Publications

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habitat structure and predators: choices and consequences for rodent habitat specialists and generalists.both habitat structure and risk of predation are thought to influence rodent community composition in different habitats, but experiments on the degree to which these factors determine the use of habitat by rodents are lacking. i sought to discover (1) if cover density altered habitat choice and (2) if cover density affected the vulnerability to predators of two rodents, a habitat specialist and a habitat generalist. in laboratory experiments, the habitat specialist, the red-backed vole (clethri ...198728312894
concentrations of metals in mink and other mammals from washington and idaho.from 1981 to 1983, concentrations of metals were determined in mink mustela vison, muskrats ondatra zibethica, and small mammals at one contaminated site in idaho and at two less contaminated sites in idaho and washington. the highest concentrations of pb and cd occurred in samples from the coeur d'alene river system near or downstream from an extensive mining-smelting complex in northern idaho. maximum concentrations of pb in the liver of a mink (22 microg g(-1)) and in pooled liver samples of ...198715092768
competitive release in microhabitat use among coexisting desert rodents: a natural experiment.competitive release among desert rodents on sand dunes of differing species richness was examined in the great basin and mohave deserts, usa. expansions in microhabitat use were exhibited by the kangaroo rats dipodomys ordii and d. merriami (granivorous heteromyid rodents, weighing 49 and 42 g, respectively) as the number of coexisting heteromyid species decreased geographically. perognathus longimembris, the only common small heteromyid species (7 g) exhibited no competitive release. this may b ...198628311364
effects of three plant growth regulators on the immune response of young and aged deer mice peromyscus maniculatus. 19863729546
a model to assess survival mechanisms of parasites in a genetically defined host system.we examined a host system (peromyscus maniculatus) in which a single autosomal gene controls susceptibility or resistance to infection by the cestode parasite hymenolepis citelli. parasite deaths of both primary and secondary (challenge) infections were examined, using a probabilistic model, to see if deaths were random and uncorrelated within each genotype. within susceptible hosts, post-patent survival of primary worms was not random and heterogeneity was due to among-host effects rather than ...19863714298
effects of intrahypothalamically administered norepinephrine, serotonin and bombesin on thermoregulation in the deermouse (peromyscus maniculatus).norepinephrine, serotonin, and bombesin administered intrahypothalamically affected thermoregulation in the deermouse, peromyscus maniculatus. at a ta of 22 degrees c, doses of 3 micrograms and 6 micrograms of ne resulted in transient hypothermia (maximum drop of 1.6 +/- 1.0 degrees c and 4.3 +/- 2.3 degrees c, respectively). a 1.5 microgram dose of 5-ht induced a persistent hyperthermia (maximum increase of 1.8 +/- 0.8 degrees c) which persisted for more than 2 h. a 6 microgram dose of 5-ht did ...19863947967
photic cues induce multiple neuroendocrine adjustments in testicular function.neuroendocrine responses were evaluated in an outbred population of deer mice (peromyscus maniculatus nebrascensis) after exposure to an inhibitory photoperiod (8:16 light-dark) for 10 wk. deer mice were chosen as an animal model for this study because they are typical of naturally selected species that rely on environmental factors to signal the onset or cessation of annual reproductive effort. short photoperiods induced multiple neuroendocrine adjustments as judged by three types of spermatoge ...19863946637
bioenergetic benefits of huddling by deer mice (peromyscus maniculatus).both short photoperiod and communal social living conserve metabolic energy by deer mice held in thermal neutral ambient temperatures. initial socialization was energetically more costly than solitary living, but huddling behaviors reduced thermal conductance and mass specific metabolic rate by 30% within 5 days. while short photoperiod reduced metabolic energy expenditure by decreasing thermoregulatory demand, huddling mediated behavioral conservation was achieved with hyperthermic core tempera ...19862879682
food hoarding and ingestion in the deer mouse, peromyscus maniculatus: selective responses to mu and kappa opiate agonists.the feeding behavior of the deer mouse, peromyscus maniculatus, includes food hoarding as well as ingestion. administration of the prototypical mu opiate agonist, morphine sulfate, 1-20 mg/kg, produced over three hours a significant dose-dependent stimulation of hoarding by free feeding deer mice. the specific kappa opiate agonist, u-50,488h, 0.10-10 mg/kg, markedly increased ingestion without having any augmentatory effects on hoarding. the mixed mu and kappa opiate agonist, ketocyclazocine hyd ...19863022306
the mechanism of autosomal synapsis and the substaging of zygonema and pachynema from deer mouse spermatocytes.surface-spread and silver-stained spermatocytes of peromyscus maniculatus and p. sitkensis were analyzed in order to develop criteria for the recognition of meiotic substages from early zygonema through early diplonema. the continuous sequence of changes in the morphology of the autosomal axes (lateral elements) of the synaptonemal complexes (sc), sex chromosome axes, and nucleoli enabled the recognition of three substages of zygonema and five of pachynema. the proposed system of subdivision is ...19863948599
comparative anatomy of the retino-hypothalamic tract in photoperiodic and non-photoperiodic rodents.this study examined whether the nearly symmetrical input from each eye to each suprachiasmatic nucleus previously reported in syrian hamsters (mesocricetus auratus) is a universal feature of retino-hypothalamic projections in photoperiodic rodents. intraocular injections of horseradish peroxidase (hrp) were used to trace the retino-hypothalamic tract in three species of photoperiodic rodents, turkish hamster (mesocricetus brandti), deer mouse (peromyscus maniculatus bairdi) and white-footed mous ...19862430681
serological and virological evidence of a hantaan virus-related enzootic in the united states.the first isolation of a hantaan-related virus from a feral rat in the united states was made from a rattus norvegicus caught in new orleans. the strain, designated tchoupitoulas virus, is antigenically related to, but distinct from, the prototype strain 76-118 of hantaan virus and is the first hantaan-like virus isolated from the pancreas of a naturally infected animal. serosurveys of wild rodents from urban and rural areas in the united states indicated that hantaan-related viruses infected ur ...19852861241
