had both uniformly distributed and highly localized components, the latter visualized as thin circular structures surrounding proximal tubules. Other parts of the kidney, such as glomeruli and distal tubules, only manifested the uniformly distributed selenium pattern that co-localized with sulfur. We found that proximal tubule selenium localized to the basement membrane. It was preserved in Selenoprotein P knockout mice, but was completely eliminated in glutathione peroxidase 3 (GPx3) knockout mice, indicating that this selenium represented GPx3. We further imaged kidneys of another model organism, the naked mole rat, which showed a diminished uniformly distributed selenium pool, but preserved the circular proximal tubule signal. We applied XFM to image selenium in mammalian tissues and identified a highly localized pool of this trace element at the basement membrane of kidneys that was associated with GPx3. XFM allowed us to define and explain the tissue topography of selenium in mammalian kidneys at submicron resolution.

  2. Biology of hyaluronan: Insights from genetic disorders of hyaluronan metabolism

    Institute of Scientific and Technical Information of China (English)

    Barbara; Triggs-Raine; Marvin; R; Natowicz

    2015-01-01

    Hyaluronan is a rapidly turned over component of the vertebrate extracellular matrix. Its levels are determined, in part, by the hyaluronan synthases, HAS1, HAS2, and HAS3, and three hyaluronidases, HYAL1, HYAL2 and HYAL3. Hyaluronan binding proteins also regulate hyaluronan levels although their involvement is less well understood. To date, two genetic disorders of hyaluronan metabolism have been reported in humans: HYAL1 deficiency(Mucopolysaccharidosis IX) in four individuals with joint pathology as the predominant phenotypic finding and HAS2 deficiency in a single person having cardiac pathology. However, inherited disorders and induced mutations affecting hyaluronan metabolism have been characterized in other species. Overproduction of hyaluronan by HAS2 results in skin folding and thickening in shar-pei dogs and the naked mole rat, whereas a complete deficiency of HAS2 causes embryonic lethality in mice due to cardiac defects. Deficiencies of murine HAS1 and HAS3 result in a predisposition to seizures. Like humans, mice with HYAL1 deficiency exhibit joint pathology. Mice lacking HYAL2 have variably penetrant developmental defects, including skeletal and cardiac anomalies. Thus, based on mutant animal models, a partial deficiency of HAS2 or HYAL2 might be compatible with survival in humans, while complete deficiencies of HAS1, HAS3, and HYAL3 may yet be recognized.

  3. Environmental adversity and uncertainty favour cooperation

    Science.gov (United States)

    Andras, Peter; Lazarus, John; Roberts, Gilbert

    2007-01-01

    Background A major cornerstone of evolutionary biology theory is the explanation of the emergence of cooperation in communities of selfish individuals. There is an unexplained tendency in the plant and animal world – with examples from alpine plants, worms, fish, mole-rats, monkeys and humans – for cooperation to flourish where the environment is more adverse (harsher) or more unpredictable. Results Using mathematical arguments and computer simulations we show that in more adverse environments individuals perceive their resources to be more unpredictable, and that this unpredictability favours cooperation. First we show analytically that in a more adverse environment the individual experiences greater perceived uncertainty. Second we show through a simulation study that more perceived uncertainty implies higher level of cooperation in communities of selfish individuals. Conclusion This study captures the essential features of the natural examples: the positive impact of resource adversity or uncertainty on cooperation. These newly discovered connections between environmental adversity, uncertainty and cooperation help to explain the emergence and evolution of cooperation in animal and human societies. PMID:18053138

  4. Environmental adversity and uncertainty favour cooperation

    Directory of Open Access Journals (Sweden)

    Lazarus John

    2007-11-01

    Full Text Available Abstract Background A major cornerstone of evolutionary biology theory is the explanation of the emergence of cooperation in communities of selfish individuals. There is an unexplained tendency in the plant and animal world – with examples from alpine plants, worms, fish, mole-rats, monkeys and humans – for cooperation to flourish where the environment is more adverse (harsher or more unpredictable. Results Using mathematical arguments and computer simulations we show that in more adverse environments individuals perceive their resources to be more unpredictable, and that this unpredictability favours cooperation. First we show analytically that in a more adverse environment the individual experiences greater perceived uncertainty. Second we show through a simulation study that more perceived uncertainty implies higher level of cooperation in communities of selfish individuals. Conclusion This study captures the essential features of the natural examples: the positive impact of resource adversity or uncertainty on cooperation. These newly discovered connections between environmental adversity, uncertainty and cooperation help to explain the emergence and evolution of cooperation in animal and human societies.

  5. Molecular cloning, sequence identification and expression profile of domestic guinea pig (Cavia porcellus UGT1A1 gene

    Directory of Open Access Journals (Sweden)

    Yang Deming

    2016-01-01

    Full Text Available Domestic guinea pig is a model animal for human disease research. Uridine diphosphate glucuronosyltransferase 1 family, polypeptide A1 (UGT1A1 is an important human disease-related gene. In this study, the complete coding sequence of domestic guinea pig gene UGT1A1 was amplified by reverse transcription-polymerase chain reaction. The open reading frame of the domestic guinea pig UGT1A1 gene is 1602 bp in length and was found to encode a protein of 533 amino acids. Sequence analysis revealed that the UGT1A1 protein of domestic guinea pig shared high homology with the UGT1A1 proteins of degu (84%, damara mole-rat (84%, human (80%, northern white-cheeked gibbon (80%, Colobus angolensis palliatus (80% and golden snub-nosed monkey (79%. This gene contains five exons and four introns, as revealed by the computer-assisted analysis. The results also showed that the domestic guinea pig UGT1A1 gene had a close genetic relationship with the UGT1A1 gene of degu. The prediction of transmembrane helices showed that domestic guinea pig UGT1A1 might be a transmembrane protein. Expression profile analysis indicated that the domestic guinea pig UGT1A1 gene was differentially expressed in detected domestic guinea pig tissues. Our experiment laid a primary foundation for using the domestic guinea pig as a model animal to study the UGT1A1-related human diseases.

  6. Aggression patterns and speciation.

    Science.gov (United States)

    Nevo, E; Naftali, G; Guttman, R

    1975-01-01

    The evolutionary significance of interspecific aggression as a factor in speciation was tested among three chromosome forms of the actively speciating fossorial rodent Spalax ehrenbergi in Israel. Laboratory experiments testing intra- and interspecific aggression were conducted on 48 adult animals from 10 populations comprising three chromosome forms with 2n = 52, 58, and 60. Twelve agonistic, motivational-conflict, and territorial behavioral variables were recorded during 72 combats involving homo- and heter-ogametic encounters between opponents. Analysis of the data matrix was carried out by the nonmetric multivariate Smallest Space Analysis (SSA-II). The results indicate that (a) aggression patterns, involving agonistic conflict and territorial variables, are higher in heterogametic encounters than in homogametic ones; and (b) aggression is higher between contiguous chromosome forms (2n = 58-60, and 2n = 52-58) than between noncontiguous ones (2n = 52-60). Both a and b suggest that high interspecific aggression appears to be adaptively selected at final stages of speciation in mole rats as a premating isolating mechanism which reinforces species identification and establishes parapatric distributions between the evolving species. PMID:1059109

  7. Alternative Strategy for Alzheimer’s Disease: Stress Response Triggers

    Directory of Open Access Journals (Sweden)

    Joan Smith Sonneborn

    2012-01-01

    Full Text Available Stress resistance capacity is a hallmark of longevity protection and survival throughout the plant and animal kingdoms. Latent pathway activation of protective cascades, triggered by environmental challenges to tolerate heat, oxygen deprivation, reactive oxygen species (ROS, diet restriction, and exercise provides tolerance to these stresses. Age-related changes and disease vulnerability mark an increase in damage, like damage induced by environmental challenges. An alternative approach to immunotherapy intervention in Alzheimer’s Disease is the use of mimetics of stress to upregulate endogenous protective cascades to repair age damage, shift the balance of apoptosis to regeneration to promote delay of onset, and even progression of Alzheimer’s disease memory dysfunction. Mimetics of environmental stress, hormetic agents, and triggers, endogenous or engineered, can “trick” activation of expression patterns of repair and rejuvenation. Examples of known candidate triggers of heat response, endogenous antioxidants, DNA repair, exercise, hibernation, and telomeres are available for AD intervention trials. Telomeres and telomerase emerge as major regulators in crossroads of senescence, cancer, and rejuvenation responsive to mimetics of telomeres. Lessons emerge from transgenic rodent models, the long-lived mole rat, clinical studies, and conserved innate pathways of stress resistance. Cross-reaction of benefits of different triggers promises intervention into seemingly otherwise unrelated diseases.

  8. Molecular phylogeny of rodents, with special emphasis on murids: evidence from nuclear gene LCAT.

    Science.gov (United States)

    Robinson, M; Catzeflis, F; Briolay, J; Mouchiroud, D

    1997-12-01

    Phylogenetic relationships among 19 extant species of rodents, with special emphasis on rats, mice, and allied Muroidea, were studied using sequences of the nuclear protein-coding gene LCAT (lecithin:cholesterol acyltransferase), an enzyme of cholesterol metabolism. Analysis of 705 base pairs from the exonic regions of LCAT confirmed known groupings in and around Muroidea. Strong support was found for the families Sciuridae (squirrel and marmot) and Gliridae (dormice) and for suprafamilial taxa Muroidea and Caviomorpha (guinea pig and allies). Within Muroidea, the first branching leads to the fossorial mole rats Spalacinae and bamboo rats Rhizomyinae. The other Muroidea appear as a polytomy from which are issued Gerbillinae (gerbils), Murinae (rats and mice), Sigmodontinae (New World cricetids), Cricetinae (hamsters), and Arvicolinae (voles). Evidence from LCAT sequences agrees with that from a number of previous molecular and morphological studies, both concerning branching orders inside Muroidea and the bush-like radiation of rodent suprafamilial taxa (caviomorphs, sciurids, glirids, muroids), thus suggesting that this nuclear gene is an appropriate candidate for addressing questions of rodents relationships.

