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Elke Zimmermann - One of the best experts on this subject based on the ideXlab platform.
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spontaneous spongiform brainstem degeneration in a young Mouse Lemur microcebus murinus with conspicuous behavioral motor growth and ocular pathologies
Comparative Medicine, 2018Co-Authors: Daniel Schmidtke, Ute Radespiel, Elke Zimmermann, Marko Dubicanac, Sabine B. R. Kästner, Charlotte Lempp, Wolfgang Baumgartner, Martin Meier, Anne Balkemabuschmann, Alan R HarrisAbstract:Here we report a case of severe growth retardation and neurologic abnormalities in a female gray Mouse Lemur (Microcebus murinus), a small NHP species for which the genomic sequence recently became available. The female Lemur we present here died on postnatal day 125. This Lemur had impaired development of motor skills and showed severe ataxia and tremors. In addition, hearing seemed normal whereas ophthalmic examination revealed incipient bilateral cataracts, abnormal pigmentation in the lens of the left eye, and a missing optokinetic nystagmus, which indicated impaired vision. Most prominently, the Lemur showed severe growth retardation. Necropsy revealed maldevelopment of the left reproductive organs and unilateral dilation of the right lateral ventricle, which was confirmed on brain MRI. Brain histology further revealed large, bilateral areas of vacuolation within the brainstem, but immunohistochemistry indicated no sign of pathologic prion protein deposition. Full genomic sequencing of the Lemur revealed a probably pathologic mutation in LARGE2 of the LARGE gene family, which has been associated with congenital muscular dystrophies. However, potentially functional mutations in other genes were also present. The observed behavioral and motor signs in the presented animal might have been linked to spongiform degeneration and resulting brainstem dysfunction and progressive muscle weakness. The macroscopic developmental abnormalities and ophthalmic findings might be genetic in origin and linked to the mutation in LARGE2.
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Does the grey Mouse Lemur use agonistic vocalisations to recognise kin
Contributions to Zoology, 2018Co-Authors: Sharon E Kessler, Alida F Hasiniaina, Ute Radespiel, Leanne T Nash, Elke ZimmermannAbstract:Frequent kin-biased coalitionary behaviour is a hallmark of mammalian social complexity. Furthermore, selection to understand complex social dynamics is believed to underlie the co-evolution of social complexity and large brains. Vocalisations have been shown to be an important mechanism with which large-brained mammals living in complex social groups recognise and recruit kin for coalitionary support during agonistic conflicts. We test whether kin recognition via agonistic calls occurs in a small-brained solitary foraging primate living in a dispersed social network, the grey Mouse Lemur (Microcebus murinus, Miller JF, 1777). As Mouse Lemurs are frequent models for ancestral solitary foraging mammals, this study examines whether kin recognition via agonistic calls could be the foundation from which more complex, kin-based coalitionary behaviour evolved. We test whether female wild Mouse Lemurs in Ankarafantsika National Park, Madagascar, react differently to agonistic calls from kin and nonkin and to calls from familiar and unfamiliar individuals during playback experiments. Subjects showed no significant differences in reactions to the different stimuli; thus they did not react differently based upon kinship or familiarity. Results suggest that this solitary foraging species does not use agonistic calls to recognise kin and monitor agonistic interactions involving kin, unlike several species of Old World monkeys and hyenas. Thus, kin recognition via agonistic calls may have evolved independently in these lineages in parallel with greater social complexity and frequent coalitionary behaviour.
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a new species of sucking louse phthiraptera anoplura polyplacidae from the gray Mouse Lemur microcebus murinus primates cheirogaleidae in madagascar
Journal of Medical Entomology, 2018Co-Authors: Lance A Durden, Sharon E Kessler, Alida F Hasiniaina, Ute Radespiel, Elke Zimmermann, Sarah ZohdyAbstract:Lemurpediculus madagascariensis sp. nov. (Phthiraptera: Anoplura: Polyplacidae) is described from the Gray Mouse Lemur, Microcebus murinus (J. F. Miller) (Primates: Cheirogaleidae), from Ankarafantsika National Park, Madagascar. Lemurs were trapped using Sherman Live Traps and visually inspected for lice, which were preserved in 90% ethanol. Adults of both sexes and the third-instar nymph of the new species are illustrated and distinguished from the four previously known species of Lemurpediculus: L. verruculosus (Ward); L. petterorum Paulian; L. claytoni Durden, Blanco, and Seabolt; and L. robbinsi Durden, Blanco, and Seabolt. It is not known if the new species of louse is a vector of any pathogens or parasites.
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High frequency/ultrasonic communication in a critically endangered nocturnal primate, Claire's Mouse Lemur (Microcebus mamiratra).
