Publications

TitleAbstractYear
Filter
PMID(sorted descending)
Filter
persistent sin nombre virus infection in the deer mouse (peromyscus maniculatus) model: sites of replication and strand-specific expression.to address sin nombre (sn) virus persistence in deer mice, we sacrificed experimentally infected deer mice at eight time points from day 21 to day 217 postinoculation (p.i.) and examined their tissues for viral nucleocapsid (n) antigen expression and both negative-strand (genomic) and positive-strand (replicative/mrna) viral s segment rna titers. all the animals that we inoculated developed persistent infections, and sn virus could be isolated from tissues throughout the course of infection. the ...200312502867
satellite imagery characterizes local animal reservoir populations of sin nombre virus in the southwestern united states.the relationship between the risk of hantaviral pulmonary syndrome (hps), as estimated from satellite imagery, and local rodent populations was examined. hps risk, predicted before rodent sampling, was highly associated with the abundance of peromyscus maniculatus, the reservoir of sin nombre virus (snv). p. maniculatus were common in high-risk sites, and populations in high-risk areas were skewed toward adult males, the subclass most frequently infected with snv. in the year after an el niño so ...200212473747
adrenal gland differences associated with puberty and reproductive inhibition in peromyscus maniculatus.laboratory populations of the prairie deermouse (peromyscus maniculatus) reach a growth asymptote due primarily to the failure of more than 90% of the young born into the population to mature sexually. this inhibition is reversible; when young are removed from the inhibiting influence of the population more than 75% will reproduce within 80 days of pairing. interestingly, the mechanism of this inhibition does not involve the degree of adrenal hypertrophy as reported in rats and housemice. we rep ...200212441120
infection dynamics of sin nombre virus after a widespread decline in host populations.many researchers have speculated that infection dynamics of sin nombre virus are driven by density patterns of its major host, peromyscus maniculatus. few, if any, studies have examined this question systematically at a realistically large spatial scale, however. we collected data from 159 independent field sites within a 1 million-hectare study area in nevada and california, from 1995-1998. in 1997, there was a widespread and substantial reduction in host density. this reduction in host density ...200212408674
spatiotemporal patterns in the hantavirus infection.we present a model of the infection of hantavirus in deer mouse, peromyscus maniculatus, based on biological observations of the system in the north american southwest. the results of the analysis shed light on relevant observations of the biological system, such as the sporadical disappearance of the infection, and the existence of foci or "refugia" that perform as reservoirs of the virus when environmental conditions are less than optimal.200212241389
developmental plasticity in aerobic performance in deer mice (peromyscus maniculatus).while several studies have examined the abiotic effects of altitude (low ambient temperatures and hypoxia) on the aerobic performance of small mammals, few have explored the effects of development and maturation at different altitudes on aerobic performance as adults. we examined the basal metabolism and aerobic performance of deer mice (peromyscus maniculatus) under four different developmental and testing regimes: (1) reared (gestation through weaning) and tested at high altitude; (2) reared a ...200212208296
in utero and lactational exposure to ammonium perchlorate in drinking water: effects on developing deer mice at postnatal day 21.the effects of in utero and lactational exposure to ammonium perchlorate (ap), a component of rocket fuel and a thyroid toxicant, on developing deer mice (peromyscus maniculatus) were evaluated. breeding pairs were dosed continuously with 0, 1 nm, 1 micro m, or 1 mm ap in drinking water, from cohabitation until pups were euthanized at postnatal day (pnd) 21. pups from the second litter were used for evaluation in this study. no significant differences were observed in any analysis performed when ...200212167219
elevated generation of reactive oxygen/nitrogen species in hantavirus cardiopulmonary syndrome.hantavirus cardiopulmonary syndrome (hcps) is a life-threatening respiratory disease characterized by profound pulmonary edema and myocardial depression. most cases of hcps in north america are caused by sin nombre virus (snv), which is carried asymptomatically by deer mice (peromyscus maniculatus). the underlying pathophysiology of hcps is poorly understood. we hypothesized that pathogenic snv infection results in increased generation of reactive oxygen/nitrogen species (rons), which contribute ...200212134039
shedding and intracage transmission of sin nombre hantavirus in the deer mouse (peromyscus maniculatus) model.the mechanism(s) by which sin nombre (sn) hantavirus is maintained in deer mouse populations is unclear. field studies indicate that transmission occurs primarily if not exclusively via a horizontal mechanism. using an experimental deer mouse infection model in an outdoor laboratory, we tested whether infected rodents shed sn virus in urine, feces, and saliva, whether infected mice transmit infection to naïve cage mates, and whether infected dams are able to vertically transmit virus or antibody ...200212097572
genetic vaccines protect against sin nombre hantavirus challenge in the deer mouse (peromyscus maniculatus).we used a deer mouse (peromyscus maniculatus) infection model to test the protective efficacy of genetic vaccine candidates for sin nombre (sn) virus that were known to provoke immunological responses in balb/c mice (bharadwaj et al., vaccine 17, 2836-2843, 1999 ). protective epitopes were localized in each of four overlapping cdna fragments that encoded portions of the sn virus g1 glycoprotein antigen; the nucleocapsid gene also was protective. the protective efficacy of glycoprotein gene fragm ...200212075094
novel potential reservoirs for borrelia sp. and the agent of human granulocytic ehrlichiosis in colorado.previous work demonstrated that ixodes spinipalpis ticks maintained an enzootic cycle of borrelia bissettii and the agent of human granulocytic ehrlichiosis (aohge) within woodrats (neotoma mexicana) and deer mice (peromyscus maniculatus) in northern colorado (usa). because i. spinipalpis is the only known vector of b. bissettii and aohge in colorado, this study was designed to determine the reservoir status of other hosts of i. spinipalpis in five distinct ecological zones along the front range ...200212038153
assessment of ecologic and biologic factors leading to hantavirus pulmonary syndrome, colorado, u.s.a.to understand the ecologic parameters of sin nombre virus (snv; family bunyaviridae, genus hantavirus) infections in the deer mouse (peromyscus maniculatus), environmental variables impacting the rodent populations, and the conditions under which snv is amplified. this may help us understand the antecedents of human risk for developing hantavirus pulmonary syndrome (hps) as a consequence of snv infection.200212035141