  9. The transcriptome of the bowhead whale Balaena mysticetus reveals adaptations of the longest-lived mammal

    Science.gov (United States)

    Seim, Inge; Ma, Siming; Zhou, Xuming; Gerashchenko, Maxim V.; Lee, Sang-Goo; Suydam, Robert; George, John C.; Bickham, John W.; Gladyshev, Vadim N.

    2014-01-01

    Mammals vary dramatically in lifespan, by at least two-orders of magnitude, but the molecular basis for this difference remains largely unknown. The bowhead whale Balaena mysticetus is the longest-lived mammal known, with an estimated maximal lifespan in excess of two hundred years. It is also one of the two largest animals and the most cold-adapted baleen whale species. Here, we report the first genome-wide gene expression analyses of the bowhead whale, based on the de novo assembly of its transcriptome. Bowhead whale or cetacean-specific changes in gene expression were identified in the liver, kidney and heart, and complemented with analyses of positively selected genes. Changes associated with altered insulin signaling and other gene expression patterns could help explain the remarkable longevity of bowhead whales as well as their adaptation to a lipid-rich diet. The data also reveal parallels in candidate longevity adaptations of the bowhead whale, naked mole rat and Brandt's bat. The bowhead whale transcriptome is a valuable resource for the study of this remarkable animal, including the evolution of longevity and its important correlates such as resistance to cancer and other diseases. PMID:25411232

  10. The First International Mini-Symposium on Methionine Restriction and Lifespan

    Directory of Open Access Journals (Sweden)

    Gene eAbles

    2014-05-01

    Full Text Available It has been 20 years since the Orentreich Foundation for the Advancement of Science, under the leadership Dr. Norman Orentreich, first reported that low methionine (Met ingestion by rats extends lifespan [1]. Since then, several studies have replicated the effects of dietary methionine restriction (MR in delaying age-related diseases [2–5]. We report the abstracts from the First International Mini-Symposium on Methionine Restriction and Lifespan held in Tarrytown, NY last September 2013. The goals were 1 to gather researchers with an interest in methionine restriction and lifespan, 2 to exchange knowledge, 3 to generate ideas for future investigations, and 4 to strengthen relationships within this community. The presentations highlighted the importance of research on cysteine, growth hormone (GH, and ATF4 in the paradigm of aging. In addition, the effects of dietary restriction or MR in the kidneys, liver, bones and the adipose tissue were discussed. The symposium also emphasized the value of other species, e.g. the naked mole rat, Brandt’s bat and drosophila in aging research. Overall, the symposium consolidated scientists with similar research interests and provided opportunities to conduct future collaborative studies.

  11. Digging for answers: contributions of density- and frequency-dependent factors on ectoparasite burden in a social mammal.

    Science.gov (United States)

    Archer, Elizabeth K; Bennett, Nigel C; Faulkes, Chris G; Lutermann, Heike

    2016-02-01

    Due to the density-dependent nature of parasite transmission parasites are generally assumed to constrain the evolution of sociality. However, evidence for a correlation between group size and parasite burden is equivocal, particularly for mammals. Host contact rates may be modified by mobility of the host and parasite as well as social barriers. In the current study, we used the common mole-rat (Cryptomys hottentotus hottentotus), a social subterranean rodent, as a model system to investigate the effect of host density and frequency of contact rates on ectoparasite burdens. To address these factors we used a study species that naturally varies in population densities and intergroup contact rates across its geographic range. We found that ectoparasite prevalence, abundance and species richness decreased with increasing host density at a regional scale. At the same time, measures of parasite burden increased with intergroup contact rates. Ectoparasite burdens decreased with colony size at the group level possibly as a result of increased grooming rates. Equating group size with population density might be too simplistic an approach when assessing parasite distributions in social mammals. Our data suggest that frequency-dependent mechanisms may play a much greater role at a population level than density-dependent mechanisms in determining parasite distributions in social species. We suggest that future studies should explicitly consider behavioural mechanisms that may affect parasite distribution.

  12. The transcriptome of the bowhead whale Balaena mysticetus reveals adaptations of the longest-lived mammal.

    Science.gov (United States)

    Seim, Inge; Ma, Siming; Zhou, Xuming; Gerashchenko, Maxim V; Lee, Sang-Goo; Suydam, Robert; George, John C; Bickham, John W; Gladyshev, Vadim N

    2014-10-01

    Mammals vary dramatically in lifespan, by at least two-orders of magnitude, but the molecular basis for this difference remains largely unknown. The bowhead whale Balaena mysticetus is the longest-lived mammal known, with an estimated maximal lifespan in excess of two hundred years. It is also one of the two largest animals and the most cold-adapted baleen whale species. Here, we report the first genome-wide gene expression analyses of the bowhead whale, based on the de novo assembly of its transcriptome. Bowhead whale or cetacean-specific changes in gene expression were identified in the liver, kidney and heart, and complemented with analyses of positively selected genes. Changes associated with altered insulin signaling and other gene expression patterns could help explain the remarkable longevity of bowhead whales as well as their adaptation to a lipid-rich diet. The data also reveal parallels in candidate longevity adaptations of the bowhead whale, naked mole rat and Brandt's bat. The bowhead whale transcriptome is a valuable resource for the study of this remarkable animal, including the evolution of longevity and its important correlates such as resistance to cancer and other diseases.

  13. Description of parasitic nematodes extracted from rhizosphere of off-season vegetables in Hainan island%海南岛反季节蔬菜根际寄生线虫种类记述

    Institute of Scientific and Technical Information of China (English)

    丁晓帆; 曹凤勤; 谢桃香; 杨燕谭; 周珊虹; 陈文惠

    2015-01-01

    从海南岛反季节蔬菜根际土壤中分离鉴定出9属12种寄生线虫,分别为肾形肾状线虫(Rotylenchulus reniformis Linford&Oliverira,1940)、双宫螺旋线虫[Helicotylenchus dihystera (Cobb,1893) Sher,1961]、刻尾螺旋线虫(H.crenacauda Sher,1966)、咖啡短体线虫[Pratylenchus coffeae (Zimmermann,1898) Filipjev&Schuurmans Stekhoven,1941]、穿刺短体线虫[P.penetrans (Cobb,1917) Chitwood,Oteifa,1952]、尖突潜根线虫[Hirschmanniella mucronata (Das,1960)Luc&Goodey,1963]、异头丝尾垫刃线虫(Filenchus heterocephalus Xie&Feng,1996)、塞氏纽带线虫(Hoplolaimus seinhorsti Luc,1958)、燕麦真滑刃线虫(Aphelenchus avenae Bastian,1865)、类双尾滑刃线虫(Aphelenchoides parabicaudatus Shavrov,1967)、内卷滑刃线虫(A.involutus Minagawa,1992)和较小拟毛刺线虫[Paratrichodorus minor (Colbran,1956) Siddiqi,1974].其中,异头丝尾垫刃线虫和内卷滑刃线虫为海南岛新纪录种.

  14. Polymorphic infection and organogenesis patterns induced by a Rhizobium leguminosarum isolate from Lotus root nodules are determined by the host genotype.

    Science.gov (United States)

    Gossmann, Jasmin A; Markmann, Katharina; Brachmann, Andreas; Rose, Laura E; Parniske, Martin

    2012-10-01

    To sample the natural variation in genes controlling compatibility in the legume-rhizobium symbiosis, we isolated rhizobia from nodules of endemic Lotus species from 21 sites across Europe. The majority of isolates were identified as Mesorhizobium- or Bradyrhizobium-related and formed nitrogen-fixing root nodules on Lotus corniculatus and L. pendunculatus, respectively, thus confirming previously defined cross-inoculation groups. Rhizobium leguminosarum (Rl) strain Norway, isolated from L. corniculatus nodules, displayed an exceptional phenotypic variation on different Lotus genotypes. On L. burttii, Rl Norway formed infected nodules, whereas tumors and elongated infected swellings were induced on L. glaber and L. japonicus ecotype Nepal, respectively. A symbiosis- and Nod-factor-responsive promoter:uidA fusion was strongly and rapidly induced in L. japonicus Gifu, but infection threads or signs of nodule organogenesis were absent. This complex phenotypic pattern was not mimicked by either of three engineered R. leguminosarum bv viciae strains producing different Nod-factor variants. Intriguingly, Rl Norway formed infection threads on Pisum sativum cv Sparkle, but failed to induce organogenesis. Rl Norway thus uncovered variation in symbiotic capabilities among diploid Lotus species and ecotypes that are obscured by optimally adapted M. loti strains. These contrasting infection and organogenesis phenotypes reveal recent diversification of recognition determinants in Lotus.