American journal of primatology, 2018Co-Authors: Alida F Hasiniaina, Blanchard Randrianambinina, Solofonirina Rasoloharijaona, Marina Scheumann, Mamy Rina Evasoa, Diane Braud, Elke ZimmermannAbstract:The critically endangered Claire's Mouse Lemur, only found in the evergreen rain forest of the National Park Lokobe (LNP) and a few lowland evergreen rain forest fragments of northern Madagascar, was described recently. The present study provides the first quantified information on vocal acoustics of calls, sound associated behavioral context, acoustic niche, and vocal activity of this species. We recorded vocal and social behavior of six male-female and six male-male dyads in a standardized social-encounter paradigm in June and July 2016 at the LNP, Nosy Be island. Over six successive nights per dyad, we audio recorded and observed behaviors for 3 hr at the beginning of the activity period. Based on the visual inspection of spectrograms and standardized multiparametric sound analysis, we identified seven different call types. Call types can be discriminated based on a combination of harmonicity, fundamental frequency variation, call duration, and degree of tonality. Acoustic features of tonal call types showed that for communication, Mouse Lemurs use the cryptic, high frequency/ultrasonic frequency niche. Two call types, the Tsak and the Grunt call, were emitted most frequently. Significant differences in vocal activity of the Tsak call were found between male-female and male-male dyads, linked primarily to agonistic conflicts. Dominant Mouse Lemurs vocalized more than subdominant ones, suggesting that signaling may present an honest indicator of fitness. A comparison of our findings of the Claire's Mouse Lemur with published findings of five bioacoustically studied Mouse Lemur species points to the notion that a complex interplay between ecology, predation pressure, and phylogenetic relatedness may shape the evolution of acoustic divergence between species in this smallest-bodied primate radiation. Thus, comparative bioacoustic studies, using standardized procedures, are promising to unravel the role of vocalization for primate species diversity and evolution and for identifying candidates for vocalization-based non-invasive monitoring for conservation purposes.
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Intraocular pressure in the smallest primate aging model: the gray Mouse Lemur
Veterinary Ophthalmology, 2018Co-Authors: Marko Dubicanac, Marine Joly, Julia Strüve, Ingo Nolte, Nadine Mestre-francés, Jean-michel Verdier, Elke ZimmermannAbstract:Objective: The aim of this study was to assess the practicability of common tonometers used in veterinary medicine for rapid intraocular pressure (IOP) screening, to calibrate IOP values gained by the tonometers, and to define a reference IOP value for the healthy eye in a new primate model for aging research, the gray Mouse Lemur. Studied animals and procedures: TonoVet® and the TonoPen™ measurements were calibrated manometrically in healthy enucleated eyes of Mouse Lemurs euthanized for veterinary reasons. For comparison of the practicability of both tonometers as a rapid IOP assessment tool for living Mouse Lemurs, the IOP of 24 eyes of 12 animals held in the hand was measured. To define a standard reference value for IOP in Mouse Lemurs, 258 healthy animals were measured using the TonoVet®. Results: Intraocular pressure measurements for the TonoVet® can be corrected using the formula: y = 0.981 + (1.962*TonoVet® value), and those for the TonoPen™ using that of y = 5.38 + (1.426*TonoPen™ value). The calibrated IOP for a healthy Mouse Lemur eye was 20.3 ± 2.8 mmHg. The TonoVet® showed advantages in practicability, for example, small corneal contact area, short and painless corneal contact, shortened total time spent on investigation, as well as the more accurate measured values. IOP measurements of healthy Mouse Lemur eyes were not affected by age, sex, eye side, or colony. Conclusion: Tonometry using TonoVet® is the more practicable assessment tool for IOP measurement of the tiny eyes of living Mouse Lemurs. Pathological deviations can be identified based on the described reference value.
Ute Radespiel - One of the best experts on this subject based on the ideXlab platform.
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host associations of ectoparasites of the gray Mouse Lemur microcebus murinus in northwestern madagascar
Journal of Parasitology, 2020Co-Authors: Lance A Durden, Sharon E Kessler, Alida F Hasiniaina, Ute Radespiel, Alexandr A Stekolnikov, Kayleigh Chalkowski, Sarah ZohdyAbstract:Eight species of ectoparasites were collected during 225 gray Mouse Lemur, Microcebus murinus (J. F. Miller), captures, in Ankarafantsika National Park, Madagascar, in 2010-2011. The ixodid tick, Haemaphysalis Lemuris Hoogstraal, was the most common ectoparasite and was mostly represented by nymphs. Other ectoparasites recorded include the polyplacid sucking louse, Lemurpediculus madagascariensis Durden, Kessler, Radespiel, Zimmermann, Hasiniaina, and Zohdy; the ixodid tick, Haemaphysalis simplex Neumann; an undescribed laelapid mite in the genus Aetholaelaps; another laelapid belonging to the genus Androlaelaps; the chigger mite Schoutedenichia microcebi Stekolnikov; an undescribed species of atopomelid mite in the genus Listrophoroides; and an undescribed species of psoroptid mite in the genus Cheirogalalges. Except for the 2 species of ticks and 1 species of chigger, these ectoparasites may be host-specific to M. murinus. Total tick (H. Lemuris and H. simplex) infestation was significantly greater in August than October, whereas louse (L. madagascariensis) infestation was significantly greater in October. There was no significant difference in tick infestations between male and female Lemurs, but male Lemurs had significantly more lice than female Lemurs. Reproductive status was not a significant predictor of tick infestation in males and females.
