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1.
Appl Microbiol Biotechnol ; 105(16-17): 6419-6433, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34402940

RESUMO

Plants produce various plant secondary compounds (PSCs) to deter the foraging of herbivorous mammals. However, little is known about whether PSCs can reshape gut microbiota and promote gut homeostasis of hosts. Using 16S rDNA sequencing to investigate the effects of PSCs on the gut microbiota of small herbivorous mammals, we studied plateau pikas (Ochotona curzoniae) fed diets containing swainsonine (SW) extracted from Oxytropis ochrocephala. Our results showed that both long- and short-term treatment of a single artificial diet in the laboratory significantly reduced alpha diversity and significantly affected beta diversity, core bacteria abundance, and bacterial functions in pikas. After SW was added to the artificial diet, the alpha diversity significantly increased in the long-term treatment, and core bacteria (e.g., Akkermansiaceae) with altered relative abundances in the two treatments showed no significant difference compared with pikas in the wild. The complexity of the co-occurrence network structure was reduced in the artificial diet, but it increased after SW was added in both treatments. Further, the abundances of bacteria related to altered alanine, aspartate, and glutamate metabolism in the artificial diet were restored in response to SW. SW further decreased the concentration of short-chain fatty acids (SCFAs) in both treatments. Our results suggest that PSCs play a key role in regulating gut microbiota community and intestinal homeostasis, thereby maintaining host health. KEY POINTS: • Swainsonine improves the intestinal bacterial diversity of plateau pikas. • Swainsonine promotes the recovery of core bacterial abundances in the gut of plateau pikas. • Swainsonine promotes the restoration of intestinal bacterial functions of plateau pikas.


Assuntos
Microbioma Gastrointestinal , Lagomorpha , Animais , Bactérias/genética , Fenômenos Fisiológicos Bacterianos , Swainsonina
2.
Cells ; 10(8)2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-34440869

RESUMO

Commercial hare and rabbit immortalized cell lines are extremely limited regarding the many species within the lagomorpha order. To overcome this limitation, researchers and technicians must establish primary cell cultures derived from biopsies or embryos. Among all cell types, fibroblasts are plastic and resilient cells, highly convenient for clinical and fundamental research but also for diagnosis, particularly for viral isolation. Here, we describe a fast and cheap method to produce primary fibroblast cell cultures from leporid species, using dispase II, a protease that allows dermal-epidermal separation, followed by a simple enzymatic digestion with trypsin. This method allows for the establishment of an in vitro cell culture system with an excellent viability yield and purity level higher than 85% and enables the maintenance and even immortalization of leporid fibroblastic cells derived from tissues already differentiated.


Assuntos
Fibroblastos/citologia , Cultura Primária de Células/métodos , Pele/citologia , Animais , Biomarcadores/metabolismo , Separação Celular , Sobrevivência Celular , Endopeptidases/metabolismo , Fibroblastos/metabolismo , Lagomorpha , Tripsina/metabolismo
3.
Glob Chang Biol ; 27(19): 4498-4515, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34236759

RESUMO

Species are frequently responding to contemporary climate change by shifting to higher elevations and poleward to track suitable climate space. However, depending on local conditions and species' sensitivity, the nature of these shifts can be highly variable and difficult to predict. Here, we examine how the American pika (Ochotona princeps), a philopatric, montane lagomorph, responds to climatic gradients at three spatial scales. Using mixed-effects modeling in an information-theoretic approach, we evaluated a priori model suites regarding predictors of site occupancy, relative abundance, and elevational-range retraction across 760 talus patches, nested within 64 watersheds across the Northern Rocky Mountains of North America, during 2017-2020. The top environmental predictors differed across these response metrics. Warmer temperatures in summer and winter were associated with lower occupancy, lower relative abundances, and greater elevational retraction across watersheds. Occupancy was also strongly influenced by habitat patch size, but only when combined with climate metrics such as actual evapotranspiration. Using a second analytical approach, acute heat stress and summer precipitation best explained retraction residuals (i.e., the relative extent of retraction given the original elevational range of occupancy). Despite the study domain occurring near the species' geographic-range center, where populations might have higher abundances and be at lower risk of climate-related stress, 33.9% of patches showed evidence of recent extirpations. Pika-extirpated sites averaged 1.44℃ warmer in summer than did occupied sites. Additionally, the minimum elevation of pika occupancy has retracted upslope in 69% of watersheds (mean: 281 m). Our results emphasize the nuance associated with evaluating species' range dynamics in response to climate gradients, variability, and temperature exceedances, especially in regions where species occupy gradients of conditions that may constitute multiple range edges. Furthermore, this study highlights the importance of evaluating diverse drivers across response metrics to improve the predictive accuracy of widely used, correlative models.