  15. Genetic diversity and symbiotic compatibility among rhizobial strains and Desmodium incanum and Lotus spp. plants.

    Science.gov (United States)

    Granada, Camille E; Strochein, Marcos; Vargas, Luciano K; Bruxel, Manuela; de Sá, Enilson Luiz Saccol; Passaglia, Luciane M P

    2014-06-01

    This work aimed to evaluate the symbiotic compatibility and nodulation efficiency of rhizobia isolated from Desmodium incanum, Lotus corniculatus, L. subbiflorus, L. uliginosus and L. glaber plants by cross-inoculation. Twelve reference strains and 21 native isolates of rhizobia were genetically analyzed by the BOX-PCR technique, which showed a high genetic diversity among the rhizobia studied. The isolates were also characterized based on their production of indolic compounds and siderophores, as well as on their tolerance to salinity. Fifteen of the 33 rhizobia analyzed were able to produce indolic compounds, whereas 13 produced siderophores. All the tested rhizobia were sensitive to high salinity, although some were able to grow in solutions of up to 2% NaCl. Most of the native rhizobia isolated from L. uliginosus were able to induce nodulation in all plant species studied. In a greenhouse experiment using both D. incanum and L. corniculatus plants, the rhizobia isolate UFRGS Lu2 promoted the greatest plant growth. The results demonstrate that there are native rhizobia in the soils of southern Brazil that have low host specificity and are able to induce nodulation and form active nodules in several plant species.

  16. Erotylidae (Insecta, Coleoptera of Poland – problematic taxa, updated keys and new records

    Directory of Open Access Journals (Sweden)

    Rafal Ruta

    2011-10-01

    Full Text Available New data concerning the occurrence of pleasing fungus beetles (Coleoptera: Erotylidae in Poland are given, with a focus on rare and difficult to identify Central European taxa. Cryptophilus cf. integer (Heer (Cryptophilinae is reported from the Polish territory for the first time based on adult and larval specimens collected in the Wielkopolska-Kujawy Lowland. Identification problems concerning species of Cryptophilus introduced to Europe are discussed. Triplax carpathica Reitter (Erotylinae is recorded from the Białowieża Primeval Forest, which is the first known non-Carpathian finding of this species, located in the close proximity of the Polish-Belarussian UNESCO World Heritage Site “Białowieża Forest”. Discussion of T. carpathica being conspecific with Siberian T. rufiventris Gebler is provided. New Polish localities of several other Erotylidae are reported, and an updated key to Central European species of Triplax is given. The Triplax key is supplemented with dorsal and ventral habitus images of all treated Triplax species. One of the rarest Central European erotyline species Combocerus glaber (Schaller is recorded from xerothermic grasslands in North-West Poland.

  17. Genetic diversity and symbiotic compatibility among rhizobial strains and Desmodium incanum and Lotus spp. plants

    Directory of Open Access Journals (Sweden)

    Camille E Granada

    2014-06-01

    Full Text Available This work aimed to evaluate the symbiotic compatibility and nodulation efficiency of rhizobia isolated from Desmodium incanum, Lotus corniculatus, L. subbiflorus, L. uliginosus and L. glaber plants by cross-inoculation. Twelve reference strains and 21 native isolates of rhizobia were genetically analyzed by the BOX-PCR technique, which showed a high genetic diversity among the rhizobia studied. The isolates were also characterized based on their production of indolic compounds and siderophores, as well as on their tolerance to salinity. Fifteen of the 33 rhizobia analyzed were able to produce indolic compounds, whereas 13 produced siderophores. All the tested rhizobia were sensitive to high salinity, although some were able to grow in solutions of up to 2% NaCl. Most of the native rhizobia isolated from L. uliginosus were able to induce nodulation in all plant species studied. In a greenhouse experiment using both D. incanum and L. corniculatus plants, the rhizobia isolate UFRGS Lu2 promoted the greatest plant growth. The results demonstrate that there are native rhizobia in the soils of southern Brazil that have low host specificity and are able to induce nodulation and form active nodules in several plant species.

  18. Měkkýši PR Velké Doly u Českého Těšína (Slezsko, Česká republika

    Directory of Open Access Journals (Sweden)

    Jiří Kupka

    2006-09-01

    Full Text Available The molluscan fauna of the Velké Doly Natural Reserve was surveyed in 1999 and 2006. In total, 27 snail species were found (26 terrestrial gastropods and 1 bivalve. The Natural Reserve is only 1.5 km far from ironworks “Třinecké železárny”. In the 18th century, there was a limestone quarry and beech plantation (as a fuel for ironworks in the reserve. At the present time the reserve represents the secondary forests society Tilio cordatae-Carpinetum with protected and regional notable plants in undergrowth (Cephalanthera damasonium, Lilium martagon, Arum alpinum, Hacquetia epipactis, etc. The present character of the Velké Doly Natural Reserve is a result of human activities, nevertheless it is preserved and favourable site for molluscs, since many stenotopic and endangered woodland species occur there (e.g. Discus perspectivus, Petasina unidentata, Oxychilus glaber. The presence of the vulnerable snail Discus perspectivus is notable as first locality in Poland part of Těšín region (the Natural Reserve Velké Doly is located on the Poland border. Occurrence of euryecious species Arion distinctus, Arion lusitanicus and Limax maximus could relate with some human impact (e.g. presence of allotted gardens colony.

  19. Nivní malakofauna Ploučnice (Severní Čechy The floodplain mollusc fauna of the Ploučnice River (North Bohemia

    Directory of Open Access Journals (Sweden)

    Lucie Juřičková

    2013-04-01

    Full Text Available This paper presents a research of the floodplain mollusc communities of the Ploučnice River (Elbe tributary, North Bohemia, Czech Republic. Altogether, 66 mollusc species (65 species of gastropods, one species of bivalve were recorded in the 35 floodplain forest sites during the research between 2007 and 2011, representing 27% of the total Czech malacofauna. More than a half of all species represents the common forest species (52% of all recorded species with some rare woodland species as Aegopinella nitidula, Daudebardia rufa, Macrogastra ventricosa, Oxychilus depressus, O. glaber and two endangered species Clausilia bidentata and Daudebardia brevipes. Rare wetland species protected by the NATURA system Vertigo angustior and vulnerable V. antivertigo were also found. The occurrence of these rare species (two of them endangered, three vulnerable, and 11 near threatened makes the Ploučnice river alluvium as an important mollusc refugium of prime conservation importance in this fragmented Czech landscape of long-term agricultural land use.

  20. Leaf anatomical structure for 15 tree species' seedlings in Zhejiang Province%浙江省15个树种苗期叶片解剖结构特征比较分析

    Institute of Scientific and Technical Information of China (English)

    刘欣欣; 张明如; 邹伶俐; 吴刚; 阴卓越; 吕钺香

    2013-01-01

    植物叶片结构与其耐阴性具有密切关系.为揭示浙江西部常见树种叶片对光环境的适应性,采用常规石蜡切片制片法,比较观察了苦槠Castanopsis sclerophylla,木荷Schima superba,杜英Elaeocarpus decipiens,乌桕Sapium sebiferum,短尾柯Lithocarpus brevicaudatus,石栎Lithocarpus glaber,浙江楠Phoebe chekiangensis,乌冈栎Quercus phillyraeoides,竹柏Podocarpus nagi,马尾松Pinus massoniana,水杉Metasequoia glyptostroboides,红豆杉Taxus chinensis,红叶石楠Photinia × fraseri,美丽胡枝子Lespedeza formosa和红花檀木Loropetalum chinense var.rubrum等15个树种叶片的解剖结构特征.结果表明:①水杉和红豆杉上、下表皮均为1层,栅栏组织和海绵组织均不发达.马尾松叶片为2针1束,横截面为半圆形.②9个阔叶树种栅栏和海绵组织平均厚度最厚;木荷、乌桕和竹柏栅栏组织为1层,短尾柯、杜英、石栎和浙江楠为2层,苦槠和乌冈栎栅栏组织最发达,为3层;海绵组织均排列疏松.③灌木树种栅栏组织、海绵组织厚度排序均为红叶石楠>美丽胡枝子>红花檀木.④对15个树种叶片解剖结构特征进行聚类分析,认为竹柏为耐荫树种;马尾松为强阳性树种;乌桕、红叶石楠、苦槠、乌冈栎归类为阳性树种;短尾柯、美丽胡枝子、浙江楠、杜英、木荷、水杉、红豆杉、石栎和红花栏木归为中性树种.研究结果可为调控现有马尾松单优群落的结构组成,恢复亚热带低山丘陵区地带性森林植被提供理论依据.%To reveal leaf adaptability to the light environment for tree species common to the Western Zhejiang,characteristics of the leaf anatomical structure in 15 tree species'seedlings:Castanopsis sclerophylla,Schima superba,Elaeocarpus decipiens,Sapium sebiferum,Lithocarpus brevicaudatus,Lithocarpus glaber,Phoebe chekiangensis,Quercus phillyraeoides,Podocarpus nagi,Pinus massoniana,Metasequoia glyptostroboides

  1. Changes in Soil Carbon Pools Induced by Substitution of Plantation for Native Forest

    Institute of Scientific and Technical Information of China (English)

    XU QIUFANG; XU JIANMING

    2003-01-01

    Changes in soil carbon pools under Chinese fir (Cunninghamia lanceolata) and bamboo (Phyllostachyspubescens) plantations substituted for a native forest ( Quereus acutissima, Cyclobalanopsis glauca, Cas-tanopsis sclerophylla, Platycarya strobilacea, Lithocarpus glaber) were studied on the hills with acid parentrock and soils classified as red soils (Ferrisols) in Huzhou, Zhejiang Province of east China. It was foundthat total soil organic carbon (TSOC), easily oxidisable carbon (EOC) and water-soluble organic carbon(WSOC) under bamboo plantation were increased, but microbial biomass carbon (MBC) was decreased. Onthe contrary, Chinese fir induced declines of all fractions of C including TSOC, EOC, WSOC and MBC.The percentages of the active fractions of soil C (EOC and WSOC) were increased in the plantations ascompared to the native broad-leaved forest, but proportions of soil organic C as MBC were decreased. Itcould be concluded that bamboo plantation had a great ability of not only fixing C but also accelerating soilC pool cycle, improving nutrient and microorganism activity; therefore, it is a good ecosystem and could berecommended for wide development. Chinese fir would shrink the soil C pool and deteriorate soil biologicalfertility, so it did not benefit CO2 fixing and land sustainable utilization.