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spontaneous spongiform brainstem degeneration in a young Mouse Lemur microcebus murinus with conspicuous behavioral motor growth and ocular pathologies
Comparative Medicine, 2018Co-Authors: Daniel Schmidtke, Ute Radespiel, Elke Zimmermann, Marko Dubicanac, Sabine B. R. Kästner, Charlotte Lempp, Wolfgang Baumgartner, Martin Meier, Anne Balkemabuschmann, Alan R HarrisAbstract:Here we report a case of severe growth retardation and neurologic abnormalities in a female gray Mouse Lemur (Microcebus murinus), a small NHP species for which the genomic sequence recently became available. The female Lemur we present here died on postnatal day 125. This Lemur had impaired development of motor skills and showed severe ataxia and tremors. In addition, hearing seemed normal whereas ophthalmic examination revealed incipient bilateral cataracts, abnormal pigmentation in the lens of the left eye, and a missing optokinetic nystagmus, which indicated impaired vision. Most prominently, the Lemur showed severe growth retardation. Necropsy revealed maldevelopment of the left reproductive organs and unilateral dilation of the right lateral ventricle, which was confirmed on brain MRI. Brain histology further revealed large, bilateral areas of vacuolation within the brainstem, but immunohistochemistry indicated no sign of pathologic prion protein deposition. Full genomic sequencing of the Lemur revealed a probably pathologic mutation in LARGE2 of the LARGE gene family, which has been associated with congenital muscular dystrophies. However, potentially functional mutations in other genes were also present. The observed behavioral and motor signs in the presented animal might have been linked to spongiform degeneration and resulting brainstem dysfunction and progressive muscle weakness. The macroscopic developmental abnormalities and ophthalmic findings might be genetic in origin and linked to the mutation in LARGE2.
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Does the grey Mouse Lemur use agonistic vocalisations to recognise kin
Contributions to Zoology, 2018Co-Authors: Sharon E Kessler, Alida F Hasiniaina, Ute Radespiel, Leanne T Nash, Elke ZimmermannAbstract:Frequent kin-biased coalitionary behaviour is a hallmark of mammalian social complexity. Furthermore, selection to understand complex social dynamics is believed to underlie the co-evolution of social complexity and large brains. Vocalisations have been shown to be an important mechanism with which large-brained mammals living in complex social groups recognise and recruit kin for coalitionary support during agonistic conflicts. We test whether kin recognition via agonistic calls occurs in a small-brained solitary foraging primate living in a dispersed social network, the grey Mouse Lemur (Microcebus murinus, Miller JF, 1777). As Mouse Lemurs are frequent models for ancestral solitary foraging mammals, this study examines whether kin recognition via agonistic calls could be the foundation from which more complex, kin-based coalitionary behaviour evolved. We test whether female wild Mouse Lemurs in Ankarafantsika National Park, Madagascar, react differently to agonistic calls from kin and nonkin and to calls from familiar and unfamiliar individuals during playback experiments. Subjects showed no significant differences in reactions to the different stimuli; thus they did not react differently based upon kinship or familiarity. Results suggest that this solitary foraging species does not use agonistic calls to recognise kin and monitor agonistic interactions involving kin, unlike several species of Old World monkeys and hyenas. Thus, kin recognition via agonistic calls may have evolved independently in these lineages in parallel with greater social complexity and frequent coalitionary behaviour.
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a new species of sucking louse phthiraptera anoplura polyplacidae from the gray Mouse Lemur microcebus murinus primates cheirogaleidae in madagascar
Journal of Medical Entomology, 2018Co-Authors: Lance A Durden, Sharon E Kessler, Alida F Hasiniaina, Ute Radespiel, Elke Zimmermann, Sarah ZohdyAbstract:Lemurpediculus madagascariensis sp. nov. (Phthiraptera: Anoplura: Polyplacidae) is described from the Gray Mouse Lemur, Microcebus murinus (J. F. Miller) (Primates: Cheirogaleidae), from Ankarafantsika National Park, Madagascar. Lemurs were trapped using Sherman Live Traps and visually inspected for lice, which were preserved in 90% ethanol. Adults of both sexes and the third-instar nymph of the new species are illustrated and distinguished from the four previously known species of Lemurpediculus: L. verruculosus (Ward); L. petterorum Paulian; L. claytoni Durden, Blanco, and Seabolt; and L. robbinsi Durden, Blanco, and Seabolt. It is not known if the new species of louse is a vector of any pathogens or parasites.
