| nucleotide sequence variation in the mitochondrial 12s rrna gene and the phylogeny of african mole-rats (rodentia: bathyergidae). | mitochondrial dna (mtdna) sequence variation was examined in eight taxa of the african rodent family bathyergidae, as well as in two taxa representative of the old-world hystricognathid rodent families petromyidae and thryonomyidae. a total of 812 bp, constituting domains i-iii of the 12s ribosomal rrna gene, were compared for each taxon. the high levels of intrafamilial mtdna sequence divergence observed (average 16.8, range 3.5-23.2) support an ancient origin for the five genera, 20-38 mya. th ... | 1992 | 1552839 |
| seismic signal transmission between burrows of the cape mole-rat, georychus capensis. | both seismic and auditory signals were tested for their propagation characteristics in a field study of the cape mole-rat (georychus capensis), a subterranean rodent in the family bathyergidae. this solitary animal is entirely fossorial and apparently communicates with its conspecifics by alternately drumming its hind legs on the burrow floor. signal production in this species is sexually dimorphic, and mate attraction is likely mediated primarily by seismic signalling between individuals in nei ... | 1992 | 1573567 |
| evidence from intron 1 of the nuclear transthyretin (prealbumin) gene for the phylogeny of african mole-rats (bathyergidae). | a 900- to 1100-bp fragment encompassing intron 1 of the nuclear transthyretin (prealbumin) gene was examined in 12 taxa of old world hystricognath rodents of the families bathyergidae, petromuridae, thryonomyidae, and hystricidae. within the bathyergidae, heterocephalus glaber (naked mole-rat) was basal, and the other east african species, heliophobius argenteocinereus (silvery mole-rat), was sister to a southern african clade containing bathyergus, cryptomys, and georychus (dune, common, and ca ... | 2000 | 10991798 |
| photic induction of fos in the suprachiasmatic nucleus of african mole-rats: responses to increasing irradiance. | african mole-rats (family bathyergidae) are strictly subterranean rodent species that are rarely exposed to environmental light. morphological and physiological adaptations to the underground environment include a severely reduced eye size and regressed visual system. responses of the circadian system to light, however, appear to be intact, since mole-rats are able to entrain their circadian activity rhythms to the light-dark cycle and light induces fos expression in the suprachiasmatic nucleus ... | 2010 | 20854133 |
| determinants of helminth infection in a subterranean rodent, the cape dune mole-rat ( bathyergus suillus ). | the helminth fauna of the largest bathyergid, the cape mole-rat ( bathyergus suillus ) was studied throughout an entire calendar year. the species richness encountered was low, with only 3 species of nematodes ( longistriata bathyergi , mammalakis macrospiculum, and trichostrongylus sp.) and 2 species of cestodes ( taenia sp. and rodentolepis sp.). at less than 10%, the prevalence for all helminths species was similarly low and may be a result of the solitary lifestyle and the subterranean habit ... | 2012 | 22263622 |
| spatial genetic diversity in the cape mole-rat, georychus capensis: extreme isolation of populations in a subterranean environment. | the subterranean niche harbours animals with extreme adaptations. these adaptations decrease the vagility of taxa and, along with other behavioural adaptations, often result in isolated populations characterized by small effective population sizes, high inbreeding, population bottlenecks, genetic drift and consequently, high spatial genetic structure. although information is available for some species, estimates of genetic diversity and whether this variation is spatially structured, is lacking ... | 2018 | 29543917 |
| hind foot drumming: morphological adaptations of the muscles and bones of the hind limb in three african mole-rat species. | seismic signalling in the form of hind foot drumming plays an integral role in the communication of several species of african mole-rats (bathyergidae). to produce these vibrational signals, alternating hind limbs strike the ground repetitively at high speeds by flexion and extension of the hip and knee. this descriptive study aimed to determine whether anatomical differences in hind limb osteology and/or musculature between drumming and non-drumming species of three bathyergidae species could b ... | 2019 | 31218687 |
| hind foot drumming: morphofunctional analysis of the hind limb osteology in three species of african mole-rats (bathyergidae). | hind foot drumming is a form of seismic signaling that plays a vital role in the communication of several bathyergidae species. hind foot drumming is initiated by the rapid movement of the whole hind limb by flexion and extension of the hip and knee. this study aimed to determine if morphological adaptations of the hind limb osteology were measurable using established morphometric analyses in two drumming (bathyergus suillus and georychus capensis) and one non-drumming (cryptomys hottentotus nat ... | 2020 | 32031740 |
| the brains of six african mole-rat species show divergent responses to hypoxia. | mole-rats are champions of self-preservation, with increased longevity compared with other rodents their size, strong antioxidant capabilities and specialized defenses against endogenous oxidative stress. however, how the brains of these subterranean mammals handle acute in vivo hypoxia is poorly understood. this study is the first to examine the molecular response to low oxygen in six different species of hypoxia-tolerant mole-rats from sub-saharan africa. protein carbonylation, a known marker ... | 2020 | 32041803 |
