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impacts of an introduced forest pathogen on the risk of lyme disease in california.global changes such as deforestation, climate change, and invasive species have the potential to greatly alter zoonotic disease systems through impacts on biodiversity. this study examined the impact of the invasive pathogen that causes sudden oak death (sod) on the ecology of lyme disease in california. the lyme disease bacterium, borrelia burgdorferi, is maintained in the far western united states by a suite of animal reservoirs including the dusky-footed woodrat (neotoma fuscipes) and deer mo ...201222607076
regulatory changes contribute to the adaptive enhancement of thermogenic capacity in high-altitude deer mice.in response to hypoxic stress, many animals compensate for a reduced cellular o(2) supply by suppressing total metabolism, thereby reducing o(2) demand. for small endotherms that are native to high-altitude environments, this is not always a viable strategy, as the capacity for sustained aerobic thermogenesis is critical for survival during periods of prolonged cold stress. for example, survivorship studies of deer mice (peromyscus maniculatus) have demonstrated that thermogenic capacity is unde ...201222586089
hantavirus pulmonary syndrome: report of four alberta cases.four alberta cases of hantavirus pulmonary syndrome are reported. three cases required intensive care, with one experiencing a fulminant course resulting in death. a fourth case with milder illness was identified after epidemiological investigations. ribavirin was used in one patient who experienced a successful outcome. a recent open label trial has not supported the efficacy of this drug. the epidemiology of peromyscus maniculatus, the primary rodent host, and the clinical features of this syn ...199522514394
prediction of peromyscus maniculatus (deer mouse) population dynamics in montana, usa, using satellite-driven vegetation productivity and weather data.deer mice (peromyscus maniculatus) are the main reservoir host for sin nombre virus, the primary etiologic agent of hantavirus pulmonary syndrome in north america. sequential changes in weather and plant productivity (trophic cascades) have been noted as likely catalysts of deer mouse population irruptions, and monitoring and modeling of these phenomena may allow for development of early-warning systems for disease risk. relationships among weather variables, satellite-derived vegetation product ...201222493110
population delimitation across contrasting evolutionary clines in deer mice (peromyscus maniculatus).despite current interest in population genetics, a concrete definition of a "population" remains elusive. multiple ecologically and evolutionarily based definitions of population are in current use, which focus, respectively, on demographic and genetic interactions. accurate population delimitation is crucial for not only evolutionary and ecological population biology, but also for conservation of threatened populations. along the pacific coast of north america, two contrasting patterns of geogr ...201122393480
buffering and plasticity in vital rates of oldfield rodents.1. under the hypothesis of environmental buffering, populations are expected to minimize the variance of the most influential vital rates; however, this may not be a universal principle. species with a life span <1 year may be less likely to exhibit buffering because of temporal or seasonal variability in vital rate sensitivities. further, plasticity in vital rates may be adaptive for species in a variable environment with reliable cues. 2. we tested for environmental buffering and plasticity in ...201222375923
estimating duration of infection with avidity assays: potential limitations and recommendations for improvement.recent infections often have higher pathogen loads. the number of recent infections can therefore be used to estimate transmission rates in a host population. antibody avidity assays are an emerging technique to infer infection age in both domestic and wild animals. these assays have the potential to supplant intensive mark-recapture efforts for identification of recent infections, but their results may be confounded by antibody titer. we examined the effectiveness of an avidity assay for identi ...201122311097
altitudinal variation at duplicated β-globin genes in deer mice: effects of selection, recombination, and gene conversion.spatially varying selection on a given polymorphism is expected to produce a localized peak in the between-population component of nucleotide diversity, and theory suggests that the chromosomal extent of elevated differentiation may be enhanced in cases where tandemly linked genes contribute to fitness variation. an intriguing example is provided by the tandemly duplicated β-globin genes of deer mice (peromyscus maniculatus), which contribute to adaptive differentiation in blood-oxygen affinity ...201122042573
microsatellite genetic structure and cytonuclear discordance in naturally fragmented populations of deer mice (peromyscus maniculatus).the great lakes impose high levels of natural fragmentation on local populations of terrestrial animals in a way rarely found within continental ecosystems. although separated by major water barriers, woodland deer mouse (peromyscus maniculatus gracilis) populations on the islands and on the upper peninsula (up) and lower peninsula (lp) of michigan have previously been shown to have a mitochondrial dna contact zone that is incongruent with the regional landscape. we analyzed 11 microsatellite lo ...201221976772
Using a comparative species approach to investigate the neurobiology of paternal responses.A goal of behavioral neuroscience is to identify underlying neurobiological factors that regulate specific behaviors. Using animal models to accomplish this goal, many methodological strategies require invasive techniques to manipulate the intensity of the behavior of interest (e.g., lesion methods, pharmacological manipulations, microdialysis techniques, genetically-engineered animal models). The utilization of a comparative species approach allows researchers to take advantage of naturally oc ...201121968462
promiscuity in mice is associated with increased vaginal bacterial diversity.differences in the number of sexual partners (i.e., mating system) have the potential to exert a strong influence on the bacterial communities present in reproductive structures like the vagina. because this structure serves as a conduit for gametes, bacteria present there may have a pronounced, direct effect on host reproductive success. as a first step towards the identification of the relationship between sexual behavior and potentially pathogenic bacterial communities inhabiting vital reprod ...201121964973
biotic resistance via granivory: establishment by invasive, naturalized, and native asters reflects generalist preference.escape from specialist natural enemies is frequently invoked to explain exotic plant invasions, but little attention has been paid to how generalist consumers in the recipient range may influence invasion. we examined how seed preferences of the widespread generalist granivore peromyscus maniculatus related to recruitment of the strongly invasive exotic centaurea stoebe and several weakly invasive exotics and natives by conducting laboratory feeding trials and seed addition experiments in the fi ...201121939071