fecal corticosteroids in agouti and non-agouti deer mice (peromyscus maniculatus).total and per gram fecal corticosteroid concentrations were determined for agouti and non-agouti deer mice (peromyscus maniculatus gracilis) over 24 h under normal caging conditions and after exposure to the stress of novel caging. per gram corticosteroid concentrations, fecal output, and 24-h corticosteroid production were greater in stressed compared with unstressed deer mice of both color morphs, whereas stressed agoutis had a greater increase in per gram corticosteroid concentrations when co ...200212020660
influences of inbreeding and genetics on telomere length in mice.we measured telomere lengths of blood leukocytes in several inbred and outbred mammalian species, using a telomere-specific fluorescent probe and flow cytometry. humans, non-human primates, and three outbred populations of peromyscus mice ( peromyscus leucopus, peromyscus maniculatus, and peromyscus polionotus) have short telomeres. two common strains of laboratory mice, c57bl/6j and dba/2j, have telomeres several times longer than most other mammals surveyed. moreover, the two inbred laboratory ...200212016510
sequence and expression analysis of deer mouse interferon-gamma, interleukin-10, tumor necrosis factor, and lymphotoxin-alpha.deer mice (peromyscus maniculatus) are the principal host species of sin nombre (sn) virus, the primary etiologic agent of hantavirus cardiopulmonary syndrome in north america. the disease is a cytokine-mediated immunopathology characterized by pulmonary mononuclear infiltrates without discernible viral pathology. infected deer mice remain life-long carriers and virus is found in many organs, including the lungs, but without pathology. it is unclear how deer mice respond to sn virus because no t ...200211991673
establishment of a deer mouse (peromyscus maniculatus rufinus) breeding colony from wild-caught founders: comparison of reproductive performance of wild-caught and laboratory-reared pairs.the deer mouse (peromyscus maniculatus) is a natural reservoir for several human pathogens, but little is known about the mechanisms by which such pathogens are maintained in nature. as a first step toward developing a colony of deer mice that were permissive for infection with sin nombre (sn) hantavirus, we collected 68 wild p. maniculatus rufinus from central new mexico. mice from this cohort were used to establish 26 breeding pairs, of which 85% were fertile. in subsequent generations, fertil ...200111924788
mhc class ii beta sequence diversity in the deer mouse (peromyscus maniculatus): implications for models of balancing selection.we studied population polymorphism at a major histocompatibility complex (mhc) class ii beta gene in the deer mouse (peromyscus maniculatus). we found that: (i) a single population of p. maniculatus has significantly higher levels of dna and protein sequence diversity than worldwide samples from homologous genes in other taxa, including humans and mice; and (ii) the genealogy of allelic sequences in p. maniculatus deviates significantly from theoretical expectation under a model of symmetric bal ...200111903890
dissociation between spontaneously emitted and apomorphine-induced stereotypy in peromyscus maniculatus bairdii.stereotyped behavior is repetitive, topographically invariant motor activity that lacks an obvious function. we have previously characterized the spontaneous and persistent stereotypies that occur in deer mice housed in standard laboratory cages. providing these animals with enriched environments markedly reduces their vulnerability to develop stereotypic behavioral repertoires, thus enabling us to generate behaviorally distinct (stereotypic and nonstereotypic) mice of the same species. as stere ...200211897261
microevolution in island rodents.we perform a meta-analysis on morphological data from four island rodent populations exhibiting microevolution (< approximately/= 100 years). data consisting of incidences of skeletal variants, cranial, and external measurements are from house mice (mus musculus) on one welsh and one scottish island, black rats (rattus rattus) on two galapagos islands, and deer mice (peromyscus maniculatus) on three california channel islands. we report extremely high rates of microevolution for many traits; 60% ...200111838768
spontaneous "regression" of enhanced immune function in a photoperiodic rodent peromyscus maniculatus.short days inhibit reproduction and enhance immune function in deer mice (peromyscus maniculatus). their reproductive inhibition is sustained by an endogenous timing mechanism: after ca. 20 weeks in short days, reproductive photorefractoriness develops, followed by spontaneous recrudescence of the reproductive system. it is unknown whether analogous seasonal timing mechanisms regulate their immune function or whether enhanced immune function is sustained indefinitely under short days. in order t ...200111674869
effect of capture and season on fecal glucocorticoid levels in deer mice (peromyscus maniculatus) and red-backed voles (clethrionomys gapperi).the effect of confinement and season on fecal glucocorticoid (gc) levels in deer mice (peromyscus maniculatus) and red-backed voles (clethrionomys gapperi) was determined. deer mice confined in a sherman trap more than 4 h had fecal gc levels that were significantly higher than those in individuals that remained in a trap 4 h or less. however, this treatment may not be stressful for red-backed voles as neither plasma nor fecal gc levels were significantly elevated after 12 h of confinement. in a ...200111589634
body and organ mass in agouti and non-agouti deer mice (peromyscus maniculatus).body, adrenal, brain, heart, liver, kidney, spleen and testis masses were determined for agouti and non-agouti deer mice (peromyscus maniculatus gracilis) of both sexes. body mass was highest for non-agouti females and lowest for agouti females; and sex differences in body mass were significant for agouti, but not non-agouti, deer mice. adrenal, brain and liver masses were similar between color morphs; heart mass was greater in agouti males; and kidney, spleen and testis masses were all signific ...200111544076
thyroxine levels in agouti and non-agouti deer mice (peromyscus maniculatus).total thyroxine was assessed by radioimmunoassay for 58 female deer mice of two subspecies (peromyscus maniculatus bairdii and p. m. gracilis) and two color morphs (agouti and non-agouti). p. m. bairdii of both color-morphs had significantly higher mean thyroxine levels than p. m. gracilis. non-agouti deer mice of both subspecies had significantly higher mean thyroxine levels than agouti deer mice. this is the first report of thyroid hormone differences associated with the non-agouti allele.200111544074
longitudinal studies of sin nombre virus in deer mouse-dominated ecosystems of montana.sin nombre virus (snv), hosted by the deer mouse (peromyscus maniculatus), is the primary etiologic agent of hantavirus pulmonary syndrome (hps) in north america. to improve our understanding of the epidemiology of hps in the western united states, we conducted studies of population dynamics and snv antibody prevalence in deer mouse populations for 6 years on 12 mark-recapture grids in montana. monthly numbers of deer mice ranged from zero to over 170 on 1-hectare grids. snv antibody prevalence ...200111504405
safety of brucella abortus strain rb51 in deer mice.brucella abortus strain rb51 is an approved brucellosis vaccine for use in cattle that may have potential as an oral vaccine for use in elk (cervus elaphus) and/or bison (bison bison). this study was designed to determine effects of strain rb51 on deer mice (peromyscus maniculatus), a nontarget species that could have access to treated baits in a field situation. in february 1994, 90 mice were orally dosed or intraperitoneally injected with 1 x 10(8) colony forming units strain rb51 and 77 contr ...200111504238