role of alcohol dehydrogenase in the swift increase in alcohol metabolism (siam). studies with deer mice deficient in alcohol dehydrogenase.previous studies have shown that rates of ethanol metabolism increase markedly 2-4 hr after the administration of ethanol in rats and in four inbred strains of mice. this phenomenon, called the swift increase in alcohol metabolism (siam), also exists in humans. to determine whether alcohol dehydrogenase (adh) is necessary for the siam response, we compared ethanol metabolism in two strains of the deer mouse, peromyscus maniculatus. one strain lacks alcohol dehydrogenase (adh-negative), whereas t ...19852932115
modoc-like virus isolated from wild deer mice (peromyscus maniculatus) in alberta.small mammals were trapped in northeastern alberta, canada during 1976. blood samples from these animals were tested for virus by inoculation of suckling mice. blood clots from two deer mice yielded isolates of the same virus. the virus was related antigenically to a number of flaviviruses which have been isolated from mammals in central america and north america and was related most closely to modoc virus. physical, chemical, and biological properties of the virus were similar also to those of ...19852987550
differential opiate influences on food hoarding and intake in the deer mouse, peromyscus maniculatus.the feeding behavior of the deer mouse, peromyscus maniculatus, includes food hoarding as well as ingestion. in this animal the mu opiate agonist, morphine, and the kappa opiate agonist, u-50, 488h, selectively stimulate food hoarding and ingestion, respectively. this suggests that mu and kappa opiate systems may differentially mediate primary components of natural feeding behavior.19852999543
immunosuppression in experimental trypanosomiasis: effects of trypanosoma equiperdum on the pathogenesis of influenza virus infection in deer mice (peromyscus maniculatus).the effects of trypanosoma equiperdum infections on the immunological and pathological responses of deer mice (peromyscus maniculatus) to influenza virus exposure were investigated. mice carrying a 5 week trypanosome infection along with an age- and sex-matched trypanosome-free control group were simultaneously exposed to influenza ao (wsn) virus. t. equiperdum infection significantly (p less than 0.01) converted a sub-lethal virus attack into a fatal pneumonic process in a small proportion of a ...19853002002
photoperiodic time measurement in the male deer mouse, peromyscus maniculatus.weanling male deer mice, peromyscus maniculatus, were exposed for three weeks either to light-dark (ld) cycles with periods (t=l+d) ranging from t=23 (1l:22d) to t=25.16 (1l:24.16d) or to 24-h ld cycles with photoperiods ranging from 1 (1l:23d) to 19 (19l:5d) h. both the circadian locomotor activity rhythms and the response of the reproductive system to these ld cycles were assessed. the results demonstrate that the photoperiodic effectiveness of light depends on the phase of the light relative ...19854005352
eimeria species (apicomplexa: eimeriidae) infecting peromyscus rodents in the southwestern united states and northern mexico with description of a new species.of 198 deermice (peromyscus spp) collected from various localities in the southwestern united states and northern mexico, 106 (54%) had eimerian oocysts in their feces when examined. these included 50 of 106 (47%) peromyscus truei, 34 of 54 (63%) peromyscus maniculatus, 4 of 17 (24%) peromyscus leucopus, and 18 of 21 (86%) peromyscus eremicus. the following eimeria were identified from infected mice: eimeria arizonensis and eimeria langebarteli from p. truei; e. arizonensis, eimeria peromysci, a ...19854057004
effects of laryngeal denervation on ultrasound production and male sexual behavior in rodents.adult male house mice (mus musculus) and deer mice (peromyscus maniculatus bairdi) were used to investigate the effects of partial denervation of the larynx on ultrasound production. in addition the masculine sexual behavior of vocalizing and muted males was assessed on tests with receptive females. for both species, unilateral transections of the inferior laryngeal nerve (iln) significantly reduced the proportion of males that emitted ultrasonic vocalizations. however, the inability to vocalize ...19854059379
heat loss regulation: role of appendages and torso in the deer mouse and the white rabbit.thermal conductance was subdivided into the component conductances of the appendages and torso using a heat transfer analysis for the deer mouse, peromyscus maniculatus, and the white rabbit, oryctolagus cuniculus. our analysis was based on laboratory measurements of skin temperature and respiratory gas exchange made between air temperatures of 8 and 34 degrees c for the deer mouse, and from published data for the white rabbit. two series conductances to heat transfer for each appendage and tors ...19853837023
evaporative water loss: thermoregulatory requirements and measurements in the deer mouse and white rabbit.using a physical model of the capacity for non-evaporative heat loss and measurements of metabolic heat production, i evaluated the evaporative requirements for thermoregulation in the deer mouse, peromyscus maniculatus, and the white rabbit, oryctolagus cuniculus. the physical limit to non-evaporative heat loss was calculated from the heat transfer properties of the two animals and expressed as a maximum thermal conductance (cmax). two physiologically-based thermal conductances were derived fro ...19853837024
chronic and acute trypanosomiasis in mice: a study by in vitro cloning of lymphohaematopoietic progenitors.a semi-solid culture system was used to study the effects of trypanosome infection in two species of mice on the propagation of progenitor cells from the bone marrow and spleen. the deer mouse (peromyscus maniculatus) survived infection with trypanosoma (t.) equiperdum for more than 15 days. during the first 10 days there was inhibition of development of granulocyte-monocyte colonies from progenitor cells in the bone marrow. b-lymphocyte progenitors in the spleen showed increased activity, produ ...19853873680
failure of 2-deoxy-d-glucose to stimulate feeding in deermice.deermice (peromyscus maniculatus) did not increase their food intake above baseline following treatment with 2-deoxy-d-glucose (2dg, 500 or 1000 mg/kg). they did eat more following food deprivation or treatment with insulin at a high dose (100 u/kg). house mice (mus musculus) showed hyperphagia to 2dg, low dose of insulin (5 u/kg) and deprivation.19853898162
studies of pericopulatory pregnancy blockage and the gestation period in deer mice (peromyscus maniculatus).it has previously been shown that female deer mice in cycling estrus that copulate with or are exposed to more than one male at the time of mating have a lower probability of delivering a litter than when mating with and being exposed to just one male. in the present research the effect of post-mating exposure to the bedding of a strange versus a familiar male was studied in females in postpartum estrus. in four experiments females in postpartum estrus were protected from pericopulatory pregnanc ...19854007797