Assuntos
Mudança Climática , Lagomorpha , Animais , Ecossistema , Estações do Ano , Temperatura
4.
Mol Ecol ; 30(17): 4173-4188, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34166550

RESUMO

Local adaptation can occur when spatially separated populations are subjected to contrasting environmental conditions. Historically, understanding the genetic basis of adaptation has been difficult, but increased availability of genome-wide markers facilitates studies of local adaptation in non-model organisms of conservation concern. The pygmy rabbit (Brachylagus idahoensis) is an imperiled lagomorph that relies on sagebrush for forage and cover. This reliance has led to widespread population declines following reductions in the distribution of sagebrush, leading to geographic separation between populations. In this study, we used >20,000 single nucleotide polymorphisms, genotype-environment association methods, and demographic modeling to examine neutral genetic variation and local adaptation in the pygmy rabbit in Nevada and California. We identified 308 loci as outliers, many of which had functional annotations related to metabolism of plant secondary compounds. Likewise, patterns of spatial variation in outlier loci were correlated with landscape and climatic variables including proximity to streams, sagebrush cover, and precipitation. We found that populations in the Mono Basin of California probably diverged from other Great Basin populations during late Pleistocene climate oscillations, and that this region is adaptively differentiated from other regions in the southern Great Basin despite limited gene flow and low effective population size. Our results demonstrate that peripherally isolated populations can maintain adaptive divergence.


Assuntos
Lagomorpha , Adaptação Fisiológica/genética , Animais , Fluxo Gênico , Genética Populacional , Genótipo , Polimorfismo de Nucleotídeo Único/genética , Densidade Demográfica , Coelhos
5.
J Wildl Dis ; 57(3): 694-700, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33961043

RESUMO

Rabbit hemorrhagic disease, a notifiable foreign animal disease in the US, was reported for the first time in wild native North American lagomorphs in April 2020 in the southwestern US. Affected species included the desert cottontail (Sylvilagus audubonii), mountain cottontail (Sylvilagus nuttallii), black-tailed jackrabbit (Lepus californicus), and antelope jackrabbit (Lepus alleni). Desert cottontails (n=7) and black-tailed jackrabbits (n=7) collected in April and May 2020 were necropsied at the US Geological Survey National Wildlife Health Center and tested positive for Lagovirus europaeus GI.2, also known as rabbit hemorrhagic disease virus 2 (GI.2/RHDV2/b), by real-time PCR at the US Department of Agriculture's Foreign Animal Disease Diagnostic Laboratory. Gross and microscopic lesions were similar to those reported in European rabbits (Oryctolagus cuniculus) and other hare (Lepus) species with GI.2/RHDV2/b infection; they included epistaxis (12/13; 92%); massive hepatocellular dissociation (14/14; 100%) and necrosis or apoptosis (11/11; 100%); pulmonary congestion (12/12; 100%), edema (12/13; 92%), and hemorrhage (11/12; 92%); and acute renal tubular injury (3/8; 38%). As in previous reports, massive hepatocellular dissociation and necrosis or apoptosis was the most diagnostically distinct finding. As North American Sylvilagus and Lepus species appear to be susceptible to fatal GI.2/RHDV2/b infection, additional work is needed to understand the host range, pathogenicity, and potential population effects of GI.2/RHDV2/b in North America.


Assuntos
Infecções por Caliciviridae , Vírus da Doença Hemorrágica de Coelhos , Lagomorpha , Lagovirus , Animais , Infecções por Caliciviridae/epidemiologia , Infecções por Caliciviridae/veterinária , Vírus da Doença Hemorrágica de Coelhos/genética , Filogenia , Coelhos
6.
Sheng Li Xue Bao ; 73(1): 51-61, 2021 Feb 25.
Artigo em Chinês | MEDLINE | ID: mdl-33665660