experimental infection of nontarget species of rodents and birds with brucella abortus strain rb51 vaccine.the brucella abortus vaccine strain rb51 (srb51) is being considered for use in the management of bnucellosis in wild bison (bison bison) and elk (cervus elaphus) populations in the greater yellowstone area (usa). evaluation of the vaccines safety in non-target species was considered necessary prior to field use. between june 1998 and december 1999, ground squirrels (spermophilus richardsonii, n = 21), deer mice (peromyscus maniculatus, n = 14), prairie voles (microtus ochrogaster, n = 21), and ...200111504226
pathogenesis of experimental vesicular stomatitis virus (new jersey serotype) infection in the deer mouse (peromyscus maniculatus).the pathogenesis of vesicular stomatitis virus (vsv) infection has not been investigated previously in native new world rodents that may have a role in the epidemiology of the disease. in the present study, 45 juvenile and 80 adult deer mice (peromyscus maniculatus) were inoculated intranasally with vsv new jersey serotype (vsv-nj) and examined sequentially over a 7-day period. virus was detected by means of immunohistochemistry and in situ hybridization in all tissues containing histologic lesi ...200111467473
mercury concentrations in deer mouse (peromyscus maniculatus) tissues from isle royale national park.we used deer mice (peromyscus maniculatus) to investigate variation in mercury exposure across the terrestrial ecosystem of isle royale national park (michigan, usa). although previous work suggested that mercury (hg) levels may be higher inside the sargent lake watershed of isle royale than outside the watershed, hg concentrations in livers were higher outside the sargent lake watershed (100.13 ng hg/g dry tissue) than inside the watershed (35.50 ng hg/g dry tissue; p = 0.06). mercury levels in ...200111443999
antibody to sin nombre virus in rodents associated with peridomestic habitats in west central montana.most human cases of hantavirus pulmonary syndrome are acquired in the peridomestic environment, yet studies of the ecology and infection dynamics in the reservoir host, the deer mouse (peromyscus maniculatus), have focused on sylvan populations. we describe a 2.5-year study of hantavirus infection in rodents associated with peridomestic habitats in west central montana. antibodies reactive with sin nombre virus (snv) were found in five species. overall snv antibody prevalence was highest among d ...200111442208
effects of altitude and temperature on organ phenotypic plasticity along an altitudinal gradient.small mammals living in high-altitude environments must endure decreased ambient temperatures and hypoxic conditions relative to sea-level environments. previously, it was noted that heart, lung and digestive tract masses and blood hematocrit increase along an altitudinal gradient in small mammals. increases in digestive organ mass were attributed to lower ambient temperatures and greater food intake, and increases in lung mass and hematocrit were attributed to hypoxia, but these assumptions wer ...200111441040
embryo implantation during the short luteal phase of the corn mouse, calomys musculinus, and the apparent lack of a lactational diapause in south american murid rodents.as the corn mouse, calomys musculinus, has a short luteal phase (2-3 days) that is not prolonged after copulation, it was hypothesized that (i) implantation would occur at the end of this phase, that is, earlier than it occurs in most murid species that have been studied, and (ii) a lactational embryonic diapause would not occur during the luteal phase. these hypotheses were tested in females that had copulated during postpartum oestrus and were either lactating or not lactating. data were recor ...200111427171
deer mice as laboratory animals.although laboratory mice (mus) and rats (rattus) are the most widely used research rodents, deer mice (peromyscus maniculatus) and their congeneric species are favored as nontraditional alternatives for some purposes. mice of the native genus peromyscus are the most abundant and widely distributed rodents in north america. they occur in a great diversity of habitats and play a significant role in natural ecosystems. because of their abundance, peromyscines are commonly hosts for larva of ticks t ...199811406688
a novel mechanism of body mass regulation.while significant attention has been devoted to the identification of hormonal factors that control body mass, little attention has been paid to the role of mechanical loading on animal mass. here, we provide evidence that intraperitoneal implantation of metabolically inert mass results in a compensatory reduction in tissue mass. deer mice (peromyscus maniculatus) were surgically implanted with weights of 1, 2 or 3 g. there was a resulting loss of tissue mass (total body mass minus implant mass) ...200111316493
genetic and serotypic characterization of sin nombre-like viruses in canadian peromyscus maniculatus mice.in canada, hantavirus infected deer mice (peromyscus maniculatus) have been collected from british columbia to newfoundland. partial sequencing of g1 and n protein encoding regions from canadian peromyscus maniculatus-borne hantaviruses demonstrated the existence of significant genotypic divergence among strains. phylogenetic analysis showed that sin nombre (sn)-like viruses from eastern and western canadian deer mice can be divided into at least two broad-based genogroups. sequencing of mitocho ...200111311430
pneumocystosis in wild small mammals from california.cyst forms of the opportunistic fungal parasite pneumocystis carinii were found in the lungs of 34% of the desert shrew, notiosorex crawfordi (n = 59), 13% of the ornate shrew, sorex ornatus (n = 55), 6% of the dusky-footed wood rat, neotoma fuscipes (n = 16), 2.5% of the california meadow vole, microtus californicus (n = 40), and 50% of the california pocket mouse, chaetodipus californicus (n = 2) caught from southern california between february 1998 and february 2000. cysts were not found in a ...200111310900
serologic evidence of hantavirus infection in sigmodontine rodents in mexico.antibodies to hantaviruses in two species of sigmodontine rodents (peromyscus maniculatus and reithrodontomys sumichrasti) collected in central mexico are reported. peromyscus maniculatus, a common species throughout much of mexico, is the reservoir of sin nombre virus (snv), the etiologic agent of the great majority of cases of hantavirus pulmonary syndrome (hps) in north america. although the identity of the virus detected in p. maniculatus in mexico could not be determined by these serologic ...200111310896
do unusual site-specific population dynamics of rodent reservoirs provide clues to the natural history of hantaviruses?between january 1995 and november 1997, longitudinal mark-recapture studies of rodent hosts of hantaviruses in a disturbed microhabitat within a shortgrass prairie ecosystem in southeastern colorado (usa) were conducted. the site was distinguished by edaphic and floristic characteristics unique to this area and associated with historical land use patterns, as well as the year-around availability of water from a functioning windmill. populations of two common rodent species that are hosts for han ...200111310878