  2. Adaptive evolution of voltage-gated sodium channels: the first 800 million years.

    Science.gov (United States)

    Zakon, Harold H

    2012-06-26

    Voltage-gated Na(+)-permeable (Nav) channels form the basis for electrical excitability in animals. Nav channels evolved from Ca(2+) channels and were present in the common ancestor of choanoflagellates and animals, although this channel was likely permeable to both Na(+) and Ca(2+). Thus, like many other neuronal channels and receptors, Nav channels predated neurons. Invertebrates possess two Nav channels (Nav1 and Nav2), whereas vertebrate Nav channels are of the Nav1 family. Approximately 500 Mya in early chordates Nav channels evolved a motif that allowed them to cluster at axon initial segments, 50 million years later with the evolution of myelin, Nav channels "capitalized" on this property and clustered at nodes of Ranvier. The enhancement of conduction velocity along with the evolution of jaws likely made early gnathostomes fierce predators and the dominant vertebrates in the ocean. Later in vertebrate evolution, the Nav channel gene family expanded in parallel in tetrapods and teleosts (∼9 to 10 genes in amniotes, 8 in teleosts). This expansion occurred during or after the late Devonian extinction, when teleosts and tetrapods each diversified in their respective habitats, and coincided with an increase in the number of telencephalic nuclei in both groups. The expansion of Nav channels may have allowed for more sophisticated neural computation and tailoring of Nav channel kinetics with potassium channel kinetics to enhance energy savings. Nav channels show adaptive sequence evolution for increasing diversity in communication signals (electric fish), in protection against lethal Nav channel toxins (snakes, newts, pufferfish, insects), and in specialized habitats (naked mole rats).

  3. Cellular adaptation to hypoxia and p53 transcription regulation

    Institute of Scientific and Technical Information of China (English)

    Yang ZHAO; Xue-qun CHEN; Ji-zeng DU

    2009-01-01

    Tumor suppressor p53 is the most frequently mutated gene in human tumors. Meanwhile, under stress conditions, p53 also acts as a transcription factor, regulating the expression of a series of target genes to maintain the integrity of genome. The target genes of p53 can be classified into genes regulating cell cycle arrest, genes involved in apoptosis, and genes inhibiting angiogenesis. p53 protein contains a transactivation domain, a sequence-specific DNA binding domain, a tetramerization domain, a non-specific DNA binding domain that recognizes damaged DNA, and a later identified proline-rich domain. Under stress, p53 proteins accumulate and are activated through two mechanisms. One, involving ataxia telangiectasia-mutated protein (ATM), is that the interaction between p53 and its down-regulation factor murine double minute 2 (MDM2) decreases, leading to p53 phosphorylation on Ser15, as determined by the post-translational mechanism; the other holds that p53 increases and is activated through the binding of ribosomal protein L26 (RPL26) or nucleolin to p53 mRNA 5' untranslated region (UTR), regulating p53 translation. Under hypoxia, p53 decreases transactivation and increases transrepression. The mutations outside the DNA binding domain of p53 also contribute to tumor progress, so further studies on p53 should also be focused on this direction. The subterranean blind mole rat Spalax in Israel is a good model for hypoxia-adaptation. The p53 of Spalax mutated in residue 172 and residue 207 from arginine to lysine, conferring it the ability to survive hypoxic conditions. This model indicates that p53 acts as a master gene of diversity formation during evolution.

  4. Life in groups: the roles of oxytocin in mammalian sociality.

    Science.gov (United States)

    Anacker, Allison M J; Beery, Annaliese K

    2013-12-11

    In recent decades, scientific understanding of the many roles of oxytocin (OT) in social behavior has advanced tremendously. The focus of this research has been on maternal attachments and reproductive pair-bonds, and much less is known about the substrates of sociality outside of reproductive contexts. It is now apparent that OT influences many aspects of social behavior including recognition, trust, empathy, and other components of the behavioral repertoire of social species. This review provides a comparative perspective on the contributions of OT to life in mammalian social groups. We provide background on the functions of OT in maternal attachments and the early social environment, and give an overview of the role of OT circuitry in support of different mating systems. We then introduce peer relationships in group-living rodents as a means for studying the importance of OT in non-reproductive affiliative behaviors. We review species differences in oxytocin receptor (OTR) distributions in solitary and group-living species of South American tuco-tucos and in African mole-rats, as well as singing mice. We discuss variation in OTR levels with seasonal changes in social behavior in female meadow voles, and the effects of OT manipulations on peer huddling behavior. Finally, we discuss avenues of promise for future investigation, and relate current findings to research in humans and non-human primates. There is growing evidence that OT is involved in social selectivity, including increases in aggression toward social outgroups and decreased huddling with unfamiliar individuals, which may support existing social structures or relationships at the expense of others. OT's effects reach beyond maternal attachment and pair bonds to play a role in affiliative behavior underlying "friendships", organization of broad social structures, and maintenance of established social relationships with individuals or groups.

  5. Response of endemic afroalpine rodents to the removal of livestock grazing pressure

    Institute of Scientific and Technical Information of China (English)

    Flavie VIAL; David W. MACDONALD; Daniel T. HAYDON

    2011-01-01

    The Bale Mountains of Ethiopia represent the world's largest continuous extent of afroalpine habitat.With a peak combined density of over 8000 individuals/km2,the endemic giant mole rat Tachyoryctes macrocephalus,Blick's grass rat Arvicanthis blicki and the brush-furred mouse Lophuromys melanonyx are the dominant wild herbivores within this ecosystem and may be affected by the presence of high densities of domestic livestock.The purpose of this study was to establish whether these endemic rodent populations could respond to the removal of grazing pressure inside three 0.25 hectare livestock exclosures (paired with grazed control plots) and to determine whether such response was mediated through concomitant changes in the vegetation structure.We hypothesised that livestock grazing negatively affects endemic rodent populations through competition or increased predation risk and we predicted an increase in rodent biomass following the removal of grazing pressure.We found no evidence of rodent populations responding to the removal of livestock after fourteen months.The short-term nature of the experimental design,environmental fluctuations and the ecosystem's inherent stochasticity may explain the apparent lack of a significant response.However,while this study is inconclusive,it emphasises the need for more long-term experimental investigations to assess the effects of domestic grazers on vegetation and on dependent communities.The effects of rapidly increasing livestock numbers in the Bale Mountains will require continued close monitoring of vegetation and endemic animal communities as the afroalpine is altered by external biotic and abiotic forces [Current Zoology 57 (6):741-750,2011].

  6. Life in groups: the roles of oxytocin in mammalian sociality

    Directory of Open Access Journals (Sweden)

    Allison eAnacker

    2013-12-01

    Full Text Available In recent decades, scientific understanding of the many roles of oxytocin in social behavior has advanced tremendously. The focus of this research has been on maternal attachments and reproductive pair-bonds, and much less is known about the substrates of sociality outside of reproductive contexts. It is now apparent that oxytocin influences many aspects of social behavior including recognition, trust, empathy, and other components of the behavioral repertoire of social species. This review provides a comparative perspective on the contributions of oxytocin to life in mammalian social groups. We provide background on the functions of oxytocin in maternal attachments and the early social environment, and give an overview of the role of oxytocin circuitry in support of different mating systems. We then introduce peer relationships in group-living rodents as a means for studying the importance of oxytocin in non-reproductive affiliative behaviors. We review species differences in oxytocin receptor distributions in solitary and group-living species of South American tuco-tucos and in African mole-rats, as well as singing mice. We discuss variation in oxytocin receptor levels with seasonal changes in social behavior in female meadow voles, and the effects of oxytocin manipulations on peer huddling behavior. Finally, we discuss avenues of promise for future investigation, and relate current findings to research in humans and non-human primates. There is growing evidence that oxytocin is involved in social selectivity, including increases in aggression toward social outgroups and decreased huddling with unfamiliar individuals, which may support existing social structures or relationships at the expense of others. Oxytocin’s effects reach beyond maternal attachment and pair bonds to play a role in affiliative behavior underlying friendships, organization of broad social structures, and maintenance of established social relationships with individuals

  7. Does the oxidative stress theory of aging explain longevity differences in birds? II. Antioxidant systems and oxidative damage.