RESUMO

In the present study, the composition and content of pulmonary surfactant (PS) were analyzed to explore the hypoxia adaptation mechanism in plateau zokors (Myospalax baileyi) and plateau pikas (Ochotona curzoniae). 36 plateau zokors and plateau pikas were trapped alive at the Laji Mountain in Guide County, Qinghai Province (at the altitude of about 3 600 m), and 36 Sprague-Dawley (SD) rats were purchased from the experimental animal center of Lanzhou University (at the altitude of about 1 500 m). All animals were lavaged after laboratory anesthesia, the blood in lung tissues was fully washed out and the lung tissues were then taken out to obtain the bronchoalveolar lavage fluid by bronchoalveolar lavage. The composition and content of phospholipids in the PS of three different kinds of animals were analyzed by using high performance liquid chromatography; the protein composition, content and types in the PS were analyzed by G-250 Coomassie brilliant blue method, polyacrylamide gel electrophoresis (PAGE) and mass spectrometry; the dissolved oxygen in the PS solutions were determined by using dissolved oxygen electrode. The results showed that the total contents of phospholipids in the PS were successively increased among plateau zokors, plateau pikas and SD rats (P < 0.05), while the total content of proteins successively decreased (P < 0.05). There were five phospholipids identified in the PS, including linoleic palmitoylphosphatidylcholine (LPPC), dipalmitoylphosphatidylcholine (DPPC), phosphatidylglyerol (PG), phosphatidylinositol (PI) and phosphatidylserine (PSe), but the relative contents of these phospholipids were different. The relative content of LPPC was successively increased among plateau zokors, plateau pikas and SD rats (P < 0.01). The relative contents of DPPC, PG and PI in the PS of plateau zokors were significantly higher than those of plateau pikas (P < 0.01), while insignificant differences between plateau pikas and SD rats (P > 0.05). The relative content of PSe had no significant differences between plateau zokors and plateau pikas (P > 0.05), but both were significantly higher than that of SD rats (P < 0.01). The serum albumin (SA) was identified in the PS of three kinds of animals, including homologous tetramer protein containing heme, which is composed of hemoglobin ß subunit, in plateau zokors and plateau pikas. Immunoglobulin (Ig) heavy chain was found in PS of plateau zokors and SD rats. The content of Ig heavy chain in plateau zokor was significantly higher than that in SD rats (P < 0.01), and the content of protein containing heme was significantly higher than that in plateau pikas (P < 0.05). The amount of dissolved oxygen was successively decreased in the PS among plateau zokors, plateau pikas and SD rats (P < 0.01), but it was significantly higher than that in saline (P < 0.01). These results suggest that the total content of proteins in the PS of plateau zokors and plateau pikas was significantly higher, while the total content of phospholipids was significantly decreased. There were high content of homologous tetramer protein containing heme in the PS of plateau zokors and plateau pikas. The relative content of DPPC, the main component of phospholipids, was significantly increased in plateau zokors. The changes of PS component and content improve the adaptability of the two plateau animals in hypoxia environment.


Assuntos
Lagomorpha , Surfactantes Pulmonares , Altitude , Animais , Hipóxia , Ratos , Ratos Sprague-Dawley
7.
Parasitology ; 148(7): 879-886, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33757604

RESUMO

Echinococcus shiquicus is currently limited to the Qinghai­Tibet plateau, a large mountainous region in China. Although the zoonotic potential remains unknown, progress is being made on the distribution and intermediate host range. In this study, we report E. shiquicus within Gansu and Qinghai provinces in regions located not only around the central areas but also the southeast edge of the plateau and describe their genetic relationship with previous isolates from the plateau. From 1879 plateau pikas examined, 2.39% (95% CI 1.79­3.18) were infected with E. shiquicus. The highest prevalence of 10.26% (4.06­23.58) was recorded in Makehe town, Qinghai province. Overall the prevalence was marginally higher in Qinghai (2.5%, CI 1.82­3.43) than in Gansu (2%, CI 1.02­3.89). The cox1 and nad1 genes demonstrated high and low haplotype and nucleotide diversities, respectively. The median-joining network constructed by the cox1­nad1 gene sequences demonstrated a star-like configuration with a median vector (unsampled haplotype) occupying the centre of the network. No peculiar distinction or common haplotype was observed in isolates originating from the different provinces. The presence of E. shiquicus in regions of the southeast and northeast edges of the Qinghai­Tibet plateau and high genetic variation warrants more investigation into the haplotype distribution and genetic polymorphism by exploring more informative DNA regions of the mitochondrial genome to provide epidemiologically useful insight into the population structure of E. shiquicus across the plateau and its axis.