the biology and methodology of assisted reproduction in deer mice (peromyscus maniculatus).although laboratory-reared species of the genus peromyscus-including deer mice-are used as model animals in a wide range of research, routine manipulation of peromyscus embryogenesis and reproduction has been lagging. the objective of the present study was to optimize conditions for oocyte and/or embryo retrieval and for in vitro culturing. on average, 6.4 oocytes per mouse were recovered when two doses of 15 iu of pregnant mare serum gonadotropin (pmsg) were given 24 h apart, followed by 15 iu ...201121924468
temporal patterns of tick-borne granulocytic anaplasmosis in california.granulocytic anaplasmosis (ga) is a tick-borne emerging infectious disease caused by the bacterium anaplasma phagocytophilum. from fall 2005 to spring 2007, a. phagocytophilum infection prevalence in small mammals and tick abundance were monitored at 4 study sites in coastal california. the abundance of different life stages of questing ixodes pacificus ticks fluctuated seasonally with the number of adults peaking december to february, nymphs peaking may to july, and larvae peaking april to june ...201121771541
disruption of adult expression of sexually selected traits by developmental exposure to bisphenol a.exposure to endocrine disrupting compounds (edcs), such as bisphenol a (bpa), may cause adverse health effects in wildlife and humans, but controversy remains as to what traits are most sensitive to edcs and might serve as barometers of exposure. expression of sexually selected traits that have evolved through intrasexual competition for mates and intersexual choice of mating partner are more dependent on developmental and physical condition of an animal than naturally selected traits and thus m ...201121709224
genetic correlation between resting metabolic rate and exploratory behaviour in deer mice (peromyscus maniculatus).according to the 'pace-of-life' syndrome hypothesis, differences in resting metabolic rate (rmr) should be genetically associated with exploratory behaviour. a large number of studies reported significant heritability for both rmr and exploratory behaviour, but the genetic correlation between the two has yet to be documented. we used a quantitative genetic approach to decompose the phenotypic (co)variance of several metabolic and behavioural measures into components of additive genetic, common e ...201121696480
expression and purification of recombinant hemoglobin in escherichia coli.recombinant dna technologies have played a pivotal role in the elucidation of structure-function relationships in hemoglobin (hb) and other globin proteins. here we describe the development of a plasmid expression system to synthesize recombinant hbs in escherichia coli, and we describe a protocol for expressing hbs with low intrinsic solubilities. since the α- and β-chain hbs of different species span a broad range of solubilities, experimental protocols that have been optimized for expressing ...201121625463
peromyscus maniculatus, a possible reservoir host of borrelia garinii, at the gannet islands, newfoundland and labrador.abstract thirty-five deer mice, peromyscus maniculatus, were trapped on gannet cluster 2 (gc-2), one of a group of islands numbered by convention, of the gannet island archipelago and examined for ectoparasites. one species each of acari (ixodes uriae) and siphonaptera (orchopeas leucopus) were recovered. samples of mice favored males to females (3.4:1). twenty-nine percent (10) of the mice were free of ectoparasites. males were more heavily parasitized than females when both parasites were cons ...201121506809
a history of the behavior program at the jackson laboratory: an overview.the behavior program at the jackson laboratory in bar harbor, me, flourished from 1945 through the late 1960s and was unique in the history of comparative psychology. the canine project was conducted on ~300 dogs of five purebred breeds reared under controlled conditions and tested on a predetermined schedule. this enabled a detailed study of genetic and environmental effects and their interaction as well as a variety of other problems in midsized mammals. i provide a comprehensive, though brief ...201121341910
counterintuitive effects of large-scale predator removal on a midlatitude rodent community.historically, small mammals have been focal organisms for studying predator-prey dynamics, principally because of interest in explaining the drivers of the cyclical dynamics exhibited by northern vole, lemming, and hare populations. however, many small-mammal species occur at relatively low and fairly stable densities at temperate latitudes, and our understanding of how complex predator assemblages influence the abundance and dynamics of these species is surprisingly limited. in an intact grassl ...201021302842
delayed density-dependent prevalence of sin nombre virus infection in deer mice (peromyscus maniculatus) in central and western montana.understanding how transmission of zoonoses takes place within reservoir populations, such as sin nombre virus (snv) among deer mice (peromyscus maniculatus), is important in determining the risk of exposure to other hosts, including humans. in this study, we examined the relationship between deer mouse populations and the prevalence of antibodies to snv, a system where the effect of host population abundance on transmission is debated. we examined the relationship between abundance of deer mice ...201121269997
persistent infection or successive reinfection of deer mice with bartonella vinsonii subsp. arupensis.bartonella infections are common in rodents. from 1994 to 2006, longitudinal studies of a rodent community, consisting mainly of deer mice (peromyscus maniculatus), were conducted in southwestern colorado to study hantaviruses. blood samples from deer mice captured one or more times during the period 2003 to 2006 (n = 737) were selected to study bartonellae in deer mice. bartonellae were found to be widely distributed in that population, with an overall prevalence of 82.4% (607/737 mice). no cor ...201121239553
a temporal dilution effect: hantavirus infection in deer mice and the intermittent presence of voles in montana.the effect of intermittently occurring, non-reservoir host species on pathogen transmission and prevalence in a reservoir population is poorly understood. we investigated whether voles, microtus spp., which occur intermittently, influenced estimated standing antibody prevalence (esap) to sin nombre hantavirus (snv, bunyaviridae: hantavirus) among deer mice, peromyscus maniculatus, whose populations are persistent. we used 14 years of data from central montana to investigate whether esap among de ...201021170746
the relative abundance of deer mice with antibody to sin nombre virus corresponds to the occurrence of hantavirus pulmonary syndrome in nearby humans.abstract sin nombre virus (snv) is the principal cause of hantavirus pulmonary syndrome (hps) in the united states and deer mice (peromyscus maniculatus) are its principal rodent host, and thus the natural cycle of the virus is related to the occurrence of hps. prevalence of rodent infection appears to be associated with fluctuations in deer mouse populations and, indirectly, with timing and amount of precipitation, a complex of biologic events. given that rodent population abundances fluctuate, ...201020954865
effects of an invasive forest pathogen on abundance of ticks and their vertebrate hosts in a california lyme disease focus.invasive species, including pathogens, can have important effects on local ecosystems, including indirect consequences on native species. this study focuses on the effects of an invasive plant pathogen on a vertebrate community and ixodes pacificus, the vector of the lyme disease pathogen (borrelia burgdorferi) in california. phytophthora ramorum, the causative agent of sudden oak death, is a non-native pathogen killing trees in california and oregon. we conducted a multi-year study using a grad ...201020941513
