The voles of the Microtus thomasi/Microtus atticus species complex (Arvicolinae) display extensive karyotypic variation, in the number of autosomes and the morphology of sex chromosomes. We analyzed the satellitome of Microtus thomasi and identified 17 satellite DNA (satDNA) families, corresponding to 6.704% of the genome. Homogenization and divergence analyses showed that some satDNA families are more homogeneous, indicative of recent amplification, while others displayed higher variation, suggesting ancient amplification. Twelve of the satDNA families are conserved across Arvicolinae with a substantial variation in the abundance and the composition. These results support the "library" hypothesis, where a shared collection of satDNAs exists across related species, with differential amplification driving species-specific genomic profiles. Localization analysis demonstrated that an increased number of satDNA families are localized in the pericentromeric and the heterochromatic regions of autosomes and sex chromosomes. Our results suggest that the heterochromatin of the X and Y chromosomes co-evolved and that satDNA families might have contributed to the chromosomal rearrangements involved in the karyotypic variation and sex chromosome polymorphism of the chromosomal races. Our study contributes to a deeper understanding of the evolutionary mechanisms underlying karyotype diversification in Microtus species, which exhibit some of the highest rates of karyotypic variation among mammals.

• Klíčová slova
• chromosomes, heterochromatin, karyotype, repeated DNAs, satellite DNA,
• MeSH
• Arvicolinae * genetika   MeSH
• genom * MeSH
• heterochromatin genetika   MeSH
• karyotyp * MeSH
• karyotypizace MeSH
• molekulární evoluce MeSH
• pohlavní chromozomy * genetika   MeSH
• satelitní DNA * genetika   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• heterochromatin MeSH
• satelitní DNA * MeSH

Coevolution of parasites with their hosts may lead to balancing selection on genes involved in determining the specificity of host-parasite interactions, but examples of such specific interactions in wild vertebrates are scarce. Here, we investigated whether the polymorphic outer surface protein C (OspC), used by the Lyme disease agent, Borrelia afzelii, to manipulate vertebrate host innate immunity, interacts with polymorphic major histocompatibility genes (MHC), while concurrently eliciting a strong antibody response, in one of its main hosts in Europe, the bank vole. We found signals of balancing selection acting on OspC, resulting in little differentiation in OspC variant frequencies between years. Neither MHC alleles nor their inferred functional groupings (supertypes) significantly predicted the specificity of infection with strains carrying different OspC variants. However, we found that MHC alleles, but not supertypes, significantly predicted the level of IgG antibodies against two common OspC variants among seropositive individuals. Our results thus indicate that MHC alleles differ in their ability to induce antibody responses against specific OspC variants, which may contribute to selection of OspC polymorphism by the vole immune system.

• Klíčová slova
• bacteria, host parasite interactions, mammals, population genetics—empirical,
• MeSH
• adaptivní imunita * genetika   MeSH
• alely MeSH
• antigeny bakteriální MeSH
• Arvicolinae * genetika   imunologie   mikrobiologie   MeSH
• Borrelia burgdorferi komplex * genetika   imunologie   patogenita   MeSH
• hlavní histokompatibilní komplex * genetika   MeSH
• imunoglobulin G imunologie   MeSH
• lymeská nemoc * imunologie   genetika   mikrobiologie   MeSH
• polymorfismus genetický MeSH
• proteiny vnější bakteriální membrány * genetika   imunologie   MeSH
• protilátky bakteriální krev   imunologie   MeSH
• selekce (genetika) genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antigeny bakteriální MeSH
• imunoglobulin G MeSH
• OspC protein MeSH Prohlížeč
• proteiny vnější bakteriální membrány * MeSH
• protilátky bakteriální MeSH

Genetic admixture introduces new variants at relatively high frequencies, potentially aiding rapid responses to environmental changes. Here, we evaluate its role in adaptive variation related to climatic conditions in bank voles (Clethrionomys glareolus) in Britain, using whole-genome data. Our results reveal loci showing excess ancestry from one of the two postglacial colonist populations inconsistent with overall admixture patterns. Notably, loci associated with climate adaptation exhibit disproportionate amounts of excess ancestry, highlighting the impact of admixture between colonist populations on local adaptation. The results suggest strong and localized selection on climate-adaptive loci, as indicated by steep clines and/or shifted cline centres, during population replacement. A subset, including a haemoglobin gene, is associated with oxidative stress responses, underscoring a role of oxidative stress in local adaptation. Our study highlights the important contribution of admixture during secondary contact between populations from distinct climatic refugia enriching adaptive diversity. Understanding these dynamics is crucial for predicting future adaptive capacity to anthropogenic climate change.

• MeSH
• aklimatizace genetika   MeSH
• Arvicolinae * genetika   fyziologie   MeSH
• fyziologická adaptace genetika   MeSH
• genetická variace MeSH
• jednonukleotidový polymorfismus MeSH
• klimatické změny * MeSH
• podnebí MeSH
• populační genetika MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Spojené království MeSH

As climate change continues, species pushed outside their physiological tolerance limits must adapt or face extinction. When change is rapid, adaptation will largely harness ancestral variation, making the availability and characteristics of that variation of critical importance. Here, we used whole-genome sequencing and genetic-environment association analyses to identify adaptive variation and its significance in the context of future climates in a small Palearctic mammal, the bank vole (Clethrionomys glareolus). We found that peripheral populations of bank vole in Britain are already at the extreme bounds of potential genetic adaptation and may require an influx of adaptive variation in order to respond. Analyses of adaptive loci suggest regional differences in climate variables select for variants that influence patterns of population adaptive resilience, including genes associated with antioxidant defense, and support a pattern of thermal/hypoxic cross-adaptation. Our findings indicate that understanding potential shifts in genomic composition in response to climate change may be key to predicting species' fate under future climates.

