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Numerous interactions between plants and animals vary in their outcome between antagonism and mutualism. Interactions between plants and scatter‐hoarding animals provide a prime example of this phenomenon. Scatterhoarders consume large quantities of seeds (potentially reducing plant establishment), yet also disperse seeds and bury them in shallow caches (potentially improving recruitment). Despite intense work on mechanisms that cause these interactions to shift along an antagonism–mutualism continuum, it remains difficult to quantify their final outcomes.We demonstrate how readily available field data can be used to reach this goal, with interactions between rodents and two oaks species (sessile oak Quercus petraea, and red oak Q. rubra) as an empirical example. Our approach consists of quantifying the net outcome of the interaction through collecting data on different vital rates (e.g. probability that cached seeds survive to germination, probability of seedling recruitment with and without rodents; near and far from conspecific trees; with and without seed pilferage) and assembling them in a simple mathematical model.We found that during the period of the study, interactions between scatter‐hoarding rodents and both focal oaks were antagonistic. Even though caching increased the likelihood of seedling establishment, this effect was not strong enough to compensate for the costs of seed predation. Furthermore, there was no evidence that the short‐distance transportation that is usually provided by small mammals benefited early oak recruitment.Synthesis. Our empirical results demonstrated that certain common assumptions – that caching by rodents invariably benefits plant recruitment; that improved seedling establishment after seed burial is sufficient to make plant–scatterhoarder interactions mutualistic; that transportation away from maternal plants is highly beneficial—do not always hold and should be tested rather than taken for granted. [ABSTRACT FROM AUTHOR]

Yellow-necked mouse (Apodemus flavicollis Melchior, 1834) is a typical representative of European fauna, whose distribution range is confined to the broad-leaved forest zone and occupies a considerable territory of Eurasia from Great Britain and northern Spain to the Urals. The Urals is the eastern boundary of the distribution of yellow-necked mouse. The yellow-necked mouse surviving in the Balkan region recolonized the main part of the Western Palearctic region after the Last Glacial Maximum. Thus, all of Europe and Western Russia were rapidly colonized. There are little data on the Holocene history of A. flavicollis in the east of the range. Therefore, regional populations in the Urals are of particular interest. We analyzed the variability of molars of yellow-necked mouse from modern populations (marginal and from the main part of the range) and fossil molars of yellow-necked mouse in the phylogeographical context. A comparative analysis of the morphological variability of yellow-necked mouse molars was performed using a set of metric and non-metric dental variables. We considered the first and second upper and lower molars of the yellow-necked mouse from recent populations: Zhytomir region (Ukraine), n = 76; Bashkortostan Republic (Russia), n = 84; Sverdlovsk region (Russia), n = 68, and Holocene samples from Nizhneirginsky Grotto sediments (Sverdlovsk Region, Russia), n = 43. As a result of this study, the morphological specificity of modern and Holocene A. flavicollis from the Urals territory was revealed. The obtained results allowed to make assumptions about the history of A. flavicollis in the Urals and to compare these results with those of the European colonization of this species. [ABSTRACT FROM AUTHOR]

Elevation is one of the most important natural gradients that is strongly shaping communities across relatively small areas. However, few studies have followed the temporal dynamics of elevational patterns, even in organisms for which population and community fluctuations have been extensively studied, such as rodents. Here we report the multiannual dynamics of small-mammal communities along an elevational gradient in the Southern Carpathians. During a 5-year survey, we conducted live-trapping in forested and shrubby habitats, at elevations between 820 and 2040 m. We used partial constrained multivariate analysis and mixed-effects models to test the effect of elevation, year, and their interaction. Community metrics differed significantly between even and odd years and temporal changes had stronger effect on small-mammal communities than elevation. The 2-year pattern of dynamics was especially marked in the yellow-necked field mouse (Apodemus flavicollis (Melchior, 1834)). Species abundance was predicted not only by year and elevation, but also by their interaction. The dominant rodent species, the bank vole (Myodes glareolus (Schreber, 1780)) and A. flavicollis, showed opposite annual patterns in relation to elevation, possibly as a strategy to avoid competition. Failure to consider the fluctuations in montane small-mammal communities may lead to wrong assessment of species' state and distribution. [ABSTRACT FROM AUTHOR]

Theoretical modelling predicts that the thermoregulatory strategies of endothermic animals range from those represented by thermal generalists to those characteristic for thermal specialists. While the generalists tolerate wide variations in body temperature (Tb), the specialists maintain Tb at a more constant level. The model has gained support from inter-specific comparisons relating to species and population levels. However, little is known about consistent among-individual variation within populations that could be shaped by natural selection. We studied the consistency of individual heterothermic responses to environmental challenges in a single population of yellow-necked mice (Apodemus flavicollis), by verifying the hypothesis that Tb variation is a repeatable trait. To induce the heterothermic response, the same individuals were repeatedly food deprived for 24 h. We measured Tb with implanted miniaturised data loggers. Before each fasting experiment, we measured basal metabolic rate (BMR). Thus, we also tested whether individual variation of heterothermy correlates with individual self-maintenance costs, and the potential benefits arising from heterothermic responses that should correlate with body size/mass. We found that some individuals clearly entered torpor while others kept Tb stable, and that there were also individuals that showed intermediate thermoregulatory patterns. Heterothermy was found to correlate negatively with body mass and slightly positively with the BMR achieved 1-2 days before fasting. Nonetheless, heterothermy was shown to be highly repeatable, irrespective of whether we controlled for self-maintenance costs and body size. Our results indicate that specialist and generalist thermoregulatory phenotypes can co-exist in a single population, creating a heterothermy continuum. [ABSTRACT FROM AUTHOR]

A specimen of the yellow-necked wood mouse Apodemus flavicollis possessing a remarkably extensive neck collar was trapped in the Slavkovský les Protected Landscape Area in November 2018. Some additional specimens with similar colouration were found in collections of the Karlovy Vary Museum. Detailed examination of a large collection of skins revealed considerable variation in neck colouration ranging from a complete absence of the yellow spot to presence of a very extensive yellow collar. [ABSTRACT FROM AUTHOR]

Abstract Information on intra- and inter-specific social tolerance is useful to evaluate the role of social interactions at shaping population dynamics. This is particularly interesting for sympatric species with similar ecological requirements that can be potential competitors. In this light, we investigated multiple captures of Apodemus flavicollis, A. sylvaticus and Myodes glareolus constituting a guild of forest- and ground-dwelling rodents in central Italy. Small mammals were live-trapped every other month for four years. Multiple captures made up 3% of total captures, with a very similar occurrence in all three species. In each species the number of multiple captures increased with both population density and amount of caught conspecifics. Individuals of the same species were caught together in 85% of multiple captures. In all three species, sexually active individuals were also involved in homosexual and interspecific multiple captures, suggesting that multiple captures are not primarily caused by reproductive behaviour. The occurrence of intra- and inter-specific captures and the absence of injury signs in individuals trapped together suggest social tolerance and support the hypothesis of weak competitive interactions between these species constituting a guild of rodents in this sub-Mediterranean deciduous oak forest. As multiple capture events can occur during live trapping, we stress the importance of utilising this secondary data to gain useful information on social factors influencing small mammal populations. [ABSTRACT FROM AUTHOR]