apparent competition with an invasive plant hastens the extinction of an endangered lupine.invasive plants may compete with native plants by increasing the pressure of native consumers, a mechanism known as "apparent competition." apparent competition can be as strong as or stronger than direct competition, but the role of apparent competition has rarely been examined in biological invasions. we used four years of demographic data and seed-removal experiments to determine if introduced grasses caused elevated levels of seed consumption on native plant species in a coastal dune system ...201020836448
aberrant growth and pattern formation in peromyscus hybrid placental development.crosses between the north american deer mouse species peromyscus maniculatus (bw) and p. polionotus (po) produce dramatic asymmetric developmental effects. bw females mated to po males (female bw × male po) produce viable growth-retarded offspring. in contrast, po females mated to bw males (female po × male bw) produce overgrown but dysmorphic conceptuses. most female po × male bw offspring are dead by midgestation; those surviving to later time points display numerous defects reminiscent of sev ...201020702850
long-term patterns of immune investment by wild deer mice infected with sin nombre virus.immunocompetence of animals fluctuates seasonally, however, there is little consensus on the cause of these fluctuations. some studies have suggested that these patterns are influenced by changes in reproductive condition, whereas others have suggested that differences result from seasonal variations in energy expenditures. the objective of our study was to examine these contrasting views of immunity by evaluating seasonal patterns of immune response and reproduction in wild populations of deer ...201020695811
natural history of sin nombre virus infection in deer mice in urban parks in oregon.sin nombre virus (snv), one of at least 45 hantaviruses described worldwide, is hosted by the deer mouse, peromyscus maniculatus, a common species throughout most of north america. herein, we describe general life-history characteristics of deer mice and the ways in which these factors relate to the incidence of snv infections among populations of this host species in and around portland, oregon. in total, 3,175 deer mice were captured from october 2002 to september 2005. transmission of snv app ...201020688636
genetic differences in hemoglobin function between highland and lowland deer mice.in high-altitude vertebrates, adaptive changes in blood-o(2) affinity may be mediated by modifications of hemoglobin (hb) structure that affect intrinsic o(2) affinity and/or responsiveness to allosteric effectors that modulate hb-o(2) affinity. this mode of genotypic specialization is considered typical of mammalian species that are high-altitude natives. here we investigated genetically based differences in hb-o(2) affinity between highland and lowland populations of the deer mouse (peromyscus ...201020639417
an experimental test of factors attracting deer mice into buildings.deer mice (peromyscus maniculatus) are the principal reservoir host of sin nombre virus (snv). deer mice use a wide variety of habitats including peridomestic settings in and around human dwellings, their presence in and around homes has been implicated as a risk factor for acquiring hantavirus pulmonary syndrome. deer mice are believed to enter buildings in order to gain access to a variety of resources including food, bedding material, and better thermal microclimates. however, no one has expe ...200920628475
cranial shape varies along an elevation gradient in gambel's white-footed mouse (peromyscus maniculatus gambelii) in the grinnell resurvey yosemite transect.environmental variation over a species's range creates differing pressures to which organisms must adjust in order to survive. taxa can respond to these pressures at population and individual levels, leading to localized phenotypic differentiation. assessing the spatial distribution of phenotypic variation can illuminate how dramatically varying environmental factors shape phenotypes and may forecast a taxon's ability to adapt should conditions change. we characterized morphological variation al ...201020623653
congenital transmission of toxoplasma gondii in deer mice (peromyscus maniculatus) after oral oocyst infection.to investigate how different routes of toxoplasma gondii transmission influence the antibody response and infection status of deer mice (peromyscus maniculatus), 80 mice were orally infected with 1, 5, 10, or 100 t. gondii oocysts. ten weeks postinfection, 15 t. gondii -seropositive female mice were bred and allowed to produce 2 litters. evidence of persistent t .gondii infection in orally infected mice was detected by serology and dna amplification in mice from all 4 oocyst treatment groups, in ...201020557196
sampling frequency differentially influences interpretation of zoonotic pathogen and host dynamics: sin nombre virus and deer mice.reports of novel emerging and resurging wildlife and zoonotic diseases have increased. consequently, integration of pathogen sampling into wildlife monitoring programs has grown. sampling frequency influences interpretations of coupled host-pathogen dynamics, with direct implication to human exposure risk, but has received little empirical attention. to address this, a 15-year study, based on monthly sampling, of deer mouse (peromyscus maniculatus) populations and sin nombre virus (snv; a virule ...201020528169
relationship of human behavior within outbuildings to potential exposure to sin nombre virus in western montana.sin nombre virus (snv) causes hantavirus cardiopulmonary syndrome (hcps) in humans. transmission of snv among the deer mouse (peromyscus maniculatus) host predominates during spring and summer, and is greater in peridomestic than sylvan settings where, protected from uv light, snv may survive longer. incidence of hcps reflects these times and settings and is associated with inhalation of mouse excreta. little is known, however, about how human use of outbuildings contributes to potential exposur ...201020508970
fire and mice: seed predation moderates fire's influence on conifer recruitment.in fire-adapted ecosystems, fire is presumed to be the dominant ecological force, and little is known about how consumer interactions influence forest regeneration. here, we investigated seed predation by deer mice (peromyscus maniculatus) and its effects on recruitment of ponderosa pine (pinus ponderosa) and douglas-fir (pseudotsuga menziesii) seedlings in unburned and recently burned fire-adapted montane forests in west-central montana, usa. deer mice were almost twice as abundant in burned th ...201020462126
roles of human disturbance, precipitation, and a pathogen on the survival and reproductive probabilities of deer mice.climate change, human disturbance, and disease can have large impacts on the dynamics of a species by affecting the likelihood of survival and reproduction of individuals. we investigated the roles of precipitation, off-road vehicle (orv) alteration of habitat, and infection with sin nombre virus on the survival and reproductive probabilities of deer mice (peromyscus maniculatus). we used generalized linear mixed models to estimate the effects of these factors and their interactions by fitting c ...201020392022