Assuntos
Distribuição Animal , Equinococose/veterinária , Echinococcus/isolamento & purificação , Lagomorpha , Animais , Equinococose/epidemiologia , Equinococose/parasitologia , Dinâmica Populacional , Prevalência , Tibet
8.
BMC Ecol Evol ; 21(1): 2, 2021 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-33514306

RESUMO

BACKGROUND: Distributional responses by alpine taxa to repeated, glacial-interglacial cycles throughout the last two million years have significantly influenced the spatial genetic structure of populations. These effects have been exacerbated for the American pika (Ochotona princeps), a small alpine lagomorph constrained by thermal sensitivity and a limited dispersal capacity. As a species of conservation concern, long-term lack of gene flow has important consequences for landscape genetic structure and levels of diversity within populations. Here, we use reduced representation sequencing (ddRADseq) to provide a genome-wide perspective on patterns of genetic variation across pika populations representing distinct subspecies. To investigate how landscape and environmental features shape genetic variation, we collected genetic samples from distinct geographic regions as well as across finer spatial scales in two geographically proximate mountain ranges of eastern Nevada. RESULTS: Our genome-wide analyses corroborate range-wide, mitochondrial subspecific designations and reveal pronounced fine-scale population structure between the Ruby Mountains and East Humboldt Range of eastern Nevada. Populations in Nevada were characterized by low genetic diversity (π = 0.0006-0.0009; θW = 0.0005-0.0007) relative to populations in California (π = 0.0014-0.0019; θW = 0.0011-0.0017) and the Rocky Mountains (π = 0.0025-0.0027; θW = 0.0021-0.0024), indicating substantial genetic drift in these isolated populations. Tajima's D was positive for all sites (D = 0.240-0.811), consistent with recent contraction in population sizes range-wide. CONCLUSIONS: Substantial influences of geography, elevation and climate variables on genetic differentiation were also detected and may interact with the regional effects of anthropogenic climate change to force the loss of unique genetic lineages through continued population extirpations in the Great Basin and Sierra Nevada.


Assuntos
Estudo de Associação Genômica Ampla , Lagomorpha , Animais , Fluxo Gênico , Genômica , Geografia , Lagomorpha/genética , Estados Unidos
9.
Artigo em Inglês | MEDLINE | ID: mdl-33502309

RESUMO

Four novel bacterial strains (ST-M6T, L-033, L-031T and Z-333) were isolated from the intestinal contents of plateau pikas (Ochotona curzoniae) collected on the Qinghai-Tibet Plateau, PR China. Cells were aerobic, non-motile, Gram-stain-positive, catalase-positive, oxidase-negative, capsuled and short-rod-shaped. Phylogenetic analyses based on the 16S rRNA gene sequences and 387 core genes indicated that the four isolates belong in the genus Microbacterium and clearly separate from recognized species. The two type strains (ST-M6T and L-031T) shared low 16S rRNA similarity, average nucleotide identity values and digital DNA-DNA hybridization relatedness with their phylogenetic neighbours (Microbacterium ginsengisoli DSM 18659T, Microbacterium hatanonis DSM 19179T, Microbacterium rhizomatis JCM 30598T, Microbacterium radiodurans CCTCC M208212T, Microbacterium oleivorans DSM 16091T and Microbacterium arborescens DSM 20754T). The genomic DNA G+C contents of strains ST-M6T and L-031T were 70.4 and 70.7 mol%, respectively. The major cellular fatty acids of strain ST-M6T were anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0, in contrast to anteiso-C17 : 0, anteiso-C15 : 0 and anteiso-C17 : 1 ω9c of strain L-031T. Both type strains (ST-M6T and L-031T) were glycolate test positive and shared the following common features: MK-11 and MK-12 as major menaquinones; rhamnose, ribose, mannose and galactose as major cell-wall sugars; diphosphatidylglycerol, phosphatidylglycerol and two glycolipids as polar lipids; and ornithine, alanine, glycine and glutamic acid as cell-wall amino acids. Comparing the phenotypic, phylogenetic and chemotaxonomic features of the four strains and their related taxa, strains ST-M6T and L-031T represent two novel species of the genus Microbacterium, for which the names Microbacterium caowuchunii sp. nov. (type strain ST-M6T=CGMCC 1.16364T=DSM 104058T) and Microbacterium lushaniae sp. nov. (type strain L-031T =CGMCC 1.16363T=DSM 106170T) are proposed.


Assuntos
Lagomorpha/microbiologia , Microbacterium/classificação , Filogenia , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Conteúdo Gastrointestinal/microbiologia , Microbacterium/isolamento & purificação , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Tibet , Vitamina K 2/química
10.
Microb Biotechnol ; 14(4): 1300-1315, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33369229