reproductive development in male deer mice exposed to aggressive behavior.male deer mice (peromyscus maniculatus bairdii) were reared in a long photoperiod and housed individually from 3 weeks of age until they were killed 2, 4, or 6 weeks later. males that were exposed to aggressive females for 2 min, three times per week, were of normal body weight and healthy, but had smaller reproductive organs than did males exposed to a control treatment. reproductive development in male deer mice is responsive to at least two classes of social stimuli: pheromones and aggressive ...19854039275
low p50 in deer mice native to high altitude.whereas it is widely believed that animals native to high altitude show lower o2 partial pressures at 50% hemoglobin saturation (p50) than do related animals native to low altitude, that "fact" has not been well documented. consequently, p50 at ph 7.4, pco2(7.4), the co2 bohr effect, and the buffer slope (delta log pco2/delta ph) were determined via the mixing technique in peromyscus maniculatus native to a range of altitudes but acclimated to 340 or 3,800 m. pco2(7.4) and buffer slope were subs ...19853917990
effects of ambient temperature and altitude on ventilation and gas exchange in deer mice (peromyscus maniculatus).the effects of different ambient temperatures (ta) on gas exchange and ventilation in deer mice (peromyscus maniculatus) were determined after acclimation to low and high altitude (340 and 3,800 m). at both low and high altitude, oxygen consumption (vo2) decreased with increasing ta at ta from -10 to 30 degrees c. the vo2 was 15-20% smaller at high altitude than at low altitude at ta below 30 degrees c. increased vo2 at ta below thermoneutrality was supported by increased minute volume (vi) at b ...19853837039
metabolic and thermoregulatory effects of photoperiod and melatonin on peromyscus maniculatus acclimatization.a photoperiod-related seasonal rhythm in active period (scotophase), metabolic rate and core temperature was documented for animals held at 21.0 +/- 0.1 degrees c ambient; animals that were habituated to long nights (10:14ld) had a greater metabolic reserve than those held in summer photoperiods (14:10ld). while relative weights of gonads and sex accessory tissues of mice show typical "winter" regression, interscapular brown adipose tissue mass was unaffected by photoperiod; moreover, ibat beta ...19852866895
experimental studies of seed predation in old-fields.in a pair of experiments conducted in old-field habitats in southwestern michigan (usa), we examined rates of seed loss to post-dispersal predators (ants and rodents). seeds from 4-6 species of "biennial" plants were tested over a range of seed densities and habitat types. we found that seed removal was significantly higher in vegetated habitats than in areas of disturbed soil (both simulated small-animal diggings and a plowed field). in the undisturbed vegetation, seed losses ranged from 1-20% ...198428312102
hypothyroidism in reproductively inhibited prairie deer mice (peromyscus maniculatus bairdi) from laboratory populations.several thyroid function parameters were compared between reproductively inhibited prairie deer mice of both sexes taken from laboratory populations and corresponding reproductively capable controls. the results of these experiments indicated the following: 1) prairie deer mice females had a statistically significant daily variation in mean serum thyroxine concentration and males displayed a similar trend; 2) total serum thyroxine and triiodothyronine were significantly lower in both male and fe ...19846518231
influence of melatonin on pubertal development in male deer mice (peromyscus maniculatus).the role of melatonin in pubertal development was assessed in male deer mice (peromyscus maniculatus bairdii) exposed to photoperiodic and social stimuli. exogenous melatonin retarded puberty in males reared in a long photoperiod, but was without effect in males reared in short days. melatonin did not retard pubertal development induced by exposure of short-day males to an adult female. these results suggest that pineal melatonin mediates photoperiodic, but not social, control of pubertal develo ...19846512757
effect of transitional photoperiods on testicular development and puberty in male deer mice (peromyscus maniculatus).in a series of five experiments, young male deer mice (peromyscus maniculatus bairdii) were exposed to photoperiods ranging in length from 3 to 19 h per 24-h period, as well as to constant light and constant darkness. reproductive organ growth as measured at 6 weeks of age was inhibited by less than or equal to 11.5 h of light. in males receiving 11.5-19 h of light, there was a quantitative increase in reproductive organ size as a function of photoperiod. rather than a 'critical' photoperiod par ...19846512756
photosensitive stages in pubertal development of male deer mice (peromyscus maniculatus).male deer mice (peromyscus maniculatus bairdii) were exposed to a long (15l:9d) or short (6l:18d) photoperiod during four stages of development. at 6 weeks of postnatal age degree of pubertal development was determined by measurement of testis and seminal vesicle weights and area of the androgen-dependent sebaceous gland. continuous exposure to a short photoperiod beginning before conception (i.e. mother kept in short days), at conception, or at birth markedly retarded pubertal development. init ...19846512755
involvement of the circadian system in photoperiodic control of pubertal development in female deer mice, peromyscus maniculatus.pubertal development in female deer mice, peromyscus maniculatus, was stimulated by exposure to light cycles of ld 16:8, ld 6:30 or ld 6:54, but not by exposure to cycles of ld 6:18 or ld 6:42. these results support the hypothesis that female deer mice use a circadian rhythm of responsiveness to light to measure photoperiodic time.19846468610
naloxone inhibition of stress-induced daily torpor.peromyscus maniculatus, deermice , were induced into daily torpor by restricting food to one-half daily ration. intraperitoneal injection of naloxone (20 mg/kg) into mice habituated to daily ip injections of saline inhibited or modified the expression of daily torpor. in those individuals demonstrating long duration/deep bouts (greater than 300 min/body temperature 20 degrees c or below) naloxone administration resulted in 1) a significant decrease in the duration of torpor, 2) a significant ele ...19846727554
