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Jason Munshisouth - One of the best experts on this subject based on the ideXlab platform.
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signatures of positive selection and local adaptation to urbanization in white footed mice Peromyscus leucopus
Molecular Ecology, 2017Co-Authors: Stephen E Harris, Jason MunshisouthAbstract:Urbanization significantly alters natural ecosystems and has accelerated globally. Urban wildlife populations are often highly fragmented by human infrastructure, and isolated populations may adapt in response to local urban pressures. However, relatively few studies have identified genomic signatures of adaptation in urban animals. We used a landscape genomic approach to examine signatures of selection in urban populations of white-footed mice (Peromyscus leucopus) in New York City. We analysed 154,770 SNPs identified from transcriptome data from 48 P. leucopus individuals from three urban and three rural populations and used outlier tests to identify evidence of urban adaptation. We accounted for demography by simulating a neutral SNP data set under an inferred demographic history as a null model for outlier analysis. We also tested whether candidate genes were associated with environmental variables related to urbanization. In total, we detected 381 outlier loci and after stringent filtering, identified and annotated 19 candidate loci. Many of the candidate genes were involved in metabolic processes and have well-established roles in metabolizing lipids and carbohydrates. Our results indicate that white-footed mice in New York City are adapting at the biomolecular level to local selective pressures in urban habitats. Annotation of outlier loci suggests selection is acting on metabolic pathways in urban populations, likely related to novel diets in cities that differ from diets in less disturbed areas.
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interferon signaling in Peromyscus leucopus confers a potent and specific restriction to vector borne flaviviruses
PLOS ONE, 2017Co-Authors: Adaeze O Izuogu, Stephen E Harris, Jason Munshisouth, Sonja M. Best, Kristin L Mcnally, Brian H Youseff, John B Presloid, Christopher Burlak, Travis R TaylorAbstract:Tick-borne flaviviruses (TBFVs), including Powassan virus and tick-borne encephalitis virus cause encephalitis or hemorrhagic fevers in humans with case-fatality rates ranging from 1-30%. Despite severe disease in humans, TBFV infection of natural rodent hosts has little noticeable effect. Currently, the basis for resistance to disease is not known. We hypothesize that the coevolution of flaviviruses with their respective hosts has shaped the evolution of potent antiviral factors that suppress virus replication and protect the host from lethal infection. In the current study, we compared virus infection between reservoir host cells and related susceptible species. Infection of primary fibroblasts from the white-footed mouse (Peromyscus leucopus, a representative host) with a panel of vector-borne flaviviruses showed up to a 10,000-fold reduction in virus titer compared to control Mus musculus cells. Replication of vesicular stomatitis virus was equivalent in P. leucopus and M. musculus cells suggesting that restriction was flavivirus-specific. Step-wise comparison of the virus infection cycle revealed a significant block to viral RNA replication, but not virus entry, in P. leucopus cells. To understand the role of the type I interferon (IFN) response in virus restriction, we knocked down signal transducer and activator of transcription 1 (STAT1) or the type I IFN receptor (IFNAR1) by RNA interference. Loss of IFNAR1 or STAT1 significantly relieved the block in virus replication in P. leucopus cells. The major IFN antagonist encoded by TBFV, nonstructural protein 5, was functional in P. leucopus cells, thus ruling out ineffective viral antagonism of the host IFN response. Collectively, this work demonstrates that the IFN response of P. leucopus imparts a strong and virus-specific barrier to flavivirus replication. Future identification of the IFN-stimulated genes responsible for virus restriction specifically in P. leucopus will yield mechanistic insight into efficient control of virus replication and may inform the development of antiviral therapeutics.