RESUMO

The previous studies have reported that the mammalian gut microbiota is a physiological consequence; nonetheless, the factors influencing its composition and function remain unclear. In this study, to evaluate the contributions of the host and environment to the gut microbiota, we conducted a sequencing analysis of 16S rDNA and shotgun metagenomic DNA from plateau pikas and yaks, two sympatric herbivorous mammals, and further compared the sequences in summer and winter. The results revealed that both pikas and yaks harboured considerably more distinct communities between summer and winter. We detected the over-representation of Verrucomicrobia and Proteobacteria in pikas, and Archaea and Bacteroidetes in yaks. Firmicutes and Actinobacteria, associated with energy-efficient acquisition, significantly enriched in winter. The diversity of the microbial community was determined by the interactive effects between the host and season. Metagenomic analysis revealed that methane-metabolism-related pathway of yaks was significantly enriched in summer, while some pathogenic pathways were more abundant in pikas. Both pikas and yaks had a higher capacity for lipid degradation in winter. Pika and yak shared more OTUs when food shortage occurred in winter, and this caused a convergence in gut microbial composition and function. From winter to summer, the network module number increased from one to five in pikas, which was different in yaks. Our study demonstrates that the host is a dominant factor in shaping the microbial communities and that seasonality promotes divergence or convergence based on dietary quality across host species identity.


Assuntos
Microbioma Gastrointestinal , Lagomorpha , Microbiota , Animais , Bactérias/genética , Firmicutes/genética
11.
PLoS One ; 15(12): e0244803, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33382847

RESUMO

Protozoan parasites of the genus Trypanosoma infect a broad diversity of vertebrates and several species cause significant illness in humans. However, understanding of the phylogenetic diversity, host associations, and infection dynamics of Trypanosoma species in naturally infected animals is incomplete. This study investigated the presence of Trypanosoma spp. in wild rodents and lagomorphs in northern New Mexico, United States, as well as phylogenetic relationships among these parasites. A total of 458 samples from 13 rodent and one lagomorph species collected between November 2002 and July 2004 were tested by nested PCR targeting the 18S ribosomal RNA gene (18S rRNA). Trypanosoma DNA was detected in 25.1% of all samples, with the highest rates of 50% in Sylvilagus audubonii, 33.1% in Neotoma micropus, and 32% in Peromyscus leucopus. Phylogenetic analysis of Trypanosoma sequences revealed five haplotypes within the subgenus Herpetosoma (T. lewisi clade). Focused analysis on the large number of samples from N. micropus showed that Trypanosoma infection varied by age class and that the same Trypanosoma haplotype could be detected in recaptured individuals over multiple months. This is the first report of Trypanosoma infections in Dipodomys ordii and Otospermophilus variegatus, and the first detection of a haplotype phylogenetically related to T. nabiasi in North America in S. audubonii. This study lends important new insight into the diversity of Trypanosoma species, their geographic ranges and host associations, and the dynamics of infection in natural populations.


Assuntos
Arvicolinae/parasitologia , Lagomorpha/parasitologia , Doenças dos Roedores/parasitologia , Trypanosoma/genética , Tripanossomíase/veterinária , Animais , New Mexico , Tripanossomíase/parasitologia
12.
Proc Biol Sci ; 287(1941): 20201825, 2020 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-33352070

RESUMO

Investigations of intercontinental dispersal between Asia and North America reveal complex patterns of geographic expansion, retraction and isolation, yet historical reconstructions are largely limited by the depth of the record that is retained in patterns of extant diversity. Parasites offer a tool for recovering deep historical insights about the biosphere, improving the resolution of past community-level interactions. We explored biogeographic hypotheses regarding the history of dispersal across Beringia, the region intermittently linking Asia and North America, through large-scale multi-locus phylogenetic analyses of the genus Schizorchis, an assemblage of host-specific cestodes in pikas (Lagomorpha: Ochotonidae). Our genetic data support palaeontological evidence for two separate geographic expansions into North America by Ochotona in the late Tertiary, a history that genomic evidence from extant pikas does not record. Pikas descending from the first colonization of Miocene age persisted into the Pliocene, subsequently coming into contact with a second wave of Nearctic colonists from Eurasia before going extinct. Spatial and temporal overlap of historically independent pika populations provided a window for host colonization, allowing persistence of an early parasite lineage in the contemporary fauna following the extinction of its ancestral hosts. Empirical evidence for ancient 'ghost assemblages' of hosts and parasites demonstrates how complex mosaic faunas are assembled in the biosphere through episodes of faunal mixing encompassing parasite lineages across deep and shallow time.