maximum oxygen consumption during exercise and cold exposure in deer mice, peromyscus maniculatus.convenient methods were developed for measuring maximum oxygen consumption (vo2 max) in untrained small mammals during treadmill exercise and cold exposure. deer mice (peromyscus maniculatus) were run once, for 6-min periods at velocities exceeding maximal aerobic running speed, while instantaneous oxygen consumption was measured. the vo2 max during cold exposure was determined using high wind speeds to increase heat loss rates. during running, the kinetics of gas exchange were rapid and similar ...19846739991
normal testicular structure and reproductive function in deermice lacking retinol and alcohol dehydrogenase activity.it was found that a strain of deermice (peromyscus maniculatus), which genetically lacks liver alcohol dehydrogenase activity also displays no such activity in the testis and is devoid of the enzyme activity that converts retinol to retinal, both in liver and in the testis; nevertheless, these animals exhibit normal reproduction and testicular histology. therefore, one must reconsider the theory that the testicular atrophy and aspermatogenesis commonly found in alcoholics is due, at least in par ...19846365975
serum acth and adrenal histology in reproductively inhibited male prairie deermice (peromyscus maniculatus bairdi).exogenous acth will cause adrenal hypertrophy and gonad dysfunction in reproductively capable male deermice. the ultrastructure of the zona fasciculata of inhibited animals is substantially different from acth stimulated animals which suggests that acth alone does not produce the inhibition. although acth concentrations were variable, there was no clear demonstration that any differences existed between reproductively capable vs inhibited animals at the time when corticosterone is known to be el ...19846146448
a possible role for the thyroid in reproductive inhibition in laboratory populations of the prairie deermouse (peromyscus maniculatus).serum thyroxine concentrations were determined and found to be reduced in reproductively inhibited deermice selected from controlled growth laboratory populations. daily injections of 1 microgram thyroxine in reproductively inhibited male deermice were shown to significantly increase testis weight and the number of spermatids with acrosome formation. daily feeding of thyroxine to a controlled growth population promoted an increase in the mean weights of the reproductive organs of both sexes that ...19846142798
evidence for heterosynaptic pairing of the inverted segment in pericentric inversion heterozygotes of the deer mouse (peromyscus maniculatus).silver-stained pachytene cells of male deer mice, peromyscus maniculatus, which were heterozygous for a naturally occurring pericentric inversion of chromosome 6, were analyzed by light microscopy. the presence of the terminally positioned inversion, involving approximately 30% of the length of chromosome 6, was detected by g-banding. within the inversion, c-band-positive heterochromatin was restricted to the centromeric region. silver-staining of spermatocytes revealed the synaptonemal complexe ...19846467983
kinetics of cytoplasmic aspartate aminotransferase from three genotypes of the deer mouse (peromyscus maniculatus).three genotypic forms of the cytoplasmic enzyme, aspartate aminotransferase from the deer mouse (peromyscus maniculatus) were each analyzed kinetically after partial purification. kmapp and vmax for aspartate decreased in value as temperature changed from 37.9 to 15 degrees c for all three forms. for the aa genotype, the binding enthalpies were highest at 37.9 degrees c and lowest at 25 degrees c, while for the a'a' form, they were lowest at 37.9 degrees and highest at 25 degrees c. results for ...19846478801
atropine esterase status of laboratory mice.fifty eight inbred strains of laboratory mice and two species of wild mice [mus castaneus (inbred) and peromyscus maniculatus bairdii (closed colony)] were tested for the presence of atropine esterase by the microhematocrit tube test of tucker and beattie. the results show clearly that laboratory mice do not have significant levels of atropine esterase as determined either by the microhematocrit tube test or by the agar plate test, and therefore that under these conditions atropine esterase is n ...19846482377
industrial lead contamination of an illinois wildlife refuge and indigenous small mammals.deer mice (peromyscus maniculatus) were trapped from a sand prairie at various distances from an adjacent battery lead reclamation plant. analysis of liver, kidney, and bone for lead concentrations showed an increase of tissue lead concentrations over controls to a distance of approximately 400 m. soil and plant lead concentrations roughly correlated with the findings in deer mouse tissues. at higher tissue lead concentrations, acid-fast staining intranuclear inclusions within renal tubular epit ...19846511573
influence of feeding chlorocholine chloride and glyphosine on selected immune parameters in deer mice, peromyscus maniculatus.exposure to the plant growth regulators, chlorocholine chloride (ccc) and glyphosine (gps), resulted in significant immunomodulatory effects after feeding to deer mice (peromyscus maniculatus) for 28 days. cyclophosphamide (cp) and saline controls were included. both ccc and gps feeding levels were equivalent to 1, 10, 20, 40 and 80 mg/kg mouse/day. the parameters assessed were: spleen plaque forming cell (pfc) assays, hemolysin titers, white blood cell counts, bone marrow cellularity, hematocri ...19846710535
effects of ingestion of chlorocholine chloride and cyclophosphamide on venezuelan equine encephalitis virus infections in deer mice (peromyscus maniculatus).we investigated the effects of chlorocholine chloride (ccc), a plant growth regulator, and cyclophosphamide (cp), a known immunosuppressant, on the ability of deer mice (peromyscus maniculatus) to resist challenge with a sublethal dose of venezuelan equine encephalitis virus ( veev ). the toxicants were continuously delivered in low doses in the feed; cp at 20 mg/kg body wt/day and ccc at 1, 10, 20 or 40 mg/kg body wt/day. mice were inoculated with 3 x 10(4) plaque forming units (pfu) of veev af ...19846729837
pathogenesis of trypanosoma brucei infection in deer mice (peromyscus maniculatus). ultrastructural pathology of the spleen, liver, heart, and kidney.trypanosoma brucei eatro 110 infection of the deer mice (peromyscus maniculatus) produced moderate to marked lesions in the spleen, liver, heart, and kidney seven to ten weeks after infection. splenic lesions consisted of marked splenomegaly, with infected spleens weighing 25.9 times control spleens. transmission electron microscopy of the sinuses and billroth's cords of the splenic red pulp demonstrated an increased cellularity with greater contact between cells due partly to proliferation of m ...19846730206