small-mammal seed predation limits the recruitment and abundance of two perennial grassland forbs.although post-dispersal seed predators are common and often reduce seed density, their influence on plant population abundance remains unclear. on the one hand, increasing evidence suggests that many plant populations are seed limited, implying that seed predators could reduce plant abundance. on the other hand,.it is generally uncertain whether the magnitude of seed limitation imposed by granivores is strong enough to overcome density-dependent processes that could compensate for seed loss at l ...201020380199
microbial ecological response of the intestinal flora of peromyscus maniculatus and p. leucopus to heavy metal contamination.heavy metal contamination negatively affects natural systems including plants, birds, fish and bacteria by reducing biodiversity at contaminated sites. at the tri-state mining district, efforts have been made to remediate sites to mitigate the detrimental effects that contamination has caused on human health. while the remediation effort has returned the site to within federal safety standards, it is unclear if this effort is sufficient to restore floral and faunal communities. intrinsic to ecos ...201020331771
indirect basal ganglia pathway mediation of repetitive behavior: attenuation by adenosine receptor agonists.repetitive behaviors are diagnostic for autism and common in related neurodevelopmental disorders. despite their clinical importance, underlying mechanisms associated with the expression of these behaviors remain poorly understood. our lab has previously shown that the rates of spontaneous stereotypy in deer mice (peromyscus maniculatus) were negatively correlated with enkephalin content, a marker of striatopallidal but not striatonigral neurons. to investigate further the role of the indirect b ...201020178817
a unique late-replicating xy to autosome translocation in peromyscus melanophrys.we report on the characterization of the peromyscus melanophrys karyotype and sex chromosome system. classic studies reported the sex chromosome system of this species may be as complex as an x(1)x(1)x(2)x(2)/x(1)x(2)y(1)y(2) and provided conflicting identification of the x chromosome. using peromyscus maniculatus chromosome paints, we have positively identified the sex chromosomes and clarified the sex determining system that once perplexed peromyscus researchers. the sex chromosomes are charac ...201020177772
modeling susceptible infective recovered dynamics and plague persistence in california rodent-flea communities.plague persists as an enzootic in several very different rodent-flea communities around the world. in california, a diversity of rodent-flea communities maintains the disease, and a single-host reservoir seems unlikely. logistic regression of plague presence on climate and topographic variables predicts plague in many localities where it is absent. thus, a dynamic community-based analysis was needed. deterministic susceptible infective recovered (sir) models were adapted for plague and analyzed ...201020158333
competition drives cooperation among closely related sperm of deer mice.among the extraordinary adaptations driven by sperm competition is the cooperative behaviour of spermatozoa. by forming cooperative groups, sperm can increase their swimming velocity and thereby gain an advantage in intermale sperm competition. accordingly, selection should favour cooperation of the most closely related sperm to maximize fitness. here we show that sperm of deer mice (genus peromyscus) form motile aggregations, then we use this system to test predictions of sperm cooperation. we ...201020090679
the effect of seasonality, density and climate on the population dynamics of montana deer mice, important reservoir hosts for sin nombre hantavirus.1. since sin nombre virus was discovered in the u.s. in 1993, longitudinal studies of the rodent reservoir host, the deer mouse (peromyscus maniculatus) have demonstrated a qualitative correlation among mouse population dynamics and risk of hantavirus pulmonary syndrome (hps) in humans, indicating the importance of understanding deer mouse population dynamics for evaluating risk of hps. 2. using capture-mark-recapture statistical methods on a 15-year data set from montana, we estimated deer mous ...201020015212
nuclear and mitochondrial dna reveal contrasting evolutionary processes in populations of deer mice (peromyscus maniculatus).we investigated a major geographic break in mitochondrial dna (mtdna) haplotypes in deer mice, peromyscus maniculatus, by analysing spatial variation in a 491-bp fragment of the mtdna control region from 455 samples distributed across a north-south transect of 2000 km in western north america. to determine whether the mtdna break was reflected in the nuclear genome, we then compared spatial variation in 13 nuclear microsatellites of 95 individuals surrounding the mtdna break. using a canonical c ...200919912541
seasonal dispersal patterns of sylvan deer mice (peromyscus maniculatus) within montana rangelands.we examined seasonal dispersal patterns and timing of new infections of sin nombre virus (snv), as determined by recent acquisition of antibodies (seroconversion), in deer mice (peromyscus maniculatus) at two montana rangeland study sites over three years, 2004-2007. one study site was located in grassland habitat, and the other was located in shrub-steppe. in montana, both of these habitats are commonly associated with peridomestic environments (in and around buildings). peridomestic environmen ...200919901376
ecology of hantaviruses and their hosts in north america.since the 1993 discovery of a highly pathogenic hantavirus associated with the north american deer mouse (peromyscus maniculatus), intensive ecological studies have led to many advances in our understanding of the natural history of new world hantaviruses as it relates to human disease. seventeen named hantaviruses have been identified in north america. field and laboratory studies of sin nombre and other hantaviruses have delineated host associations, geographical distributions, mechanisms of t ...201019874190
hantavirus transmission in sylvan and peridomestic environments.we developed a compartmental model for hantavirus infection in deer mice (peromyscus maniculatus) with the goal of comparing relative importance of direct and indirect transmission in sylvan and peridomestic environments. a direct transmission occurs when the infection is mediated by the contact of an infected and an uninfected mouse, while an indirect transmission occurs when the infection is mediated by the contact of an uninfected mouse with, for instance, infected soil. based on population d ...201019821001
cold acclimation in peromyscus: individual variation and sex effects in maximum and daily metabolism, organ mass and body composition.we studied metabolic and organ mass responses to thermal acclimation (7 weeks at 5 degrees c or 23 degrees c) in deer mice, peromyscus maniculatus. cold acclimation resulted in significantly higher maximal oxygen consumption in thermogenesis (v(o(2)max)) and daily mean oxygen consumption (v(o(2)mean)), an increase in the mass of most visceral organs, a lower absolute body fat and a marginally significant increase in hematocrit. the mass of digestive organs and body fat content differed significa ...200919684213
evolutionary and functional insights into the mechanism underlying high-altitude adaptation of deer mouse hemoglobin.adaptive modifications of heteromeric proteins may involve genetically based changes in single subunit polypeptides or parallel changes in multiple genes that encode distinct, interacting subunits. here we investigate these possibilities by conducting a combined evolutionary and functional analysis of duplicated globin genes in natural populations of deer mice (peromyscus maniculatus) that are adapted to different elevational zones. a multilocus analysis of nucleotide polymorphism and linkage di ...200919667207
