Isolation of spotted fever group rickettsia from Apodemus speciosus in an endemic area in Japan.

A spotted fever group rickettsia was isolated from Apodemus mice captured near the site where a person had been infected in Miyazaki Prefecture. Antigenic characteristics of the isolate designated as strain TO-1 were compared with those of Rickettsia japonica (strain YH) and Rickettsia montana (ATCC VR611) by the indirect fluorescent antibody test with 14 serum specimens obtained from Apodemus speciosus, immune rat antisera against the strains TO-1 and YH, and three patients' sera. The titers of these sera measured with strain TO-1 were identical to those with strain YH, suggesting the antigenic similarity between these two organisms. It was also suggested that Apodemus speciosus is likely to be an important vertebrate host for a spotted fever group rickettsia in Japan.     

Ectoparasites on small mammals in Iceland: Origin and population characteristics of a species-poor insular community

The Icelandic small mammal fauna is depauperated as is the associated ectoparasite fauna. Three small mammal species occur, viz. Apodemus sylvaticus L., Mus musculus L., and Rattus norvegicus Berk. ( R. rattus is probably not a regular member). The mice supposedly came to the island by settlers from the 10th century and onwards.
Apodemus and Mus from five localities altogether had seven ectoparasite species, five mites and two fleas. All species occurred on Apodemus whereas Mus was infested by four. Compared with the numbers of ectoparasite species recorded in similar studies in the Nordic countries, there are conspicuously few species in Iceland. Further, Apodemus had an overall higher infestation frequency than Mus (90% and 30%, respectively) and a higher total density of ectoparasites (3.3–20.3 and 0.5 inds/host, respectively). The density figures were high compared with those for mainland Apodemus . Especially the mite Laelaps agilis C. L. Koch and the flea Ctenophthalmus agyrtes (Heller) were common on Icelandic Apodemus . Reduced competition among parasites and/or low predator pressure on small mammals may explain the density figures obtained.
The ectoparasite species compositions on small mammals in Scandinavia and Iceland have many features in common that renders it probable that Apodemus originate from Scandinavia.     

Chromosomal aberrancy and the level of fluctuating asymmetry in black-striped mouse (Apodemus agrarius): effects of disturbed environment

Analysis of chromosomal aberrations in bone marrow cells and determination of the level of fluctuating asymmetry (FA) for eight bilateral cranial traits were used to estimate effects of disturbed environment on natural populations of small mammals. During the spring and fall of 1994-2000 (except in 1999) black-striped mice (Apodemus agrarius) were collected from a polluted industrial area (Pancevo) and from an unpolluted reference site (Cer) in Serbia and Montenegro. Mice from the polluted area had significantly higher mean number of aberrant cells per individual than those in the reference site (p<0.01). Both sexes had the greater number of lesions in the polluted site than in the reference one. Also, there were no significant differences between sexes, neither within the same site/season nor between sites/seasons. Chi-square analysis of the difference between lesions per individual and aberrant cells per individual among sites showed that no site deviated from the expected difference (p=1.000). Developmental stability, assessed as FA, was reduced in the polluted area for two traits (width of lower jaw and length of the diastema lower jaw). Juvenile animals from the polluted area had significantly higher levels of FA compared to those from the reference site for three traits (length of the foramina incisiva, distance between incisor and the third upper molar, and length of the upper molars row). Juvenile animals from the polluted area had significantly higher levels of FA for three traits (length of the foramina incisiva, length of the lower molars row and width of lower jaw) compared to adult ones. In the polluted area seasonal differences were detected for two traits (length of the foramina incisiva and length of the upper molars row). Finally, Apodemus agrarius may be an important species for environmental quality evaluation studies based on an assay using a combination of end-points.     

Movements of field mice Apodemus agrarius (Pallas) in a suburban mosaic of habitats

Summary Movements of field mice (Apodemus agrarius) were studied using snap traps and coloured bait. The presence of coloured bait was recorded in 35% of field mice captured. Of animals with coloured bait, 60% had moved further than 100 m. The longest distances traversed by field mice exceeded 1000 m. It is suggested that live-trapping on a grid of several hectares is not an adequate method of studying small-mammal movements.     