pathogenesis of trypanosoma brucei infection in deer mice (peromyscus maniculatus). light and electron microscopic study of testicular lesions.the results of light and electron microscopic studies demonstrated that trypanosoma brucei infection produced marked testicular degeneration in deer mice (peromyscus maniculatus) with highly significant (p less than 0.001) decreases in testicular weight, seminiferous tubular diameter, and epithelial thickness. lesions in seminiferous tubules consisted of necrosis of spermatids, spermatocytes, and sometimes the spermatogonia. sertoli's cells had marked vacuolation and accumulation of phagocytic m ...19846730207
non-alcohol dehydrogenase-mediated metabolism of methylazoxymethanol in the deer mouse, peromyscus maniculatus.the concept that alcohol dehydrogenase (adh) is involved in the metabolism of methylazoxymethanol (mam) was examined in a model consisting of two strains of the deer mouse, peromyscus maniculatus, one of which has a normal complement of the enzyme [adh(+)], and the other, which completely lacks it [adh(-)]. both the adh(+) and the adh(-) strains rapidly metabolized [14c]mam, administered in the form of the acetic acid ester, [14c] mamoac , to 14co2, and the rates and extents of metabolism were v ...19846372998
reservoirs of giardia spp. in southwestern alberta.a survey of potential hosts of giardia spp. was carried out during 1982 and 1983 in the kananaskis valley and banff national park, alberta, canada. diagnosis was based mainly on fecal analysis but a few animals were examined at necropsy and scrapings from the small intestine analyzed. a total of 304 specimens was examined from humans (homo sapiens l.) and a variety of animal species. cysts and/or trophozoites of giardia were found in 10.5% of the specimens examined. positive samples were found f ...19846397598
effect of indomethacin on reproduction under laboratory and field conditions in deermice (peromyscus maniculatus).the purpose of this investigation was to determine the long-term effect of enterically administered indomethacin (a prostaglandin synthetase inhibitor) on reproduction in peromyscus maniculatus (deermice) under both laboratory and field conditions. indomethacin-coated wheat (1 mg/kg wheat) was provided to the experimental animals in the laboratory and under field conditions ad libitum. rat chow was also provided to the animals in the laboratory. the laboratory data indicate that the number and s ...19836403066
pathogenesis of trypanosoma brucei infection in deer mice (peromyscus maniculatus). v. macrophage ultrastructure and function.macrophage numbers increased in the spleen, liver, testes, heart, and kidney of deer mice infected for seven to ten weeks with trypanosoma brucei eatro 110. the macrophages were activated as indicated by their increased size and significant increases in numbers of cell organelles including profiles of rough endoplasmic reticulum (which also increased in length), mitochondria, primary and secondary lysosomes, bundles of golgi's apparatus, and free lysosomes compared to macrophages from control mi ...19836636469
development and characterization of a homologous radioimmunoassay for deer mouse (peromyscus maniculatus bairdii) prolactin.a highly specific and sensitive homologous radioimmunoassay has been developed for the secreted form of prolactin from the deer mouse peromyscus maniculatus bairdii. peromyscus serum and pituitary homogenates displayed parallel dilution response curves, and no cross reaction was seen with either mouse prolactin, mouse growth hormone or rat prolactin. the assay was sensitive to 25 picograms per tube and the intra- and inter-assay coefficients of variation were 5 and 3.6%, respectively. in additio ...19836645802
linkage relationships among eleven biochemical loci in peromyscus.interspecific f1 hybrids of peromyscus maniculatus (deermice) and p. polionotus (oldfield mice) were backcrossed to p. maniculatus. backcross progeny were electrophoretically typed for 11 variant protein markers: albumin, transferrin, leucine aminopeptidase, amylase, 6-phosphogluconate dehydrogenase, nucleoside phosphorylase, dipeptidase, tripeptidase, glutamate oxaloacetate transaminase, alcohol dehydrogenase, and sorbitol dehydrogenase. genetic variation for each protein was attributed to a si ...19836200103
isolation, purification, and characterization of deer mouse (peromyscus maniculatus bairdii) prolactin.prolactin (prl) secreted by peromyscus maniculatus bairdii anterior pituitaries was purified by gel filtration on sephadex g-100 and ion-exchange chromatography on deae-cellulose. peromyscus prl (pmprl) eluted from sephadex g-100 with an elution-to-void volume ratio of 1.9 and at a salt concentration of 100 mm nacl on deae-cellulose. electrophoretic homogeneity of the hormone was demonstrated in several gel systems. on 7 1/2% alkaline polyacrylamide gels, pmprl migrated with an rf of 0.65. the m ...19836847207
pathogenesis of trypanosoma brucei infection in deer mice (peromyscus maniculatus): hematologic, erythrocyte biochemical, and iron metabolic aspects.trypanosoma brucei eatro 110 infection in deer mice (peromyscus maniculatus) produced anemia in 15 of 42 mice between postinoculation days 14 and 70. the infected anemic (ia) mice had significantly higher reticulocyte counts (p less than 0.025), spleen (p less than 0.001) and liver (p less than 0.005) weights, and higher parasitemia than did infected nonanemic (ina) mice. gamma-globulin concentrations of infected mice were markedly increased, and values for ina mice were 10% higher than values f ...19836869960
pathogenesis of trypanosoma brucei infection in deer mice (peromyscus maniculatus): light and electron microscopic studies on erythrocyte pathologic changes and phagocytosis.light microscopic and scanning and transmission electron microscopic studies demonstrated that trypanosoma brucei eatro 110 produced several alterations in rbc structure including microspherocytes, schistocytosis, vacuolation, doughnut-cell formation, and keratocytosis. mature rbc and reticulocytes were constantly observed to adhere firmly to trypanosomes in heart blood and in blood vessels of the testes, heart, liver, and kidney, as well as in the sinuses and pulp cords of the spleen. adhesion ...19836869961
medroxyprogesterone, immunosuppression, and conceptus size in peromyscus.effects of exogenous medroxyprogesterone acetate (mpa) on skin transplant retention and conceptus size were studied in the deer mouse, peromyscus maniculatus, and the oldfield mouse peromyscus polionotus. daily injections of 2 mg mpa significantly prolonged survival of allografts in p. maniculatus and transspecific grafts between p. maniculatus and p. polionotus. allografts were retained significantly longer than transspecific grafts (17.2 vs 12.4 days) on mpa-treated p. maniculatus. near-term f ...19836345716
factors determining the abundance and distribution of rodents in a shrub-steppe ecosystem: the role of shrubs.this study addressed the relative importances of shrub "resources" on a rodent community in a sagebrush dominated shrub-steppe ecosystem in southwestern wyoming. direct effects of shrubs (i.e., providing rodents with "food and cover") were assessed by removing shrubs from a 1.25 ha study plot and monitoring both rodent populations and their food resources. shrub architecture and shrub-related food resources were found to be unimportant to deermice (peromyscus maniculatus), great basin pocket mic ...198328310227