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Additional file 1: of Population genetics of Mouse Lemur vomeronasal receptors: current versus past selection and demographic inference
2017Co-Authors: Philipp Hohenbrink, Nicholas Mundy, Ute RadespielAbstract:IDs of the sampled individuals; the table contains the IDs of all males and females that were used for sequencing 17 VR loci in the two Mouse Lemur species Microcebus murinus (n = 20) and M. ravelobensis (n = 20) in the study site JBA. (DOCX 14 kb
Fabienne Aujard - One of the best experts on this subject based on the ideXlab platform.
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Strengths and Weaknesses of the Gray Mouse Lemur (Microcebus murinus) as a Model for the Behavioral and Psychological Symptoms and Neuropsychiatric Symptoms of Dementia
Frontiers in pharmacology, 2019Co-Authors: Fabien Pifferi, Jacques Epelbaum, Fabienne AujardAbstract:To face the burden of the prevalence of Alzheimer’s disease in the aging population, there is an urgent need to develop more translatable animal models with similarities to humans in both the symptomatology and physiopathology of dementia. Due to their close evolutionary similarity to humans, non-human primates are of primary interest. Of the non-human primates, to date, the gray Mouse Lemur (Microcebus murinus) has shown promising evidence of its translatability to humans. The present review reports the known advantages and limitations of using this species at all levels of investigation in the context of neuropsychiatric conditions. In this easily bred Malagasy primate with a relatively short life span (approximately 12 years), age-related cognitive decline, amyloid angiopathy and risk factors (i.e., glucoregulatory imbalance) are congruent with those observed in humans. More specifically, analogous behavioral and psychological symptoms and neuropsychiatric symptoms of dementia (BPSD/NPS) to those in humans can be found in the aging Mouse Lemur. Aged Mouse Lemurs show typical age-related alterations of locomotor activity daily rhythms such as decreased rhythm amplitude, increased fragmentation, and increased activity during the resting-sleeping phase of the day and desynchronization with the light-dark cycle. In addition, sleep deprivation successfully induces cognitive deficits in adult Mouse Lemurs, and the effectiveness of approved cognitive enhancers such as acetylcholinesterase inhibitors or N-methyl-D-aspartate antagonists is demonstrated in sleep-deprived animals. This result supports the translational potential of this animal model, especially for unravelling the mechanisms underlying dementia and for developing novel therapeutics to prevent age-associated cognitive decline. In conclusion, actual knowledge of BPSD/NPS-like symptoms of age-related cognitive deficits in the gray Mouse Lemur and the recent demonstration of the similarity of these symptoms with those seen in humans offer promising new ways of investigating both the prevention and treatment of pathological aging.
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daily torpor and sleep in a non human primate the gray Mouse Lemur microcebus murinus
Frontiers in Neuroanatomy, 2019Co-Authors: Julie Royo, Fabienne Aujard, Fabie PifferiAbstract:Daily torpor is an energy-saving process that evolved as an extension of non-rapid eye movement (NREM) sleep mechanisms. In many heterothermic species there is a relation between torpor expression and the repartition of the different behavioral states of sleep. Despite the presence of sleep during this period of hypothermia, torpor induces an accumulation of sleep debt which results in a rebound of sleep in mammals. We aimed to investigate the expression of sleep-wake rhythms and delta waves during daily torpor at various ambient temperatures in a non-human primate model, the gray Mouse Lemur (Microcebus murinus). Cortical activity was measured with telemetric electroencephalography (EEG) recordings in the prefrontal cortex (PFC) during the torpor episode and the next 24 h following hypothermia. Gray Mouse Lemurs were divided into two groups: the first group was subjected to normal ambient temperatures (25°C) whereas the second group was placed at lower ambient temperatures (10°C). Contrary to normal ambient temperatures, sleep-wake rhythms were maintained during torpor until body temperature (Tb) of the animals reached 21°C. Below this temperature, NREM and REM sleep strongly decreased or were absent whereas the EEG became isoelectric. The different states of sleep were proportional to Tbmin during prior torpor in contrast to active phases. Delta waves increased after torpor but low Tb did not induce greater delta power compared to higher temperatures. Our results showed that Tb was a determining factor for the quality and quantity of sleep. Low Tb might be inconsistent with the recovery function of sleep. Heterothermy caused a sleep debt thus there was a rebound of sleep at the beginning of euthermia to compensate for the lack of sleep.