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morphological differentiation in white footed mouse mammalia rodentia cricetidae Peromyscus leucopus populations from the new york city metropolitan area
Bulletin of The Peabody Museum of Natural History, 2017Co-Authors: Jason Munshisouth, Eric J SargisAbstract:Abstract Genetic studies have shown that New York City white-footed mouse (Peromyscus leucopus) populations exhibit substantial genetic structure and high levels of allelic diversity and heterozygosity. These studies have also identified mutations and genes involved in the divergence of urban and rural P. leucopus populations. To investigate whether morphological change mirrors the genetic differentiation observed in New York City P. leucopus populations, we conducted univariate and multivariate analyses on 4 external and 14 skull variables to compare urban, suburban and rural P. leucopus populations from in and around New York City. The only significant morphological differences among the three populations were in upper and lower toothrow lengths, both of which had high loadings in our principal components analyses. In general, rural individuals were found to have longer upper and lower toothrows than urban ones. This difference is likely due to the relationship between food quality and size of dental oc...
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signatures of positive selection and local adaptation to urbanization in white footed mice Peromyscus leucopus
bioRxiv, 2016Co-Authors: Stephen E Harris, Jason MunshisouthAbstract:Urbanization significantly alters natural ecosystems and has accelerated globally as humans move into dense urban centers. Urban wildlife populations are often highly fragmented by an inhospitable matrix of human infrastructure. Isolated populations may adapt in response to novel urban pressures, but few studies have found evidence of selection in urban environments. We used multiple approaches to examine signatures of selection in transcriptomes from white-footed mice (Peromyscus leucopus) in New York City. We analyzed transcriptomes from 48 P. leucopus individuals from three urban and three rural populations for evidence of rapid local adaption in isolated urban habitats. We generated a dataset of 154,770 SNPs and analyzed patterns of genetic differentiation between urban and rural sites. We also used genome scans and genotype-by-environment (GEA) analyses to identify signatures of selection in a large subset of genes. Neutral demographic processes may create allele frequency patterns that are indistinguishable from positive selection. Thus, we accounted for demography by simulating a neutral SNP dataset under the inferred demographic history for the sampled P. leucopus populations to serve as a null model for outlier analysis. We then annotated outlier genes and further validated them by associating allele frequency differences with two urbanization variables: percent impervious surface and human population density. Many candidate genes were involved in metabolic functions, especially dietary specialization. A subset of these genes have well-established roles in metabolizing lipids and carbohydrates, including transport of cholesterol and desaturation of fatty acids. Our results reveal clear genetic differentiation between rural and urban sites that resulted from rapid local adaptation and drift in urbanizing habitats. The specific outlier loci that we identified suggest that populations of P. leucopus are using novel food resources in urban habitats and selection pressures are acting to change metabolic pathways. Our findings support the idea that cities represent novel ecosystems with a unique set of selective pressures.
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urbanization shapes the demographic history of a native rodent the white footed mouse Peromyscus leucopus in new york city
Biology Letters, 2016Co-Authors: Stephen E Harris, J T Boehm, Tyler Joseph, Diego F Alvaradoserrano, Michael J Hickerson, Jason MunshisouthAbstract:How urbanization shapes population genomic diversity and evolution of urban wildlife is largely unexplored. We investigated the impact of urbanization on white-footed mice, Peromyscus leucopus, in ...
Randy J Nelson - One of the best experts on this subject based on the ideXlab platform.