Supernumerary chromosomes sporadically arise in many eukaryotic species as a result of genomic rearrangements. If present in a substantial part of species population, those are called B chromosomes, or Bs. This is the case for 70 mammalian species, most of which are rodents. In humans, the most common types of extra chromosomes, sSMCs (small supernumerary marker chromosomes), are diagnosed in approximately 1 of 2000 postnatal cases. Due to low frequency in population, human sSMCs are not considered B chromosomes. Genetic content of both B-chromosomes and sSMCs in most cases remains understudied. Here, we apply microdissection of single chromosomes with subsequent low-pass sequencing on Ion Torrent PGM and Illumina MiSeq to identify unique and repetitive DNA sequences present in a single human sSMC and several B chromosomes in mice Apodemus flavicollis and Apodemus peninsulae. The pipeline for sequencing data analysis was made available in Galaxy interface as an addition to previously published command-line version. Human sSMC was attributed to the proximal part of chromosome 15 long arm, and breakpoints leading to its formation were located into satellite DNA arrays. Genetic content of Apodemus B chromosomes was species-specific, and minor alterations were observed in both species. Common features of Bs in these Apodemus species were satellite DNA and ERV enrichment, as well as the presence of the vaccinia-related kinase gene Vrk1. Understanding of the non-essential genome elements content provides important insights into genome evolution in general. [ABSTRACT FROM AUTHOR]

Wood mice of the genus Apodemus belong to the most frequent and epidemiologically important rodents of Europe and adjacent regions. Previous studies showed that in the Middle East region species of this genus exhibit extraordinary morphological similarity precluding their proper determination without application of molecular characters. In order to determine the species of the studied populations and to obtain an insight into their phylogeographic history, we analyzed their genetic variation. We sequenced 1139 bp fragment of the mitochondrial DNA control region and flanking tRNA genes in samples collected from six localities. Phylogenetic analyses revealed presence of distinct clades corresponding to species A. uralensis and A. witherbyi. In most localities we confirmed presence of both species which suggests their large sympatric and syntopic occurrence. We recognized an extensive genetic variability, 38 specimens of A. uralensis belong to 32 distinct haplotypes, while 19 specimens of A. witherbyi to 14 haplotypes. We confirmed presence of several distinct haplotypes that may originate from multiple wood mouse colonization waves from distinct geographic regions. [ABSTRACT FROM AUTHOR]

Abstract: The identification of field mice Apodemus flavicollis, Apodemus sylvaticus, and Apodemus alpicola represents a challenge for field scientists due to their highly overlapping morphological traits and habitats. Here, we propose a new fast real‐time PCR method to discriminate the three species by species‐specific TaqMan assays. Primers and probes were designed based on the alignment of 54 cyt‐b partial sequences from 25 different European countries retrieved from GenBank. TaqMan assays were then tested on 133 samples from three different areas of Italy. Real‐time PCR analysis showed 92 samples classified as A. flavicollis, 13 as A. sylvaticus, and 28 as A. alpicola. We did not observe any double amplification and DNA sequencing confirmed species assignment obtained by the TaqMan assays. The method is implementable on different matrices (ear tissues, tail, and blood). It can be used on dead specimens or on alive animals with minimally invasive sampling, and given the high sensitivity, the assay may be also suitable for degraded or low‐DNA samples. The method proved to work well to discriminate between the species analyzed. Furthermore, it gives clear results (amplified or not) and it does not require any postamplification handling of PCR product, reducing the time needed for the analyses and the risk of carryover contamination. It therefore represents a valuable tool for field ecologists, conservationists, and epidemiologists. [ABSTRACT FROM AUTHOR]

Variation of the 838-bp fragment of the mitochondrial cytb gene was analyzed in Sylvaemus uralensis from the northern macroslope of the Western Caucasus. On the basis of two fixed nonsynonymous substitutions, cytb sequences of the population sample studied can be considered as a distinct Lago-Naki haplogroup, which is clustered in the European cytb lineage. As estimated on the basis of the known rate of substitutions per third codon position in S. sylvaticus, the population must have been isolated for all or a part of the last glaciation period (10000 to 100000 years ago). The observed differentiation of cytb haplotypes is indicative of the refugial distribution of S. uralensis in the northern macroslope of the Western Caucasus, as well as of a secondary contact between the Caucasian and the Russian Plain populations during the Holocene. [ABSTRACT FROM AUTHOR]

Having a thorough understanding of animal feeding behaviour is a basic aim in ecology. Food represents a crucial resource that can strongly rule animal populations, especially where food supplies are seasonal, such as in temperate areas. In Italy, sub-Mediterranean forests dominated by deciduous oaks are commonly inhabited by the yellow-necked mouseApodemus flavicollis, the wood mouseA. sylvaticusand the bank voleMyodes glareolus. Despite the rich literature regarding their diet composition in northern Europe, to our knowledge no studies have been published on food preferences of these rodents in syntopy in sub-Mediterranean deciduous forests. Feeding preferences of 33A. flavicollis, 10A. sylvaticusand 18 M. glareoluson reproductive parts (flowers, unripe and ripe fruits) of 26 representative plant species in a deciduous oak forest of central Italy were investigated through seasonal cafeteria-style experiments. Our findings evidence thatA. flavicollisexhibited distinct preferences in all seasons, highlighting a relevant affinity only for a strict array of plant species, and acting as seed specialist.Apodemussylvaticusshowed generalist food habits, eating all foods with similar consumption patterns, whereasM. glareolusoccupied an intermediate position between theApodemusspp. Indeed the bank vole did not show a clear preference for some foods over others in spring and summer, while in autumn the consumption significantly differed resulting in a strong preferences overlap withA. flavicollis. This result suggests potential competitive interactions between these rodents in our study area, especially regarding a crucial resource such as acorns. By using seasonal cafeteria-style experiments we were able to delineate the feeding behaviour and preferences ofA. flavicollis,A. sylvaticusandM. glareolustowards several plant parts pertaining to a wide array of species. Our findings can help future studies regarding these rodents focusing on factors influencing their population dynamics, such as trophic resources and competition. [ABSTRACT FROM AUTHOR]

Near infrared reflectance spectroscopy is a highly promising method for estimating food quality in small mammals. The method used to prepare rodent stomach content samples, however, may influence nitrogenous substance results. In this study, we focus on comparing methods of preparation of samples and finding the optimal preparation method, which means saving time and costs as well as maintenance of reliability and precision of estimation. We examined 1497 stomachs of the following species: Apodemus flavicollis , A. sylvaticus, Clethrionomys glareolus and Microtus arvalis . We used two preparation methods (grinding and abrasion). Where possible, cardiac and pyloric stomach sections were also examined separately. We found no significant difference between these data, hence only financial, time and equipment factors need determine the processing method in future studies. [ABSTRACT FROM AUTHOR]

The diversity of small mammal communities (SMCs) shows the sustainability of habitats, especially agricultural ones. Gathered over three years, data from 18 sites in Lithuania were used to analyse factors related to several dependent parameters, namely, diversity (Shannon's H, dominance index and number of species trapped); the relative abundance of species in SMCs; and the abundances and proportions of the four most numerous species, specifically common vole, striped field mouse, yellow-necked mouse and bank vole. Using the General Linear Model, we assessed the influence of habitat type (commercial orchards, berry plantations, control meadows and control forests with at least two of these present at every investigation site), age of the orchard or plantation, intensity of agriculture, season and location (central, northern, eastern, southern and western parts of the country). To control temporal data variability, the year was used as a continuous predictor. The model was valid, and explained 14–31% of the listed parameters with p < 0.005 or higher, with the exception of the dominance index and the proportion of the common vole. The time factor (year and season, p < 0.001), intensity of agriculture and site location (p < 0.05) had the highest influences on the model, while those of the habitat type and its age were not significant. Univariate results suggest that old commercial orchards with low intensities of agricultural practice play a role in maintaining the diversity and abundance of SMCs. [ABSTRACT FROM AUTHOR]