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the biological clock in gray Mouse Lemur adaptive evolutionary and aging considerations in an emerging non human primate model
Frontiers in Physiology, 2019Co-Authors: Clara Hozer, Fabienne Aujard, Fabien Pifferi, Martine PerretAbstract:Circadian rhythms, which measure time on a scale of 24 h, are genetically generated by the circadian clock, which plays a crucial role in the regulation of almost every physiological and metabolic process in most organisms. This review gathers all the available information about the circadian clock in a small Malagasy primate, the gray Mouse Lemur (Microcebus murinus), and reports 30 years data from the historical colony at Brunoy (France). Although the Mouse Lemur has long been seen as a "primitive" species, its clock displays high phenotypic plasticity, allowing perfect adaptation of its biological rhythms to environmental challenges (seasonality, food availability). The alterations of the circadian timing system in M. murinus during aging show many similarities with those in human aging. Comparisons are drawn with other mammalian species (more specifically, with rodents, other non-human primates and humans) to demonstrate that the gray Mouse Lemur is a good complementary and alternative model for studying the circadian clock and, more broadly, brain aging and pathologies.
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Drivers of in vivo bite performance in wild brown Mouse Lemurs and a comparison with the grey Mouse Lemur
Journal of Zoology, 2018Co-Authors: P. B. Zablocki Thomas, Fabienne Aujard, Caitlin J Karanewsky, J. L. Pendleton, Emmanuelle Pouydebat, Anthony HerrelAbstract:Physical performance is crucial for animal survival and fitness. In this context, greater bite forces can provide advantages and may allow an individual to gain access to reproductive partners and/or different food resources. Here, we explored the determinants of bite force in a wild population of the brown Mouse Lemur (Microcebus rufus). Our objectives were to elucidate (1) if sex, head width, heart rate (as an indicator of overall physical fitness) and body condition drive variation in bite force in this population of wild Mouse Lemurs; and (2) the relative importance of the ecological niche in determining bite force by comparing results from this wild population with previously published results on bite force, body mass and head width from a laboratory colony of the grey Mouse Lemur (Microcebus murinus). We captured 32 wild brown Mouse Lemurs at night in the Ranomafana National Park in Madagascar during the beginning of the rainy season from 1st to 31st October 2016. We measured bite force, heart rate, body mass and head width of all individuals, and assigned sex and body condition (estimated as the unstandardized residual of a regression of body mass against head size). Although maximum bite force was positively correlated with body mass, it was not correlated with body condition. Residual bite force was highly correlated with residual head width and heart rate. The mean bite force of wild brown Mouse Lemurs was much lower than that of grey Mouse Lemurs in captivity, but showed similar relationships to head dimension and body mass. Even when corrected by body condition, grey Mouse Lemurs bit significantly harder than brown Mouse Lemurs. The difference in bite force between species could be explained by differences in head size and niche divergence with brown Mouse Lemurs eating mostly soft fruits and grey Mouse Lemurs eating more hard insects.
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metabolic and genomic adaptations to winter fattening in a primate species the grey Mouse Lemur microcebus murinus
International Journal of Obesity, 2018Co-Authors: Jérémy Terrien, M Gaudubois, Delphine Champeval, V Zaninotto, L Roger, Jeanfrancois Riou, Fabienne AujardAbstract:Metabolic and genomic adaptations to winter fattening in a primate species, the grey Mouse Lemur ( Microcebus murinus )
Caitlin J Karanewsky - One of the best experts on this subject based on the ideXlab platform.
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Drivers of in vivo bite performance in wild brown Mouse Lemurs and a comparison with the grey Mouse Lemur
Journal of Zoology, 2018Co-Authors: P. B. Zablocki Thomas, Fabienne Aujard, Caitlin J Karanewsky, J. L. Pendleton, Emmanuelle Pouydebat, Anthony HerrelAbstract:Physical performance is crucial for animal survival and fitness. In this context, greater bite forces can provide advantages and may allow an individual to gain access to reproductive partners and/or different food resources. Here, we explored the determinants of bite force in a wild population of the brown Mouse Lemur (Microcebus rufus). Our objectives were to elucidate (1) if sex, head width, heart rate (as an indicator of overall physical fitness) and body condition drive variation in bite force in this population of wild Mouse Lemurs; and (2) the relative importance of the ecological niche in determining bite force by comparing results from this wild population with previously published results on bite force, body mass and head width from a laboratory colony of the grey Mouse Lemur (Microcebus murinus). We captured 32 wild brown Mouse Lemurs at night in the Ranomafana National Park in Madagascar during the beginning of the rainy season from 1st to 31st October 2016. We measured bite force, heart rate, body mass and head width of all individuals, and assigned sex and body condition (estimated as the unstandardized residual of a regression of body mass against head size). Although maximum bite force was positively correlated with body mass, it was not correlated with body condition. Residual bite force was highly correlated with residual head width and heart rate. The mean bite force of wild brown Mouse Lemurs was much lower than that of grey Mouse Lemurs in captivity, but showed similar relationships to head dimension and body mass. Even when corrected by body condition, grey Mouse Lemurs bit significantly harder than brown Mouse Lemurs. The difference in bite force between species could be explained by differences in head size and niche divergence with brown Mouse Lemurs eating mostly soft fruits and grey Mouse Lemurs eating more hard insects.