rhythms of barbiturate-induced sleep time in deermice entrained to non-twenty-four hour photocycles.the present experiment examined whether entrainment to twenty-four hour days is advantageous for physiological and behavioral adaptations to a pharmacological challenge. adult, male deermice (peromyscus maniculatus) were injected with sodium pentobarbital at 8.5, 14.5, 20.5, 2.5 and again at 8.5 hr after light onset while entrained to a 24 hr day (light/dark (ld) 14:10). time to recover from anesthesia was recorded. subsequently, the dark phase of the ld cycle was reduced 15-20 min every 10 days ...19836635008
influence of photoperiod and social environment on sexual maturation in female deer mice (peromyscus maniculatus bairdii).female deer mice (peromyscus maniculatus) were reared on either a long photoperiod (15:9 hr light/dark) or on short days (8:16 hr light/dark) from birth. beginning at weaning, females were housed with an adult male, with an adult female, or in social isolation. in the first experiment, vaginas opened more slowly in females on short days than in those on long days. vaginal introitus was also retarded in females reared with an adult female in comparison with females reared in isolation. when exami ...19836872508
gonadal hormone activation of male courtship ultrasonic vocalizations and male copulatory behavior in castrated male deer mice (peromyscus maniculatus bairdi).the influence of testosterone (t), a 5 alpha-reduced metabolite of t, dihydrotestosterone, and an aromatized metabolite of t, estradiol, on 35-khz ultrasonic calling and male copulatory behavior by male deer mice (peromyscus maniculatus bairdi) was examined. daily treatment with testosterone propionate (tp), dihydrotestosterone propionate (dhtp), or estradiol benzoate (eb) restored male ultrasonic calling in long-term castrated males. both tp and dhtp restored male copulatory behavior, but eb wa ...19836871034
selection components affecting hemoglobins in peromyscus maniculatus: a re-evaluation. 198328563308
gametic selection and hemoglobin polymorphisms in peromyscus maniculatus: a rejoinder. 198328563302
photoperiodic stimulation of pubertal development in male deer mice: involvement of the circadian system.pubertal development in prairie deer mice (peromyscus maniculatus bairdii) is accelerated by exposure of juveniles to a long-day photoperiod, and, conversely, retarded by exposure to short days. the purpose of the present study was to evaluate the possible involvement of the circadian system in the photoperiodic regulation of puberty. weanling males, previously housed on a short-day light cycle of 6l:18d, were subjected to a "resonance" protocol in which they received one of the following light ...19836850042
recovery from sexual satiety in deer mice (peromyscus maniculatus bairdi).two experiments were completed in order to delineate the time course of recovery from sexual satiety in deer mice, peromyscus maniculatus bairdi. the total numbers of ejaculations and intromissions attained in satiety tests were significantly decreased on the day following satiation and recovered gradually as measured in tests run after 3 and 7 days of recovery. whereas some measures characteristic of individual series were altered by incomplete recovery, others were unaffected. in experiment 2, ...19836872505
latitude of origin influences photoperiodic control of reproduction of deer mice (peromyscus maniculatus).three subspecies of peromyscus maniculatus originating from different latitudes were maintained from birth in light dark cycles that provided between 10 and 18 h of light per day. at 50 days of age, chihuahua, mexico mice (latitude of origin 27 degrees n) and south dakota, u.s.a. mice (44 degrees n) kept in the 10l:14d photoperiod had reduced gonadal and seminal vesicle weights and a lower spermatogenic index than corresponding mice kept in a 14l:10d photoperiod. some chihuahua and south dakota ...19836681991
extensive genetic variation in mitochondrial dna's among geographic populations of the deer mouse, peromyscus maniculatus. 198328568029
immunological factors in peromyscus speciation.reciprocal interspecific f1 hybrids of deermice (peromyscus maniculatus) and oldfield mice (p. polionotus) differ significantly and substantially in fetal and placental, as well as adult, size and weight. hybrid fetal mortality is associated with large conceptus size. skin grafts were exchanged between and within the two species to ascertain whether any relationship exists between mean graft retention time and body size of fetuses and adults. p. maniculatus skin grafted to p. polionotus rejected ...19826757375
an assessment of "hidden" heterogeneity within electromorphs at three enzyme loci in deer mice.allelic heterogeneity within protein electromorphs at three loci was examined in populations of deer mice (peromyscus maniculatus) collected from five localities across north america. we used a variety of electrophoretic techniques (including several starch and acrylamide conditions, gel-sieving, and isoelectric focusing) plus heat denaturation. of particular interest was the supernatant glutamate oxalate transaminase system (got-1; aspartate aminotransferase-1 of some authors), which under stan ...19827152246
social stimulation of reproductive development in male deer mice housed on a short-day photoperiod.male deer mice (peromyscus maniculatus), born of mothers housed on a long-day (ld) photoperiod (15:9 hr light/dark), were either switched to a short-day (sd) photoperiod (6:18 hr) at birth or continued on their prenatal ld photoperiod. from weaning until 6 wk of age, the males were housed either in cohabitation with an adult female or in social isolation. males reared on an sd photoperiod had smaller testes, seminal vesicles, and ventral sebaceous glands than did males reared on ld. postweaning ...19827096680
testosterone acts as a prohormone to stimulate male copulatory behavior in male deer mice (peromyscus maniculatus bairdi).in order to determine the importance of reduced and aromatized metabolites of testosterone for male sexual behavior in peromyscus maniculatus bairdi, castrated males were treated with 5 alpha-reductase and aromatase inhibitors. in the first experiment, testosterone propionate (tp) activation of male copulatory behavior was blocked by the administration of the 5 alpha-reductase inhibitor 4-androsten-3-one-17-beta carboxylic acid (17 beta c). these treatments also prevented tp stimulation of semin ...19827056894