Stochastic processes play an important role in the infectious disease dynamics of wildlife, especially in species subject to large population oscillations., Here, we study the case of a free ranging population of yellow-necked mice ( Apodemus flavicollis) in northern Italy, where circulation of Dobrava-Belgrade hantavirus (DOBV) has been detected intermittently since 2001, until an outbreak emerged in 2010., We analysed the transmission dynamics of the recent outbreak using a computational model that accounts for seasonal changes of the host population and territorial behaviour. Model parameters were informed by capture-mark-recapture data collected over 14 years and longitudinal seroprevalence data from 2010 to 2013., The intermittent observation of DOBV before 2010 can be interpreted as repeated stochastic fadeouts after multiple introductions of infectious rodents migrating from neighbouring areas. We estimated that only 20% of introductions in a naïve host population results in sustained transmission after 2 years, despite an effective reproduction number well above the epidemic threshold (mean 4·5, 95% credible intervals, CI: 0·65-15·8). Following the 2010 outbreak, DOBV has become endemic in the study area, but we predict a constant probability of about 4·7% per year that infection dies out, following large population drops in winter. In the absence of stochastic fadeout, viral prevalence is predicted to continue its growth to an oscillating equilibrium around a value of 24% (95% CI: 3-57)., We presented an example of invasion dynamics of a zoonotic virus where stochastic fadeout have played a major role and may induce future extinction of the endemic infection. [ABSTRACT FROM AUTHOR]

B chromosomes (Bs) are known for more than hundred years but their origin, structure and pattern of evolution are not well understood. In the past few years new methodological approaches, involving isolation of Bs followed by whole DNA amplification, DNA probe generation, and fluorescent in situ hybridization (FISH) or the B chromosome DNA sequencing, has allowed detailed analysis of their origin and molecular structure in different species. In this study we explored the origin of Bs in the yellow-necked wood mouse, Apodemus flavicollis, using generation of microdissected DNA probes followed by FISH on metaphase chromosomes. Bs of A. flavicollis were successfully isolated and DNA was used as the template for B-specific probes for the first time. We revealed homology of DNA derived from the analyzed B chromosomes to the pericentromeric region (PR) of sex chromosomes and subtelomeric region of two pairs of small autosomes, but lower homology to the rest of the Y chromosome. Moreover, all analysed Bs had the same structure regardless of their number per individual or the great geographic distance between examined populations from the Balkan Peninsula (Serbia) and Eastern Europe (south region of Russia and central Belarus). Therefore, it was suggested that B chromosomes in A. flavicollis have a unique common origin from the PR of sex chromosomes, and/or similar evolutionary pattern. [ABSTRACT FROM AUTHOR]

Vertical stratification of the arboreal habitat allows the coexistence of several species in a given area, because the complex arboreal strata can be used in different ways by arboreal and scansorial mammals. The present report experimentally investigated the gait metrics on different arboreal substrates, of three sympatric rodents living in a deciduous forest in Poznań, Poland. Arboreal locomotion was compared between the burrowing striped field mouse, Apodemus agrarius , the scansorial bank vole, Myodes glareolus , and the more arboreal yellow-necked mouse, Apodemus flavicollis . We filmed two wild-caught individuals from each species walking on four different substrate diameters (2 mm, 5 mm, 10 mm, 25 mm) and three different inclinations (45° descending, horizontal, 45° ascending) at 240 fps and collected a set of gait parameters from a total of 273 complete cycles. Our results did not demonstrate clear relationships between arboreal locomotion and the ecology of the three species. Only A. flavicollis exhibited locomotor features partly associated with arboreal competence, including lower velocity and diagonality on narrow substrates and asymmetrical gaits on wider ones. On the other hand, the two Apodemus species, despite their different ecologies, shared a few locomotor similarities, such as velocity regulation primarily by stride frequency, and similar effects of substrate size and inclination on diagonality, duty factor, and duty factor index indicating the possibility of a phylogenetic signal. Because the selected gait parameters provided limited insight into the ability of small mammals to move competently through an arboreal habitat, these findings indicate that the relationship between behaviour and ecology is complex. [ABSTRACT FROM AUTHOR]

Several studies regarding acorn choice by granivorous rodents have been conducted in dry Mediterranean oak forests, mainly composed by evergreen oaks. However, a lack of knowledge still persists about this subject in sub-Mediterranean forests dominated by deciduous oaks. We investigated the choice betweenQuercus cerrisandQ. pubescensacorns by terrestrial small mammals in a deciduous oak forest of Central Italy, dominated byQ. cerris. Using a cafeteria-style feeding experiment, we tested 14Apodemus flavicollis, and 10Myodes glareolus. Animals were kept in outdoor experimental enclosures and given simultaneously a sample of acorns of the two oak species collected in situ. All seeds were sound and of the same size, shape and weight. Seed consumption was checked regularly, to record the percentage of consumed acorn sample. To evaluate a possible influence of pericarp on choice, acorns were presented both whole and shelled. Biochemical composition of seeds was analysed. Acorns of both oaks were similar in protein, lipid, carbohydrate and ash contents and energetic value, differing only in tannins and fibre content, withQ. pubescenshaving 51% less tannins and 35% less fibres thanQ. cerris. The cafeteria experiments revealed a significant feeding preference by rodents for the less commonQ. pubescensacorns, except forM. glareoluswhen presented with whole acorns. This overall preference, observed also at the individual level, could reflect a general foraging strategy aimed at maximising metabolisable energy and nutrients intake, avoiding anti-nutrients (i.e. tannins). To our knowledge, this is the first study on acorn choice by terrestrial rodents in sub-Mediterranean deciduous oak forests. Our findings not only provide information about the feeding behaviour of these species, but also may help future researchers to evaluate the role of these food resources in small mammal abundance, spatial distribution and population dynamics. [ABSTRACT FROM AUTHOR]

Home range size generally decreases with increasing population density, but testing how this relationship is influenced by other factors (e.g., food availability, kin structure) is a difficult task. We used spatially explicit capture-recapture models to examine how home range size varies with population density in the yellow-necked mouse ( Apodemus flavicollis). The relationship between population density and home range size was studied at two distinct phases of population fluctuations induced by beech ( Fagus sylvatica) masting: post-mast peak in abundance (first summer after mast, n = 2) and subsequent crash (second summer after mast, n = 2). We live-trapped mice from June to September to avoid the confounding effects of autumn seedfall on home range size. In accordance with general predictions, we found that home range size was negatively associated with population density. However, after controlling for the effect of density, home ranges of mice were larger in post-mast years than during the crash phase. This indicates a higher spatial overlap among neighbors in post-mast years. We suggest that the increased spatial overlap is caused by negative density-dependent dispersal that leads to high relatedness of individuals within population in the peak phase of the cycle. [ABSTRACT FROM AUTHOR]