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a biogeographical perspective on the variation in Mouse Lemur density throughout madagascar
Mammal Review, 2017Co-Authors: Casey M Setash, Sarah Zohdy, Caitlin J Karanewsky, Brian D GerberAbstract:Madagascar is home to the smallest primates in the world, the Mouse Lemurs (Microcebus species). Twenty-four species of Mouse Lemur are currently recognised and are found in variable ecosystems, from dry forests and spiny deserts to humid forests. Due to their widespread distribution and the large number of sympatric species, Mouse Lemurs can be used as a model to understand the linkages among species richness, population density, and habitat. As all Lemurs are threatened by habitat loss and fragmentation, this information can also be used to inform conservation management. We hypothesise that on an island-wide scale, we will find higher population densities in western dry forests than in eastern humid forests because the western dry forests exhibit lower species richness, more sympatric habitat use, and lower resource stability than the eastern humid forests. We conducted a literature review of population density estimates of known Mouse Lemur species, and used those data to conduct a meta-analysis and estimate overall average population density by geographic region. Our findings suggest that Mouse Lemur species living in western dry forest generally exhibit higher densities than those in eastern humid forests. This may be partly explained by higher habitat fragmentation in western dry forests, where species co-occur, but is likely to be a function of the magnitude and variability in seasonally available resources in each forest type. Higher seasonality results in less constant food availability and lower levels of environmental predictability, fostering species capable of coping with environmental change and maintaining high densities throughout periods of resource paucity. Our study highlights the importance of conducting Microcebus population density research that adheres to standardised methodological approaches. We point to the need for population density estimates for several species for which data are lacking. Such knowledge is important to assess the conservation status of these species, but also to enhance our ability to identify the macro-biogeographical and local ecological drivers of interspecific and intraspecific variability in population density.
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the Mouse Lemur a genetic model organism for primate biology behavior and health
Genetics, 2017Co-Authors: Camille Ezran, Sarah Zohdy, Caitlin J Karanewsky, Jozeph L Pendleton, Alex Sholtz, Maya R Krasnow, Jason Willick, Andriamahery Razafindrakoto, Megan A AlbertelliAbstract:Systematic genetic studies of a handful of diverse organisms over the past 50 years have transformed our understanding of biology. However, many aspects of primate biology, behavior, and disease are absent or poorly modeled in any of the current genetic model organisms including mice. We surveyed the animal kingdom to find other animals with advantages similar to mice that might better exemplify primate biology, and identified Mouse Lemurs (Microcebus spp.) as the outstanding candidate. Mouse Lemurs are prosimian primates, roughly half the genetic distance between mice and humans. They are the smallest, fastest developing, and among the most prolific and abundant primates in the world, distributed throughout the island of Madagascar, many in separate breeding populations due to habitat destruction. Their physiology, behavior, and phylogeny have been studied for decades in laboratory colonies in Europe and in field studies in Malagasy rainforests, and a high quality reference genome sequence has recently been completed. To initiate a classical genetic approach, we developed a deep phenotyping protocol and have screened hundreds of laboratory and wild Mouse Lemurs for interesting phenotypes and begun mapping the underlying mutations, in collaboration with leading Mouse Lemur biologists. We also seek to establish a Mouse Lemur gene “knockout” library by sequencing the genomes of thousands of Mouse Lemurs to identify null alleles in most genes from the large pool of natural genetic variants. As part of this effort, we have begun a citizen science project in which students across Madagascar explore the remarkable biology around their schools, including longitudinal studies of the local Mouse Lemurs. We hope this work spawns a new model organism and cultivates a deep genetic understanding of primate biology and health. We also hope it establishes a new and ethical method of genetics that bridges biological, behavioral, medical, and conservation disciplines, while providing an example of how hands-on science education can help transform developing countries.