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photoperiodic regulation of cerebral blood flow in white footed mice Peromyscus leucopus
eNeuro, 2016Co-Authors: Jeremy C Borniger, Randy J Nelson, Seth Teplitsky, Surya Gnyawali, Cameron RinkAbstract:Abstract Individuals living outside the tropics need to adjust their behavioral and physiological repertoires throughout the year to adapt to the changing seasons. White-footed mice ( Peromyscus leucopus ) reduce hippocampal volumes, hippocampal-dependent memory function, long-term potentiation, and alter neurogenesis in response to short (winter-like) day lengths (photoperiods). During winter, these mice putatively shunt energy away from the brain to maximize peripheral thermogenesis, immune function, and survival. We hypothesized that these changes in brain function are accompanied by alterations in brain vasculature. We maintained white-footed mice in short (8 h light/16 h dark) or long (16 h light/8 h dark) photoperiods for 8–9 weeks. Mice were then perfused with fluorescein isothiocyanate (FITC)-conjugated tomato ( Lycopersicon esculentum ) lectin to visualize the perfused cerebrovasculature. Short-day mice reduced hippocampal and cortical capillary density (FITC + area); vessels isolated from short day-exposed mice expressed higher mRNA levels of the gelatinase matrix metalloproteinase 2 (MMP2). Additionally, short-day mice reduced cerebral blood flow ∼15% compared with their long-day counterparts, as assessed by laser speckle flowmetry. Immunohistochemistry revealed higher levels of MMP2 in the hippocampus of mice maintained in short days compared with long days, potentially contributing to the observed vascular remodeling. These data demonstrate that a discrete environmental signal (i.e., day length) can substantially alter cerebral blood flow in adult mammals.
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photoperiodic regulation of hippocampal neurogenesis in adult male white footed mice Peromyscus leucopus
European Journal of Neuroscience, 2014Co-Authors: James C Walton, Zachary M Weil, Randy J Nelson, Taryn G Aubrecht, Benedetta LeunerAbstract:Photoperiodic organisms monitor environmental day length to engage in seasonally appropriate adaptions in physiology and behavior. Among these adaptations are changes in brain volume and neurogenesis, which have been well described in multiple species of birds, yet few studies have described such changes in the brains of adult mammals. White-footed mice (Peromyscus leucopus) are an excellent species in which to investigate the effects of day length on adult hippocampal neurogenesis, as males, in addition to having reduced hippocampal volume in short days (SD) with concomitant impairments in hippocampus-mediated behaviors, have photoperiod-dependent changes in olfactory bulb neurogenesis. We performed the current experiment to assess the effects of photoperiod on hippocampal neurogenesis longitudinally, using the thymidine analog bromodeoxyuridine at multiple time points across 10 weeks of SD exposure. Compared with counterparts held in long day (LD) lengths, across the first 8 weeks of SD exposure hippocampal neurogenesis was reduced. However, at 10 weeks in SD lengths neurogenic levels in the hippocampus were elevated above those levels in mice held in LD lengths. The current findings are consistent with the natural photoperiodic cycle of hippocampal function in male white-footed mice, and may help to inform research on photoperiodic plasticity in neurogenesis and provide insight into how the complex interplay among the environment, genes and adaptive responses to changing day lengths affects brain structure, function and behavior at multiple levels.
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photoperiod mediated changes in olfactory bulb neurogenesis and olfactory behavior in male white footed mice Peromyscus leucopus
PLOS ONE, 2012Co-Authors: James C Walton, Leah M Pyter, Zachary M Weil, Randy J NelsonAbstract:Brain plasticity, in relation to new adult mammalian neurons generated in the subgranular zone of the hippocampus, has been well described. However, the functional outcome of new adult olfactory neurons born in the subventricular zone of the lateral ventricles is not clearly defined, as manipulating neurogenesis through various methods has given inconsistent and conflicting results in lab mice. Several small rodent species, including Peromyscus leucopus, display seasonal (photoperiodic) brain plasticity in brain volume, hippocampal function, and hippocampus-dependent behaviors; plasticity in the olfactory system of photoperiodic rodents remains largely uninvestigated. We exposed adult male P. leucopus to long day lengths (LD) and short day lengths (SD) for 10 to 15 weeks and then examined olfactory bulb cell proliferation and survival using the thymidine analog BrdU, olfactory bulb granule cell morphology using Golgi-Cox staining, and behavioral investigation of same-sex conspecific urine. SD mice did not differ from LD counterparts in granular cell morphology of the dendrites or in dendritic spine density. Although there were no differences due to photoperiod in habituation to water odor, SD mice rapidly habituated to male urine, whereas LD mice did not. In addition, short day induced changes in olfactory behavior were associated with increased neurogenesis in the caudal plexiform and granule cell layers of the olfactory bulb, an area known to preferentially respond to water-soluble odorants. Taken together, these data demonstrate that photoperiod, without altering olfactory bulb neuronal morphology, alters olfactory bulb neurogenesis and olfactory behavior in Peromyscus leucopus.