| surveys and literature review of parasites among african mole-rats: proposing hypotheses for the roles of geography, ecology, and host phylogenetic relatedness in parasite sharing. | hosts that overlap geographically, are less phylogenetically divergent, and/or share similar ecological conditions (e.g., climate, habitat type) are also likely to share parasites. here we assessed the ectoparasite communities sustained by 3 solitary species of bathyergidae (georychus capensis, bathyergus suillus, and bathyergus janetta) as well as the endoparasites exploiting g. capensis and compared them with those reported in the literature for other sympatric and parapatric african mole-rat ... | 2020 | 31977284 |
| subterranean mammals: reservoirs of infection or overlooked sentinels of anthropogenic environmental soiling? | global reports of emergent pathogens in humans have intensified efforts to identify wildlife reservoirs. subterranean mammals, such as bathyergid mole rats, are largely overlooked, despite their high-level exposure to soil-dwelling microbes. initial assessment of bathyergid reservoir potential was determined using a broad-range 16s rrna pcr approach, which revealed an 83% pcr-positivity for the 234 bathyergid lung samples evaluated. the presence of the bacillus cereus complex, a ubiquitous bacte ... | 2017 | 29094221 |
| nutrition and burrowing energetics of the cape mole-rat georychus capensis. | at 22°c the resting oxygen consumption of g. capensis is 1.13±0.05 cm(3)o2·g(-1)·h(-1) (mean± s.e.). in loose sandy soil the burrowing metabolic rate was approximately three times that of resting (3.41±0.19 cm(3)o2·g(-1)· h(-1)). rate of oxygen consumption while burrowing bears a linear relationship with rate of burrowing. the equation of the regression line describing this relationship was used to construct a model for calculating energy expenditure of burrowing in free-living mole-rats. the di ... | 1985 | 28310816 |
| circadian activity rhythms in the solitary cape molerat (georychus capensis: bathyergidae) with some evidence of splitting. | circadian activity patterns were measured in the solitary, subterranean cape molerat, georychus capensis, under fixed 12:12 ld, constant dark dd, and constant light ll photoperiods for 250 consecutive days using passive infra-red activity sensors. the molerats displayed significant nocturnal activity rhythms under 12:12 ld and free-running rhythms (23.5 h < tau > 25.8 h) under constant conditions. in one individual evidence was found of splitting of the activity rhythm under constant dark; the s ... | 1995 | 8559776 |
| effects of laboratory housing on exploratory behaviour, novelty discrimination and spatial reference memory in a subterranean, solitary rodent, the cape mole-rat (georychus capensis). | 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 en ... | 2013 | 24040422 |
| sleep in the cape mole rat: a short-sleeping subterranean rodent. | the cape mole rat georychus capensis is a solitary subterranean rodent found in the western and southern cape of south africa. this approximately 200-gram bathyergid rodent shows a nocturnal circadian rhythm, but sleep in this species is yet to be investigated. using telemetric recordings of the electroencephalogram (eeg) and electromyogram (emg) in conjunction with video recordings, we were able to show that the cape mole rat, like all other rodents, has sleep periods composed of both rapid eye ... | 2016 | 27088160 |
| adult neurogenesis and its anatomical context in the hippocampus of three mole-rat species. | african mole-rats (family bathyergidae) are small to medium sized, long-lived, and strictly subterranean rodents that became valuable animal models as a result of their longevity and diversity in social organization. the formation and integration of new hippocampal neurons in adult mammals (adult hippocampal neurogenesis, ahn) correlates negatively with age and positively with habitat complexity. here we present quantitative data on ahn in wild-derived mole-rats of 1 year and older, and briefly ... | 2014 | 24904308 |
| sociality and the telencephalic distribution of corticotrophin-releasing factor, urocortin 3, and binding sites for crf type 1 and type 2 receptors: a comparative study of eusocial naked mole-rats and solitary cape mole-rats. | various aspects of social behavior are influenced by the highly conserved corticotrophin-releasing factor (crf) family of peptides and receptors in the mammalian telencephalon. this study has mapped and compared the telencephalic distribution of the crf receptors, crf1 and crf2 , and two of their ligands, crf and urocortin 3, respectively, in african mole-rat species with diametrically opposed social behavior. naked mole-rats live in large eusocial colonies that are characterized by exceptional ... | 2015 | 25921928 |
| subterranean sympatry: an investigation into diet using stable isotope analysis. | 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 ... | 2012 | 23139795 |
| ear structures of the naked mole-rat, heterocephalus glaber, and its relatives (rodentia: bathyergidae). | although increasingly popular as a laboratory species, very little is known about the peripheral auditory system of the naked mole-rat, heterocephalus glaber. in this study, middle and inner ears of naked mole-rats of a range of ages were examined using micro-computed tomography and dissection. the ears of five other bathyergid species (bathyergus suillus, cryptomys hottentotus, fukomys micklemi, georychus capensis and heliophobius argenteocinereus) were examined for comparative purposes. the mi ... | 2016 | 27926945 |
| telencephalic binding sites for oxytocin and social organization: a comparative study of eusocial naked mole-rats and solitary cape mole-rats. | african mole-rats provide a unique taxonomic group for investigating the evolution and neurobiology of sociality. the two species investigated here display extreme differences in social organization and reproductive strategy. naked mole-rats (nmrs) live in colonies, dominated by a queen and her consorts; most members remain nonreproductive throughout life but cooperate in burrowing, foraging, and caring for pups, for which they are not biological parents (alloparenting). in contrast, cape mole-r ... | 2010 | 20235093 |
