Jan Zima

Mediterranean Europe as an area of endemism for small mammals rather than a source for northwards postglacial colonization

There is a general perception that central and northern Europe were colonized by range expansion from Mediterranean refugia at the end of the last glaciation. Data from various species support this scenario, but we question its universality. Our mitochondrial DNA studies on three widespread species of small mammal suggest that colonization may have occurred from glacial refugia in central Europe–western Asia. The haplotypes on the Mediterranean peninsulae are distinctive from those found elsewhere. Rather than contributing to the postglacial colonization of Europe, Mediterranean populations of widespread small mammals may represent long–term isolates undergoing allopatric speciation. This could explain the high endemism of small mammals associated with the Mediterranean peninsulae.

A northern glacial refugium for bank voles (Clethrionomys glareolus)

There is controversy and uncertainty on how far north there were glacial refugia for temperate species during the Pleistocene glaciations and in the extent of the contribution of such refugia to present-day populations. We examined these issues using phylogeographic analysis of a European woodland mammal, the bank vole (Clethrionomys glareolus). A Bayesian coalescence analysis indicates that a bank vole population survived the height of the last glaciation (≈25,000–10,000 years B.P.) in the vicinity of the Carpathians, a major central European mountain chain well north of the Mediterranean areas typically regarded as glacial refugia for temperate species. Parameter estimates from the fitted isolation with migration model show that the divergence of the Carpathian population started at least 22,000 years ago, and it was likely followed by only negligible immigration from adjacent regions, suggesting the persistence of bank voles in the Carpathians through the height of the last glaciation. On the contrary, there is clear evidence for gene flow out of the Carpathians, demonstrating the contribution of the Carpathian population to the colonization of Europe after the Pleistocene. These findings are consistent with data from animal and plant fossils recovered in the Carpathians and provide the clearest phylogeographic evidence to date of a northern glacial refugium for temperate species in Europe.

GENETIC ANALYSIS OF AUTOSOMAL AND X‐LINKED MARKERS ACROSS A MOUSE HYBRID ZONE

Abstract In this paper, we present results of the first comprehensive study of the introgression of both autosomal and sex-chromosome markers across the central European portion of the hybrid zone between two house mouse subspecies, Mus musculus musculus and M. m. domesticus. More than 1800 individuals sampled from 105 sites were analyzed with a set of allozyme loci (hopefully representing neutral or nearly neutral markers) and X-linked loci (which are assumed to be under selection). The zone center is best modeled as a single straight line independent of fine-scale local geographic or climatic conditions, being maintained by a balance between dispersal and selection against hybrids. The width (w) of the multilocus autosomal cline was estimated as 9.6 km whereas the estimate for the compound X-chromosome cline was about 4.6 km only. As the former estimate is comparable to that of the Danish portion of the zone (assumed to be much younger than the central European one), zone width does not appear to be related to its age. The strength (B) of the central barrier was estimated as about 20 km; with dispersal (σ) of about 1 km/gen1/2, this means effective selection (s*) is approximately 0.06–0.09 for autosomal loci and about 0.25 for X-linked loci. The number of loci under selection was estimated as N = 56–99 for autosomes and about 380 for X-linked loci. Finally, we highlight some potential pitfalls in hybrid zone analyses and in comparisons of different transects. We suggest that conclusions about parts of the mouse genome involved in reproductive isolation and speciation should be drawn with caution and that analytical approaches always providing some estimates should not be used without due care regarding the support or confidence of such estimates, especially if conclusions are based on the difference between these estimates. Finally, we recommend that analysis in two-dimensional space, dense sampling, and rigorous treatment of data, including inspection of likelihood profiles, are essential for hybrid zone studies.

Increasing Incidence of Geomyces destructans Fungus in Bats from the Czech Republic and Slovakia

Background White-nose syndrome is a disease of hibernating insectivorous bats associated with the fungus Geomyces destructans. It first appeared in North America in 2006, where over a million bats died since then. In Europe, G. destructans was first identified in France in 2009. Its distribution, infection dynamics, and effects on hibernating bats in Europe are largely unknown. Methodology/Principal Findings We screened hibernacula in the Czech Republic and Slovakia for the presence of the fungus during the winter seasons of 2008/2009 and 2009/2010. In winter 2009/2010, we found infected bats in 76 out of 98 surveyed sites, in which the majority had been previously negative. A photographic record of over 6000 hibernating bats, taken since 1994, revealed bats with fungal growths since 1995; however, the incidence of such bats increased in Myotis myotis from 2% in 2007 to 14% by 2010. Microscopic, cultivation and molecular genetic evaluations confirmed the identity of the recently sampled fungus as G. destructans, and demonstrated its continuous distribution in the studied area. At the end of the hibernation season we recorded pathologic changes in the skin of the affected bats, from which the fungus was isolated. We registered no mass mortality caused by the fungus, and the recorded population decline in the last two years of the most affected species, M. myotis, is within the population trend prediction interval. Conclusions/Significance G. destructans was found to be widespread in the Czech Republic and Slovakia, with an epizootic incidence in bats during the most recent years. Further development of the situation urgently requires a detailed pan-European monitoring scheme.