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photoperiod alters fear responses and basolateral amygdala neuronal spine density in white footed mice Peromyscus leucopus
Behavioural Brain Research, 2012Co-Authors: James C Walton, Achikam Haim, James M Spieldenner, Randy J NelsonAbstract:a b s t r a c t Photoperiodism is a biological phenomenon in which environmental day length is monitored to ascertain time of year to engage in seasonally appropriate adaptations. This trait is common among organisms living outside of the tropics. White-footed mice (Peromyscus leucopus) are small photoperiodic rodents which display a suite of adaptive responses to short day lengths, including reduced hippocampal volume, impairments in hippocampal-mediated memory, and enhanced hypothalamic-pituitary-adrenal axis reactivity. Because these photoperiodic changes in brain and behavior mirror some of the etiology of post-traumatic stress disorder (PTSD), we hypothesized that photoperiod may also alter fear memory and neuronal morphology within the hippocampus–basolateral amygdala–prefrontal cortex fear circuit. Ten weeks of exposure to short days increased fear memory in an auditory-cued fear conditioning test. Short days also increased dendritic spine density of the neurons of the basolateral amygdala, without affecting morphology of pyramidal neurons within the infralimbic region of the medial prefrontal cortex. Taken together, photoperiodic phenotypic changes in brain morphology and physiology induced by a single environmental factor, exposure to short day lengths, affect responses to fearful stimuli in white-footed mice. These results have potential implications for understanding seasonal changes in fear responsiveness, as well as for expanding translational animal models for studying gene–environment interactions underlying psychiatric diseases, such as PTSD.
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enrichment and photoperiod interact to affect spatial learning and hippocampal dendritic morphology in white footed mice Peromyscus leucopus
European Journal of Neuroscience, 2008Co-Authors: Joanna L Workman, Stephanie L K Bowers, Randy J NelsonAbstract:In seasonally changing environments, individuals must coordinate endogenous processes with ambient conditions. Winter is a challenging time to survive and reproduce. In order to anticipate decreased food availability and low temperatures in winter, many rodents use decreasing day lengths as a precise temporal cue. Short day lengths alter several adaptations, including reproduction, immune function, aggressive behavior and spatial learning in non-tropical rodents. Specifically, short days impair spatial learning in white-footed mice (Peromyscus leucopus) and alter dendritic complexity in the hippocampus. The goal of the current study was to determine whether short days constrain neural plasticity. If short days limit the capacity for plasticity, then environmental enrichment, a manipulation that induces morphological changes, should alter dendritic morphology in long, but not short, days. Male white-footed mice were assigned to long (16 : 8 LD) or short (8 : 16 LD) photoperiod in either enriched or standard cages. Enrichment consisted of
Maria A Diukwasser - One of the best experts on this subject based on the ideXlab platform.
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vertical transmission a vector independent transmission pathway of babesia microti in the natural reservoir host Peromyscus leucopus
The Journal of Infectious Diseases, 2021Co-Authors: Danielle M Tufts, Maria A DiukwasserAbstract:BACKGROUND Babesia microti, a malaria-like pathogen, is increasing in mammal and human populations in endemic areas and is unlikely to be the sole result of horizontal pathogen transmission. METHODS Peromyscus leucopus mice, natural reservoir hosts, were infected via Ixodes scapularis nymphs. Infected parental females (n = 6) produced F1 offspring (n = 36) that were screened for B. microti using quantitative PCR. Xenodiagnostic larvae were fed on infected offspring to determine horizontal transmission and pathogen viability. Fifty engorged larvae were screened; the rest were allowed to molt and then screened to determine transstadial transmission. Infected F1 generation offspring were placed in breeding groups, producing 34 F2 offspring and screened for B. microti infection. Chronic infection was monitored in parental females since time of initial vector infection. RESULTS Vertical transmission of B. microti was 74% efficient in offspring born in the first 6 months. Horizontal transmission occurred in larvae (61% prevalence) and molted nymphs (58% prevalence); these nymphs were able to infect susceptible hosts. F2 generation offspring infection prevalence was 38%. Chronic infection persisted for 1 year in some adults. CONCLUSIONS These results demonstrate that vertical transmission is an important nonvector-mediated pathway of B. microti transmission in the natural reservoir host.