Bartonellae cause zoonotic diseases and are transmitted by arthropods. Rodents are reservoirs for most Bartonella spp. As the knowledge about Bartonella in rodents and their parasitizing ectoparasites is scarce in Germany, this study's objectives were to investigate Bartonella spp. in small mammals and in their ectoparasites. A total of 79 small mammals (seven species) were captured and their ectoparasites collected at seven sites around Leipzig, Saxony, Germany, in 2010 and 2011. Altogether, 79 spleen samples, 135 fleas (five species) and 365 ticks (three species) were investigated for Bartonella spp. by PCR targeting the ITS 16S-23S rRNA region. In total, 52 (65.8 %) small mammals, 73 (54.1 %) fleas and 51 (16.3 %) ticks were positive for Bartonella spp. Most small mammals were positive for uncultured Bartonella sp. ( n = 29) followed by Bartonella grahamii ( n = 12), Bartonella taylorii ( n = 8) and Bartonella sp. N40 ( n = 3). Likewise, most fleas were positive for uncultured Bartonella sp. ( n = 45) followed by B. grahamii ( n = 14), B. taylorii ( n = 8), B. sp. N40 ( n = 5) and Bartonella elizabethae ( n = 2). Most ticks were positive for B. sp. ( n = 19) followed by B. grahamii ( n = 10), Bartonella chomelii ( n = 3), B. taylorii ( n = 2) and B. sp. N40 ( n = 1). This study's results suggest that rodents and fleas may be reservoirs and vectors, respectively. Zoonotic B. grahamii and B. elizabethae were found in rodents and their fleas. Therefore, humans may contract Bartonella infection by contact to wild rodents. Ticks seem of minor importance in transmitting Bartonella spp. found in fleas and rodents. However, ticks might be vectors of B. chomelii. [ABSTRACT FROM AUTHOR]

Studying the isotopic composition of the hair of two rodent species trapped in the territories of Great Cormorant colonies, we aimed to show that Great Cormorants transfer biogens from aquatic ecosystems to terrestrial ecosystems, and that these substances reach small mammals through the trophic cascade, thus influencing the nutrient balance in the terrestrial ecosystem. Analysis of δ 13 C and δ 15 N was performed on two dominant species of small mammals, Apodemus flavicollis and Myodes glareolus , inhabiting the territories of the colonies. For both species, the values of δ 13 C and δ 15 N were higher in the animals trapped in the territories of the colonies than those in control territories. In the hair of A. flavicollis and M. glareolus , the highest values of δ 15 N (16.31 ± 3.01‰ and 17.86 ± 2.76‰, respectively) were determined in those animals trapped in the biggest Great Cormorant colony. δ 15 N values were age dependent, highest in adult A. flavicollis and M. glareolus and lowest in juvenile animals. For δ 13 C values, age-dependent differences were not registered. δ 15 N values in both small mammal species from the biggest Great Cormorant colony show direct dependence on the intensity of influence. Biogenic pollution is at its strongest in the territories of the colonies with nests, significantly diminishing in the ecotones of the colonies and further in the control zones, where the influence of birds is negligible. Thus, Great Cormorant colonies alter ecosystem functioning by enrichment with biogens, with stable isotope values in small mammals significantly higher in the affected territories. [ABSTRACT FROM AUTHOR]

The behavioral responses of male mound-building mice Mus spicilegus to odours from males of their own species and odors from males of another species - house mouse Mus musculus musculus and yellow-necked mouse Apodemus flavicollis were studied in an attraction-avoidance test in order to clarify the role of odour in their relationships in wild populations in agricultural land. The experiments were carried out in the breeding season. M. spicilegus males showed attraction to conspecific odours from the same sex, but indifference to heterospecific odours of male M. m. musculus, and avoidance to odours of male A. flavicollis. The behavioural responses to conspecific and heterospecific odours are discussed in terms of attractiveness of odour cues, according to their significance in social relationships and spacing behaviour. [ABSTRACT FROM AUTHOR]

Since the density of simple sequence repeats (SSRs) may vary between different chromosomes of the same species in eukaryotic genomes, we screened SSRs of the whole genome of the yellow necked mouse, Apodemus flavicollis, in order to reveal SSR profiles specific for animals carrying B chromosomes. We found that the 2200 bp band was amplified by primer (CAG)4AC to a highly increased level in samples with B chromosomes. This quantitative difference (B-marker) between animals with (+B) and without (0B) B chromosomes was used to screen 20 populations (387 animals). The presence/absence of Bs was confirmed in 96.5% of 342 non mosaic individuals, which recommends this method for noninvasive B-presence detection. A group of 45 animals with mosaic and micro B (μB) karyotypes was considered separately and showed 55.6% of overall congruence between karyotyping and molecular screening results. Relative quantification by qPCR of two different targeted sequences from B-marker indicated that these B-specific fragments are multiplied on B chromosomes. It also confirms our assumption that different types of Bs with variable molecular composition may exist in the same individual and between individuals of this species. Our results substantiate the origin of Bs from the standard chromosomal complement. The B-marker showed 98% sequence identity with the serine/threonine protein kinase VRK1 gene, similarly to findings reported for Bs from phylogenetically highly distant mammalian species. Evolutionarily conserved protein-coding genes found in Bs, including this one in A. flavicollis, could suggest a common evolutionary pathway. [ABSTRACT FROM AUTHOR]

The identification of the wood mouse Apodemus sylvaticus and the yellow-necked mouse Apodemus flavicollis in the field has challenged many generations of field mammalogists, particularly in northern Spain and continental Italy. These two species present highly similar morphologic and morphometric characteristics especially when they are sympatric. Existing identification methods rely on morphometric and biometric measurements collected on killed or etherized animals, whereas in many field studies measurement may be taken only on live and awake animals. Genetic methods, instead, are time consuming, expensive and do not allow immediate identification in the field, which is a requirement in many types of ecological works. To contribute in filling this knowledge gap, the aims of this research were: 1) to assess biometric measurements (weight and length of hind foot) that allow species identification on live and awake animals and 2) to develop a predictive model and related software that, subject to refinement based on study area, will allow researchers to prioritise the selection of individuals to be identified by molecular approach. This model, based on a large (>1500) sample of individuals captured in two different sites in central Italy, should help to classify live and awake individuals of Apodemus species. Attached to this paper is a Microsoft Excel spreadsheet that may be used to apply the model to new data. [ABSTRACT FROM AUTHOR]

The impact of two different environments (climax forest and glade) on spatial density of Yellow-Necked Mouse and Bank Vole was studied during the years 2011–2013. Species range (95% Kernel) of both species was calculated based on data obtained from live traps placed in trap grids. Eight levels of density probability that surround regions of constant probability density were used to define (i) activity centres of observed species and (ii) areas that tended to be of rather peripheral interest. Results suggest that glade with rich herbal- -ground cover represented significantly more suitable habitat, as well as habitat richer in resources for Bank Vole in comparison to climax forest. In contrary, Yellow-necked Mouse had provably the highest spatial density in climax forest habitat where was lack of herbal-grounded cover typical for the glade. In particular, we suggest that different diet specialization may be one of elements in explaining the different spatial density. [ABSTRACT FROM AUTHOR]