feeding pattern in peromyscus maniculatus: the response to periodic food deprivation.the prairie deermouse (peromyscus maniculatus bairdi) is strongly nocturnal on a 12:12 ld-cycle with a bimodal, dusk-dawn feeding pattern. it has been suggested for the rat that the dusk peak is more dependent on the animal's immediate energy needs while the dawn peak has an anticipatory function in storing food. the present study investigates this pattern in terms of the feeding response of deermice following periodic food deprivation. it was found that the response is not uniform within the d- ...19827079329
2,3-diphosphoglycerate in high- and low-altitude populations of the deer mouse.erythrocyte dpg concentrations were studied in populations of peromyscus maniculatus native to different altitudes. deer mice native to, and resident at, high altitude showed higher dpg/hb ratios than did deer mice native to, and resident at, low altitude. however, after prolonged acclimation to low altitude, the high-altitude natives showed lower dpg/hb ratios than did low-altitude natives. the differences in baseline dpg levels appear to be determined primarily by genetic factors. the heritabi ...19827111916
blood oxygen affinity in high- and low-altitude populations of the deer mouse.there is little solid evidence for specific genetic adaptations in animal populations native to high altitude. there is also continuing debate over what oxygen transport characteristics are truly adaptive at high altitude. we have attempted to elucidate both problems through population genetic and physiological studies of the deer mouse, peromyscus maniculatus. that species is noteworthy because it inhabits the widest range of altitudes of any north american mammal, and it shows a high degree of ...19827111920
effects of experimental infection of the deer mouse (peromyscus maniculatus) with mouse hepatitis virus.three deer mice (peromyscus maniculatus) given 10(4) tcid50 of mouse hepatitis virus -s intranasally all had significant serum neutralization titers to mouse hepatitis virus -s 3 weeks later. ten other deer mice were given 10(3) tcid50 of mouse hepatitis virus -3 intranasally and placed with sentinel laboratory mice (cf1, c3h/rv, and nu/nu) and uninoculated deer mice. one inoculated deer mouse died, but mouse hepatitis virus was not isolated. no other inoculated or uninoculated animals exhibited ...19826285078
hepatic aldehyde dehydrogenase activity in peromyscus genetically deficient in alcohol dehydrogenase.1. hepatic aldehyde dehydrogenase (aldh) activity was measured in two strains of deer-mouse, peromyscus maniculatus. 2. there is no difference in the subcellular distribution of aldh activity in the two strains. animals of adhn/adhn genotype, lacking liver alcohol dehydrogenase (adh), had 90% of total aldh activity in the mitochondrial fraction compared to 94% for the adhf/adhf animals with normal adh activity. almost all of the remaining aldh activity was in the hepatic cytosol with less than 1 ...19826751681
experimental colorado tick fever virus infection in colorado mammals.one hundred and twenty-four small mammals of six species were inoculated with three strains of colorado tick fever (ctf) virus to define viremia and neutralizing (n) antibody responses. adult eutamias minimus and eutamias embrinus, and juvenile peromyscus maniculatus and spermophilus lateralis, were highly susceptible to development of viremic infection. adult s. lateralis and p. maniculatus were moderately susceptible (greater than or equal to 50% viremic). five sylvilagus nuttalli did not beco ...19816259958
the ecology of colorado tick fever in rocky mountain national park in 1974. ii. infection in small mammals.field studies of colorado tick fever (ctf) in small mammals in rocky mountain national park (rmnp) in 1974 established that eutamias minimus and spermophilus lateralis were the most important hosts for ctf virus and were the source of virus for immature stages of the tick vector, dermacentor andersoni. other species (peromyscus maniculatus, spermophilus richardsonii, eutamias umbrinus) are secondary hosts. the intensity of viral activity in rodents varied greatly from locality to locality. highe ...19816263122
effects of extra food on peromyscus and clethrionomys populations in the southern yukon.if food supply limits density in rodent populations, the addition of supplemental food ought to increase population size. from may to september we added food on 2-hectare areas of white spruce forest in the southern yukon. in 1977, we used oats with no measurable impact. in 1978 and 1979 we used sunflower seeds and doubled or tripled the population densities of peromyscus maniculatus and clethrionomys rutilus. supplemental feeding with sunflower seeds increased juvenile production in both specie ...198128310015
ultrasonic vocalizations in male deer mice (peromyscus maniculatus bairdi): their role in male sexual behavior. 19817323194
male sexual behavior in deer mice (peromyscus maniculatus) following castration and hormone replacement. 19817250909
selection components of four allozymes in natural populations of peromyscus maniculatus. 198128563465
adult-young interactions in island and mainland populations of the deermouse peromyscus maniculatus.the demographic and ecological characteristics of island populations of small mammals have received increasing attention in recent years, but few studies have compared the behavioral characteristics of island populations with those of mainland populations. behavior is considered an important variable because it is believed by many to be a crucial factor affecting the population dynamics and demography of natural populations. in particular, among many species of rodents, the social behavior of ad ...198128310030
effects of urine from conspecifics on sexual maturation in female prairie deermice, peromyscus maniculatus bairdii. 19807217792
modes of ectoparasite reinfestations of deer mice (peromyscus maniculatus).modes of ectoparasite reinfestations were studied on ectoparasite-free deer mice (peromyscus maniculatus) returned to their natural habitat on the tule lake national wildlife refuge, siskiyou county, california, during the summer of 1977. the age of the host made no significant difference in the mode of reinfestation of lice, fleas, or mites. flea reinfestation rates were related to the sex of the host, requiring 4 and 2 days, respectively, to reach control levels on male and female hosts. mite ...19807463612
social factors influencing delayed reproductive maturation in prairie deermice (peromyscus maniculatus bairdii) in laboratory populations. 19807462866
cataract-webbed trait in peromyscus. ii. biomicroscopy and histology of eyes.a longitudinal biomicroscopic study of lenses and fundi of over 2,000 peromyscus maniculatus (deer mice) which have cataracts as an autosomal recessive trait has been correlated with histologic development of cataracts. by selective breeding, early-onset cataracts (type i), which are frequently associated with abnormal closure of the fetal fissure and hyaloid vascular abnormalities, have been separated from later-onset (type ii) cataracts, which are more heterogeneous. type i cataracts occur in ...19807350132