| the comparative anatomy of the abdominal gastrointestinal tract of six species of african mole-rats (rodentia, bathyergidae). | the gastrointestinal tracts (gits) of six species of african mole-rats (bathyergidae) were compared. the aim was to provide a comprehensive anatomical comparison between the different species. the relative shape, length, and surface areas were taken into account to determine whether the gits are phylogenetically constrained or exhibit anatomical adaptations in response to diets. in all six species the stomach was simple and glandular. with the exception of heterocephalus glaber, the caecum was c ... | 2010 | 19623625 |
| spatial learning and memory in african mole-rats: the role of sociality and sex. | spatial learning and memory is an important skill for the survival and fitness and may vary between the sexes depending on differences in space use. this is particularly true for animals that explore the subterranean niche as it is associated with high travelling costs. in subterranean rodents the complexity of burrow systems varies with differing degrees of sociality possibly posing stronger selective pressures regarding spatial abilities on species with more complex burrow structures. this cou ... | 2009 | 18824187 |
| an immunohistochemical study of the gonadotrophin-releasing hormone 1 system in solitary cape mole-rats, georychus capensis, and social natal mole-rats, cryptomys hottentotus natalensis. | mole-rat species within the family bathyergidae exhibit a wide range of reproductive strategies and social systems. various forms of reproductive suppression are displayed within this family: in the solitary species, breeding is suspended for part of the year and in the social species, reproduction is suppressed in subordinate animals. this study investigated the gonadotrophin-releasing hormone 1 (gnhr-1) systems of breeding and non-breeding solitary cape mole-rats and social natal mole-rats for ... | 2008 | 18817850 |
| the energy costs of sexual dimorphism in mole-rats are morphological not behavioural. | different reproductive strategies of males and females may lead to the evolution of differences in their energetic costs of reproduction, overall energetic requirements and physiological performances. sexual dimorphism is often associated with costly behaviours (e.g. large males might have a competitive advantage in fighting, which is energetically expensive). however, few studies of mammals have directly compared the energy costs of reproductive activities between sexes. we compared the daily e ... | 2006 | 16519235 |
| fos expression in the suprachiasmatic nucleus in response to light stimulation in a solitary and social species of african mole-rat (family bathyergidae). | mole-rats are strictly subterranean rodents that are rarely exposed to environmental light. they are well adapted to their environment and have reduced eyes and a severely regressed visual system. it has been shown, however, that mole-rats do exhibit endogenous circadian rhythms that can be entrained, suggesting an intact and functional circadian system. to determine whether light is the entraining agent in these animals, fos expression in response to light pulses at different circadian times wa ... | 2005 | 15878641 |
| circadian rhythms of locomotor activity in solitary and social species of african mole-rats (family: bathyergidae). | mole-rats are strictly subterranean and hardly, if ever, come into contact with external light. as a result, their classical visual system is severely regressed and the circadian system proportionally expanded. the family bathyergidae presents a unique opportunity to study the circadian system in the absence of the classical visual system in a range of species. daily patterns of activity were studied in the laboratory under constant temperature but variable lighting regimes in individually house ... | 2003 | 14667149 |
| the use of seismic signals by fossorial southern african mammals: a neuroethological gold mine. | behavioral adaptations exhibited by two african fossorial mammals for the reception of vibrational signals are discussed. the namib desert golden mole (eremitalpa granti namibensis) is a functionally blind, nocturnal insectivore in the family chrysochloridae that surface forages nightly in the namib desert. both geophone and microphone recordings in the substrate suggest that the golden mole is able to detect termite colonies and other prey items solely using seismic cues. this animal exhibits a ... | 1997 | 9365810 |
| optic disc and optic nerve of the blind cape mole-rat (georychus capensis): a proposed model for naturally occurring reactive gliosis. | recent studies of the visual system of animal species that live in a subterranean environment show not only regressive but also progressive morphological features. in this regard the aim of the present investigation is to describe the structural organisation of the eye and optic nerve of the adult cape mole-rat, with special emphasis on both glial cell population and myelination. the main results are: (a) astrocytes show identical features to those occurring in reactive gliosis; (b) optic fibers ... | 1997 | 9365808 |
| circadian body temperature rhythms of the solitary cape mole rat georychus capensis (bathyergidae). | simultaneous measurements of activity and telemeterized body temperature were measured under 12:12 ld and constant light conditions in the solitary, subterranean rodent georychus capensis for 137 consecutive days. the objectives of the study were twofold: a) to determine whether g. capensis display circadian body temperature rhythms similar to those of nonsubterranean mammals, and b) to determine whether body temperature rhythms provide a more reliable measure than those of activity of endogenou ... | 1996 | 8873281 |