The predator satiation and predator dispersal hypotheses provide alternative explanations for masting. Both assume satiation of seed-eating vertebrates. They differ in whether satiation occurs before or after seed removal and caching by granivores (predator satiation and predator dispersal, respectively). This difference is largely unrecognized, but it is demographically important because cached seeds are dispersed and often have a microsite advantage over nondispersed seeds. We conducted rodent exclosure experiments in two mast and two nonmast years to test predictions of the predator dispersal hypothesis in our study system of yellow-necked mice ( Apodemus flavicollis) and European beech ( Fagus sylvatica). Specifically, we tested whether the fraction of seeds removed from the forest floor is similar during mast and nonmast years (i.e., lack of satiation before seed caching), whether masting decreases the removal of cached seeds (i.e., satiation after seed storage), and whether seed caching increases the probability of seedling emergence. We found that masting did not result in satiation at the seed removal stage. However, masting decreased the removal of cached seeds, and seed caching dramatically increased the probability of seedling emergence relative to noncached seeds. European beech thus benefits from masting through the satiation of scatterhoarders that occurs only after seeds are removed and cached. Although these findings do not exclude other evolutionary advantages of beech masting, they indicate that fitness benefits of masting extend beyond the most commonly considered advantages of predator satiation and increased pollination efficiency. [ABSTRACT FROM AUTHOR]

Up to six nematode species were identified from 86 specimens of the yellow-necked field mouse Apodemus flavicollis from three mountainous localities known as Avala, Cer and Liškovac in Serbia. The highest prevalence of infection of 97% was recorded from Mt. Avala. Only one nematode species, Syphacia frederici, occurred in all three localities. There was complete overlap in nematode species from Mts. Avala and Liškovac, whereas the taxonomic distinctness of Mt. Cer was seen in the presence of the insect-transmitted species Rictularia proni. Locality was a statistically significant factor in all the best-fitted generalized linear models of variation in abundances. The highest level of both species richness and parasite alpha diversity (Shannon's H= 1.47) was found in the easternmost Mt. Liškovac, whereas the diversity indices were lowest for the westernmost Mt. Cer (Shannon's H= 0.48). In view of this geographical difference, the beta diversity indices were calculated along a west to east longitudinal gradient. [ABSTRACT FROM AUTHOR]

Investigations into small mammals within the territory of a breeding colony of great cormorants (Phalacrocorax carbo sinensis), carried out in 2011-2014 near Juodkrantė (West Lithuania), demonstrated the colony's impact on the dominant rodent, yellow-necked mouse (Apodemus flavicollis). The age and sex structure of the sampled mice (n = 432), along with body weight, body condition index, and residuals from the linear regression, were used to analyse data from five zones of the colony and the surrounding forest. We found that in the most active zones of the cormorant colony, the age structure of the population was tilted towards a prevalence of juveniles, while sex structure was towards a prevalence of males (P < 0.0001). Despite males being significantly longer in body and heavier, body condition index was the same in both sexes. The effect of the zone of the colony was confirmed for body weight and its residuals; body length and body condition index (main effects ANOVA) were negative in the zones where cormorants were nesting actively. [ABSTRACT FROM AUTHOR]

The gut microbiota is vital to host health and, as such, it is important to elucidate the mechanisms altering its composition and diversity. Intestinal helminths are host immunomodulators and have evolved both temporally and spatially in close association with the gut microbiota, resulting in potential mechanistic interplay. Host-helminth and host-microbiota interactions are comparatively well-examined, unlike microbiota-helminth relationships, which typically focus on experimental infection with a single helminth species in laboratory animals. Here, in addition to a review of the literature on helminth-microbiota interactions, we examined empirically the association between microbiota diversity and composition and natural infection of multiple helminth species in wild mice (Apodemus flavicollis), using 16S rRNA gene catalogues (metataxonomics). In general, helminth presence is linked with high microbiota diversity, which may confer health benefits to the host. Within our wild rodent system variation in the composition and abundance of gut microbial taxa associated with helminths was specific to each helminth species and occurred both up- and downstream of a given helminth's niche (gut position). The most pronounced helminth-microbiota association was between the presence of tapeworms in the small intestine and increased S24-7 (Bacteroidetes) family in the stomach. Helminths clearly have the potential to alter gut homeostasis. Free-living rodents with a diverse helminth community offer a useful model system that enables both correlative (this study) and manipulative inference to elucidate helminth-microbiota interactions. [ABSTRACT FROM AUTHOR]

Background: Wild rodents are suitable for monitoring environmental pollution and exposure risk assessment for people living in contaminated areas. The content of selected risk elements in the femora of bank vole (Myodes glareolus), yellow-necked mouse (Apodemus flavicollis) and wood mouse (Apodemus sylvaticus) was estimated from the Kolíňany area of Slovakia, which is characterized by a high degree of environmental pollution. The rodents were trapped in February 2011 using standard theriological methods. All animals (n = 32) were adult males in good physical condition. The concentrations of Fe, Cu, Zn and Ni in their bones were determined by atomic absorption spectrophotometry. Results: The highest concentrations of Fe and Cu were detected in the bones of yellow-necked mouse. Significant differences were observed for the content of Fe between A. flavicollis and M. glareolus (P < 0.05). The highest levels of Zn and Ni were found in the femora of wood mouse; however, significant differences were not detected between the rodents. Moreover, the concentrations of Cu, Zn and Ni were significantly higher in the bones of all three species (P < 0.05) in comparison with the values obtained in the same animal species at the same site in February 2007. Conclusions: Our results demonstrate an increased accumulation of Cu, Zn and Ni in the femora of M. glareolus, A. flavicollis and A. sylvaticus from the Kolíňany area and thus indicate towards ongoing contamination of this locality. [ABSTRACT FROM AUTHOR]

Background: Borrelia miyamotoi, the newly discovered human pathogenic relapsing fever spirochete, and Borrelia burgdorferi sensu lato are maintained in natural rodent populations. The aim of this study was to investigate the natural cycle of B. miyamotoi and B. burgdorferi s.l. in a forest habitat with intensive hunting, forestry work and recreational activity in Southern Hungary. Methods: We collected rodents with modified Sherman-traps during 2010-2013 and questing ticks with flagging in 2012. Small mammals were euthanized, tissue samples were collected and all ectoparasites were removed and stored. Samples were screened for pathogens with multiplex quantitative real-time polymerase chain reaction (qPCR) targeting a part of flagellin gene, then analysed with conventional PCRs and sequencing. Results: 177 spleen and 348 skin samples of six rodent species were individually analysed. Prevalence in rodent tissue samples was 0.2 % (skin) and 0.5 % (spleen) for B. miyamotoi and 6.6 % (skin) and 2.2 % (spleen) for B. burgdorferi s.l. Relapsing fever spirochetes were detected in Apodemus flavicollis males, B. burgdorferi s.l. in Apodemus spp. and Myodes glareolus samples. Borrelia miyamotoi was detected in one questing Ixodes ricinus nymph and B. burgdorferi s.l in nymphs and adults. In the ticks removed from rodents DNA amplification of both pathogens was successful from I. ricinus larvae (B. miyamotoi 5.6 %, B. burgdorferi s.l. 11.1 %) and one out of five nymphs while from Ixodes acuminatus larvae, and nymph only B. burgdorferi s.l. DNA was amplified. Sequencing revealed B. lusitaniae in a questing I. ricinus nymph and altogether 17 B. afzelii were identified in other samples. Two Dermacentor marginatus engorged larva pools originating from uninfected hosts were also infected with B. afzelii. Conclusions: This is the first report of B. miyamotoi occurrence in a natural population of A. flavicollis as well as in Hungary. We provide new data about circulation of B. burgdorferi s.l. in rodent and tick communities including the role of I. acuminatus ticks in the endophilic pathogen cycle. Our results highlight the possible risk of infection with relapsing fever and Lyme borreliosis spirochetes in forest habitats especially in the high-risk groups of hunters, forestry workers and hikers. [ABSTRACT FROM AUTHOR]