sin nombre virus and rodent species diversity: a test of the dilution and amplification hypotheses.species diversity is proposed to greatly impact the prevalence of pathogens. two predominant hypotheses, the "dilution effect" and the "amplification effect", predict divergent outcomes with respect to the impact of species diversity. the dilution effect predicts that pathogen prevalence will be negatively correlated with increased species diversity, while the amplification effect predicts that pathogen prevalence will be positively correlated with diversity. for many host-pathogen systems, the ...200919649283
increased host species diversity and decreased prevalence of sin nombre virus.emerging outbreaks of zoonotic diseases are affecting humans at an alarming rate. until the ecological factors associated with zoonoses are better understood, disease emergence will continue. for lyme disease, disease suppression has been demonstrated by a dilution effect, whereby increasing species diversity decreases disease prevalence in host populations. to test the dilution effect in another disease, we examined 17 ecological variables associated with prevalence of the directly transmitted ...200919624913
temporal and geographic evidence for evolution of sin nombre virus using molecular analyses of viral rna from colorado, new mexico and montana.all viruses in the family bunyaviridae possess a tripartite genome, consisting of a small, a medium, and a large rna segment. bunyaviruses therefore possess considerable evolutionary potential, attributable to both intramolecular changes and to genome segment reassortment. hantaviruses (family bunyaviridae, genus hantavirus) are known to cause human hemorrhagic fever with renal syndrome or hantavirus pulmonary syndrome. the primary reservoir host of sin nombre virus is the deer mouse (peromyscus ...200919602267
effects of local point source polychlorinated biphenyl (pcb) contamination on bone mineral density in deer mice (peromyscus maniculatus).a former local source of pcbs has contaminated soil and the terrestrial food web at saglek, labrador. the relationship between pcb exposure and bone mineral density as an osteoporosis biomarker in deer mice (peromyscus maniculatus) was investigated at two sites at saglek: a contaminated beach and a reference area. bone mineral density was measured on the femur of twenty-six deer mice using dual-energy x-ray absorptiometry (dxa) technology. bone mineral density was significantly lower in deer mic ...200919580994
testing mechanisms of the dilution effect: deer mice encounter rates, sin nombre virus prevalence and species diversity.species diversity has been shown to decrease prevalence of disease in a variety of host-pathogen systems, in a phenomenon termed the dilution effect. several mechanisms have been proposed by which diversity may decrease prevalence, though few have been tested in natural host-pathogen systems. we investigated the mechanisms by which diversity influenced the prevalence of sin nombre virus (snv), a directly transmitted virus in deer mice (peromyscus maniculatus). we monitored both intra and intersp ...200919495881
gape and bite force in the rodents onychomys leucogaster and peromyscus maniculatus: does jaw-muscle anatomy predict performance?compared with the deer mouse, peromyscus maniculatus, the grasshopper mouse, onychomys leucogaster, exhibits modifications in its jaw-muscle architecture that promote wide gapes and large bite forces at wide gapes to prey upon large vertebrate prey. in this study, we determine whether jaw-muscle anatomy predicts gape and biting performance in o. leucogaster, and we also assess the influence of gape on bite force in the two species. although o. leucogaster has an absolutely longer jaw, which faci ...200919480012
seasonal variation in sin nombre virus infections in deer mice: preliminary results.the proportion of deer mice (peromyscus maniculatus) with recently acquired sin nombre virus (snv) infections is an indicator of epizootic intensity and may be key in predicting outbreaks of hantavirus cardio-pulmonary syndrome in humans. we investigated whether incidence of recent infections was related to season, sex, reproductive status, or habitat disturbance. in may and september, 2006, we sampled 912 deer mice at six sites in utah. we determined snv antibody prevalence and estimated the nu ...200919395752
small mammals collected from a site with elevated selenium concentrations and three reference sites.small mammals were trapped in july, august, and september 1999 at kesterson reservoir (merced county, ca), a site with elevated concentrations of selenium (se), and at three nearby reference sites. deer mice (peromyscus maniculatus) were the most frequently trapped species at all of the sites, and western harvest mice (reithrodontomys megalotis) and house mice (mus musculus) were also trapped frequently. about half the animals collected from the reference sites were in reproductive condition, co ...200919373506
factors associated with the risk of giardia species infection in two sympatric species of peromyscus mice.an epidemiologic case-control study was conducted to identify factors that predispose peromyscus spp. to the risk of infection with giardia sp. in watersheds. a total of 200 giardia sp.-positive mice (cases) and a similar number of giardia sp.-negative mice (controls) were selected from a population 2,528 mice captured in a watershed in southeastern new york state. the giardia sp. infection status of the mice was determined by centrifugation concentration flotation and an enzyme-linked immunosor ...200919366280
forest rodents provide directed dispersal of jeffrey pine seeds.some species of animals provide directed dispersal of plant seeds by transporting them nonrandomly to microsites where their chances of producing healthy seedlings are enhanced. we investigated whether this mutualistic interaction occurs between granivorous rodents and jeffrey pine (pinus jeffreyi) in the eastern sierra nevada by comparing the effectiveness of random abiotic seed dispersal with the dispersal performed by four species of rodents: deer mice (peromyscus maniculatus), yellow-pine an ...200919341138
responses of glutamate cysteine ligase and glutathione to oxidants in deer mice (peromyscus maniculatus).sensitivities of a wildlife species, deer mice, to oxidants were evaluated. a single dose (1589 mg/kg body weight by intraperitoneal injection) of carbon tetrachloride, a typical hepatotoxicant, caused changes in gcl activity and gsh content in multiple organs of deer mice. hepatic gcl activity and gsh content were depleted substantially (p<0.01), renal gcl activity increased (p<0.05). blood, brain and heart gcl activities increased (p<0.05), whereas gsh contents decreased significantly. deer mi ...200919328550
multigenerational effects in deer mice (peromyscus maniculatus) exposed to hexahydro-1,3,5-trinitroso-1,3,5-triazine (tnx).contamination by hexahydro-1,3,5-trinitro-1,3,5-triazine (rdx) has been identified at areas of explosive manufacturing, processing, storage, and usage. anaerobic conversion of rdx to n-nitroso metabolites (hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (mnx), hexahydro-1,3-dinitroso-5-nitro-1,3,5-triazine (dnx), and hexahydro-1,3,5-trinitroso-1,3,5-triazine (tnx)) has been demonstrated in the environment and in gastrointestinal tracts of mammals in vivo. thus, potential exists for exposure to th ...200919230956