    Science.gov (United States)

    Montgomery, Magdalene K; Buttemer, William A; Hulbert, A J

    2012-03-01

    The oxidative damage hypothesis of aging posits that the accumulation of oxidative damage is a determinant of an animal species' maximum lifespan potential (MLSP). Recent findings in extremely long-living mammal species such as naked mole-rats challenge this proposition. Among birds, parrots are exceptionally long-living with an average MLSP of 25 years, and with some species living more than 70 years. By contrast, quail are among the shortest living bird species, averaging about 5-fold lower MLSP than parrots. To test if parrots have correspondingly (i) superior antioxidant protection and (ii) lower levels of oxidative damage compared to similar-sized quail, we measured (i) total antioxidant capacity, uric acid and reduced glutathione (GSH) levels, as well as the activities of enzymatic antioxidants (superoxide dismutase, glutathione peroxidase and catalase), and (ii) markers of mitochondrial DNA damage (8-OHdG), protein damage (protein carbonyls) and lipid peroxidation (lipid hydroperoxides and TBARS) in three species of long-living parrots and compared these results to corresponding measures in two species of short-living quails (average MLSP=5.5 years). All birds were fed the same diet to exclude differences in dietary antioxidant levels. Tissue antioxidants and oxidative damage were determined both 'per mg protein' and 'per g tissue'. Only glutathione peroxidase was consistently higher in tissues of the long-living parrots and suggests higher protection against the harmful effects of hydroperoxides, which might be important for parrot longevity. The levels of oxidative damage were mostly statistically indistinguishable between parrots and quails (67%), occasionally higher (25%), but rarely lower (8%) in the parrots. Despite indications of higher protection against some aspects of oxidative stress in the parrots, the pronounced longevity of parrots appears to be independent of their antioxidant mechanisms and their accumulation of oxidative damage. Copyright

  8. Transcriptome analysis of the spalax hypoxia survival response includes suppression of apoptosis and tight control of angiogenesis

    Directory of Open Access Journals (Sweden)

    Malik Assaf

    2012-11-01

    Full Text Available Abstract Background The development of complex responses to hypoxia has played a key role in the evolution of mammals, as inadequate response to this condition is frequently associated with cardiovascular diseases, developmental disorders, and cancers. Though numerous studies have used mice and rats in order to explore mechanisms that contribute to hypoxia tolerance, these studies are limited due to the high sensitivity of most rodents to severe hypoxia. The blind subterranean mole rat Spalax is a hypoxia tolerant rodent, which exhibits unique longevity and therefore has invaluable potential in hypoxia and cancer research. Results Using microarrays, transcript abundance was measured in brain and muscle tissues from Spalax and rat individuals exposed to acute and chronic hypoxia for varying durations. We found that Spalax global gene expression response to hypoxia differs from that of rat and is characterized by the activation of functional groups of genes that have not been strongly associated with the response to hypoxia in hypoxia sensitive mammals. Using functional enrichment analysis of Spalax hypoxia induced genes we found highly significant overrepresentation of groups of genes involved in anti apoptosis, cancer, embryonic/sexual development, epidermal growth factor receptor binding, coordinated suppression and activation of distinct groups of transcription factors and membrane receptors, in addition to angiogenic related processes. We also detected hypoxia induced increases of different critical Spalax hub gene transcripts, including antiangiogenic genes associated with cancer tolerance in Down syndrome human individuals. Conclusions This is the most comprehensive study of Spalax large scale gene expression response to hypoxia to date, and the first to use custom Spalax microarrays. Our work presents novel patterns that may underlie mechanisms with critical importance to the evolution of hypoxia tolerance, with special relevance to

  9. Taxonomic separation of hippocampal networks: principal cell populations and adult neurogenesis

    Directory of Open Access Journals (Sweden)

    Roelof Maarten evan Dijk

    2016-03-01

    Full Text Available While many differences in hippocampal anatomy have been described between species, it is typically not clear if they are specific to a particular species and related to functional requirements or if they are shared by species of larger taxonomic units. Without such information, it is difficult to infer how anatomical differences may impact on hippocampal function, because multiple taxonomic levels need to be considered to associate behavioral and anatomical changes. To provide information on anatomical changes within and across taxonomic ranks, we present a quantitative assessment of hippocampal principal cell populations in 20 species or strain groups, with emphasis on rodents, the taxonomic group that provides most animals used in laboratory research. Of special interest is the importance of adult hippocampal neurogenesis in species-specific adaptations relative to other cell populations. Correspondence analysis of cell numbers shows that across taxonomic units, phylogenetically related species cluster together, sharing similar proportions of principal cell populations. CA3 and hilus are strong separators that place rodent species into a tight cluster based on their relatively large CA3 and small hilus while non-rodent species (including humans and non-human primates are placed on the opposite side of the spectrum. Hilus and CA3 are also separators within rodents, with a very large CA3 and rather small hilar cell populations separating mole-rats from other rodents that, in turn, are separated from each other by smaller changes in the proportions of CA1 and granule cells. When adult neurogenesis is included, the relatively small populations of young neurons, proliferating cells and hilar neurons become main drivers of taxonomic separation within rodents. The observations provide challenges to the computational modeling of hippocampal function, suggest differences in the organization of hippocampal information streams in rodent and non

  10. Elevated proteasome capacity extends replicative lifespan in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Undine Kruegel

    2011-09-01

    Full Text Available Aging is characterized by the accumulation of damaged cellular macromolecules caused by declining repair and elimination pathways. An integral component employed by cells to counter toxic protein aggregates is the conserved ubiquitin/proteasome system (UPS. Previous studies have described an age-dependent decline of proteasomal function and increased longevity correlates with sustained proteasome capacity in centenarians and in naked mole rats, a long-lived rodent. Proof for a direct impact of enhanced proteasome function on longevity, however, is still lacking. To determine the importance of proteasome function in yeast aging, we established a method to modulate UPS capacity by manipulating levels of the UPS-related transcription factor Rpn4. While cells lacking RPN4 exhibit a decreased non-adaptable proteasome pool, loss of UBR2, an ubiquitin ligase that regulates Rpn4 turnover, results in elevated Rpn4 levels, which upregulates UPS components. Increased UPS capacity significantly enhances replicative lifespan (RLS and resistance to proteotoxic stress, while reduced UPS capacity has opposing consequences. Despite tight transcriptional co-regulation of the UPS and oxidative detoxification systems, the impact of proteasome capacity on lifespan is independent of the latter, since elimination of Yap1, a key regulator of the oxidative stress response, does not affect lifespan extension of cells with higher proteasome capacity. Moreover, since elevated proteasome capacity results in improved clearance of toxic huntingtin fragments in a yeast model for neurodegenerative diseases, we speculate that the observed lifespan extension originates from prolonged elimination of damaged proteins in old mother cells. Epistasis analyses indicate that proteasome-mediated modulation of lifespan is at least partially distinct from dietary restriction, Tor1, and Sir2. These findings demonstrate that UPS capacity determines yeast RLS by a mechanism that is distinct

  11. Comparative endocrinology of aging and longevity regulation

    Directory of Open Access Journals (Sweden)

    John eAllard

    2011-11-01

    Full Text Available Hormones regulate growth, development, metabolism, and other complex processes in multicellular animals. For many years it has been suggested that hormones may also influence the rate of the aging process. Aging is a multifactorial process that causes biological systems to break down and cease to function in adult organisms as time passes, eventually leading to death. The exact underlying causes of the aging process remain a topic for debate, and clues that may shed light on these causes are eagerly sought after. In the last two decades, gene mutations that result in delayed aging and extended longevity have been discovered, and many of the affected genes have been components of endocrine signaling pathways. In this review we summarize the current knowledge on the roles of endocrine signaling in the regulation of aging and longevity in various animals. We begin by discussing the notion that conserved systems, including endocrine signaling pathways, regulate the aging process. Findings from the major model organisms: worms, flies and rodents, are then outlined. Unique lessons from studies of non-traditional models: bees, salmon and naked mole rats, are also discussed. Finally, we summarize the endocrinology of aging in humans, including changes in hormone levels with age, and the involvement of hormones in aging-related diseases. The most well studied and widely conserved endocrine pathway that affects aging is the insulin/insulin-like growth factor system. Mutations in genes of this pathway increase the lifespan of worms, flies, and mice. Population genetic evidence also suggests this pathway’s involvement in human aging. Other hormones including steroids have been linked to aging only in a subset of the models studied. Because of the value of comparative studies, it is suggested that the aging field could benefit from adoption of additional model organisms.

  12. Biophysics of Magnetic Orientation: Radical Pairs, Biogenic Magnetite, or both?

    Science.gov (United States)

    Kirschvink, Joe

    2011-03-01

    Two major biophysical mechanisms for magnetoreception in terrestrial animals, one based on biogenic magnetite and another on radical-pair biochemical reactions, have been the subject of experiment and debate for the past 30 years. The magnetite hypothesis has stood the test of time: biogenic magnetite is synthesized biochemically in Bacteria, Protists, and numerous Animal phyla, as well as in some plants. Chains of single-domain crystals have been detected by clean-lab based SQUID magnetometry in animal tissues in all major phyla, followed by high-resolution TEM in selected model organisms, as well as by electrophysiological studies demonstrating the role of the ophthalmic branch of the trigeminal nerve in the magnetoreceptive process. Pulse-remagnetization - configured to uniquely flip the polarity of single-domain ferromagnets - has dramatic effects on the behavior of many birds, honeybees, mole rats, turtles, and bats, to cite a growing list. Magnetite-containing cells in the vicinity of these neurons in fish are now the subject of intense study by our consortium. The existence of a specialized class of magnetite-containing magnetoreceptor cells in animal tissues is no longer controversial. In contrast, less success has been achieved in gaining experimental support across a range of taxa for the radical-pair hypothesis. Although this mechanism was proposed to explain an early observation that birds would not respond to complete inversion of the magnetic vector, many organisms (even some birds) do indeed respond to the field polarity. We also note that few, if any, of these critical experiments have been done using fully double-blind methods. This is joint work with: M. M. Walker (University of Auckland, New Zealand) and M. Winklhofer (LMU Munich, Germany).