Eimerians from different karyotypes of the Japanese wood mouse (Apodemus spp.), with descriptions of two new species and a redescription of Eimeria montgomeryae Lewis and Ball, 1983

Examination of 131 wood mice (Apodemus spp.) representing 2 species and 6 subspecies collected from the Japanese islands of Hokkaido, Honshu, Kyushu, and Tsushima showed that 70 mice (53%) had coccidian oocysts in their feces. These included 21 of 42 (50%) Apodemus argenteus argenteus; 7 of 14 (50%) Apodemus argenteus hokkaidi; 2 of 3 (67%) Apodemus argenteus sagax; 3 of 9 (33%) Apodemus speciosus ainu; 36 of 61 (59%) Apodemus speciosus speciosus; and 1 of 2 (50%) Apodemus speciosus tusimaensis. Four distinct coccidians were identified: Eimeria argenteus n. sp. from A. a. argenteus, A. a. hokkaidi, A. a. sagax, and A. s. speciosus; Eimeria inuyamensis n. sp. from A. a. argenteus, A. s. speciosus, and A. s. tusimaensis; Eimeria montgomeryae Lewis and Ball, 1983, from A. a. argenteus, A. a. hokkaidi, A. a. sagax, A. s. ainu, and A. s. speciosus; and Eimeria uptoni Lewis and Ball, 1983, from A. a. argenteus, A. a. hokkaidi, and A. s. speciosus. Standard karyotypes were prepared from selected specimens of each host subspecies. All 3 subspecies of A. argenteus and A. s. tusimaensis have a 2n = 46; A. s. ainu, from Hokkaido, has a 2n = 48; and A. s. speciosus has at least 2 chromosomal races, 1 on northern (2n = 48) and 1 on southern (2n = 46) Honshu. Both chromosomal races of A. s. speciosus, as well as the other subspecies of Apodemus examined, shared their coccidian parasites freely.     

A novel approach to field identification of cryptic Apodemus wood mice: calls differ more than morphology

Field identification of European wood mice Apodemus spp. is challenging due to their morphological resemblance and frequent sympatry. We developed discriminant functions based on body mass and acoustic variables of distress calls to identify three cryptic species of wood mice (Apodemus alpicola, Apodemus flavicollis and Apodemus sylvaticus) in Italy. We achieved an overall correct classification rate of 86–98%; the best results (100% correct classification) were obtained for Apodemus sylvaticus calls. This minimally invasive, effective and low‐cost method highlights the potential role of bioacoustics as a powerful tool for field discrimination of cryptic species of terrestrial mammals.     

A phylogenetic study of the genus Apodemus by sequencing the mitochondrial DNA control region

The sequences of the mitochondrial DNA control region (D-loop) and flanking tRNA genes (about 1000 bp) of 20 samples of wood mice (genus Apodemus ) were analyzed in order to clarify the relationships between different species belonging to the genus. The phylogenetic trees obtained using different methods showed similar topologies with distinct Karstomys ( Apodemus epimelas and Apodemus mystacinus ) and Sylvaemus ( Apodemus alpicola , Apodemus flavicollis , Apodemus hermonensis , Apodemus sylvaticus and Apodemus uralensis ) subtrees. Within Sylvaemus all species appeared to be closely related to each other, probably as result of a bush-like radiation event. Nevertheless, A. hermonensis seemed to be the first diverging branch followed by A. sylvaticus ; A. alpicola and A. flavicollis appeared to be very closely related. Three individuals of uncertain taxonomical status were included in the analysis: hypotheses as to their status are discussed. Further phylogenetic analysis was carried out combining the D-loop sequences of part of the samples of certain taxonomical status with 12S rRNA and cytochrome b sequences obtained by other researchers. Furthermore, I present a structure analysis of the D-loop in Apodemus as compared other rodent species.     

Small mammal populations in relation to hedgerow structure in an arable landscape

The population ecology of small mammals in hedgerows in arable farmland in eastern England is described. Features of hedgerows of importance to individual species are examined. Some 97% of the total 3042 mammals captured were wood mouse Apodemus sylvaticus , yellow-necked mouse Apodemus flavicollis , bank vole Clethrionomys glareolus and common shrew Sorex araneus . Small numbers of harvest mice Micromys minutus , field voles Microtus agrestis , pygmy shrews Sorex minutus and water shrews Neomys fodiens were also caught. Wood mouse, the most numerous species, showed a typical pattern of large numbers in autumn and winter, followed by a simultaneous decline over all hedges in early spring. Population changes were less clear in yellow-necked mouse and bank vole but the yellow-necked mouse was more scarce in the second year of study. Common shrews were most numerous in summer and declined rapidly in autumn. Hedgerow coppicing had a marked effect on yellow-necked mouse numbers but not on wood mouse. In an extensive survey of mammal numbers in relation to hedgerow features, ground cover was found to be the single largest factor influencing size of bank vole populations. Hedgerow condition (lack of gaps) was important to yellow-necked mice, which thrived only in well-established hedgerows. Wood mice appeared little influenced by the characteristics of the hedge. Common shrews were more abundant in hedgerows with adjacent permanent water.     