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vertical transmission a vector independent transmission pathway of babesia microti in the natural reservoir host Peromyscus leucopus
The Journal of Infectious Diseases, 2020Co-Authors: Danielle M Tufts, Maria A DiukwasserAbstract:BACKGROUND Babesia microti, a malaria-like pathogen, is increasing in mammal and human populations in endemic areas and is unlikely to be the sole result of horizontal pathogen transmission. METHODS Peromyscus leucopus mice, natural reservoir hosts, were infected via Ixodes scapularis nymphs. Infected parental females (n = 6) produced F1 offspring (n = 36) that were screened for B. microti using quantitative PCR. Xenodiagnostic larvae were fed on infected offspring to determine horizontal transmission and pathogen viability. Fifty engorged larvae were screened; the rest were allowed to molt and then screened to determine transstadial transmission. Infected F1 generation offspring were placed in breeding groups, producing 34 F2 offspring and screened for B. microti infection. Chronic infection was monitored in parental females since time of initial vector infection. RESULTS Vertical transmission of B. microti was 74% efficient in offspring born in the first 6 mo. Horizontal transmission occurred in larvae (61% prevalence) and molted nymphs (58% prevalence); these nymphs were able to infect susceptible hosts. F2 generation offspring infection prevalence was 38%. Chronic infection persisted for 1 yr in some adults. CONCLUSIONS These results demonstrate that vertical transmission is an important non-vector mediated pathway of B. microti transmission in the natural reservoir host.
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transplacental transmission of tick borne babesia microti in its natural host Peromyscus leucopus
Parasites & Vectors, 2018Co-Authors: Danielle M Tufts, Maria A DiukwasserAbstract:Babesia microti is an emerging tick-borne pathogen and the causative agent of human babesiosis. Mathematical modeling of the reproductive rate of B. microti indicates that it cannot persist in nature by horizontal tick-host transmission alone. We hypothesized that transplacental transmission in the reservoir population contributes to B. microti persistence and emergence in North American rodent populations. Peromyscus leucopus were collected from Connecticut and Block Island, Rhode Island and analyzed using a highly specific quantitative PCR (qPCR) assay for infection with B. microti. In April, 100% (n = 103) of mice were infected with B. microti. Females exhibited significantly higher parasitemia than their offspring (P < 0.0001) and transplacental transmission was observed in 74.2% of embryos (n = 89). Transplacental transmission of B. microti is thus a viable and potentially important infectious pathway in naturally infected rodent species and should be considered in future theoretical and empirical studies. To our knowledge, this study is the first to report transplacental transmission of B. microti occurring in its natural reservoir host, P. leucopus, in the United States and the only study that provides a quantitative estimate of parasitemia. This vector-independent pathway could contribute to the increased geographic range of B. microti or increase its abundance in endemic areas.
Stephen E Harris - One of the best experts on this subject based on the ideXlab platform.