feeding preferences of the immature stages of three western north american ixodid ticks (acari) for avian, reptilian, or rodent hosts.larval and nymphal ixodes pacificus cooley and kohls, i. (ixodes) jellisoni cooley and kohls, and dermacentor occidentalis marx were tested for host preference when simultaneously presented with a deer mouse (peromyscus maniculatus wagner), california kangaroo rat (dipodomys californicus merriam), western fence lizard (sceloporus occidentalis baird and girard), and california towhee (pipilo crissalis vigors) in an experimental apparatus. differences were observed in the preferences among the thr ...200919198525
contact heterogeneity in deer mice: implications for sin nombre virus transmission.heterogeneities within disease hosts suggest that not all individuals have the same probability of transmitting disease or becoming infected. this heterogeneity is thought to be due to dissimilarity in susceptibility and exposure among hosts. as such, it has been proposed that many host-pathogen systems follow the general pattern whereby a small fraction of the population accounts for a large fraction of the pathogen transmission. this disparity in transmission dynamics is often referred to as ' ...200919129136
molecular evolution of cytochrome b in high- and low-altitude deer mice (genus peromyscus).patterns of amino-acid polymorphism in human mitochondrial genes have been interpreted as evidence for divergent selection among populations that inhabit climatically distinct environments. if similar patterns are mirrored in other broadly distributed mammalian species, then adaptive modifications of mitochondrial protein function may be detected in comparisons among locally adapted populations of a single wide-ranging species, or among closely related species that have adapted to different envi ...200919107138
genomic organization and phylogenetic utility of deer mouse (peromyscus maniculatus) lymphotoxin-alpha and lymphotoxin-beta.deer mice (peromyscus maniculatus) are among the most common mammals in north america and are important reservoirs of several human pathogens, including sin nombre hantavirus (snv). snv can establish a life-long apathogenic infection in deer mice, which can shed virus in excrement for transmission to humans. patients that die from hantavirus cardiopulmonary syndrome (hcps) have been found to express several proinflammatory cytokines, including lymphotoxin (lt), in the lungs. it is thought that t ...200818976466
conservation and diversity of foxp2 expression in muroid rodents: functional implications.foxp2, the first gene causally linked to a human language disorder, is implicated in song acquisition, production, and perception in oscine songbirds, the evolution of speech and language in hominids, and the evolution of echolocation in bats. despite the evident relevance of foxp2 to vertebrate acoustic communication, a comprehensive description of neural expression patterns is currently lacking in mammals. here we use immunocytochemistry to systematically describe the neural distribution of fo ...200918972576
rapid and sensitive handheld biosensor for detection of hantavirus antibodies in wild mouse blood samples under field conditions.hantavirus cardiopulmonary syndrome (hcps) is an acute, life threatening viral illness that was first recognized in the spring of 1993 during an outbreak in the four corners region of the southwest united states. the etiologic agent, sin nombre (sn) virus, is a zoonotic infection that is enzootic in deer mice (peromyscus maniculatus). both human and rodent infections lead to specific antibody responses, and detection of such antibodies is the mainstay of diagnosis of infection in both species. m ...200218968779
the role of heterogeneity in the persistence and prevalence of sin nombre virus in deer mice.many diseases persist at a relatively low prevalence, seemingly close to extinction. for a chronic disease in a homogeneous population, reducing the transmission rate by a fraction proportional to the prevalence would be sufficient to eradicate the disease. this study examines how higher prevalence of the sin nombre virus in male deer mice (peromyscus maniculatus) might contribute to disease persistence. analyzing data from over 2,000 individual mice captured in 19 sites over 4 years, we found p ...200818959490
patterns of hybrid loss of imprinting reveal tissue- and cluster-specific regulation.crosses between natural populations of two species of deer mice, peromyscus maniculatus (bw), and p. polionotus (po), produce parent-of-origin effects on growth and development. bw females mated to po males (bwxpo) produce growth-retarded but otherwise healthy offspring. in contrast, po females mated to bw males (poxbw) produce overgrown and severely defective offspring. the hybrid phenotypes are pronounced in the placenta and include poxbw conceptuses which lack embryonic structures. evidence t ...200818958286
addressing arsenic bioaccessibility in ecological risk assessment: a novel approach to avoid overestimating risk.the risk of arsenic exposure to deer mice (peromyscus maniculatus) living in areas of naturally and anthropogenically elevated arsenic levels was determined using three separate calculations of arsenic daily intake: estimated daily intake (edi), bioaccessible edi (bedi), and actual daily intake (adi). the present work is of particular interest, because the risk assessments were determined for animals naturally exposed to arsenic. gastric fluid extraction was used to obtain bioaccessibility data ...200918939889
indirect genetic effects and the evolution of aggression in a vertebrate system.aggressive behaviours are necessarily expressed in a social context, such that individuals may be influenced by the phenotypes, and potentially the genotypes, of their social partners. consequently, it has been hypothesized that indirect genetic effects (iges) arising from the social environment will provide a major source of heritable variation on which selection can act. however, there has been little empirical scrutiny of this to date. here we test this hypothesis in an experimental populatio ...200918842544
weed-biocontrol insects reduce native-plant recruitment through second-order apparent competition.small-mammal seed predation is an important force structuring native-plant communities that may also influence exotic-plant invasions. in the intermountain west, deer mice (peromyscus maniculatus) are prominent predators of native-plant seeds, but they avoid consuming seeds of certain widespread invasives like spotted knapweed (centaurea maculosa). these mice also consume the biological-control insects urophora spp. introduced to control c. maculosa, and this food resource substantially increase ...200818767624
peromyscus maniculatus--mus musculus chromosome homology map derived from reciprocal cross species chromosome painting.the mus musculus and rattus norvegicus genomes have been extensively studied, yet despite the emergence of peromyscus maniculatus as an nih model for genome sequencing and biomedical research much remains unknown about the genome organization of peromyscines. contrary to their phylogenetic relationship, the genomes of rattus and peromyscus appear more similar at the gross karyotypic level than either does to mus. we set out to define the chromosome homologies between peromyscus, mus and rattus. ...200818758174