The dynamics of Wood mouse (Apodemus sylvaticus) populations in the Camargue

The ecology of two monospecific populations of Wood mice ( Apodemus sylvaticus ) was studied using mark-recapture techniques in a high grassland and a low grassland of the Camargue. Annual changes in population size resembled the classical pattern of variation for European Wood mice. Numbers were low in summer, and peaks in numbers occurred in autumn and decreased sharply in early spring. However, the densities of the populations in winter were higher than many other European Wood mouse populations. The Wood mouse population in the high grassland area was dense and showed regular variations throughout the year. In the low grassland area, the population was lower and showed less regular variations, especially in winter, coinciding with soil flooding. Reproduction-related differences between the demographic parameters of the two sexes pointed to the use of differential space use strategies by males and females.     

Multiplicity of B microchromosomes in a siberian population of mice <Emphasis Type="Italic">Apodemus peninsulae</Emphasis> (2<Emphasis Type="Italic">n</Emphasis> = 48 + 4–30 B chromosomes)

Differentiation of four Siberian populations of East-Asian (Korean) field mice (Apodemus peninsulae) inhabiting the basin of the mid-stream of the Yenisei River was carried out according to the variants of the B chromosome system. A multiplicity of B microchromosomes (from 4 to 30) was found for the first time in all 26 mice from the left shore of the Yenisei River in the mid-stream area. All of them probably belong to a population with B microchromosomes. It is likely that in this population further reorganization of B microchromosomes into B macrochromosomes typical of this species does not occur. Two mice from this population had a large number of B chromosomes (26) earlier not observed in this species. In one mouse, the modal number of B microchromosomes was 30. This is a new maximum number of B chromosomes in this mouse species.     

Selection of nest sites by wood mice Apodemus sylvaticus in a Mediterranean agro-forest landscape

One of the most important structures for an individual’s survival is a refuge, especially for species subject to significant predatory pressure or living in environments affected by severe climatic conditions. We studied how wood mice (Apodemus sylvaticus), inhabiting a Mediterranean environment, use nests and the factors that could be determining this use. Radio-tracking of 16 mice allowed us to detect 24 diurnal nests, which were used with a high fidelity rate (1.75 nests/animal). Nest sites that had been identified using radio-tracking were matched with 24 randomly selected non-nest sites (located within an area defined by the sum of all individual home ranges), and all sites were characterized according to their macro- and micro-habitat parameters. Using a generalized linear model, we tested three hypotheses: (1) a nest’s use is influenced by its proximity to food patches; (2) the degree of sheltering provided by each site influences its use; and (3) nest use is constrained by a combination of food- and shelter-related features. Females had higher nest fidelity than males, and the degree of sheltering provided by each site had a positive significant influence on its use. Nests offering higher protection (e.g., under thick vegetation), good drainage (e.g., sleep slopes), and lower human and predatory disturbance (far from orchards) were most often used. The proximity to food patches seemed to negatively influence nest use. Results indicate the need to preserve patches of natural dense vegetation near riparian habitats, which is in agreement with the focus of mammalian protection plans in Mediterranean agricultural landscapes. These patches are important areas for Apodemus sylvaticus, an acorn disperser species, which is preyed on by raptors and mammalian carnivores.     

EP-1对雄性中华姬鼠和黑线姬鼠繁殖力的影响

为了检测左炔诺孕酮-炔雌醚（EP-1）对雄性中华姬鼠和黑线姬鼠的不育效果, 将32只雄性中华姬鼠和30只雄性黑线姬鼠分为 30mg/kg 单剂量组、30mg/kg多剂量组和对照组, 15d 和 45d 后剖检, 比较睾丸、附睾、储精囊、精子密度、睾酮含量及睾丸组织形态的变化。结果发现：给药后第 15 天,两种试鼠的睾丸、附睾、储精囊的重量较对照组明显降低; 精子密度、睾酮含量显著下降; 曲细精管结构破坏明显。给药后第45天,处理组各生理指标继续下降,但与第15天相比差别不显著;单剂量组和多剂量组在两个时间点的差别并不显著。结果表明,EP-1对雄性中华姬鼠和黑线姬鼠的繁殖器官有显著抑制效果,单次给药与多次给药的不育效果差别不大。     

Genetic relationships between European and Transcaucasian mice of the genus Apodemus Kaup]

Genetic relations between four European mice species of the genus Apodemus (Apodemus sylvaticus, A. flavicollis, A. microps and A. falzfeini) and five Transcaucasian ones (A. mystacinus, A. microps, and the forms No 2, 3p, 3f) were studied for 37 biochemical loci. Close genetic relations were demonstrated between the mice of subgenus Sylvaemus and A. mystacinus. A. microps and A. falzfeini from the Caucasus were shown conspecific to these species from the Ukraine and the presence of the two new different species--the form No 2 and 3p in the Caucasus was established.     