  13. Updated neuronal scaling rules for the brains of Glires (rodents/lagomorphs).

    Science.gov (United States)

    Herculano-Houzel, Suzana; Ribeiro, Pedro; Campos, Leandro; Valotta da Silva, Alexandre; Torres, Laila B; Catania, Kenneth C; Kaas, Jon H

    2011-01-01

    Brain size scales as different functions of its number of neurons across mammalian orders such as rodents, primates, and insectivores. In rodents, we have previously shown that, across a sample of 6 species, from mouse to capybara, the cerebral cortex, cerebellum and the remaining brain structures increase in size faster than they gain neurons, with an accompanying decrease in neuronal density in these structures [Herculano-Houzel et al.: Proc Natl Acad Sci USA 2006;103:12138-12143]. Important remaining questions are whether such neuronal scaling rules within an order apply equally to all pertaining species, and whether they extend to closely related taxa. Here, we examine whether 4 other species of Rodentia, as well as the closely related rabbit (Lagomorpha), conform to the scaling rules identified previously for rodents. We report the updated neuronal scaling rules obtained for the average values of each species in a way that is directly comparable to the scaling rules that apply to primates [Gabi et al.: Brain Behav Evol 2010;76:32-44], and examine whether the scaling relationships are affected when phylogenetic relatedness in the dataset is accounted for. We have found that the brains of the spiny rat, squirrel, prairie dog and rabbit conform to the neuronal scaling rules that apply to the previous sample of rodents. The conformity to the previous rules of the new set of species, which includes the rabbit, suggests that the cellular scaling rules we have identified apply to rodents in general, and probably to Glires as a whole (rodents/lagomorphs), with one notable exception: the naked mole-rat brain is apparently an outlier, with only about half of the neurons expected from its brain size in its cerebral cortex and cerebellum. Copyright © 2011 S. Karger AG, Basel.

  14. Updated Neuronal Scaling Rules for the Brains of Glires (Rodents/Lagomorphs)

    Science.gov (United States)

    Herculano-Houzel, Suzana; Ribeiro, Pedro; Campos, Leandro; Valotta da Silva, Alexandre; Torres, Laila B.; Catania, Kenneth C.; Kaas, Jon H.

    2011-01-01

    Brain size scales as different functions of its number of neurons across mammalian orders such as rodents, primates, and insectivores. In rodents, we have previously shown that, across a sample of 6 species, from mouse to capybara, the cerebral cortex, cerebellum and the remaining brain structures increase in size faster than they gain neurons, with an accompanying decrease in neuronal density in these structures [Herculano-Houzel et al.: Proc Natl Acad Sci USA 2006;103:12138–12143]. Important remaining questions are whether such neuronal scaling rules within an order apply equally to all pertaining species, and whether they extend to closely related taxa. Here, we examine whether 4 other species of Rodentia, as well as the closely related rabbit (Lagomorpha), conform to the scaling rules identified previously for rodents. We report the updated neuronal scaling rules obtained for the average values of each species in a way that is directly comparable to the scaling rules that apply to primates [Gabi et al.: Brain Behav Evol 2010;76:32–44], and examine whether the scaling relationships are affected when phylogenetic relatedness in the dataset is accounted for. We have found that the brains of the spiny rat, squirrel, prairie dog and rabbit conform to the neuronal scaling rules that apply to the previous sample of rodents. The conformity to the previous rules of the new set of species, which includes the rabbit, suggests that the cellular scaling rules we have identified apply to rodents in general, and probably to Glires as a whole (rodents/lagomorphs), with one notable exception: the naked mole-rat brain is apparently an outlier, with only about half of the neurons expected from its brain size in its cerebral cortex and cerebellum. PMID:21985803

  15. 浙江省常见15个树种的光合特性%Photosynthetic characteristics for fifteen potted seedlings common to Zhejiang Province

    Institute of Scientific and Technical Information of China (English)

    刘欣欣; 张明如; 温国胜; 张俊; 邹伶俐; 吴刚

    2012-01-01

    为比较不同树种对光的适应能力和耐荫性,探讨树种在植被恢复过程中的配置依据,利用Licor-6400便携式光合仪,于2010年秋季测定了苦槠Castanopsis sclerophylla,木荷Schima superba,杜英Elaeocarpus decipiens等15个浙江常见树种的光响应过程和光合日进程,并计算上述树种的光能利用率.研究结果表明:①所测15个树种的净光合速率日变化均呈单峰型,无“光合午休”现象.②东南石栎Lithocarpus harlandii,红豆杉Taxus chinensis,美丽胡枝子Lespedeza formosa分别是阔叶、针叶和灌木树种中光能利用率峰值较高的树种.③光饱和点苦槠最高,浙江楠Phoebe chekiongensis最低;光补偿点马尾松Pinusmassoniana最高,红豆杉最低.④对光补偿点和光饱和点进行聚类分析,认为马尾松,乌冈Quercus phillyraeoides,属于强阳性树种;苦槠,美丽胡枝子,水杉Metasequoia glyptostroboide,东南石栎归属于阳性树种;红花(槛)木Loropetalum chinense,红叶石楠Photinia×fraseri,杜英,乌桕Sapium sebiferum,木荷,石栎Lithocarpus glaber,竹柏Podocarpus nagi,红豆杉和浙江楠归类为耐荫树种,对弱光的利用能力较强.图5表1参16%To compare the light adaptation anil shade tolerance of 15 different tree species, and to provide development bases for tree species in the vegetative recovery process, diurnal changes of photosynthesis and light response characteristics for Castanopsis sclerophyila, Schima superba, Elaeocarpus decipiens, Sapium sebiferum, Lithocarpus harlandii, Lithocarpus glaber, Phoebe chekiangensis, Quercus phillyraeoides, Podocarpus nagi, Pinus massoniana, Metasequoia glyptostroboides , Taxus chinensis, Photinia x fraseri, Les-pedeza formosa, and Loropetaium chinense var. rubrum were measured by Li-6400 portable photosynthesis system in the autumn of 2010, Then, light use efficiency of the 15 potted seedlings was determined. Results showed that: 1) the diurnal process of the net

  16. Resource partitioning amongst five coexisting species of gurnards (Scorpaeniforme: Triglidae): Role of trophic and habitat segregation

    Science.gov (United States)

    Lopez-Lopez, L.; Preciado, I.; Velasco, F.; Olaso, I.; Gutiérrez-Zabala, J. L.

    2011-08-01

    Feeding habits and habitat preferences of five related species ( Aspitrigla cuculus, Chelidonichthys lucerna, Chelidonichthys obscurus, Eutrigla gurnardus and Trigla lyra) (Scorpaeniformes: Triglidae) were studied in the southern Bay of Biscay. Specimens were collected during annual bottom trawl surveys carried out every autumn between 1990 and 2008 on soft bottoms of the Galician and Cantabrian Sea continental shelf between 30 and 800 m depth. All species were found to display a different depth distribution, despite co-occurring in many of the hauls (co-occurrence percentage ranged between 4.45 and 34.77%). Although depth was the main variable explaining the triglid distribution, latitude, temperature and sediment type were also important driving factors. Regarding feeding habits all triglids fed mainly on crustaceans, their main prey being Alpheus glaber, Polybius henslowii, Scyllarus arctus, Chlorotocus crassicornis and Pagurus prideaux. However, fish accounted for a considerable proportion of the diet with Gadiculus argenteus, Callionymus spp., and Cepola rubescens being the most common fish prey. Ontogenetic changes in diet were evident in all species but C. obscurus. Dietary overlap, determined by the Schoener Index greatly differed amongst species pairs ranging between 0.10 and 0.63. Considering all ontogenetic groups in the triglid assemblage, either diet or habitat segregation occurred between most of them. This fact suggests that any of these strategies on their own would suffice in order to avoid inter and intra specific competitions. Nevertheless, habitat partitioning occurred mainly at the inter-specific level and trophic segregation at the intra-specific level. A. cuculus and E. gurnardus showed the poorest resource partitioning in the assemblage, possibly as a consequence of the increasing abundance of the population of the first during the last decades.

  17. New World species of the genus Calliscelio Ashmead (Hymenoptera, Platygastridae, Scelioninae)

    Science.gov (United States)

    Chen, Hua-yan; Masner, Lubomír; Johnson, Norman F.

    2017-01-01

    Abstract The genus Calliscelio Ashmead is presumed to be a diverse group of parasitoids of the eggs of crickets (Orthoptera: Gryllidae). A least one species has been found to be an important factor in depressing cricket pest populations. The New World species of Calliscelio are revised. Forty-two species are recognized, 3 are redescribed: Calliscelio bisulcatus (Kieffer), Calliscelio laticinctus Ashmead, Calliscelio rubriclavus (Ashmead), comb. n.; and 38 are described as new: Calliscelio absconditum Chen & Johnson, sp. n., Calliscelio absum Chen & Johnson, sp. n., Calliscelio alcoa Chen & Masner, sp. n., Calliscelio amadoi Chen & Johnson, sp. n., Calliscelio armila Chen & Masner, sp. n., Calliscelio bidens Chen & Masner, sp. n., Calliscelio brachys Chen & Johnson, sp. n., Calliscelio brevinotaulus Chen & Johnson, sp. n., Calliscelio brevitas Chen & Johnson, sp. n., Calliscelio carinigena Chen & Johnson, sp. n., Calliscelio crater Chen & Johnson, sp. n., Calliscelio crena Chen & Johnson, sp. n., Calliscelio eboris Chen & Johnson, sp. n., Calliscelio extenuatus Chen & Johnson, sp. n., Calliscelio flavicauda Chen & Johnson, sp. n., Calliscelio foveolatus Chen & Johnson, sp. n., Calliscelio gatineau Chen & Johnson, sp. n., Calliscelio glaber Chen & Masner, sp. n., Calliscelio granulatus Chen & Masner, sp. n., Calliscelio latifrons Chen & Johnson, sp. n., Calliscelio levis Chen & Johnson, sp. n., Calliscelio longius Chen & Johnson, sp. n., Calliscelio magnificus Chen & Masner, sp. n., Calliscelio migma Chen & Johnson, sp. n., Calliscelio minutia Chen & Johnson, sp. n., Calliscelio paraglaber Chen & Johnson, sp. n., Calliscelio pararemigio Chen & Masner, sp. n., Calliscelio prolixus Chen & Johnson, sp. n., Calliscelio punctatifrons Chen & Johnson, sp. n., Calliscelio remigio Chen & Masner, sp. n., Calliscelio ruga Chen & Johnson, sp. n., Calliscelio rugicoxa Chen & Masner, sp. n., Calliscelio sfina Chen & Johnson, sp. n., Calliscelio storea Chen & Johnson, sp. n

  18. Interactions between a sap beetle, sabal palm, scale insect, filamentous fungi and yeast, with discovery of potential antifungal compounds.