the incubation period of hantavirus pulmonary syndrome.in 1993 sin nombre virus was recognized as the cause of hantavirus pulmonary syndrome (hps) and the deer mouse (peromyscus maniculatus) was identified as the reservoir host. surveillance by the centers for disease control and prevention and state health departments includes investigation to determine the likely site(s) and activities that led to infection, an environmental assessment of the home and workplace, and possibly rodent trappings at these sites. as of december 31, 1998, there were 200 ...200011304061
arenavirus antibody in rodents indigenous to coastal southern california.the purpose of this study was to extend our knowledge on the geographic and natural rodent host ranges of new world arenaviruses in california. sera from 1,094 sigmodontine and 112 murine rodents were tested for antibody against whitewater arroyo and amapari viruses. antibody was found in 55 (4.6%) of the 1,206 rodents: 4 from northwestern san diego county, 3 from los angeles county, and 48 from orange county. the antibody-positive rodents included 8 (7.8%) of 103 neotoma fuscipes, 1 (0.6%) of 1 ...200011289675
oxygen consumption and carbon dioxide production in male prairie deermice (peromyscus maniculatus bairdii) in different reproductive conditions and group densities.natural and laboratory populations of peromyscus exhibit a profound but reversible reproductive inhibition related to population density. our earlier studies described the endocrine physiology of inhibited animals which resembles a condition of delayed puberty, but they did not reveal a primary mechanism for the induction and maintenance of the inhibition. these studies indicated that reproductive inhibition could be associated with an overall change in general metabolism. to test this hypothesi ...199811253796
genetic (rapd) diversity in peromyscus maniculatus populations in a naturally fragmented landscape.we assessed the effects of long-term habitat fragmentation on genetic (random amplified polymorphic dna) diversity in 11 peromyscus maniculatus populations in the lake superior watershed. we analysed genetic structure at two spatial scales and the effect of island size and isolation on genetic diversity. at the regional scale, island populations differed from mainland populations (fst = 0.36), but mainland populations did not differ from each other (fst = 0.01). at the local scale, populations o ...200111251785
a comparative study of mammalian and reptilian alternative pathway of complement-mediated killing of the lyme disease spirochete (borrelia burgdorferi).the potential bactericidal activity of the alternative complement pathway of mammalian and reptilian sera to borrelia burgdorferi sensu stricto (s.s.) was evaluated in vitro. complement-mediated killing was observed when cultured spirochetes were inoculated into sera from the western fence lizard (sceloporus occidentalis) and from the southern alligator lizard (elgaria multicarinata), but not when they were inoculated into serum from either the deer mouse (peromyscus maniculatus) or from humans. ...200011191895
sex differences in conditioned taste aversion and in the effects of exposure to a specific pulsed magnetic field in deer mice peromyscus maniculatus.although conditioned taste aversion (cta) has been investigated and described in laboratory rodents and domestic animals, less is known regarding wild rodents. here, we describe cta in males and females of a "wild" species of rodent, the deer mouse (peromyscus maniculatus). in addition, as cta has often been induced by exposure to intense electromagnetic, x or gamma, radiation, in a second study, we also investigated the effects of a specifically designed, pulsed extremely low-frequency and low- ...200011150555
nonlethal method for forensic evaluation of aldicarb exposure in wildlife.forensic evaluation of aldicarb exposure is difficult due to the rapid hydrolysis and oxidation of the parent compound. oxidation products-aldicarb sulfoxide and aldicarb sulfone-are commonly analyzed, but hydrolytic products-aldicarb nitrile, aldicarb nitrile sulfoxide, aldicarb nitrile sulfone-are infrequently analyzed even though they are the primary stable products of aldicarb degradation. nitrile analyses provide an important avenue to verify aldicarb exposure or aldicarb-induced mortality. ...200111116343
responses to lactation and cold exposure by deer mice (peromyscus maniculatus).recently, much interest has been expressed in understanding how animals use phenotypic plasticity of tissue size and function to meet increased metabolic demands. we set out to learn (i) whether female deer mice (peromyscus maniculatus) given lactation (two to seven pups per litter), cold (5 degrees c), or cold plus lactation as energy demands display phenotypic plasticity in organ size and function; (ii) whether that plasticity is similar to laboratory mice given the same demands; and (iii) whe ...200811073789
microsatellite markers for the deer mouse peromyscus maniculatus. 200011050566
experimental infection model for sin nombre hantavirus in the deer mouse (peromyscus maniculatus).the relationship between hantaviruses and their reservoir hosts is not well understood. we successfully passaged a mouse-adapted strain of sin nombre virus from deer mice (peromyscus maniculatus) by i.m. inoculation of 4- to 6-wk-old deer mouse pups. after inoculation with 5 id(50), antibodies to the nucleocapsid (n) antigen first became detectable at 14 d whereas neutralizing antibodies were detectable by 7 d. viral n antigen first began to appear in heart, lung, liver, spleen, and/or kidney by ...200010973478
transmission of the agent of human granulocytic ehrlichiosis by ixodes spinipalpis ticks: evidence of an enzootic cycle of dual infection with borrelia burgdorferi in northern colorado.previous work described an enzootic cycle of borrelia burgdorferi sensu lato (hereafter referred to as b. burgdorferi) maintained by the rodent neotoma mexicana and the tick ixodes spinipalpis in northern colorado. we investigated the incidence of coinfection among rodents with the agent of human granulocytic ehrlichiosis (aohge). aohge was detected in 23.5% of 119 rodent spleens examined. biopsy results indicated that 78 (65.5%) of the 119 rodents were positive for b. burgdorferi, whereas 22 (7 ...200010915099
sin nombre virus in deer mice captured inside homes, southwestern montana.from 1996 through 1999, 35 deer mice (peromyscus maniculatus) were captured in 25 urban and suburban homes in southwestern montana. mice were captured throughout the year except for january; seven mice (20%) from seven (28%) of the homes were seropositive for sin nombre virus. the infected mice were mostly adult males captured in the spring and fall.200010905973
remote sensing and geographic information systems: charting sin nombre virus infections in deer mice.we tested environmental data from remote sensing and geographic information system maps as indicators of sin nombre virus (snv) infections in deer mouse (peromyscus maniculatus) populations in the walker river basin, nevada and california. we determined by serologic testing the presence of snv infections in deer mice from 144 field sites. we used remote sensing and geographic information systems data to characterize the vegetation type and density, elevation, slope, and hydrologic features of ea ...200010827114
vector competence of ixodes angustus (acari: ixodidae) for borrelia burgdorferi sensu stricto.the vector competence of ixodes angustus for borrelia burgdorferi sensu stricto (s.s.) was investigated in the laboratory. the larval progeny of female ticks from washington state were placed on swiss-webster mice that had been inoculated intravenously with 10(8) spirochetes each of a californian isolate of b. burgdorferi. spirochetes were detected in 6 (12%) of 50 nymphs derived from larvae that had fed on these animals. ten nymphs from the same cohort of experimentally infected ticks were plac ...200010823359