Evaluation of cytophysiological state of testis in forest voles living in the radioactively contaminated areas

We made a cytophysiological analys of testis in Clethrionomus rutilus and Apodemus sylvaticus inhabiting a contaminated area of the East Ural Radioactive Trace (EURT). The study showed that in the norm these species differed in the total number of cells of spermatogenous epithelium, due to interspecific difference. In the sampling plot a concentration of 90Sr in Clethrionomus rutilus was 2 times higher than that in Apodemus sylvaticus. Maximum destructive changes in endocrine and exocrine (seminiferous tubules) section of testis and increased proliferation activity of spermatogenous epithelium were observed in Clethrionomus rutilus.Increased proliferation activity was found as a compensatory-protective reaction which promote the maintenance of the germ cell number. Such changes were not observed in Apodemus sylvaticus.     

How many species of Apodemus and Rattus occur in China? A survey based on mitochondrial cyt b and morphological analyses

Apodemus(mice) and Rattus(rats) are the top rodent reservoirs for zoonoses in China, yet little is known about their diversity. We reexamined the alpha diversity of these two genera based on a new collection of specimens from China and their cyt b sequences in Gen Bank. We also tested whether species could be identified using external and craniodental measurements exclusively. Measurements from 147 specimens of Apodemus and 233 specimens of Rattus were used for morphological comparisons. We analysed 74 cyt b sequences of Apodemus and 100 cyt b sequences of Rattus to facilitate phylogenetic estimations. Results demonstrated that nine species of Apodemus and seven species of Rattus, plus a new subspecies of Rattus nitidus, are distributed in China. Principal component analysis using external and craniodental measurements revealed that measurements alone could not separate the recognized species. The occurrence of Rattus pyctoris in China remains uncertain.     

The relationships and ecology of Apodemus sylvaticus from the Small Isles of the Inner Hebrides, Scotland

Island "races" of the field mouse ( Apodemus sylvaticus ) have often been used to support particular theories of colonization or microevolution. Comparisons between Apodemus from a group of four islands in the Inner Hebrides (Rhum, Muck, Eigg and Canna) give support to the idea that the amimals were introduced onto these islands by man—mice first becoming established on Eigg and thence being transported to the other islands.     

农田生态保留带中小林姬鼠的种群动态和结构

栖息地状况对小型兽类种群动态具有明显影响。在质量好,食物资源丰富,隐蔽条件优良的栖息地中小型兽类具有较高的存活率,种群繁殖时间更长,体重比较高。有关栖息地和种群动态方面国内外已有研究报道（Brown,1988;Corp et al．,1997;Quinn et al．,2003;Schnurr et al．,2004）。     

黑线姬鼠种群结构与携带汉坦病毒相关性

汉坦病毒(Hantavirus,HV)是肾综合症出血热(Hemorrhagic fever with renal syndrome,HFRS)的主要病原体之一,HV的主要宿主动物为黑线姬鼠(Apodemus agrarius).针对西安市HFRS的持续高发病率,2010年7月-9月对西安市HFRS 疫区捕获的110只黑线姬鼠(阳性62只)进行年龄、性别鉴定.通过病毒RNA提取分析,发现黑线姬鼠雌雄个体携带病毒无显著差异,但是不同年龄段黑线姬鼠携带汉坦病毒却具有显著差异,年龄结构与病毒携带具有极显著的相关性.     

Absence of spermatozoal CD46 protein expression and associated rapid acrosome reaction rate in striped field mice (Apodemus agrarius)

Background  

In rodents, the cell surface complement regulatory protein CD46 is expressed solely on the spermatozoal acrosome membrane. Ablation of the CD46 gene is associated with a faster acrosome reaction. Sperm from Apodemus flavicollis (yellow-necked field mice), A. microps (pygmy field mice) and A. sylvaticus (European wood mice) fail to express CD46 protein and exhibit a more rapid acrosome reaction rate than Mus (house mice) or BALB/c mice. A. agrarius (striped field mice) belong to a different Apodemus subgenus and have pronounced promiscuity and large relative testis size. The aim of this study was to determine whether A. agrarius sperm fail to express CD46 protein and, if so, whether A. agrarius have a faster acrosome reaction than Mus.     

Borrelia japonica in Nature: Genotypic Identification of Spirochetes Isolated from Japanese Small Mammals

Spirochetes were isolated from earlobe tissues of shrews (Sorex unguiculatus, Sorex caecutiens, and Crocidura dsinezumi), voles (Clethrionomys rufocanus), and mice (Apodemus argenteus and Apodemus speciosus) captured in various localities in Japan. The isolates were identified as Borrelia japonica by rRNA gene restriction fragment length polymorphism analysis. The data suggest that these small mammals are candidates of reservoir hosts for B. japonica.