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signatures of positive selection and local adaptation to urbanization in white footed mice Peromyscus leucopus
Molecular Ecology, 2017Co-Authors: Stephen E Harris, Jason MunshisouthAbstract:Urbanization significantly alters natural ecosystems and has accelerated globally. Urban wildlife populations are often highly fragmented by human infrastructure, and isolated populations may adapt in response to local urban pressures. However, relatively few studies have identified genomic signatures of adaptation in urban animals. We used a landscape genomic approach to examine signatures of selection in urban populations of white-footed mice (Peromyscus leucopus) in New York City. We analysed 154,770 SNPs identified from transcriptome data from 48 P. leucopus individuals from three urban and three rural populations and used outlier tests to identify evidence of urban adaptation. We accounted for demography by simulating a neutral SNP data set under an inferred demographic history as a null model for outlier analysis. We also tested whether candidate genes were associated with environmental variables related to urbanization. In total, we detected 381 outlier loci and after stringent filtering, identified and annotated 19 candidate loci. Many of the candidate genes were involved in metabolic processes and have well-established roles in metabolizing lipids and carbohydrates. Our results indicate that white-footed mice in New York City are adapting at the biomolecular level to local selective pressures in urban habitats. Annotation of outlier loci suggests selection is acting on metabolic pathways in urban populations, likely related to novel diets in cities that differ from diets in less disturbed areas.
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interferon signaling in Peromyscus leucopus confers a potent and specific restriction to vector borne flaviviruses
PLOS ONE, 2017Co-Authors: Adaeze O Izuogu, Stephen E Harris, Jason Munshisouth, Sonja M. Best, Kristin L Mcnally, Brian H Youseff, John B Presloid, Christopher Burlak, Travis R TaylorAbstract:Tick-borne flaviviruses (TBFVs), including Powassan virus and tick-borne encephalitis virus cause encephalitis or hemorrhagic fevers in humans with case-fatality rates ranging from 1-30%. Despite severe disease in humans, TBFV infection of natural rodent hosts has little noticeable effect. Currently, the basis for resistance to disease is not known. We hypothesize that the coevolution of flaviviruses with their respective hosts has shaped the evolution of potent antiviral factors that suppress virus replication and protect the host from lethal infection. In the current study, we compared virus infection between reservoir host cells and related susceptible species. Infection of primary fibroblasts from the white-footed mouse (Peromyscus leucopus, a representative host) with a panel of vector-borne flaviviruses showed up to a 10,000-fold reduction in virus titer compared to control Mus musculus cells. Replication of vesicular stomatitis virus was equivalent in P. leucopus and M. musculus cells suggesting that restriction was flavivirus-specific. Step-wise comparison of the virus infection cycle revealed a significant block to viral RNA replication, but not virus entry, in P. leucopus cells. To understand the role of the type I interferon (IFN) response in virus restriction, we knocked down signal transducer and activator of transcription 1 (STAT1) or the type I IFN receptor (IFNAR1) by RNA interference. Loss of IFNAR1 or STAT1 significantly relieved the block in virus replication in P. leucopus cells. The major IFN antagonist encoded by TBFV, nonstructural protein 5, was functional in P. leucopus cells, thus ruling out ineffective viral antagonism of the host IFN response. Collectively, this work demonstrates that the IFN response of P. leucopus imparts a strong and virus-specific barrier to flavivirus replication. Future identification of the IFN-stimulated genes responsible for virus restriction specifically in P. leucopus will yield mechanistic insight into efficient control of virus replication and may inform the development of antiviral therapeutics.