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effects of sex and age on heterothermy in goodman s Mouse Lemur microcebus lehilahytsara
International Journal of Primatology, 2015Co-Authors: Martin R Bauert, Caitlin J Karanewsky, Patricia C. WrightAbstract:All habitats of Madagascar go through a dry season from April to September each year, resulting in a period of fruit scarcity lasting up to 6 months and creating selection pressure for adaptation to fluctuations in resources. Some Cheirogaleid Lemurs, including Mouse Lemurs (Microcebus), use daily torpor and long-term hibernation during this period, saving energy through inactivity. Capture–recapture studies in some Mouse Lemur populations have suggested a pattern of biased sex ratio throughout the winter as a result of females hibernating while most males remain active. We studied winter activity in a captive population of Microcebus lehilahytsara, Goodman’s Mouse Lemur, in a large enclosure at Zoo Zurich, Switzerland using capture–recapture methods to determine how this behavior varies with sex and age, and what this pattern suggests about the ultimate cause of torpor use in this clade. Our results suggest that Goodman’s Mouse Lemurs use torpor to avoid seasonal food shortage, even though they experience less extreme seasonal variability of food availability than western dry forest Mouse Lemurs. Male and female Goodman’s Mouse Lemurs are equally capable of winter torpor, and most remaining active individuals are young that have not sufficiently fattened. This suggests that the “ideal” winter behavior for both males and females is torpor, which ultimately avoids periods of seasonal food scarcity.
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Effects of Sex and Age on Heterothermy in Goodman’s Mouse Lemur (Microcebus lehilahytsara)
International Journal of Primatology, 2015Co-Authors: Caitlin J Karanewsky, Martin R Bauert, Patricia C. WrightAbstract:All habitats of Madagascar go through a dry season from April to September each year, resulting in a period of fruit scarcity lasting up to 6 months and creating selection pressure for adaptation to fluctuations in resources. Some Cheirogaleid Lemurs, including Mouse Lemurs (Microcebus), use daily torpor and long-term hibernation during this period, saving energy through inactivity. Capture–recapture studies in some Mouse Lemur populations have suggested a pattern of biased sex ratio throughout the winter as a result of females hibernating while most males remain active. We studied winter activity in a captive population of Microcebus lehilahytsara, Goodman’s Mouse Lemur, in a large enclosure at Zoo Zurich, Switzerland using capture–recapture methods to determine how this behavior varies with sex and age, and what this pattern suggests about the ultimate cause of torpor use in this clade. Our results suggest that Goodman’s Mouse Lemurs use torpor to avoid seasonal food shortage, even though they experience less extreme seasonal variability of food availability than western dry forest Mouse Lemurs. Male and female Goodman’s Mouse Lemurs are equally capable of winter torpor, and most remaining active individuals are young that have not sufficiently fattened. This suggests that the “ideal” winter behavior for both males and females is torpor, which ultimately avoids periods of seasonal food scarcity.
Peter M. Kappeler - One of the best experts on this subject based on the ideXlab platform.
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Agent-mediated spatial storage effect in heterogeneous habitat stabilizes competitive Mouse Lemur coexistence in Menabe Central, Western Madagascar
BMC Ecology, 2015Co-Authors: Livia Schäffler, Joachim Saborowski, Peter M. KappelerAbstract:Background Spatio-temporal distribution patterns of species in response to natural and anthropogenic drivers provide insight into the ecological processes that determine community composition. We investigated determinants of ecological structure in a species assemblage of 4 closely related primate species of the family Cheirogaleidae (Microcebus berthae, Microcebus murinus, Cheirogaleus medius, Mirza coquereli) in western Madagascar by extensive line transect surveys across spatial and temporal heterogeneities with the specific goal of elucidating the mechanisms stabilizing competitive coexistence of the two Mouse Lemur species (Microcebus spp.).
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mhc class ii variation in a rare and ecological specialist Mouse Lemur reveals lower allelic richness and contrasting selection patterns compared to a generalist and widespread sympatric congener
Immunogenetics, 2015Co-Authors: Eva Pechouskova, Peter M. Kappeler, Melanie Dammhahn, Claudia Fichtel, Markus Brameier, Elise HuchardAbstract:The polymorphism of immunogenes of the major histocompatibility complex (MHC) is thought to influence the functional plasticity of immune responses and, consequently, the fitness of populations facing heterogeneous pathogenic pressures. Here, we evaluated MHC variation (allelic richness and divergence) and patterns of selection acting on the two highly polymorphic MHC class II loci (DRB and DQB) in the endangered primate Madame Berthe’s Mouse Lemur (Microcebus berthae). Using 454 pyrosequencing, we examined MHC variation in a total of 100 individuals sampled over 9 years in Kirindy Forest, Western Madagascar, and compared our findings with data obtained previously for its sympatric congener, the grey Mouse Lemur (Microcebus murinus). These species exhibit a contrasting ecology and demography that were expected to affect MHC variation and molecular signatures of selection. We found a lower allelic richness concordant with its low population density, but a similar level of allelic divergence and signals of historical selection in the rare feeding specialist M. berthae compared to the widespread generalist M. murinus. These findings suggest that demographic factors may exert a stronger influence than pathogen-driven selection on current levels of allelic richness in M. berthae. Despite a high sequence similarity between the two congeners, contrasting selection patterns detected at DQB suggest its potential functional divergence. This study represents a first step toward unravelling factors influencing the adaptive divergence of MHC genes between closely related but ecologically differentiated sympatric Lemurs and opens new questions regarding potential functional discrepancy that would explain contrasting selection patterns detected at DQB.