    Science.gov (United States)

    Cline, Andrew R; Skelley, Paul E; Kinnee, Scott A; Rooney-Latham, Suzanne; Winterton, Shaun L; Borkent, Christopher J; Audisio, Paolo

    2014-01-01

    The multi-trophic relationship between insects, yeast, and filamentous fungi is reported on sabal palm (Sabal palmetto (Walter) Lodd. ex Schult. & Schult. f.). Gut content analyses and observations of adult and larval feeding of the sap beetle Brachypeplus glaber LeConte indicate that niche partitioning of fungal food substrata occurs between adults and larvae. This is the first report of specific mycophagous niche partitioning among beetle life stages based on gut content analyses. Fungi isolated from the beetle gut of adults, larvae, and pupae include species of Fusarium Link, Cladosporium Link, and Penicillium Link, which were differentially ingested by larvae and adults; Fusarium solani and Penicillium species in larvae, whereas F. oxysoproum, F. verticillioides, and Cladosporium in adults. These data indicate the first species-level host data for Brachypeplus Erichson species. Fusarium proliferatum (Matsush.) Nirenberg was the most commonly occurring fungal gut component, being isolated from the palm as well as gut of larvae, pupae, and adults; representing a commonly shared food resource. One species of yeast, Meyerozyma caribbica (Vaughan-Mart. et al.) Kurtzman & Suzuki (basionym = Pichia caribbica), was isolated from all life stages and is likely responsible for anti-fungal properties observed in the pupae and represents a promising source of antifungal compounds; rearing and diagnostic protocols are provided to aid biomedical researchers. Feeding and cleaning behaviors are documented using time-lapse video-micrography, and discussed in a behavioral and functional morphological context. Adults spent long periods feeding, often >1/3 of the two-hour observation period. A generic adult body posture was observed during feeding, and included substrate antennation before and after ingestion. Adult grooming behaviors were manifested in distinct antennal and tarsal cleaning mechanisms. Larval behaviors were different from adults, and larvae feeding on Fusarium

  19. Interactions between a sap beetle, sabal palm, scale insect, filamentous fungi and yeast, with discovery of potential antifungal compounds.

    Directory of Open Access Journals (Sweden)

    Andrew R Cline

    Full Text Available The multi-trophic relationship between insects, yeast, and filamentous fungi is reported on sabal palm (Sabal palmetto (Walter Lodd. ex Schult. & Schult. f.. Gut content analyses and observations of adult and larval feeding of the sap beetle Brachypeplus glaber LeConte indicate that niche partitioning of fungal food substrata occurs between adults and larvae. This is the first report of specific mycophagous niche partitioning among beetle life stages based on gut content analyses. Fungi isolated from the beetle gut of adults, larvae, and pupae include species of Fusarium Link, Cladosporium Link, and Penicillium Link, which were differentially ingested by larvae and adults; Fusarium solani and Penicillium species in larvae, whereas F. oxysoproum, F. verticillioides, and Cladosporium in adults. These data indicate the first species-level host data for Brachypeplus Erichson species. Fusarium proliferatum (Matsush. Nirenberg was the most commonly occurring fungal gut component, being isolated from the palm as well as gut of larvae, pupae, and adults; representing a commonly shared food resource. One species of yeast, Meyerozyma caribbica (Vaughan-Mart. et al. Kurtzman & Suzuki (basionym = Pichia caribbica, was isolated from all life stages and is likely responsible for anti-fungal properties observed in the pupae and represents a promising source of antifungal compounds; rearing and diagnostic protocols are provided to aid biomedical researchers. Feeding and cleaning behaviors are documented using time-lapse video-micrography, and discussed in a behavioral and functional morphological context. Adults spent long periods feeding, often >1/3 of the two-hour observation period. A generic adult body posture was observed during feeding, and included substrate antennation before and after ingestion. Adult grooming behaviors were manifested in distinct antennal and tarsal cleaning mechanisms. Larval behaviors were different from adults, and larvae feeding

  20. Life history of the bathyal octopus Pteroctopus tetracirrhus (Mollusca, Cephalopoda) in the Mediterranean Sea

    Science.gov (United States)

    Quetglas, Antoni; Ordines, Francesc; González, María; Franco, Ignacio

    2009-08-01

    The life cycle of the deep-sea octopus Pteroctopus tetracirrhus was studied from monthly samples obtained throughout the year in different areas of the western Mediterranean (mainly around the Balearic Islands and along the coast of the Iberian Peninsula). A total of 373 individuals (205 females, 168 males) were analyzed; females ranged from 4.5 to 14.0 cm mantle length (ML) and males from 4.5 to 11.5 cm ML. There were few small-sized octopuses (reproduction took place. Females grew from 8 to 10 cm ML from winter to spring, but this modal size did not increase further in summer; males grew from 7 to 9 cm ML from winter to spring. The total disappearance of large individuals after summer suggests a life cycle lasting a single year. The evolution of the monthly mean sizes showed that the growth was best described by log-linear functions in both sexes. The length at first maturity was clearly higher in females (12 cm ML) than in males (8 cm ML). A total of 30 different prey items, belonging to four major taxonomic groups (crustaceans, osteichthyes, cephalopods and gastropods), were identified in the stomach contents. The diet of the octopus was based on crustaceans and teleosts, which accounted for 75% and 23% of the prey items, respectively. Cephalopods and gastropods were accessory prey as they only represented 1.6% and 0.7%, respectively, of the total. The octopus showed a marked preference for the benthic fish Symphurus nigrescens and the endobenthic crustacean Alpheus glaber. The bathymetric distribution of P. tetracirrhus coincides with those of these two main prey, which suggests that the distribution of the octopus might be strongly linked to its trophic resources.

  1. 中亚热带四种森林凋落物及碳氮贮量比较%Litter biomass and its carbon and nitrogen storage in four subtropical forests in central Southern China

    Institute of Scientific and Technical Information of China (English)

    路翔; 项文化; 任辉; 彭长辉

    2012-01-01

    在湖南省长沙县大山冲省级森林公园内,选择立地条件基本一致的4种森林类型为研究对象,于2011年12月(凋落物高峰期)对森林凋落物现存量及其碳、氮贮量进行调查.结果表明:4种森林凋落物现存量大小依次为青冈-石栎林(12.04±3.60)t·hm-2>马尾松-石栎林(11.65±2.15) t·hm-2>南酸枣林(9.12±2.30)t·hm-2>杉木林(8.92±1.80)t·hm-2;凋落叶在凋落物未分解层中所占比例最高,凋落果在4种林分中比例最小(<5%),凋落物各分解亚层现存量规律性不明显;4种森林凋落物C含量的变化范围为177.90 ~ 581.34 g·kg-1,N含量的变化范围为5.18~15.48 g· kg-1,C含量变化随凋落物分解程度的加深而下降,且变化极显著( P<0.0001);凋落物半分解层和已分解层现存量在总凋落物现存量中所占比例与C/N呈负相关;4种森林凋落物C贮量为3.37 ~ 5.69t·hm-2,N贮量为81.52 ~152.18 kg·hm-2;马尾松-石栎针阔叶混交林由于凋落物分解较慢,凋落物现存量较大,林下凋落物层C、N贮量最高.%Four subtropical forests with similar site conditions in the hilly area of Dashanchong Forest Park in central Hunan Province of China were selected to compare the existing litter biomass and its carbon (C) and nitrogen (N) storage. The litters were collected in the peak time of litter-fall. Among the four forests, Cyclobalanopsis glauca-Lithocarpus glaber mixed forest had the highest litter biomass (12. 04 ± 3. 60 t · hm-2) , followed by Pinus massoniana-L. glaber mixed forest (11. 65±2. 15 t · hm ) , Choerospondias axillaris forest (9. 12±2. 30 t · hm-2) , and Cunninghamia lanceolata plantation (8. 92±1. 80 t · hm-2 ). In litter layer, leaf litter had the largest proportion, while fruit litter had the smallest one ( <5% ). No significant differences were observed in the amounts of the litters with different decomposition degrees. The C concentration of the litters in the four

  2. Cryptosporidium proliferans n. sp. (Apicomplexa: Cryptosporidiidae: Molecular and Biological Evidence of Cryptic Species within Gastric Cryptosporidium of Mammals.