Assuntos
Evolução Biológica , Cestoides/fisiologia , Lagomorpha/parasitologia , Animais , Ásia , Interações Hospedeiro-Parasita , América do Norte , Parasitos
13.
Parasit Vectors ; 13(1): 590, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33228776

RESUMO

BACKGROUND: Cystic or alveolar echinococcosis caused by the larval stages of Echinococcus spp. is a very severe zoonotic helminth infection. Echinococcus shiquicus is a newly discovered species that has only been reported in the Qinghai and Sichuan provinces of the Qinghai-Tibet plateau, China where, to date, it has only been confirmed in Tibetan foxes and wild small mammal populations of the Tibetan plateau. Information on its genetic and evolutionary diversity is scanty. The aim of this study was to investigate the prevalence of E. shiquicus in plateau pikas (Ochotona curzoniae), a known intermediate host, and to determine the genetic variation and phylogenetic relationship of the E. shiquicus population in the Tibet region of China based on mitochondrial DNA. METHODS: Echinococcus shiquicus samples were collected from Damxung and Nyêmo counties (located in Tibet Autonomous Region, China). The mitochondrial cox1 and nad1 gene sequences were analyzed, and the genetic diversity and epidemiology of E. shiquicus in the region were discussed based on the results. RESULTS: The prevalence of E. shiquicus in pikas in Damxung and Nyêmo counties was 3.95% (6/152) and 6.98% (9/129), respectively. In combination with previous public sequence data, the haplotype analysis revealed 12 haplotypes (H) characterized by two distinct clusters (I and II), and a sequence distance of 99.1-99.9% from the reference haplotype (H1). The diversity and neutrality indices for the entire E. shiquicus populations were: haplotype diversity (Hd) ± standard deviation (SD) 0.862 ± 0.035; nucleotide diversity (Hd ± SD) 0.0056 ± 0.0003; Tajima's D 0.876 (P > 0.05); and Fu's F 6.000 (P > 0.05). CONCLUSIONS: This was the first analysis of the newly discovered E. shiquicus in plateau pikas in the Tibet Autonomous Region of China. The neutrality indices suggest a deficiency of alleles, indicative of a recent population bottleneck.


Assuntos
Equinococose/epidemiologia , Equinococose/veterinária , Echinococcus/genética , Variação Genética , Lagomorpha/parasitologia , Filogenia , Animais , China/epidemiologia , Equinococose/parasitologia , Echinococcus/classificação , Echinococcus/isolamento & purificação , Raposas/parasitologia , Genótipo , Prevalência , Tibet/epidemiologia
14.
Ecohealth ; 17(3): 333-344, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-33200238

RESUMO

The American pika, Ochotona princeps, is projected to decline throughout North America as climate change reduces its range, and pikas have already disappeared from several locations. In addition to climate, disease spillover from lower elevation mammalian species might affect pikas. We sampled pika fleas in Colorado and Montana across elevations ranging from 2896 to 3612 m and screened them for the presence of DNA from rodent-associated bacterial pathogens (Bartonella species and Yersinia pestis) to test the hypothesis that flea exchange between pikas and rodents may lead to occurrence of rodent-associated pathogens in pika ectoparasites. We collected 275 fleas from 74 individual pikas at 5 sites in Colorado and one site in Montana. We found that 5.5% of 275 pika fleas in this study tested positive for rodent-associated Bartonella DNA but that variation in Bartonella infection prevalence in fleas among sites was not driven by elevation. Specifically, we detected DNA sequences from two loci (gltA and rpoB) that are most similar to Bartonella grahamii isolates collected from rodents in Canada. We did not detect Y. pestis DNA in our survey. Our results demonstrate evidence of rodent-associated flea-borne bacteria in pika fleas. These findings are also consistent with the hypothesis that rodent-associated pathogens could be acquired by pikas. Flea-borne pathogen spillover from rodents to pikas has the potential to exacerbate the more direct effects of climate that have been suggested to drive pika declines.


Assuntos
Vetores de Doenças , Lagomorpha/parasitologia , Sifonápteros/microbiologia , Animais , Bartonella/isolamento & purificação , Bartonella/patogenicidade , Infecções por Bartonella , Mudança Climática , Colorado , Montana , Peste/transmissão , Roedores/parasitologia
15.
PLoS One ; 15(10): e0240435, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33044983