We examined changes in genetic diversity in populations of two small mammal species inhabiting islands on a lake. We hypothesized that a less mobile species, such as the bank vole, would lose genetic diversity quicker than the yellow-necked mouse, which can more easily cross habitat barriers. In contrast to this we found that the effects of isolation were much more prominent in the case of the mouse than the vole. In the vole population, on the larger island, genetic diversity remained constant over subsequent years in spite of marked isolation. On the smaller island, we noted an increase in genetic diversity which was probably caused by immigration of a small group of individuals. Genetic diversity in the mouse population decreased markedly over the course of the study. In the bank vole, the preservation of genetic diversity, especially on the larger island, may have been possible due to the specific spatial and social organization of this species, which allows the maintenance of a relatively stable number of individuals. In contrast to the bank vole, the lack of territorial behavior in adult females of yellow-necked mice may lead to frequent dramatic seasonal 'booms and busts' in population size and genetic diversity. This can lead to extremely low numbers of mice, which are likely to lead to the extinction of some island populations. [ABSTRACT FROM AUTHOR]

Aim We assessed the phenotypic responses of body size and organ weights of two small rodent species ( Myodes glareolus and Apodemus flavicollis) to elevation, a surrogate for temperature and other environmental conditions. We expected not only an increase in body size (Bergmann's rule), but also an increase in relative heart weight with increasing elevation (Hesse's rule). Location The Bohemian Forest, south-eastern Germany. Methods We measured body length, body mass, and mass of the heart, lung, liver, kidneys and spleen of 386 adult specimens (188 of A flavicollis and 198 of M. glareolus) from 28 localities at 300-1450 m a.s.l., and also recorded the number of ectoparasites. We analysed body length using linear mixed models, with site as a random factor and species, sex, population density and elevation as fixed factors, and included all two-way interactions between species and the remaining fixed variables. For the organ masses, we included body length and body mass in the calculations to account for allometric variation of organ mass with body size. For a subset of individuals, we sequenced the mitochondrial D-loop to analyse genetic variation along the elevational gradient. Results For both species, we found no support for Bergmann's rule. The body size of A. flavicollis even decreased with elevation. In contrast, the relative heart weight of both species significantly increased with elevation, thereby supporting Hesse's rule. Lung mass also increased with elevation. The mass of other internal organs showed no such consistent relationship with elevation. Neither species showed genetic differentiation across the elevational gradient. Main conclusions Our results suggest that both rodent species respond to increasing elevation by decreasing overall energy expenditure and by increasing overall aerobic capacity. In the context of climate change, our results indicate that biogeographers should pay more attention to the potential significance of genetic and/or phenotypic plasticity of relative organ mass to environmental heterogeneity. [ABSTRACT FROM AUTHOR]

The spread of tick-borne pathogens represents an important threat to human and animal health in many parts of Eurasia. Here, we analysed a 9-year time series of Ixodes ricinus ticks feeding on Apodemus flavicollis mice (main reservoir-competent host for tick-borne encephalitis, TBE) sampled in Trentino (Northern Italy). The tail of the distribution of the number of ticks per host was fitted by three theoretical distributions: Negative Binomial (NB), Poisson-LogNormal (PoiLN), and Power-Law (PL). The fit with theoretical distributions indicated that the tail of the tick infestation pattern on mice is better described by the PL distribution. Moreover, we found that the tail of the distribution significantly changes with seasonal variations in host abundance. In order to investigate the effect of different tails of tick distribution on the invasion of a non-systemically transmitted pathogen, we simulated the transmission of a TBE-like virus between susceptible and infective ticks using a stochastic model. Model simulations indicated different outcomes of disease spreading when considering different distribution laws of ticks among hosts. Specifically, we found that the epidemic threshold and the prevalence equilibria obtained in epidemiological simulations with PL distribution are a good approximation of those observed in simulations feed by the empirical distribution. Moreover, we also found that the epidemic threshold for disease invasion was lower when considering the seasonal variation of tick aggregation. [ABSTRACT FROM AUTHOR]

Genetic background underlying wild populations immune response to different parasites is still not well understood. We studied immune response to multiple infections and to competition between different parasite species at different developmental stages in population of yellow-necked mouse, Apodemus flavicollis. Quantitative real-time PCR was used to investigate associations of MHC II-DRB, IL-10 and Tgf-β genes expressions with presence of intestinal parasites at different developmental stages. Furthermore, we were interested whether the host related characteristics (sex, age, body condition, presence of B chromosomes or expression of other genes) or characteristics of present parasites (number of adult parasites of each identified species, egg count of each parasite genus, total number of nematode individuals) affect differential expression of the studied genes. A significant invert association between the expression of MHC II-DRB and Tgf-β gene was found, which together with absence of IL-10 association confirmed modified Th2 as the main type of immune response to nematode infections. Effect of recorded parasites and parasite life-cycle stage on expression levels of MHC II-DRB gene was detected only through interactions with host-related characteristics such as sex, age, and the presence of B chromosomes. The presence of B chromosomes is associated with lower expression level of Tgf-β gene. Although the influence of host genetic background on parasite infection has already been well documented, this is the first study in mammals that gave presence of B chromosomes on immune response full consideration. [ABSTRACT FROM AUTHOR]

We examined the changes in the amount of nitrogenous substances in 1497 stomachs of four small forest rodent species [yellow-necked mouse (Apodemus flavicollis), wood mouse (Apodemus sylvaticus), bank vole (Clethrionomys glareolus), and common vole (Microtus arvalis)] using near-infrared reflectance spectroscopy (NIRS). The amount of nitrogenous substances varied from 9.31% to 65.39% of dry matter. Significant differences were observed between species, with both Apodemus species displaying higher variability and higher mean nitrogenous substance content in the diet compared with M. arvalis. Results for C. glareolus were intermediate for both variability and mean value. In general, concentrations of nitrogenous substances were higher in the diet of juveniles. Differences in diet composition (or ratio of nitrogenous substance) in different biotopes were only demonstrated for C. glareolus. Moreover, C. glareolus diet varied within the same biotope over different years. Clethrionomys glareolus was the only species to display differences in diet between males and females, with males having higher nitrogen concentrations. These findings are in agreement with the C. glareolus broad dietary niche. This study confirmed the suitability of NIRS for determining nitrogenous substance content in the diet of small rodent species. [ABSTRACT FROM AUTHOR]

Hemorrhagic fever with renal syndrome (HFRS) has been confirmed by serological methods during recent years in Romania. In the present study, focus-reduction neutralization tests (FRNT) confirmed Dobrava hantavirus (DOBV) as the causative agent in some HFRS cases, but could not distinguish between DOBV and Saaremaa virus (SAAV) infections in other cases. DOBV was detected by a DOBV-specific TaqMan assay in sera of nine patients out of 22 tested. Partial sequences of the M genomic segment of DOBV were obtained from sera of three patients and revealed the circulation of two DOBV lineages in Romania. Investigation of rodents trapped in Romania found three DOBV-positive Apodemus flavicollis out of 83 rodents tested. Two different DOBV lineages were also detected in A. flavicollis as determined from partial sequences of the M and S genomic segments. Sequences of DOBV in A. flavicollis were either identical or closely related to the sequences obtained from the HFRS patients. The DOBV strains circulating in Romania clustered in two monophyletic groups, together with strains from Slovenia and the north of Greece. This is the first evidence for the circulation of DOBV in wild rodents and for a DOBV etiology of HFRS in Romania. [ABSTRACT FROM AUTHOR]