genetic and epigenetic incompatibilities underlie hybrid dysgenesis in peromyscus.crosses between the two north american rodent species peromyscus polionotus (po) and peromyscus maniculatus (bw) yield parent-of-origin effects on both embryonic and placental growth. the two species are approximately the same size, but a female bw crossed with a male po produces offspring that are smaller than either parent. in the reciprocal cross, the offspring are oversized and typically die before birth. rare survivors are exclusively female, consistent with haldane's rule, which states tha ...200010802670
fecal glucocorticoids: a noninvasive method of measuring adrenal activity in wild and captive rodents.to determine the utility of fecal corticosteroid concentration as a measure of chronic stress under laboratory and field conditions, we biochemically and physiologically validated a radioimmunoassay for corticosteroids in three rodent species, house mice (mus musculus), deer mice (peromyscus maniculatus), and red-back voles (clethrionomys gapperi). the biochemical validations demonstrated that the assay accurately and precisely measured corticosteroid concentration in the feces. the physiologica ...200010685902
role of maternal antibody in natural infection of peromyscus maniculatus with sin nombre virus.data from naturally infected deer mice (peromyscus maniculatus) were used to investigate vertical transmission of sin nombre virus (snv) and snv-specific antibody. the antibody prevalence in juvenile mice (14 g or less) was inversely proportional to the mass of the animal, with juvenile deer mice weighing less than 11 g most likely to be antibody positive (26.9%) and juvenile mice weighing between 13 and 14 g least likely to be antibody positive (12.9%). although a significant sex bias in seropo ...200010666274
cross-transmission studies with eimeria arizonensis, e. arizonensis-like oocysts and eimeria langebarteli: host specificity at the genus and species level within the muridae.cross-transmission experiments were done using sporulated oocysts of eimeria arizonensis from peromyscus truei and peromyscus maniculatus, and oocysts of 2 putative species that resemble e. arizonensis, i.e., eimeria albigulae from neotoma albigula, and eimeria onychomysis from onychomys leucogaster. oocysts of each species were inoculated into representatives of p. maniculatus and the latter 2 rodent species. other experiments were conducted wherein oocysts of eimeria langebarteli from peromysc ...199910577723
morphological and physiological responses to altitude in deer mice peromyscus maniculatus.individuals within a species, living across a wide range of habitats, often display a great deal of phenotypic plasticity for organ mass and function. we investigated the extent to which changes in organ mass are variable, corresponding to environmental demand, across an altitudinal gradient. are there changes in the mass of oxygen delivery organs (heart and lungs) and other central processing organs (gut, liver, kidney) associated with an increased sustainable metabolic rate that results from d ...200610521329
effects of morphine on electrically evoked contractions of the vas deferens in two congeneric rodent species differing in sperm competition intensity.an early prediction of sperm competition theory was that males should adjust the number of sperm they deliver according to the risk of double mating and this has received empirical support in recent years. it has been suggested that adaptive regulation of sperm delivery in mammals may depend on changes in vas deferens contractility. in laboratory mice, the vas deferens is sensitive to opioid agonists and the secretion of endogenous opioid peptides can be affected by social interactions that may ...199910518324
temporal and spatial analysis of sin nombre virus quasispecies in naturally infected rodents.sin nombre virus (snv) is thought to establish a persistent infection in its natural reservoir, the deer mouse (peromyscus maniculatus), despite a strong host immune response. snv-specific neutralizing antibodies were routinely detected in deer mice which maintained virus rna in the blood and lungs. to determine whether viral diversity played a role in snv persistence and immune escape in deer mice, we measured the prevalence of virus quasispecies in infected rodents over time in a natural setti ...199910516063
modulation of endocrine pathways by 4,4'-dde in the deer mouse peromyscus maniculatus.4,4'-ddt and 4,4'-dde are widespread environmental contaminants that cause eggshell thinning in birds, altered sex ratios in the american alligator, and changes in the anal-genital distance in rodents. these contaminants are known to cause some of their toxicity by altering steroid receptor-mediated mechanisms. however, chemical-specific alterations in the expression of hormone-metabolizing enzymes may also be a mechanism for endocrine disruption, by altering the half-life of hormones in critica ...199910492900
isolation of borrelia burgdorferi from neotoma fuscipes, peromyscus maniculatus, peromyscus boylii, and ixodes pacificus in oregon.the number of lyme disease cases in oregon has increased in recent years despite the fact that the pathogen, borrelia burgdorferi, has never been isolated in the state. rodent and tick surveys were undertaken in 1997 to isolate and characterize strains of b. burgdorferi from oregon and to identify potential reservoirs and vectors of lyme disease. borrelia burgdorferi was isolated from neotoma fuscipes, peromyscus maniculatus, p. boylii, and ixodes pacificus. both n. fuscipes and p. maniculatus w ...199910466976
update: hantavirus pulmonary syndrome--united states, 1999.hantavirus pulmonary syndrome (hps) is a rodentborne viral disease characterized by severe pulmonary illness and a case-fatality ratio of 43%. sin nombre virus is the primary hantavirus that causes hps in the united states, and the deer mouse (peromyscus maniculatus) is its predominant carrier. cdc-sponsored studies of rodent populations since 1994 have yielded data that suggest an increased risk for infection for humans in some areas of the southwestern united states during the summer of 1999. ...199910401910
mus and peromyscus chromosome homology established by fish with three mouse paint probes.fluorescence-labeled dna probes constructed from three whole house mouse (mus domesticus) chromosomes were hybridized to metaphase spreads from deer mouse (peromyscus maniculatus) to identify homologies between the species. mus chr 7 probe hybridized strongly to the ad-centromeric two-thirds of peromyscus chr 1q. most of mus 3 probe hybridized principally to two disjunct segments of peromyscus chr 3. mus chr 9 probe hybridized entirely to the whole peromyscus chr 7. three peromyscus linkage grou ...199910384049
relationships of deer mouse movement, vegetative structure, and prevalence of infection with sin nombre virus.the effects of vegetative structure on movement of deer mice (peromyscus maniculatus) were examined in two distinct vegetation associations, one near hesperus and the other near molina in western colorado (usa) from june-october 1994 to october 1998. we monitored movement by live-trapping small mammals within gambel's oak/mixed-grass (hesperus) and sage brush/juniper (molina) vegetation types. vegetative structure differed between the sites with molina having more cover provided by shrubs and he ...199910231758