RESUMO

Acclimation to environmental changes driven by alterations in gene expression will serve as an important response for some species facing rapid Anthropogenic climate change. Pikas, genus Ochotona, are particularly vulnerable to climate change and current trends suggest that only the highest, coldest elevations within their ranges may remain suitable habitat for these species. In this study we aimed to assess the role of changes in gene expression in potentially facilitating elevational movements in pikas by measuring gene expression in the only known captive pika population, Ochotona dauurica, in response to hypoxic conditions. Using a controlled experiment, we exposed four male pikas to oxygen concentrations characteristic of sea-level, 2,000 m, and 4,000 m for 5 days each. Using blood samples collected after each treatment, we used RNAseq to determine if candidate pathways were undergoing significant changes in gene expression at different levels of oxygen (~100%, ~77%, and ~61% of sea-level oxygen concentrations). Gene set enrichment analyses showed that gene sets associated with the oxidative phosphorylation pathway and electron transport chain were significantly enriched for up-regulated genes in the 4,000 m samples compared to samples from the same individuals at lower-elevation conditions. Up-regulation of these pathways is consistent with known mechanisms of oxygen compensation. Our results suggest that these pikas have the acclimation capacity to tolerate oxygen concentrations characteristic of any elevation within their species range and that gene expression can be changed in a matter of days to accommodate drastically different oxygen concentrations. Thus, rapid and radical elevational movements that may be required of some pika species to avoid warmer temperatures in the Anthropocene will likely not be limited by hypoxic stress.


Assuntos
Aclimatação/genética , Mudança Climática , Ecossistema , Regulação da Expressão Gênica , Hipóxia/fisiopatologia , Lagomorpha , Oxigênio/metabolismo , Altitude , Animais , Perfilação da Expressão Gênica , Masculino , Temperatura
16.
Exp Appl Acarol ; 81(4): 609-619, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32740688

RESUMO

Dermacentor everestianus is an important vector for several pathogens endemic in the Qinghai-Tibet Plateau. However, knowledge of its seasonal activity and abundance is limited. Hence, the seasonal dynamics of questing and host-feeding D. everestianus were investigated from March 2014 to February 2016 in Damxung County, north of Lhasa City in Tibet. During the 2-year period, questing ticks were collected weekly from two habitats (grassland and shrubs) by flag-dragging. Host-feeding ticks were removed weekly from sheep and their attachment sites were recorded. Plateau pikas (Ochotona curzoniae) captured by traps were examined for immature ticks from May to September 2014. Results revealed that questing D. everestianus were primarily distributed in grassland, whereas host-feeding adults and nymphs were mainly found on sheep, and larvae usually were on plateau pikas. Dermacentor everestianus can complete one generation per year with population overlap between the larvae and nymphs. Adults were mainly observed from February to April with the major peak occurring in late March. Additionally, unfed adults were detected on sheep from August to next February. Nymphs were found from late May to July and reached their peak in late June. Larvae collected during May and June reached peak numbers in late May.


Assuntos
Dermacentor/fisiologia , Lagomorpha/parasitologia , Estações do Ano , Ovinos/parasitologia , Animais , Tibet
17.
Vet Rec ; 187(3): 106-107, 2020 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-32764001

RESUMO

This focus article has been prepared by Paul Duff, Caroline Fenemore and Paul Holmes (APHA Wildlife Expert Group), with Beverley Hopkins (Wales Veterinary Science Centre), Jeff Jones (APHA Carmarthen Veterinary Investigation Centre), Maggie He and David Everest (APHA) and Mara Rocchi (Moredun Research Institute).


Assuntos
Infecções por Caliciviridae/veterinária , Surtos de Doenças/veterinária , Vírus da Doença Hemorrágica de Coelhos , Lagomorpha , Vigilância de Evento Sentinela/veterinária , Animais , Infecções por Caliciviridae/epidemiologia , Infecções por Caliciviridae/virologia , Reino Unido/epidemiologia
18.
Int J Syst Evol Microbiol ; 70(10): 5287-5295, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32841110

RESUMO

Four unknown strains belonging to the genus Arthrobacter were isolated from plateau wildlife on the Qinghai-Tibet Plateau of PR China. Phylogenetic analysis based on 16S rRNA gene sequences showed that the four isolates were separated into two clusters. Cluster I (strains 785T and 208) had the greatest 16S rRNA gene sequence similarity to Arthrobacter citreus (98.6 and 98.7 %, respectively), Arthrobacter luteolus (98.0 and 98.1%, respectively), Arthrobacter gandavensis (97.9 and 98.0 %, respectively) and Arthrobacter koreensis (97.6 and 97.7 %, respectively). Likewise, cluster II (strains J391T and J915) had the highest sequence similarity to Arthrobacter ruber (98.6 and 98.3 %, respectively) and Arthrobacter agilis (98.1 and 97.9  %, respectively). Average nucleotide identity and the digital DNA-DNA hybridization values illustrated that the two type strains, 785T and J391T, represented two separate novel species that are distinct from all currently recognized species in the genus Arthrobacter. These strains had DNA G+C contents of 66.0-66.1 mol% (cluster I) and 68.0 mol% (cluster II). The chemotaxonomic properties of strains 785T and J391T were in line with those of the genus Arthrobacter: anteiso-C15:0 (79.3 and 40.8 %, respectively) as the major cellular fatty acid, MK-8(H2) (65.8 %) or MK-9(H2) (75.6 %) as the predominant respiratory quinone, a polar lipid profile comprising diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, glycolipids and phospholipid, and A3α or A4α as the cell wall peptidoglycan type. On the basis of our results, two novel species in the genus Arthrobacter are proposed, namely Arthrobacter yangruifuii sp. nov. (type strain, 785T=CGMCC 1.16725T=GDMCC 1.1592T=JCM 33491T) and Arthrobacter zhaoguopingii sp. nov. (type strain, J391T=CGMCC 1.17382T=GDMCC 1.1667T=JCM 33841T).