In 2009, human Dobrava-Belgrade virus (DOBV) infections were reported on the Black Sea coast of Turkey. Serologic and molecular studies of potential rodent reservoirs demonstrated DOBV infections in Apodemus flavicollis and A. uralensis mice. Phylogenetic analysis of DOBV strains showed their similarityto A. flavicollis mice-borne DOBV in Greece, Slovenia,and Slovakia. [ABSTRACT FROM AUTHOR]

Samples of small rodent populations inhabiting Crabapple Island on Beldany Lake in NE Poland revealed that Clethrionomys glareolus was continously present there, whereas Apodemus flavicollis and Microtus agrestis appeared, stayed for some period, vanished and reappeared. It appears that sexually mature females of the bank vole are strictly territorial, their numbers are limited, and immature individuals hardly disperse at high population size. Sexually mature females of the yellow-necked mouse seem to be territorial only at low population numbers, and their numbers increase linearly with population size. Sexually mature females of the field vole exhibit high level of aggregation, and their numbers increase in streight line with growing population size. We discuss the idea that different social organization of the rodent populations is connected with various strategies (sedentary and nomadic) supporting local population persistence. [ABSTRACT FROM AUTHOR]

Mandibles of yellow-necked mouse ( Apodemus flavicollis) were used to explore modularity. We tested a biological hypothesis that two separate modules (alveolar region and ascending ramus) can be recognized within the mandible. As a second research goal, we compared two different morphometric procedures under the assumption that methodological approaches that use either geometric or traditional morphometric techniques should give similar results. Besides confirmation of the predicted hypothesis of modularity, the application of both approaches revealed that: (i) modularity was somewhat more evident when it was analysed on the asymmetric (fluctuating asymmetry, FA) than on the symmetric (individual variation) component of variation; (ii) there is correspondence in the patterns of individual variation and FA, which indicates that integration of mandibular traits among individuals is primarily due to direct developmental interactions; and (iii) allometry does not obscure the hypothesized modularity for individual variation or for FA. In addition, traditional morphometric method allowed us to check whether allometry influenced each module to the same extent and to conclude that the ascending ramus is more heavily influenced by general size than the alveolar region. In studies of modularity, differences in methods can lead to discrepancies in the results, and therefore, some caution is required when comparing findings from different investigations. The substantial agreement between our results provides evidence that, when considering two-module organization of the mouse mandible, direct comparison among studies that use the methods applied herein is, in great part, reliable. [ABSTRACT FROM AUTHOR]

Five wood mice Apodemus species occur across China, in allopatry but also in sympatry up to cases of syntopy. They all share a similar external appearance, similar habitats of grasslands and forests and a generalist feeding behaviour. This overall similarity raises questions about the mechanisms insuring competition avoidance and allowing the coexistence of the species. In this context, a morphometric analysis of two characters related to feeding (mandible and molar) addressed the following issues: (1) Were the species actually different in size and/or shape of these characters, supporting their role in resource partitioning? (2) Did this pattern of phenotypic divergence match the neutral genetic differentiation, suggesting that differentiation might have occurred in a former phase of allopatry as a result of stochastic processes? (3) Did the species provide evidence of character displacement when occurring in sympatry, supporting an ongoing role of competition in the interspecific divergence? Results evidenced first that different traits, here mandibles and molars, provided discrepant pictures of the evolution of the Apodemus group in China. Mandible shape appeared as prone to vary in response to local conditions, blurring any phylogenetic or ecological pattern, whereas molar shape evolution appeared to be primarily driven by the degree of genetic differentiation. Molar size and shape segregated the different species in the morphospace, suggesting that these features may be involved in a resource partitioning between Apodemus species. The morphological segregation of the species, likely achieved by processes of differentiation in isolation promoted by the complex landscape of China, could contribute to competition avoidance and hence explain why no evidence was found of character displacement. [ABSTRACT FROM AUTHOR]

Differential predation on certain classes of individuals within prey populations might make owls strong selective agents on their prey. We investigated selective predation of tawny owls (Strix aluco) on yellow-necked mice (Apodemus flavicollis, A.f.) and bank voles (Myodes glareolus, M.g.) for two years by comparing prey from owl nests with live-trapped individuals. The owls killed significantly more male M.g. (73%) than females, but not more than expected from traps (57%). For A.f, owls selected adults in favour of subadults, and for adults, individuals with longer femurs. Adult males of A.f. killed by owls had significantly heavier testes in relation their size than the trapped males. Prey selection did not correlate with size-adjusted body or spleen mass. Owl-killed Af. had higher prevalences of the intestinal helminth Heligmosomoides sp. than trapped individuals, but hosted similar numbers of parasite species. Differential predation of tawny owls on yellow-necked mice and bank voles seems to reflect higher exposure to predator encounters of prime individuals rather than selection for substandard individuals. [ABSTRACT FROM AUTHOR]

Background: Candidatus Neoehrlichia mikurensis (CNM) has been described in the hard tick Ixodes ricinus and rodents as well as in some severe cases of human disease. The aims of this study were to identify DNA of CNM in small mammals, the ticks parasitizing them and questing ticks in areas with sympatric existence of Ixodes ricinus and Dermacentor reticulatus in Germany. Methods: Blood, transudate and organ samples (spleen, kidney, liver, skin) of 91 small mammals and host-attached ticks from altogether 50 small mammals as well as questing I. ricinus ticks (n=782) were screened with a real-time PCR for DNA of CNM. Results: 52.7% of the small mammals were positive for CNM-DNA. The majority of the infected animals were yellow-necked mice (Apodemus flavicollis) and bank voles (Myodes glareolus). Small mammals with tick infestation were more often infected with CNM than small mammals without ticks. Compared with the prevalence of ~25% in the questing I. ricinus ticks, twice the prevalence in the rodents provides evidence for their role as reservoir hosts for CNM. Conclusion: The high prevalence of this pathogen in the investigated areas in both rodents and ticks points towards the need for more specific investigation on its role as a human pathogen. [ABSTRACT FROM AUTHOR]

Background: The aims of this study were to evaluate the host-tick-pathogen interface of Babesia spp. and Anaplasma phagocytophilum in restored areas in both questing and host-attached Ixodes ricinus and Dermacentor reticulatus and their small mammalian hosts. Methods: Questing ticks were collected from 5 sites within the city of Leipzig, Germany, in 2009. Small mammals were trapped at 3 of the 5 sites during 2010 and 2011. DNA extracts of questing and host-attached I. ricinus and D. reticulatus and of several tissue types of small mammals (the majority bank voles and yellow-necked mice), were investigated by PCR followed by sequencing for the occurrence of DNA of Babesia spp. and by real-time PCR for A. phagocytophilum. A selected number of samples positive for A. phagocytophilum were further investigated for variants of the partial 16S rRNA gene. Co-infection with Rickettsia spp. in the questing ticks was additionally investigated. Results: 4.1% of questing I. ricinus ticks, but no D. reticulatus, were positive for Babesia sp. and 8.7% of I. ricinus for A. phagocytophilum. Sequencing revealed B. microti, B. capreoli and Babesia spp. EU1 in Leipzig and sequence analysis of the partial 16S RNA gene of A. phagocytophilum revealed variants either rarely reported in human cases or associated with cervid hosts. The statistical analysis revealed significantly less ticks infected with A. phagocytophilum in a city park in Leipzig as compared to the other sampling sites. A. phagocytophilum-DNA was detected in 2 bank voles, DNA of B. microti in 1 striped field-mouse and of Babesia sp. EU1 in the skin tissue of a mole. Co-infections were detected. Conclusion: Our results show the involvement of small mammals in the natural endemic cycles of tick-borne pathogens. A more thorough understanding of the interactions of ticks, pathogens and hosts is the essential basis for effective preventive control measures. [ABSTRACT FROM AUTHOR]