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signatures of positive selection and local adaptation to urbanization in white footed mice Peromyscus leucopus
bioRxiv, 2016Co-Authors: Stephen E Harris, Jason MunshisouthAbstract:Urbanization significantly alters natural ecosystems and has accelerated globally as humans move into dense urban centers. Urban wildlife populations are often highly fragmented by an inhospitable matrix of human infrastructure. Isolated populations may adapt in response to novel urban pressures, but few studies have found evidence of selection in urban environments. We used multiple approaches to examine signatures of selection in transcriptomes from white-footed mice (Peromyscus leucopus) in New York City. We analyzed transcriptomes from 48 P. leucopus individuals from three urban and three rural populations for evidence of rapid local adaption in isolated urban habitats. We generated a dataset of 154,770 SNPs and analyzed patterns of genetic differentiation between urban and rural sites. We also used genome scans and genotype-by-environment (GEA) analyses to identify signatures of selection in a large subset of genes. Neutral demographic processes may create allele frequency patterns that are indistinguishable from positive selection. Thus, we accounted for demography by simulating a neutral SNP dataset under the inferred demographic history for the sampled P. leucopus populations to serve as a null model for outlier analysis. We then annotated outlier genes and further validated them by associating allele frequency differences with two urbanization variables: percent impervious surface and human population density. Many candidate genes were involved in metabolic functions, especially dietary specialization. A subset of these genes have well-established roles in metabolizing lipids and carbohydrates, including transport of cholesterol and desaturation of fatty acids. Our results reveal clear genetic differentiation between rural and urban sites that resulted from rapid local adaptation and drift in urbanizing habitats. The specific outlier loci that we identified suggest that populations of P. leucopus are using novel food resources in urban habitats and selection pressures are acting to change metabolic pathways. Our findings support the idea that cities represent novel ecosystems with a unique set of selective pressures.
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urbanization shapes the demographic history of a native rodent the white footed mouse Peromyscus leucopus in new york city
Biology Letters, 2016Co-Authors: Stephen E Harris, J T Boehm, Tyler Joseph, Diego F Alvaradoserrano, Michael J Hickerson, Jason MunshisouthAbstract:How urbanization shapes population genomic diversity and evolution of urban wildlife is largely unexplored. We investigated the impact of urbanization on white-footed mice, Peromyscus leucopus, in ...
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urbanization shapes the demographic history of a native rodent the white footed mouse Peromyscus leucopus in new york city
bioRxiv, 2016Co-Authors: Stephen E Harris, J T Boehm, Diego F Alvaradoserrano, Michael J Hickerson, Alexander T Xue, Tyler A Joseph, Jason MunshisouthAbstract:How urbanization shapes population genomic diversity and evolution of urban wildlife is largely unexplored. We investigated the impact of urbanization on white-footed mice, Peromyscus leucopus, in the New York City metropolitan area using coalescent-based simulations to infer demographic history from the site frequency spectrum. We assigned individuals to evolutionary clusters and then inferred recent divergence times, population size changes, and migration using genome-wide SNPs genotyped in 23 populations sampled along an urban-to-rural gradient. Both prehistoric climatic events and recent urbanization impacted these populations. Our modeling indicates that post-glacial sea level rise led to isolation of mainland and Long Island populations. These models also indicate that several urban parks represent recently-isolated P. leucopus populations, and the estimated divergence times for these populations are consistent with the history of urbanization in New York City.
Virginie Millien - One of the best experts on this subject based on the ideXlab platform.
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genomic signatures of selection along a climatic gradient in the northern range margin of the white footed mouse Peromyscus leucopus
Journal of Heredity, 2019Co-Authors: Alan Garciaelfring, Rowan D H Barrett, Virginie MillienAbstract:Identifying genetic variation involved in thermal adaptation is likely to yield insights into how species adapt to different climates. Physiological and behavioral responses associated with overwintering (e.g., torpor) are thought to serve important functions in climate adaptation. In this study, we use 2 isolated Peromyscus leucopus lineages on the northern margin of the species range to identify single nucleotide polymorphisms (SNPs) showing a strong environmental association and test for evidence of parallel evolution. We found signatures of clinal selection in each lineage, but evidence of parallelism was limited, with only 2 SNPs showing parallel allele frequencies across transects. These parallel SNPs map to a gene involved in protection against iron-dependent oxidative stress (Fxn) and to a gene with unknown function but containing a forkhead-associated domain (Fhad1). Furthermore, within transects, we find significant clinal patterns in genes enriched for functions associated with glycogen homeostasis, synaptic function, intracellular Ca2+ balance, H3 histone modification, as well as the G2/M transition of cell division. Our results are consistent with recent literature on the cellular and molecular basis of climate adaptation in small mammals and provide candidate genomic regions for further study.