endocrine, immune, and behavioral effects of aldicarb (carbamate), atrazine (triazine) and nitrate (fertilizer) mixtures at groundwater concentrations.this paper describes the results of 5 years of research on interactive effects of mixtures of aldicarb, atrazine, and nitrate on endocrine, immune, and nervous system function. the concentrations of chemicals used were the same order of magnitude as current maximum contaminant levels (mcls) for all three compounds. such levels occur in groundwater across the united states. dosing was through voluntary consumption of drinking water. we used fractional and full factorial designs with center replic ...199910188196
natural history of sin nombre virus in western colorado.a mark-recapture longitudinal study of immunoglobulin g (igg) antibody to sin nombre virus (snv) in rodent populations in western colorado (1994-results summarized to october 1997) indicates the presence of snv or a closely related hantavirus at two sites. most rodents (principally deer mice, peromyscus maniculatus, and pinyon mice, p. truei) did not persist on the trapping webs much beyond 1 month after first capture. some persisted more than 1 year, which suggests that even a few infected deer ...199910081680
genetic diversity and distribution of peromyscus-borne hantaviruses in north america.the 1993 outbreak of hantavirus pulmonary syndrome (hps) in the southwestern united states was associated with sin nombre virus, a rodent-borne hantavirus; the virus' primary reservoir is the deer mouse (peromyscus maniculatus). hantavirus-infected rodents were identified in various regions of north america. an extensive nucleotide sequence database of an 139 bp fragment amplified from virus m genomic segments was generated. phylogenetic analysis confirmed that snv-like hantaviruses are widely d ...199910081674
phenotypic differences in the gnrh neuronal system of deer mice peromyscus maniculatus under a natural short photoperiod.the neural mechanisms by which short photoperiod induces gonadal regression among seasonally breeding mammals are not well understood. one hypothesis suggests that the proximate cause of seasonal gonadal regression is a photoperiod-induced modification in gnrh secretion. this hypothesis is indirectly supported by our recent findings using immunocytochemistry which identified specific photoperiod-induced adjustments in the number and morphology of gnrh containing neurones between reproductively c ...199810070352
hantavirus (bunyaviridae) infections in rodents from orange and san diego counties, california.during a screening program to determine the extent of hantavirus activity in orange and san diego counties, california, serum samples from 2,365 rodents representing nine genera and 15 species were tested for hantavirus antibodies. a reverse transcription-polymerase chain reaction on selected seropositive rodents was used to identify the specific hantavirus. rodents positive for sin nombre virus (snv) antibodies by western blot included 86 (9.1%) of 948 deer mice (peromyscus maniculatus), four ( ...19999988327
physiological responses of deer mice (peromyscus maniculatus) to infection with capillaria hepatica (nematoda).negative effects due to infection have not been documented for most natural host-parasite associations. i performed an infection experiment to measure the physiological consequences of infection by capillaria hepatica in deer mice (peromyscus maniculatus gracilis). compared to their uninfected siblings, infected mice displayed increased serum concentrations of alkaline phosphatase and total proteins and reduced concentrations of albumin. infected mice also had higher hematocrits and enlarged liv ...19989920299
sin nombre virus pathogenesis in peromyscus maniculatus.sin nombre virus (snv), a member of the hantavirus genus, causes acute viral pneumonia in humans and is thought to persistently infect mice. the deer mouse, peromyscus maniculatus, has been identified as the primary reservoir host for snv. to understand snv infection of p. maniculatus, we examined wild deer mice for localization of viral antigens and nucleic acid. morphologic examination consistently revealed septal edema within lung tissue and mononuclear cell infiltrates in portal areas of the ...19999847363
genomic imprinting is disrupted in interspecific peromyscus hybrids.genomic imprinting, the unequal expression of gene alleles on the basis of parent of origin, is a major exception to mendelian laws of inheritance. by maintaining one allele of a gene in a silent state, imprinted genes discard the advantages of diploidy, and for this reason the rationale for the evolution of imprinting has been debated. one explanation is the parent-offspring conflict model, which proposes that imprinting arose in polyandrous mammals as the result of a parental conflict over the ...19989843208
host preferences and temporal trends of the tick ixodes angustus in north-central alberta.we examined host preferences and temporal trends of the tick ixodes angustus on small mammals in north-central alberta. small mammals were live-trapped from 1 june to 29 september 1994 and 3 may to 30 june 1995 in mature aspen (populus tremuloides) forest near lac la biche, alberta. abundance of female i. angustus was high in early may (0.90 +/- 0.20 [se]) and peaked again in late june (0.58 +/- 0.16), whereas abundance of immature i. angustus peaked (1.2 +/- 0.35) in mid-july. red-backed voles ...19989794628
development and validation of a fecal testosterone biomarker in mus musculus and peromyscus maniculatus.this is a report on the development and validation of an elisa method to determine fecal testosterone levels, and on their evaluation as a biomarker for adverse effects of endocrine-disrupting chemicals on reproductive health using male rodents of the peromyscus maniculatus and mus musculus species as an animal model. the elisa antibody had the highest specificity for testosterone (100%), followed by dihydrotestosterone (57.4%) and androstenediol (0.27%). radiolabeled testosterone was injected i ...19989780305
sex differences in opioid and n-methyl-d-aspartate mediated non-opioid biting fly exposure induced analgesia in deer mice.there is evidence for sex differences in responses to noxious stimuli and in the expression and mediation of analgesia. in particular, results of investigations with swim stress and the more ethologically appropriate stress of predator odor exposure have suggested sex differences in n-methyl-d-aspartate (nmda) receptor system involvement in the mediation of analgesia. whether or not this sex difference generalizes to other environmental stressors is, however, not clear. biting flies are a natura ...19989766834
short photoperiod affects reproductive function but not dehydroepiandrosterone concentrations in male deer mice (peromyscus maniculatus).cessation of breeding is central among the suite of winter-coping strategies used by small rodents to survive energy-demanding winter conditions. animals use photoperiod to predict the onset of winter and initiate, well in advance of deteriorating conditions, seasonal adaptations. exposure to short photoperiod leads to regression of the reproductive system in long-day breeding animals. likewise, exposure to short days leads to enhanced immune function among several rodent species studied. becaus ...19989755031