contribution of shivering and nonshivering thermogenesis to thermogenic capacity for the deer mouse (peromyscus maniculatus).small mammals that are active all year must develop ways to survive the cold winters. endotherms that experience prolonged cold exposure often increase their thermogenic capacity. thermogenic capacity incorporates basal metabolic rate (bmr), nonshivering thermogenesis (nst), and shivering thermogenesis (st). increasing the capacity of any of these components will result in increased thermogenic capacity. it is often thought that nst should be the most plastic component of thermogenic capacity an ...200818729765
effects of spatially varying selection on nucleotide diversity and linkage disequilibrium: insights from deer mouse globin genes.an important goal of population genetics is to elucidate the effects of natural selection on patterns of dna sequence variation. here we report results of a study to assess the joint effects of selection, recombination, and gene flow in shaping patterns of nucleotide variation at genes involved in local adaptation. we first describe a new summary statistic, z(g), that measures the between-sample component of linkage disequilibrium (ld). we then report results of a multilocus survey of nucleotide ...200818716337
geographic variation in rodent-flea relationships in the presence of black-tailed prairie dog colonies.we characterized the relationship between fleas and their rodent hosts in the presence of prairie dog colonies and compared them to adjacent assemblages away from colonies. we evaluated the rodent-flea relationship by quantifying prevalence, probability of infestation, flea load, and intensity of fleas on rodents. as prairie dog burrows provide refugia for fleas, we hypothesized that prevalence, flea load, and intensity would be higher for rodents that are associated with black-tailed prairie do ...200818697322
comparative analysis of testis protein evolution in rodents.genes expressed in testes are critical to male reproductive success, affecting spermatogenesis, sperm competition, and sperm-egg interaction. comparing the evolution of testis proteins at different taxonomic levels can reveal which genes and functional classes are targets of natural and sexual selection and whether the same genes are targets among taxa. here we examine the evolution of testis-expressed proteins at different levels of divergence among three rodents, mouse (mus musculus), rat (rat ...200818689890
prevalence of yersinia pestis in rodents and fleas associated with black-tailed prairie dogs (cynomys ludovicianus) at thunder basin national grassland, wyoming.rodents (and their fleas) that are associated with prairie dogs are considered important for the maintenance and transmission of the bacterium (yersinia pestis) that causes plague. our goal was to identify rodent and flea species that were potentially involved in a plague epizootic in black-tailed prairie dogs at thunder basin national grassland. we collected blood samples and ectoparasites from rodents trapped at off- and on-colony grids at thunder basin national grassland between 2002 and 2004 ...200818689663
exposure of small rodents to plague during epizootics in black-tailed prairie dogs.plague, caused by the bacterium yersinia pestis, causes die-offs of colonies of prairie dogs (cynomys ludovicianus). it has been argued that other small rodents are reservoirs for plague, spreading disease during epizootics and maintaining the pathogen in the absence of prairie dogs; yet there is little empirical support for distinct enzootic and epizootic cycles. between 2004 and 2006, we collected blood from small rodents captured in colonies in northern colorado before, during, and for up to ...200818689662
development of an elisa to detect sin nombre virus-specific igm from deer mice (peromyscus maniculatus).peromyscus maniculatus (deer mouse) is the primary reservoir for sin nombre virus (snv). although the presence of igg antibodies is often used as a marker of infection, it provides little information on active infections in a population but usually is an indicator of past infections. the presence of igm antibodies is a much better marker for determining whether active infections are present in a population. a mu-capture snv-specific igm enzyme linked immunosorbent assay (elisa) was developed. fr ...200818586333
mitigating exotic impacts: restoring deer mouse populations elevated by an exotic food subsidy.the threat posed by exotic organisms to native systems has led to extensive research on exotic invaders, yet management of invasives has progressed relatively slowly. this is partly due to poor understanding of how exotic species management influences native organisms. to address this shortfall, we experimentally evaluated the efficacy of an invasives management tool for restoring native deer mouse (peromyscus maniculatus) populations elevated by exotic species. the exotic insects, urophora spp. ...200818488599
seroprevalence against sin nombre virus in resident and dispersing deer mice.through dispersal, deer mice (peromyscus maniculatus) enter peridomestic settings (e.g., outbuildings, barns, cabins) and expose humans and other deer mouse populations to sin nombre virus (snv). in june 2004, research on deer mouse dispersal was initiated at 2 locations in montana. during the course of the study, over 6000 deer mouse movements were recorded, and more than 1000 of these movements were classified as dispersal movements. more than 1700 individual deer mice were captured and tested ...200818447620
no evidence of deer mouse involvement in plague (yersinia pestis) epizootics in prairie dogs.plague, the disease caused by the bacterium yersinia pestis, can have devastating impacts on black-tailed prairie dog (cynomys ludovicianus) colonies. one suggested mechanism behind sporadic prairie dog die-offs involves an alternative mammal host, such as the deer mouse (peromyscus maniculatus), which often inhabits prairie dog colonies. we examined the flea populations of deer mice to investigate the potential of flea-borne transmission of plague between deer mice and prairie dogs in northern ...200818447619
food restriction compromises immune memory in deer mice (peromyscus maniculatus) by reducing spleen-derived antibody-producing b cell numbers.immune activity is variable in many wild animals, despite presumed strong selection against immune incompetence. much variation may be due to changes in prevalence and abundance of pathogens (and/or their vectors) in time and space, but the costs of immune defenses themselves may also be important. induction of immune activity often increases energy and protein expenditure, sometimes to the point of compromising fitness. whether immune defenses are expensive to maintain once they are generated, ...200818419561
comparative genome mapping of the deer mouse (peromyscus maniculatus) reveals greater similarity to rat (rattus norvegicus) than to the lab mouse (mus musculus).deer mice (peromyscus maniculatus) and congeneric species are the most common north american mammals. they represent an emerging system for the genetic analyses of the physiological and behavioral bases of habitat adaptation. phylogenetic evidence suggests a much more ancient divergence of peromyscus from laboratory mice (mus) and rats (rattus) than that separating latter two. nevertheless, early karyotypic analyses of the three groups suggest peromyscus to be exhibit greater similarities with r ...200818302785