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microsatellite markers reveal low frequency of natural hybridization between the white footed mouse Peromyscus leucopus and deer mouse Peromyscus maniculatus in southern quebec canada
Genome, 2017Co-Authors: Virginie MillienAbstract:In some parts of southern Quebec, two closely related rodent species — the white-footed mouse (Peromyscus leucopus) and the deer mouse (Peromyscus maniculatus) — have recently come in contact because of climate-driven changes in the distribution of the former. Both species share similar morphology, ecology, and life history traits, which suggests that natural hybridization may be possible. Hybridization among these two species can have important implications on the ecological roles these rodents play in disease transmission, yet few researchers have attempted to examine this phenomenon and results from previous hybridization experiments have remained inconclusive and conflicting. In this study, we attempt to investigate the occurrence of hybridization among white-footed mice and deer mice in southern Quebec by genotyping wild caught specimens with selectively neutral, polymorphic microsatellite markers. Our analyses suggest that hybridization may be occurring at extremely low frequency between both specie...
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liver microbiome of Peromyscus leucopus a key reservoir host species for emerging infectious diseases in north america
Infection Genetics and Evolution, 2017Co-Authors: Adrien Andre, Virginie Millien, Alice Mouton, Johan MichauxAbstract:Microbiome studies generally focus on the gut microbiome, which is composed of a large proportion of commensal bacteria. Here we propose a first analysis of the liver microbiome using next generation sequencing as a tool to detect potentially pathogenic strains. We used Peromyscus leucopus, the main reservoir host species of Lyme disease in eastern North America, as a model and sequenced V5-V6 regions of the 16S gene from 18 populations in southern Quebec (Canada). The Lactobacillus genus was found to dominate the liver microbiome. We also detected a large proportion of individuals infected by Bartonella vinsonii arupensis, a human pathogenic bacteria responsible for endocarditis, as well as Borrelia burgdorferi, the pathogen responsible for Lyme disease in North America. We then compared the microbiomes among two P. leucopus genetic clusters occurring on either side of the St. Lawrence River, and did not detect any effect of the host genotype on their liver microbiome assemblage. Finally, we report, for the first time, the presence of B. burgdorferi in a small mammal host from the northern side of the St. Lawrence River, in support of models that have predicted the northern spread of Lyme disease in Canada.
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the microbiome from the lyme disease principal reservoir host in southern quebec Peromyscus leucopus
2015Co-Authors: Adrien Andre, Virginie Millien, Alice Mouton, Johan MichauxAbstract:• Peromyscus leucopus is the principal reservoir for Lyme disease (Borreliosis) in North America. • The species is expanding its northern range into southern Quebec causing the emergence of the illness in the region. •Monitoring its health has become critical to determine its ability to colonize new territories. •Studying its microbiome in particular can help estimating the pathogen pressure acting on the different populations.
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poleward expansion of the white footed mouse Peromyscus leucopus under climate change implications for the spread of lyme disease
PLOS ONE, 2013Co-Authors: Emilie Roydufresne, Travis Logan, Julie A Simon, Gail L Chmura, Virginie MillienAbstract:The white-footed mouse (Peromyscus leucopus) is an important reservoir host for Borrelia burgdorferi, the pathogen responsible for Lyme disease, and its distribution is expanding northward. We used an Ecological Niche Factor Analysis to identify the climatic factors associated with the distribution shift of the white-footed mouse over the last 30 years at the northern edge of its range, and modeled its current and potential future (2050) distributions using the platform BIOMOD. A mild and shorter winter is favouring the northern expansion of the white-footed mouse in Quebec. With more favorable winter conditions projected by 2050, the distribution range of the white-footed mouse is expected to expand further northward by 3° latitude. We also show that today in southern Quebec, the occurrence of B. burgdorferi is associated with high probability of presence of the white-footed mouse. Changes in the distribution of the white-footed mouse will likely alter the geographical range of B. burgdorferi and impact the public health in northern regions that have yet to be exposed to Lyme disease.