    Directory of Open Access Journals (Sweden)

    Martin Kváč

    Full Text Available The morphological, biological, and molecular characteristics of Cryptosporidium muris strain TS03 are described, and the species name Cryptosporidium proliferans n. sp. is proposed. Cryptosporidium proliferans obtained from a naturally infected East African mole rat (Tachyoryctes splendens in Kenya was propagated under laboratory conditions in rodents (SCID mice and southern multimammate mice, Mastomys coucha and used in experiments to examine oocyst morphology and transmission. DNA from the propagated C. proliferans isolate, and C. proliferans DNA isolated from the feces of an African buffalo (Syncerus caffer in Central African Republic, a donkey (Equus africanus in Algeria, and a domestic horse (Equus caballus in the Czech Republic were used for phylogenetic analyses. Oocysts of C. proliferans are morphologically distinguishable from C. parvum and C. muris HZ206, measuring 6.8-8.8 (mean = 7.7 μm × 4.8-6.2 μm (mean = 5.3 with a length to width ratio of 1.48 (n = 100. Experimental studies using an isolate originated from T. splendens have shown that the course of C. proliferans infection in rodent hosts differs from that of C. muris and C. andersoni. The prepatent period of 18-21 days post infection (DPI for C. proliferans in southern multimammate mice (Mastomys coucha was similar to that of C. andersoni and longer than the 6-8 DPI prepatent period for C. muris RN66 and HZ206 in the same host. Histopatologicaly, stomach glands of southern multimammate mice infected with C. proliferans were markedly dilated and filled with necrotic material, mucus, and numerous Cryptosporidium developmental stages. Epithelial cells of infected glands were atrophic, exhibited cuboidal or squamous metaplasia, and significantly proliferated into the lumen of the stomach, forming papillary structures. The epithelial height and stomach weight were six-fold greater than in non-infected controls. Phylogenetic analyses based on small subunit rRNA, Cryptosporidium

  3. 浙江省常见15个树种的光合特性

    Institute of Scientific and Technical Information of China (English)

    刘欣欣; 张明如; 温国胜; 张俊; 邹伶俐; 吴刚

    2012-01-01

    为比较不同树种对光的适应能力和耐荫性,探讨树种在植被恢复过程中的配置依据,利用Licor-6400便携式光合仪,于2010年秋季测定了苦槠Castanopsis sclerophylla,木荷Schima superba,杜英Elaeocarpus decipiens等15个浙江常见树种的光响应过程和光合日进程,并计算上述树种的光能利用率。研究结果表明:①所测15个树种的净光合速率日变化均呈单峰型,无"光合午休"现象。②东南石栎Lithocarpus harlandii,红豆杉Taxus chinensis,美丽胡枝子Lespedeza formosa分别是阔叶、针叶和灌木树种中光能利用率峰值较高的树种。③光饱和点苦槠最高,浙江楠Phoebe chekiangensis最低;光补偿点马尾松Pinus massoniana最高,红豆杉最低。④对光补偿点和光饱和点进行聚类分析,认为马尾松,乌冈Quercus phillyraeoides,属于强阳性树种;苦槠,美丽胡枝子,水杉Metasequoiaglyptostroboide,东南石栎归属于阳性树种;红花木Loropetalum chinense,红叶石楠Photinia×fraseri,杜英,乌桕Sapium sebiferum,木荷,石栎Lithocarpus glaber,竹柏Podocarpus nagi,红豆杉和浙江楠归类为耐荫树种,对弱光的利用能力较强。

  4. Effects of environmental factors on soil CH4 and N2O lfuxes in three forest types in central subtropical China%中亚热带森林地表CH4和N2O通量影响因素分析

    Institute of Scientific and Technical Information of China (English)

    黄志宏; 张宇鸿; 沈燕; 张强; 王瑶; 凌威

    2016-01-01

    中亚热带森林是我国重要而独特的植被类型。本研究以本区域中3种典型的林分类型—杉木人工纯林、马尾松+石栎针阔混交林、青冈+石栎常绿阔叶林为研究对象,采用静态箱法—气相色谱法分析地表温室气体CH4、N2O浓度,同时观测样地环境因子。运用典型相关分析方法分析地表温室气体通量与环境因子的相关关系,并且对环境因子进行主成分分析。结果表明:(1)从总体来看,中亚热带森林地表温室气体通量是受多因素综合作用的结果,林地温室气体通量与林地环境因子间存在显著相关性(P<0.05),二者间的相关性程度也因不同林型而异;(2)在诸多环境因素中,温度是其中的主导因子,对地表温室气体影响相对较大,尤其是地表和地下5 cm处土壤温度;(3)其它非生物因素(如土壤水分、土壤碳氮含量、坡位等)对温室气体通量所起作用的大小则因具体的林型而异;(4)生物因素中不同林型间地表温室气体通量存在显著差异(P<0.05);(5)不同林型地表温室气体存在明显的季节动态。%Forest stands surface greenhouse gasfluxes play a pivotal role in the global carbon balance and global climate change. Forests in central subtropical is an important and special vegetation type in China. The typical forest types including Chinesefir plantation, Pinus massoniana + Lthocarpus glaber mixed forest, andCyclobalanopsis glauca + Lithocarpus glaber mixed evergreen broad-leaved forest were selected for the sampling plots using static chamber technique and gas chromatography analysis of soilsurface greenhouse gases (CH4 and N2O). The local environmental factors were recorded including soil surface temperature, soil temperature at 5 cm depth, air temperature, air temperature in the static chamber, soil moisture content in thefield. And soil total organic carbon and soil total organic nitrogen were measured

  5. Revision of the Oriental subfamily Heteropteryginae Kirby, 1896, with a re-arrangement of the family Heteropterygidae and the descriptions of five new species of Haaniella Kirby, 1904. (Phasmatodea: Areolatae: Heteropterygidae).

    Science.gov (United States)

    Hennemann, Frank H; Conle, Oskar V; Brock, Paul D; Seow-Choen, Francis

    2016-09-01

    -established as a valid species (rev. stat.). The Sumatran Haaniella glaber (Redtenbacher, 1906) is removed from synonymy with H. muelleri (Haan, 1842) and re-established as a valid species (rev. stat.). Leocrates glaber Redtenbacher, 1906 and Haaniella muelleri simplex Günther, 1944 are removed from synonymy with H. muelleri (Haan, 1842) (rev. stat.) and synonymised with H. glaber. Haaniella mecheli (Redtenbacher, 1906) and H. rosenbergii (Kaup, 1871) are removed from synonymy with H. muelleri (Haan, 1842) and re-established as valid species (rev. stat.). Haaniella erringtoniae novaeguineae Günther, 1934 and Haaniella muelleri var. b. (Haan, 1842) are synonymized with H. rosenbergii (Kaup, 1871) (n. syn.). The type-species Haaniella muelleri (Haan, 1842) is shown to be a fairly rare species that is restricted to Sumatra. All subsequent records of H. muelleri from outside Sumatra and references to captive breeding of stock originating from Peninsular Malaysia in Europe relate to H. erringtoniae (Redtenbacher, 1906). The previously unknown males and eggs of H. rosenbergii (Kaup, 1871) as well as the previously unknown females and eggs of H. parva Günther, 1944 are described and illustrated for the first time. Based on morphological characters of the insects and eggs three distinct species-groups are recognized within Haaniella. The muelleri species-group contains nine species that are distributed throughout Sumatra, the Mentawei Islands, Singapore and Peninsular Malaysia. These are characterized by the smooth ventral surface of the meso- and metafemora and lemon-shaped eggs which entirely lack the setae seen in the two other species-groups. The grayii species-group comprises four species, two of which are endemic in Borneo, one endemic in Sumatra and the fourth species being the only known representative of the subfamily in Vietnam. These species are characteristic for the prominent pair of spines on the abdominal tergites II-IV of males and long apically multidentate epiproct

  6. Ouabaina como Hormona

    Directory of Open Access Journals (Sweden)

    J. Hernando Ordoñez

    1996-04-01

    Full Text Available

    Comentario sobre su origen endógeno y sus aplicaciones terapéuticas

    Pocas drogas han sido más estudiadas que el grupo de los digitálicos, estrofantinas y ouabaina, cuyo estudio es objeto del presente trabajo.

    La ouabaina empezó a ser estudiada desde el siglo pasado. La primera referencia conocida corresponde a Pelikan, 1865 (1, como veneno que empleaban para las flechas en Gabón (Africa. (.

    (. Vinieron luego los trabajos de Fraser, 1869, (2, 3, 6, Polaillon, 1871 (4, Amaud, 1888 (5, Vaquez y Lutembacher, 1917 (7, Stoll, 1939 (8, Lapicque, 1929 (9, Wiggers, 1927 (10, Ytantos otros (11, 12, 13. En la obra de Kisch (14 aparecen más de 700 referencias bibliográficas sobre el particular.

    Ouabaina de origen endógeno. Purificación
    Durante muchos años se conoció la ouabaina como de origen vegetal, elaborada por las plantas Strophanthus Glaber(k-estrofantina,AcocantheraOuabaio(Ouabaina yStrophanthus Kombe (k-estrofantina y kestrofantósido. Una propiedad común a todos los digitálicos, estrofantina y ouabaina es que todos son inhibidores de la bomba de Na-K, encargada de regular la salida de Na y la entrada de K celular.

    Estudiando los inhibido res de esta bomba han encontrado en años recientes resultados extraordinarios en relación con el origen endógeno de algunos de estos inhibidores, entre ellos la ouabaina. Por considerarlos de extrema importancia y actualidad científica me permito citar algunos de ellos. Hamlyn y Manunta (15, 16, 17, 18, Y 19 hicieron estudios sobre el particular y lograron identificar en el plasma humano un compuesto igual a la ouabaina. Estos hallazgos fueron confirmados después por otros autores (20, 21, 22, 23 Y24.

    Ham bl yn (19 da varios argumentos que ponen en evidencia que el compuesto químico encontrado es ouabaina pura, y, lo que es más interesante, que tiene un origen endógeno. a Por espectroscopia de alta resoluci