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Spatial memory in the grey Mouse Lemur (Microcebus murinus).
Animal cognition, 2009Co-Authors: Mia-lana Lührs, Peter M. Kappeler, Melanie Dammhahn, Claudia FichtelAbstract:Wild animals face the challenge of locating feeding sites distributed across broad spatial and temporal scales. Spatial memory allows animals to find a goal, such as a productive feeding patch, even when there are no goal-specific sensory cues available. Because there is little experimental information on learning and memory capabilities in free-ranging primates, the aim of this study was to test whether grey Mouse Lemurs (Microcebus murinus), as short-term dietary specialists, rely on spatial memory in relocating productive feeding sites. In addition, we asked what kind of spatial representation might underlie their orientation in their natural environment. Using an experimental approach, we set eight radio-collared grey Mouse Lemurs a memory task by confronting them with two different spatial patterns of baited and non-baited artificial feeding stations under exclusion of sensory cues. Positional data were recorded by focal animal observations within a grid system of small foot trails. A change in the baiting pattern revealed that grey Mouse Lemurs primarily used spatial cues to relocate baited feeding stations and that they were able to rapidly learn a new spatial arrangement. Spatially concentrated, non-random movements revealed preliminary evidence for a route-based restriction in Mouse Lemur space; during a subsequent release experiment, however, we found high travel efficiency in directed movements. We therefore propose that Mouse Lemur spatial memory is based on some kind of mental representation that is more detailed than a route-based network map.
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mutualism reciprocity or kin selection cooperative rescue of a conspecific from a boa in a nocturnal solitary forager the gray Mouse Lemur
American Journal of Primatology, 2008Co-Authors: Manfred Eberle, Peter M. KappelerAbstract:Predator mobbing is a widespread phenomenon in many taxa but the evolution of cooperative mobbing as an adaptive behavior is still subject to debate. Here, we report evidence for cooperative predator defense in a nocturnal solitarily foraging primate, the gray Mouse Lemur (Microcebus murinus). Several Mouse Lemurs mobbed a snake that held a non-related male conspecific until he could escape. Evolutionary hypotheses to explain cooperative mobbing include (1) by-product mutualism, when individuals defend others in the process of defending themselves; (2) reciprocity, where animals achieve a higher fitness when helping each other than when they do not cooperate; and (3) kin selection where animals help each other only if they share genes by common descent. Owing to the solitary activity of this species, reciprocity seems to be least likely to explain our observations. By-product mutualism cannot be ruled out entirely but, if costs of snake mobbing are relatively low, the available detailed socio-genetic information indicates that kin selection, rather than any of the other proposed mechanisms, is the primary evolutionary force behind the observed cooperative rescue. Am. J. Primatol. 70:410‐414, 2008. c 2007 Wiley-Liss, Inc.
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the genetic population structure of the gray Mouse Lemur microcebus murinus a basal primate from madagascar
Behavioral Ecology and Sociobiology, 2002Co-Authors: Barbara Wimmer, Diethard Tautz, Peter M. KappelerAbstract:The genetic structure of a population is closely connected to fundamental evolutionary processes and aspects of social behavior. Information on genetic structure is therefore instrumental for the interpretation of social behavior and evolutionary reconstructions of social systems. Gray Mouse Lemurs (Microcebus murinus) are basal primates endemic to Madagascar whose social organization is characterized by solitary foraging at night and communal resting during the day. Conflicting reports about population structure based on behavioral observations led us to examine the genetic structure of one population in detail in order to: (1) identify natural genetic units in this solitary primate, and (2) to test the assumption of current models of primate social evolution that solitary primates are organized in matrilines. DNA was extracted from tissue samples of 85 individuals from Kirindy forest to determine their variability at a 530 bp fragment of the mitochondrial D-loop and at six microsatellite loci. We found that this population was characterized by a great general diversity among mtDNA haplotypes, a pronounced sex difference in mtDNA haplotype diversity and spatial clustering of females with a particular haplotype, but low average relatedness among members of haplotype clusters. Specifically, we identified 13 different haplotypes, which were unevenly distributed among individuals. About 80% of all individuals, most of which were females or juvenile males, shared a single haplotype. Rare haplotypes were almost exclusively represented by single adult males, who apparently migrated into this population. One other haplotype was represented by a small group of females living at one edge of the study area. Microsatellite analysis revealed above-average relatedness among females with overlapping home ranges, as well as no signs of inbreeding, implying that male dispersal results in high levels of gene flow among matrilineal groups. We conclude that gray Mouse Lemur populations are hierarchically organized in small family units of closely related females that form stable sleeping groups, several of which are connected through a common mtDNA haplotype and form spatially distinct clusters. The presence of such matrilines supports a basic assumption of current models of primate social evolution.