procedural learning and cognitive flexibility in a mouse model of restricted, repetitive behaviour.restricted, repetitive behaviours (e.g., stereotypies, compulsions, rituals) in neurodevelopmental disorders have been linked to alterations in cortico-basal ganglia circuitry. cognitive processes mediated by this circuitry (e.g., procedural learning, executive function) are likely to be impaired in individuals exhibiting high rates of repetitive behaviour. to test this hypothesis, we assessed both procedural learning and cognitive flexibility (reversal learning) using a t-maze task in deer mice ...200818272239
sin nombre virus shedding patterns in naturally infected deer mice (peromyscus maniculatus) in relation to duration of infection.a 2-year capture-mark-recapture study was conducted in southern manitoba, canada, to test for an association between the duration of sin nombre virus (snv) infection in deer mice (peromyscus maniculatus) and virus shedding. hantavirus-specific igg antibodies were detected in 22.2% of captured deer mice, and recently infected deer mice were identified based on the detection of low-avidity igg antibodies. snv rna was detected in blood samples from the majority of seropositive deer mice with no sig ...200818266564
serologic evidence of a rickettsia akari-like infection among wild-caught rodents in orange county and humans in los angeles county, california.we detected antibodies reactive with rickettsia akari, the etiologic agent of rickettsialpox in humans and in 83 of 359 (23%) rodents belonging to several species, collected in orange county, ca. reciprocal antibody titers >1:16 to r. akari were detected in native mice and rats (peromyscus maniculatus, p. eremicus, and neotoma fuscipes) and in old world mice and rats (mus musculus, rattus rattus, and r. norvegicus), representing the first time that antibodies reactive with this agent have been d ...200718260508
rapid field immunoassay for detecting antibody to sin nombre virus in deer mice.we developed a 1-hour field enzyme immunoassay (eia) for detecting antibody to sin nombre virus in deer mice (peromyscus maniculatus). the assay specificity and sensitivity were comparable to those of a standard eia. this test will permit identification of rodents with antibody to this and perhaps other hantaviruses.200718258020
adaptive functional divergence among triplicated alpha-globin genes in rodents.the functional divergence of duplicated genes is thought to play an important role in the evolution of new developmental and physiological pathways, but the role of positive selection in driving this process remains controversial. the objective of this study was to test whether amino acid differences among triplicated alpha-globin paralogs of the norway rat (rattus norvegicus) and the deer mouse (peromyscus maniculatus) are attributable to a relaxation of purifying selection or to a history of p ...200818245844
hantavirus pulmonary syndrome in manitoba.the first confirmed case of hantavirus pulmonary syndrome in manitoba was diagnosed in 1999. to define better the risk of exposure to hantaviruses in this area, the clinical features and epidemiological factors pertaining to this case were described, and a serological survey of rodents collected near the patient's residence was undertaken. small mammals were collected using live traps, were anesthetized via inhalation of isoflurane and were bled. human and mouse serologies were undertaken using ...200118159335
red eyed peromyscus maniculatus. 194818100301
development partly determines the aerobic performance of adult deer mice, peromyscus maniculatus.previous studies suggest that genetic factors and acclimation can account for differences in aerobic performance (v(o(2)max)) between high and low altitude populations of small mammals. however, it remains unclear to what extent development at different oxygen partial pressures (p(o(2))) can affect aerobic performance during adulthood. here we compared the effects of development at contrasting altitudes versus effects of acclimation during adulthood on v(o(2)max). two groups of deer mice were bo ...200818083730
differential regulation of pathogens: the role of habitat disturbance in predicting prevalence of sin nombre virus.deer mice (peromyscus maniculatus) are the primary reservoir for sin nombre virus (snv), a north american hantavirus that causes disease with high mortality in humans. recent studies have proposed that habitat disturbance affects prevalence of snv in deer mice; however, the outcomes proposed in these studies are in opposition to each other. our objectives were to test these divergent hypotheses by: (1) measuring snv infection in deer mice within a patchwork of disturbance; and (2) evaluating the ...200818064494
the interaction of parasites and resources cause crashes in a wild mouse population.1. populations of white-footed mice peromyscus leucopus and deer mice peromyscus maniculatus increase dramatically in response to food availability from oak acorn masts. these populations subsequently decline following this resource pulse, but these crashes cannot be explained solely by resource depletion, as food resources are still available as population crashes begin. 2. we hypothesized that intestinal parasites contribute to these post-mast crashes; peromyscus are infected by many intestina ...200818028357
old mice, young islands and competing biogeographical hypotheses.naturally occurring variation within a small rodent species native to the southeastern usa, peromyscus polionotus, has interested biologists for nearly a century. this species has contributed significantly to our understanding of geographical variation and has often been presented as an example of adaptive evolution. much of the interest in this organism has been predicated on assumptions that the species is relatively young (<300 000 bp) and that coastal populations have a very recent history ( ...200717956552
short photoperiod and testosterone-induced modification of gnrh release from the hypothalamus of peromyscus maniculatus.seasonally breeding animals undergo numerous physiological changes in response to changes in the length of the photoperiod. in most warm-weather breeding rodents, these changes result in reproductive quiescence during short photoperiods. it has been hypothesized that this change is mediated by changes in the activity of gonadotropin-releasing (gnrh) hormone neurons of the hypothalamus. this study was designed to test whether there are changes in the releasable pool of gnrh in the hypothalamus in ...200717949700
alterations in immune function and cyp450 activity in adult male deer mice (peromyscus maniculatus) following exposure to benzo[a]pyrene, pyrene, or chrysene.polycyclic aromatic hydrocarbons (pahs) are among the most common classes of chemical contaminants found at hazardous waste sites. deer mice (peromyscus maniculatus) exhibit a wide geographic distribution throughout north america and have been suggested as a terrestrial biomonitoring species to facilitate comparisons between superfund sites. chemicals tested were benzo[a]pyrene (bap; cas number 50-32-8), pyrene (pyr; cas number 129-00-0), and chrysene (chr; cas number 218-01-9). adult male deer ...200717934950
stereotypic behaviour in the deer mouse: pharmacological validation and relevance for obsessive compulsive disorder.stereotypy is an important manifestation of obsessive compulsive disorder (ocd). ocd involves disturbed serotonin and dopamine pathways, and demonstrates a selective response to serotonin reuptake inhibitors (sri), with limited to no response to noradrenaline reuptake inhibitors (nri). deer mice (peromyscus maniculatus bairdii) engage in various spontaneous stereotypic behaviours, including somersaulting, jumping and pattern running, and has to date not been explored for possible relevance for o ...200817888556
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