Assuntos
Arthrobacter/classificação , Fezes/microbiologia , Filogenia , Animais , Arthrobacter/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Patos/microbiologia , Equidae/microbiologia , Ácidos Graxos/química , Lagomorpha/microbiologia , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
19.
FEMS Microbiol Lett ; 367(16)2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32840567

RESUMO

The Qinghai-Tibet Plateau is a harsh environment characterized by low temperature, high altitude and hypoxia, although some native mammals may adapt well to the extreme climate. However, how animal gut microbial community structure and function adapt to extreme cold climates is not well understood. Plateau pika (Ochotona curzoniae) is an ideal animal model with which to study the effects of climate change on host adaptation by studing intestinal microorganisms. Here, we used 16S rRNA sequencing technology combined with physiological methods to investigate plateau pika gut microbiota in summer and winter. Due to limited diet resources, the pikas in winter have a lower ability of degradation and fermentation for plant-based food (reduced cellulase activity and total short-chain fatty acids) by decreasing gut microbial diversity and some functional microbes, such as fiber-degrading bacteria Oscillospira and Treponema. Metagenomic prediction showed that most of those gene functions associated with metabolism (e.g. energy metabolism and lipid metabolism) were less abundant in winter, implying that the plateau pika slows diet fermentation and weakens energy requirements in the cold season. Our results have significance for explaining the mechanism of wild plateau mammals adapting to a high-altitude cold environment from the perspective of gut microbiome.


Assuntos
Adaptação Fisiológica/fisiologia , Temperatura Baixa , Microbioma Gastrointestinal/fisiologia , Lagomorpha/microbiologia , Animais , China , Ecossistema , Estações do Ano , Tibet
20.
BMC Vet Res ; 16(1): 235, 2020 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-32646425

RESUMO

BACKGROUND: Bartonella bacteria have been associated with an increasingly wide range of human and animal diseases. These emerging pathogens have been identified as being globally dispersed. Ticks and small rodents are known hosts of Bartonella and play a significant role in the preservation and circulation of Bartonella in nature. This study investigated the occurrence of hoist spp. in ticks (Acari: Ixodidae) and plateau pikas (Ochotona curzoniae) in Shiqu County, which is located on the eastern Qinghai-Tibetan Plateau in China. Shiqu County is spread over approximately 26,000 km2, with an average altitude of above 4200 m and a vast area of pastureland. RESULTS: A total of 818 ticks (Dermacentor everestianus, 79.0%, 646/818; Haemaphysalis qinghaiensis, 21.0%, 172/818) were collected from yaks in 4 villages of Shiqu County. Only Bartonella melophagi was detected in tick samples, with a total prevalence of 30.1% (246/818). The infection rates of B. melophagi in ticks from Arizha, Maga, Derongma, and Changxgma were 4.8, 76.8, 12.5, and 18.0%, respectively. The infection rate of B. melophagi in Maga was higher (p < 0.01) than those in other villages. Regarding plateau pikas, the total infection rate of Bartonella spp. was 21.7% (62/286), with 16.7% (12/72), 30.9% (25/81), 13.8% (9/65), and 23.5% (16/68) in Arizha, Maga, Derongma, and Changxgma, respectively. Finally, B. queenslandensis and B. grahamii were detected in plateau pika. No significant difference was observed (p > 0.05) in the infection rates between these study sites. CONCLUSION: To date, only D. everestianus and H. qinghaiensis were found in Shiqu County with high infection of Bartonella spp. in the ticks and plateau pika. The threats of Bartonella species to public health should be closely monitored.


Assuntos
Bartonella/genética , Bovinos/microbiologia , Bovinos/parasitologia , Ixodidae/microbiologia , Lagomorpha/microbiologia , Lagomorpha/parasitologia , Animais , Bartonella/isolamento & purificação , China , DNA Bacteriano/genética
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