Abstract: Due to their key role in recognizing foreign antigens and triggering the subsequent immune response the genes of the major histocompatibility complex (MHC) provide a potential target for parasites to attack in order to evade detection and expulsion from the host. A diminished MHC gene expression results in less activated T cells and might serve as a gateway for pathogens and parasites. Some parasites are suspected to be immune suppressors and promote co-infections of other parasites even in other parts of the body. In our study we found indications that the gut dwelling nematode Heligmosomoides polygyrus might exert a systemic immunosuppressive effect in yellow-necked mice (Apodemus flavicollis). The amount of hepatic MHC class II DRB gene RNA transcripts in infected mice was negatively associated with infection intensity with H. polygyrus. The hepatic expression of immunosuppressive cytokines, such as transforming growth factor β and interleukin 10 was not associated with H. polygyrus infection. We did not find direct positive associations of H. polygyrus with other helminth species. But the prevalence and infection intensity of the nematodes Syphacia stroma and Trichuris muris were higher in multiple infected individuals. Furthermore, our data indicated antagonistic effects in the helminth community of A. flavicollis as cestode infection correlated negatively with H. polygyrus and helminth species richness. Our study shows that expression analyses of immune relevant genes can also be performed in wildlife, opening new aspects and possibilities for future ecological and evolutionary research. [Copyright &y& Elsevier]

The MHV-68 (designed as Murid herpesvirus 4 (MuHV 4) strain 68) isolated from two rodents, Myodes glareolus and Apodemus flavicollis, is considered as a natural pathogen of free-living murid rodents. Recently, the detection of MHV antibodies in the blood of animals living in the same biotope as MHV-infected mice has suggested that ticks may have a role in the transmission of this pathogen. Ixodes ricinus is one the most abundant tick species in Europe known to transmit multiple pathogens causing human and animal diseases. In this study, nymphs and larvae feeding on 116 individuals of a temperate lizard species-the green lizard Lacerta viridis captured in the Slovak Karst National Park, were examined for MHV-68. The specific sequence of virion glycoprotein 150 was amplified in DNA individually isolated from I. ricinus ticks using single-copy sensitive nested polymerase chain reaction. MHV-68 was detected in ten of 649 nymphs and in five of 150 larvae, respectively. We found that 9.6% of green lizards fed at least one MHV-68-infected immature tick. Occurrence of MHV-68 within all ticks tested was 1.8%. This study is first to show that immature I. ricinus ticks feeding on free-living lizards in a Central European region could be infected with gammaherpesvirus (MHV-68), naturally infecting free-living murid rodents. Our results provide evidence supporting the hypothesis that ticks may play a mediating role in circulation of MHV-68 in nature. [ABSTRACT FROM AUTHOR]

Abstract: Growth patterns are nearly unknown in free-ranging rodents. Here we analyse growth patterns (in body length) in relation to sex, year, and population density in a population of yellow-necked wood mice, Apodemus flavicollis. This population was studied by capture-mark-recapture at a mountainous site in central Italy during 1988–1995, and 2000–2005. In our study, (i) the growth of females was accelerated compared to males of comparable body length, (ii) growth rates strongly varied inter-annually, and (iii) there was a clear density-dependence mechanism between population density and intrinsic growth rate, with growth being decelerated at density increases in both males and females. The general implications of these patterns are discussed. [Copyright &y& Elsevier]

The nuclear disaster at Chernobyl, Ukraine, in April of 1986 continues to impact the environment on many different levels. Studies of epidemiological, environmental, and genetic impacts have been prolific since the accident, revealing interesting results concerning the effects of radiation. The long-tailed field mouse, Apodemus flavicollis, was collected from distinct localities near the Chernobyl site and evaluated based on in vivo responses to the current clinically employed chemotherapeutic agents bleomycin (BLM) and vinblastine (VBL), as well as the immune modulator lipopolysaccharide (LPS). Maximum tolerable doses of three different cancer drugs were administered to the rodents from three different lifestyles: native mice living and reproducing in a radioactive environment, native mice living and reproducing in an uncontaminated region, and laboratory-reared mice ( Mus musculus BALB/c) with a known sensitivity to the chemical agents tested. The endpoints employed include micronucleus formation, immune cell induction, differential gene expression, and chemotherapeutic side effects such as lethargy and weight loss. In accordance with the well-studied phenomenon termed radio-adaptation, we observed varied tolerance to chemotherapeutic treatment dependent on history of ionizing radiation exposure. The results of the present study demonstrate a differential response to chemotherapeutic treatment with respect to previous levels of radiation exposure, suggesting a potential benefit associated with low-dose radiation exposure. Data reported herein could have a profound impact on the development of novel cancer treatments involving low-dose ionizing radiation. Environ. Toxicol. Chem. 2011; 30:640-649. © 2010 SETAC [ABSTRACT FROM AUTHOR]

The lower and upper incisors has been studied in striped field mice ( Apodemus agrarius), yellow-necked mice ( A. flavicollis), and migratory hamsters ( Cricetulus migratorius) trapped in the Volgograd Region from April to March. The incisors of all animals have been found to have a striated surface, with series of slight ridges and grooves. As shown by analyzing the incisors of animals labeled with tetracycline, these are daily increments of dentin. The total numbers of increments (the period of complete tooth renewal) in the upper and lower incisors of the same animal are similar, but the degrees of their distinctness can be different. The number of daily increments increases but their width (daily growth rate) decreases with age even in adult animals and, in addition, varies by seasons. These two trends-the decrease in tooth increment with age and its seasonal variation-have proved to mask each other when an uneven-aged sample of animals trapped over several months is studied. Therefore, the season of death of an animal cannot be reliably estimated from the width of daily tooth increment unless the age of this animal is taken into account. The increment width in young animals in autumn may be the same as in older animals in spring and summer. In attempts to use the incisor surface sculpture for determining the season of animal death, it is necessary to separate the young from adults (at least by the criterion of incisor length). The decrease of increment width with age and its seasonal variation in the absence of obvious changes in the diet and pattern of incisor attrition indicate that the incisor growth rate is subject to age-dependent and seasonal changes, as is the growth rate of the organism as a whole. The distinctness and internal structure of daily increments also vary depending on animal age and species, which is due apparently to differences in the circadian rhythms of incisor growth. The presence of one or, less frequently, several grooves within a daily increment, which has occurred in all species studied, is evidence for not only circadian but also ultradian rhythms in the growth of incisors. [ABSTRACT FROM AUTHOR]

In this paper we describe an interesting case of adult coloration in juveniles of Apodemus flavicollis (Melchior, 1834). It is well known that juveniles and also subadults of wood mice of the subgenus Sylvaemus are gray and they change this juvenile coloration to adult coloration when they mature. Among 271 juveniles of A. flavicollis caught in three localities of Slovakia during the years 2000-2006, two juveniles were adult coloured. These juveniles were very young, one had not even left the nest (weight 2.5 g) and the other one had probably just left the nest (weight 5 g). Usually older juveniles are caught. There are several possible explanations for these cases - individual variability in the development of coloration of juveniles, colour mutation or possibility that juveniles change the colour of their pelage twice. [ABSTRACT FROM AUTHOR]