ecology and demographics of hantavirus infections in rodent populations in the walker river basin of nevada and california.to study the ecologic correlates of hantavirus in deer mice (peromyscus maniculatus), we sampled 114 sites in the walker river basin of nevada and california in 1995-1996. blood samples were tested for antibody to hantavirus, and a subset of samples was also tested for virus rna by reverse transcription-polymerase chain reaction. average prevalence of antibody-positive mice was 17%, with heavier males the most likely to be infected. antibody prevalence varied within repeatedly sampled sites from ...19989749642
short-day enhancement of immune function is independent of steroid hormones in deer mice (peromyscus maniculatus).the effects of photoperiod and steroid hormones on immune function were assessed in male and female deer mice (peromyscus maniculatus). in experiment 1, male deer mice were castrated, castrated and given testosterone replacement, or sham-operated. half of each experimental group were subsequently housed in either long (ld 16:8) or short days (ld 8:16) for 10 weeks. short-day deer mice underwent reproductive regression and displayed elevated lymphocyte proliferation in response to the t-cell mito ...19989747522
molecular evolution of two lineages of l1 (line-1) retrotransposons in the california mouse, peromyscus californicus.the large number of l1 [long interspersed elements (line)-1] sequences found in the genome is due to the insertion of copies of the retrotransposon over evolutionary time. the majority of copies appear to be replicates of a few active, or "master" templates. a continual replacement of master templates over time gives rise to lineages distinguishable by their own unique set of shared-sequence variants. a previous analysis of l1 sequences in deer mice, peromyscus maniculatus and p. leucopus, revea ...19989725851
spatial learning and hippocampal volume in male deer mice: relations to age, testosterone and adrenal gland weight.spatial learning and various physiological parameters were examined in old (57 month), middle aged (38 month), adult (18 month) and young (3-3.5 month) male deer mice (peromyscus maniculatus). performance during acquisition of a water maze task was not significantly reduced for middle aged and adult mice relative to young reproductively active (breeding) mice. performance was deteriorated in old mice relative to young breeding mice on block 4 of training. retention of this spatial task, however, ...19989697116
hantavirus pulmonary syndrome--colorado and new mexico, 1998.hantavirus pulmonary syndrome (hps) is a severe cardiopulmonary illness resulting in death in approximately 45% of cases. the most frequently recognized etiologic agent of hps in north america, sin nombre virus (snv), is transmitted to humans from its primary rodent reservoir, peromyscus maniculatus (deer mouse), by direct contact with infected rodents, rodent droppings, or nests or through inhalation of aerosolized virus particles from mouse urine and feces. sporadic cases occur throughout the ...19989639364
photoperiod, ambient temperature, and food availability interact to affect reproductive and immune function in adult male deer mice (peromyscus maniculatus).winter is often stressful. increased energetic demands in winter and concurrent reductions in energy availability can lead to an energetic imbalance and compromise survival. to increase the odds of surviving winter, individuals of some nontropical rodent species have evolved mechanisms to enhance immune function in advance of harsh winter conditions. short day lengths provide a proximate cue for enhancement of immune function, an adaptive functional response to counter environmental stress-induc ...19989615289
exogenous melatonin enhances cell-mediated, but not humoral, immune function in adult male deer mice (peromyscus maniculatus).many nontropical rodent species display seasonal changes in reproductive physiology and metabolism, as well as in immune function. field studies of seasonal changes in immune function typically report decreased immune function in the short days of winter compared to summer; presumably, reduced immunity in winter reflects increased glucocorticoid secretion in response to environmental stressors. in contrast, laboratory studies of photoperiodic changes in immunity invariably demonstrate increased ...19989615288
tissue distribution of hantavirus antigen in naturally infected humans and deer mice.the sin nombre virus (snv) is the etiologic agent of hantavirus pulmonary syndrome in humans but does not cause disease in chronically infected deer mice (peromyscus maniculatus), the natural host. in this study, murine antiserum raised against recombinant snv nucleocapsid protein was utilized to localize viral antigen immunohistochemically in tissues from both humans (n = 20; 11 positive, 9 negative) and deer mice (n = 6; 4 positive, 2 negative). viral infection status was confirmed by western ...19989607851
a survey of hantavirus antibody in small-mammal populations in selected united states national parks.hantavirus activity in 39 national parks in the eastern and central united states was surveyed by testing 1,815 small mammals of 38 species for antibody reactive to sin nombre virus. antibody-positive rodents were found throughout the area sampled, and in most biotic communities. antibody was detected in 7% of 647 deer mice (peromyscus maniculatus), 2% of 590 white-footed mice (p. leucopus), 17% of 12 rice rats (oryzomys palustris), 3% of 31 cotton rats (sigmodon hispidus), and 33% of 18 western ...19989574803
genetic reassortment among viruses causing hantavirus pulmonary syndrome.in order to determine the frequency and characteristics of reassortment among viruses causing hantavirus pulmonary syndrome (hps), mixed infections were initiated in tissue culture by using two closely related strains of sin nombre virus, cc107 (from eastern california) and nmr11 (from new mexico), which share the same species of rodent host in nature, the deer mouse (peromyscus maniculatus). potential reassortant virus plaques were screened by multiplex rt-pcr, using primers specific for indivi ...19989501041
effect of transatlantic transport on reproduction of agouti and nonagouti deer mice, peromyscus maniculatus.in conjunction with establishing colonies of deer mice in the uk, effects of transportation on reproduction in agouti (a) and nonagouti (a) deer mice were assessed. adults were shipped via ground courier and air freight from northampton, massachusetts, usa to sutton bonington, leicestershire, england in february and june. deer mice were paired upon arrival in sutton bonington, whereas matched controls were paired in the original colonies at shipping. to assess reproduction, the following variabl ...19989481695
effects of the nonagouti coat-color allele on behavior of deer mice (peromyscus maniculatus): a comparison with norway rats (rattus norvegicus).the agouti locus influences coat color by antagonizing melanocyte-stimulating hormone (msh) at its receptor on pigment cells and may antagonize msh in neural tissue. this study replicates work on rats to assess whether behavioral (neural) effects of the agouti locus are as similar across mammals as those on coat color. handling, open-field, platform jump, and food-novelty tests were conducted on agouti and nonagouti deer mice (peromyscus maniculatus) following protocols in c. a. cottle and e. o. ...19979419886
comparison of alkaline single cell gel (comet) and peripheral blood micronucleus assays in detecting dna damage caused by direct and indirect acting mutagens.the alkaline single cell gel (scg) or 'comet' and peripheral blood micronucleus (pbmn) assay have been used to compare the effects of the direct acting mutagens, methyl methanesulfonate (mms) and n-nitroso-n-methylurea (nmu), and the indirect acting mutagens, benzo[a]pyrene (bap), cyclophosphamide (cp) 9, 10-dimethyl-1,2-benzanthracene (dmba), and mitomycin c (mmc) in an inbred house mouse (mus domesticus) strain. the alkaline scg assay was able to detect dna damage from direct acting mutagens. ...19979403028