Histopathology confirms white-nose syndrome in bats in Europe.

White-nose syndrome, associated with the fungal skin infection geomycosis, caused regional population collapse in bats in North America. Our results, based on histopathology, show the presence of white-nose syndrome in Europe. Dermatohistopathology on two bats (Myotis myotis) found dead in March 2010 with geomycosis in the Czech Republic had characteristics resembling Geomyces destructans infection in bats confirmed with white-nose syndrome in US hibernacula. In addition, a live M. myotis, biopsied for histopathology during hibernation in April 2011, had typical fungal infection with cupping erosion and invasion of muzzle skin diagnostic for white-nose syndrome and conidiospores identical to G. destructans that were genetically confirmed as G. destructans.

Chromosomal rearrangements do not seem to affect the gene flow in hybrid zones between karyotypic races of the common shrew (Sorex araneus).

Chromosomal rearrangements are proposed to promote genetic differentiation between chromosomally differentiated taxa and therefore promote speciation. Due to their remarkable karyotypic polymorphism, the shrews of the Sorex araneus group were used to investigate the impact of chromosomal rearrangements on gene flow. Five intraspecific chromosomal hybrid zones characterized by different levels of karyotypic complexity were studied using 16 microsatellites markers. We observed low levels of genetic differentiation even in the hybrid zones with the highest karyotypic complexity. No evidence of restricted gene flow between differently rearranged chromosomes was observed. Contrary to what was observed at the interspecific level, the effect of chromosomal rearrangements on gene flow was undetectable within the S. araneus species.

The mammalian model for population studies of B chromosomes: the wood mouse (Apodemus)

The presence of B chromosomes was reported in six species of the genus Apodemus (A. peninsulae, A. agrarius, A. sylvaticus, A. flavicollis, A. mystacinus, A. argenteus). High frequencies of Bs were recorded particularly in A. peninsulae and A. flavicollis. The origin of Bs in Apodemus seems to be rather ancient, and it is possible that the supernumerary elements, and/or a tendency for their appearance, were inherited from the common ancestor of the extant species. We have not found any correlated changes between frequencies of Bs and the level of protein polymorphism and/or heterozygosity assessed in electrophoretic studies. No measurable effect of Bs on overall genetic variability was thus revealed in studied populations. The pattern of evolutionary dynamics of Bs can be distinctly different between geographical populations, and both the parasitic and the heterotic models can be applied to explain the maintenance of Bs in different populations. Further studies are desirable to improve our understanding of the complicated evolutionary dynamics of Bs in the Apodemus species. An essential condition for success in this respect is much more detailed information on inheritance and the molecular structure of Bs.

Karyotypes of the mammals of Turkey and neighbouring regions: a review

Abstract. Available data on karyotypes of the mammals from Turkey and neighbouring regions (the Balkans, the Caucasus, and the Middle East) were summarized and reviewed in respect of their implications to taxonomy and systematics. In this review, previously unpublished data are presented in 20 species. Terrestrial mammals were taken into consideration, both the native and introduced. Altogether, 156 species occurring in the region concerned were included. The karyotype was studied in 109 of these species in Turkey, in most other species data are available from other geographic regions, and only three species remain unstudied cytogenetically. Intraspecific chromosomal variation (polymorphism or polytypy) was reported in 22 species. A karyotype different from the findings made in other regions was reported in Turkish populations of 17 species. Possible future directions of the cytogenetic investigations of mammals in the region are proposed.

Feeding Habits of the Long-Eared Desert Bat, Otonycteris hemprichi (Chiroptera: Vespertilionidae)

We studied food habits of the long-eared desert bat, Otonycteris hemprichi , in a subdesert area of Kirghizstan (central Asia) by fecal analysis and light-tagging. The bulk of the diet of 13 individuals in September consisted of arachnids (Solifugae, Scorpiones, and Araneae; 49.9% of total volume) and orthopterans (Acrididae, Gryllidae, and Tettigoniidae; 34.7%). Visual nocturnal observations confirmed that this species captures its prey from the surface of the ground.

Karyotypic Variation in Rhinolophid and Hipposiderid Bats (Chiroptera: Rhinolophidae, Hipposideridae)

According to current phylogenetic hypotheses, the bats of the families Rhinolophidae and Hipposideridae are sister groups nested within the clade of Pteropodiformes. A conservative nature of karyotypic evolution was previously reported within the two families. Karyotypes with diploid number (2n) varying between 58 and 62 chromosomes were assumed to prevail among the rhinolophid species, whereas, karyotypes with 32 chromosomes were found in most of the hipposiderid bats. However, divergent lower or higher 2n numbers have been recorded in some species in both families. Variation is documented in the present paper by examination of non-differentially stained karyotypes in 10 species belonging to genera Rhinolophus and Hipposideros from western Africa and southern India. Among the species studied, the karyotypes with a 2n of 32, 36, 52, 56, 58, and 62, and with relatively stable number of autosomal arms (FNa = 60, 62, 64) were recorded.