baseline levels of selected trace elements in colorado oil shale region animals.baseline levels of boron, fluorine, molybdenum, and copper are described for 18 mule deer (odocoileus hemionus) and for 45 composite samples of deer mice (peromyscus maniculatus) from the piceance creek basin, rio blanco county, colorado. these data were collected before oil shale mining took place, and can be used to compare with levels found after mining is initiated. the data can thus be used to monitor changes in levels in animal tissues and as a basis for mitigating possible harmful effects ...19807431515
sarcocystis idahoensis sp. n. in deer mice peromyscus maniculatus (wagner) and gopher snakes pituophis melanoleucus (daudin). 19806768882
transmission studies with sarcocystis idahoensis of deer mice (peromyscus maniculatus) and gopher snakes (pituophis melanoleucus).transmission studies with sarcocystis idahoensis of deer mice (peromyscus maniculatus) and gopher snakes (pituophis melanoleucus) were conducted to determine host specificity of various stages of the parasite. sporocysts were not passed by four dogs or four cats fed infected skeletal muscle from deer mice. seven white mice (mus musculus) and 34 white-footed mice (peromyscus leucopus) were negative for sarcocysts and liver meronts following oral inoculation with s. idahoensis sporocysts; however, ...19806776292
aggressive behaviour of female prairie deer mice in laboratory populations.prairie deer mice (peromyscus maniculatus bairdii), living in asymptotic laboratory populations established two years earlier, were observed for agonistic responses to conspecific intruders. in the first experiment, intruders of six age-sex classes were placed into 10 of the populations for 10 min. the sex of the intruder did not influence the behaviour of the residents, but juveniles elicited more regression than did adults. a second experiment revealed that female residents were responsible fo ...19807194609
experimental trypanosoma brucei infection in deer mice: splenic changes.forty deer mice (peromyscus maniculatus) were infected with trypanosoma brucei organisms and were killed 33 to 83 days after inoculation (average, 63). the outstanding lesion was infiltration of plasma cells in various tissues. these cells caused disruption of the periarteriolar lymphocytic sheaths and thickening of red pulp cords in the spleen. the lymph node was almost completely replaced by plasma cells. the spleen and lymph nodes also had marked hyperplasia of germinal centers and granulomat ...19807361379
ultrastructure and acid phosphatase activity in hereditary cataracts of deer mice.lenses of cataract-webbed (cw) peromyscus maniculatus were examined by electron microscopy and compared to age-matched normal deer mouse lenses. precataractous lenses of offspring of cw/cw matings were examined and compared to early cataract development in the opposite eye of the same animal. the earliest ultrastructural change leading to disturbance of lens transparency was cell fusion and formation of fiber cell syncytia in the posterior subcapsular region. fiber cells lost their regular hexag ...19807390724
a study of hetero-specific sperm-egg interactions in the rat, mouse, and deer mouse using in vitro fertilization and sperm injection.hetero-specific fertilization of zone-free eggs is used in these experiments as a tool to analyze the barriers to hybridization and to gain insight into the mechanisms of normal fertilization. when the zonae of rat eggs, which are a barrier to hetero-specific fertilization, are removed with pronase, the eggs can be fertilized by mouse sperm and the zygotes start to develop normally. a rat egg fertilized with mouse sperm completes meiosis and forms both male and female pronuclei. chromosomes from ...19807420048
sex affects the initial strength but not the extinction of poison-based taste aversions in deer mice (peromyscus maniculatus bairdi). 19807447866
evolutionary conservation of linkage groups: additional evidence from murid and cricetid rodents.in mus musculus, family muridae, the glucosephosphate isomerase (gpi-l), pink-eyed dilution (p), albinism (c), and beta-type globin (hbb) loci are known to be linked in the order gpi-l-p-c-hbb. in rattus norvegicus, another murid rodent, the p, c, and hbb loci are known to be linked in the same order and with similar recombination frequencies. in peromyscus maniculatus, family cricetidae, it was previously known that p and c are linked and by analogy to mus musculus that linkage group should be ...19807447921
rodent models of the human isoniazid-acetylator polymorphism.inbred strains and subpopulations of rats, laboratory mice, and deer mice were examined for individual variation in the ability to metabolize several arylamines (p-aminobenzoic acid, sulfamethazine, aniline, alpha-naphthylamine, and aminofluorene) by n-acetylation. individual differences within species were found to be dependent upon the tissue source of n-acetyltransferase activity and the acetyl acceptor employed. long-evans rats possessed about 2-fold more p-aminobenzoic acid n-acetyltransfer ...197940765
a soluble immunosuppressor substance in spleen in deer mice infected with trypanosoma brucei.a soluble substance that blocks b-cell response was extracted from spleen of deer mice (peromyscus maniculatus) chronically infected with trypanosoma brucei. immunosuppressor activity of this substance was demonstrated by plaque-forming cell assays of spleen cells from swiss/webster mice inoculated with sheep red blood cells and simultaneously given the suppressor substance, and of spleen cell cultures treated with sheep red blood cells and suppressor substance. studies by light and electron mic ...1979316660
cataract--webbed peromyscus. i. genetics of cataract in p. maniculatus.cataract--webbed (cw) in the deer mouse (peromyscus maniculatus) is a recessive mutant that is manifested by syndactyly (involving soft tissues) and eye defects including cataract. within cw/cw mice, the age at which cataract first appears is genetically controlled. evidence for the activity of genetic modifiers is the early appearance of cataracts in the offspring of parents that developed cataracts at early ages.1979469220
in vitro fertilization of two species of deer mouse eggs by homologous or heterologous sperm and penetration of laboratory mouse eggs by deer mouse sperm.newly ovulated eggs from immature deer mice (peromyscus maniculatus and p. polionotus) and mature laboratory mice (mus musculus) treated with pmsg and hcg were inseminated in vitro with spermatozoa recovered from the cauda epididymidis of mature males. the time required for capacitation of deer mouse sperm in culture was estimated to be about two to five hours based on the dispersal of sperm agglutination and increase of sperm motility. the rate of sperm penetration through the zona pellucida of ...1979572865
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