dynamics of plague in a gunnison's prairie dog colony complex from new mexico.a plague (yersinia pestis) epizootic spread through gunnison's prairie dogs (cynomys gunnisoni), and possibly other rodent species, in the moreno valley in north-central new mexico between winter 1984-1985 and autumn 1987. we observed the progress of the epizootic and subsequent population recovery at four prairie dog towns within the valley during this period. at two towns (midlake and val verde) the prairie dogs were marked prior to the epizootic. at two additional towns (vega and south entran ...19979391954
new pathogens for respiratory infections.the emergence of new pathogens and the increasing antimicrobial resistance patterns of old pathogens are contributing factors to the high epidemiologic impact of lower respiratory tract infections. hantaviruses, chlamydia pneumoniae, and penicillin-resistant streptococcus pneumoniae have recently gained most of the attention of international researchers. hantavirus pulmonary syndrome has been confirmed in 100 cases with a very high mortality (52%). risk factors for infection are peridomestic cle ...19969363136
hemorrhagic gastritis in free-living rodents in idaho.between february 1992 and march 1994, four species of rodent from the snake river birds of prey area near boise, idaho (usa) were necropsied. hemorrhagic gastritis was observed in 16 of 131 townsend's ground squirrels (spermophilus townsendii), one of 11 ord's kangaroo rats (dipodomys ordii) and the one great basin pocket mouse (perognathus parvus) evaluated. no lesions were observed in 14 white-footed deer mice (peromyscus maniculatus). tissue from one townsend's ground squirrel was negative fo ...19969359067
the effects of photoperiod and food intake on reproductive development in male deer mice (peromyscus maniculatus).seasonal breeding is a tactic that has evolved in rodents that limits reproduction to specific times of the year to increase reproductive success. in order to time breeding accurately, many animals respond to changes in daily photoperiod. short day lengths inhibit breeding in many nontropical rodent species. restricted food availability can also inhibit reproductive function among some individuals in these so-called "photoperiodic" populations. rodents born at the end of the breeding season typi ...19979333185
population dynamics of the deer mouse (peromyscus maniculatus) and sin nombre virus, california channel islands.hantavirus pulmonary syndrome, first documented in 1993, is caused by sin nombre virus (snv), which is carried by the peromyscus species. in 1994, high snv antibody prevalence was identified in deer mice from two california channel islands. we sampled two locations on three islands to estimate mouse population density and snv prevalence. population flux and snv prevalence appear to vary independently.19979284383
sex differences in immunocompetence differ between two peromyscus species.males generally exhibit reduced immunocompetence and greater susceptibility to disease than females. the explanations for why males may be more susceptible to disease than females fall into two categories: 1) the proximate mechanisms mediating immunity, such as hormonal mechanisms, and 2) variation in reproductive success between the sexes. the present study examined the extent to which these factors contribute to sex differences in cell-mediated immune function in polygynous peromyscus manicula ...19979277551
how common are common fragile sites: variation of aphidicolin-induced chromosomal fragile sites in a population of the deer mouse (peromyscus maniculatus).aphidicolin (apc)-induced chromosomal gaps and breaks were analyzed for ten deer mice (peromyscus maniculatus) from a natural population. the fsm statistical methodology was used to identify fragile sites as chromosomal loci exhibiting significantly non-random numbers of gaps/breaks in each individual and enabled an assessment of variation in fragile sites among the individuals. the individual deer mice exhibited as few as 7 to as many as 19 of the populational total of 34 sites. two sites were ...19979254846
glycolytic enzyme binding during entrance to daily torpor in deer mice (peromyscus maniculatus).associations of glycolytic enzymes with the subcellular particulate fraction of skeletal muscle and heart were examined during entrance to daily torpor in deer mice (peromyscus maniculatus). in skeletal muscle a significant decrease in enzyme binding occurred during torpor entrance for phosphofructokinase, glyceraldehyde-3-phosphate dehydrogenase, and pyruvate kinase, with an additional significant decrease for phosphofructokinase and pyruvate kinase during the deepest state of torpor. reduction ...20069231377
seroepidemiologic studies of hantavirus infection among wild rodents in california.a total of 4,626 mammals were serologically tested for antibodies to sin nombre virus. all nonrodent species were antibody negative. among wild rodents, antibody prevalence was 8.5% in murids, 1.4% in heteromyids, and < 0.1% in sciurids. of 1,921 peromyscus maniculatus (deer mice), 226 (11.8%) were antibody positive, including one collected in 1975. the highest antibody prevalence (71.4% of 35) was found among p. maniculatus on santa cruz island, off the southern california coast. prevalence of ...19979204301
experimental evaluation of rodent exclusion methods to reduce hantavirus transmission to humans in rural housing.an experimental assessment of methods to reduce rodent infestations in rural housing was conducted in yosemite national park, california, sequoia/kings canyon national parks, california, and shenandoah national park, virginia. during pretreatment surveys, nearly all (63 of 68) selected units had past or ongoing rodent activity inside. active infestations were found in 58.8% of the units. peromyscus spp. represented 91.2% of all animals caught inside housing units. despite little harborage, roden ...19979158040
phenotypic variation in seasonal adjustments of testis size, body weight, and food intake in deer mice: role of pineal function and ambient temperature.we investigated pineal function as well as reproductive and energetic characteristics in male deer mice (peromyscus maniculatus) that differentially respond to short photoperiod with full, partial or no gonadal regression. in mice at both high (23 degrees c) and low temperature (1 degree c), these phenotypic differences in reproductive responses to short days were not reflected by differences in urinary excretion of 6-sulphatoxy-melatonin, the main metabolite of pineal melatonin. neither duratio ...19979151428
metabolic fuel availability influences thermoregulation in deer mice (peromyscus maniculatus).body temperature (tb) was monitored telemetrically in adult deer mice kept in an environmental chamber at low ambient temperature (ta = 15 degrees c). mice were challenged with various doses of 2-deoxy-d-glucose (2dg, a glycolysis inhibitor) or mercaptoacetate (ma, a fatty acid oxidation inhibitor) or a combination of the two drugs. a preliminary study suggested that higher doses of 2dg and ma, either individually or together, tended to produce a transient decrease in tb. in the main experiment, ...19979108570
Refresh
firstprev
123456789
nextlast
Displaying items 401 - 500 of 818