• MeSH
• Arvicolinae genetika   MeSH
• fyziologická adaptace genetika   MeSH
• genom MeSH
• hlodavci * genetika   MeSH
• klimatické změny MeSH
• savci * genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The narrow-headed vole, collared lemming and common vole were the most abundant small mammal species across the Eurasian Late Pleistocene steppe-tundra environment. Previous ancient DNA studies of the collared lemming and common vole have revealed dynamic population histories shaped by climatic fluctuations. To investigate the extent to which species with similar adaptations share common evolutionary histories, we generated a dataset comprised the mitochondrial genomes of 139 ancient and 6 modern narrow-headed voles from several sites across Europe and northwestern Asia covering approximately the last 100 thousand years (kyr). We inferred Bayesian time-aware phylogenies using 11 radiocarbon-dated samples to calibrate the molecular clock. Divergence of the main mtDNA lineages across the three species occurred during marine isotope stages (MIS) 7 and MIS 5, suggesting a common response of species adapted to open habitat during interglacials. We identified several time-structured mtDNA lineages in European narrow-headed vole, suggesting lineage turnover. The timing of some of these turnovers was synchronous across the three species, allowing us to identify the main drivers of the Late Pleistocene dynamics of steppe- and cold-adapted species.

• Klíčová slova
• Pleistocene, climate change, habitat, interstadials, mitochondrial DNA, paleoclimate,
• MeSH
• Arvicolinae * genetika   MeSH
• Bayesova věta MeSH
• fylogeneze MeSH
• genetická variace MeSH
• mitochondriální DNA genetika   MeSH
• populační dynamika MeSH
• starobylá DNA * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• mitochondriální DNA MeSH
• starobylá DNA * MeSH

The most likely pathway for many species to survive future climate change is by pre-existing trait variation providing a fitness advantage under the new climate. Here we evaluate the potential role of haemoglobin (Hb) variation in bank voles under future climate change. We model gene-climate relationships for two functionally distinct Hb types, HbS and HbF, which have a north-south distribution in Britain presenting an unusually tractable system linking genetic variation in physiology to geographical and temporal variation in climate. Projections to future climatic conditions suggest a change in relative climatic suitability that would result in HbS being displaced by HbF in northern Britain. This would facilitate local adaptation to future climate-without Hb displacement, populations in northern Britain would likely be suboptimally adapted because their Hb would not match local climatic conditions. Our study shows how pre-existing physiological differences can influence the adaptive capacity of species to climate change.

• MeSH
• aklimatizace * MeSH
• Arvicolinae genetika   MeSH
• fyziologická adaptace MeSH
• hemoglobiny MeSH
• klimatické změny * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• hemoglobiny MeSH

The voles of the Microtus thomasi/M. atticus species complex demonstrate a remarkable variability in diploid chromosomal number (2n = 38-44 chromosomes) and sex chromosome morphology. In the current study, we examined by in situ hybridization the topology of four satellite DNA motifs (Msat-160, Mth-Alu900, Mth-Alu2.2, TTAGGG telomeric sequences) and two transposons (LINE, SINE) on the karyotypes of nine chromosome races (i.e., populations with unique cytogenetic traits) of Microtus thomasi, and two chromosomal races of M. atticus. According to the topology of the repetitive DNA motifs, we were able to identify six types of biarmed chromosomes formed from either Robertsonian or/and tandem fusions. In addition, we identified 14 X chromosome variants and 12 Y chromosome variants, and we were able to reconstruct their evolutionary relations, caused mainly by distinct mechanisms of amplification of repetitive DNA elements, including the telomeric sequences. Our study used the model of the Microtus thomasi/M. atticus species complex to explore how repetitive centromeric content can alter from chromosomal rearrangements and can shape the morphology of sex chromosomes, resulting in extensive inter-species cytogenetic variability.

• Klíčová slova
• Microtus, Msat-160, polymorphism, repeated DNAs, sex chromosomes heterochromatin, telomeric sequences,
• MeSH
• Arvicolinae genetika   MeSH
• genetická variace * MeSH
• heterochromatin genetika   MeSH
• molekulární evoluce MeSH
• pohlavní chromozomy genetika   MeSH
• telomery genetika   MeSH
• transpozibilní elementy DNA genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• heterochromatin MeSH
• transpozibilní elementy DNA MeSH

The history of repeated northern glacial cycling and southern climatic stability has long dominated explanations for how genetic diversity is distributed within temperate species in Eurasia and North America. However, growing evidence indicates the importance of cryptic refugia for northern colonization dynamics. An important geographic region to assess this is Fennoscandia, where recolonization at the end of the last glaciation was restricted to specific routes and temporal windows. We used genomic data to analyse genetic diversity and colonization history of the bank vole (Myodes glareolus) throughout Europe (>800 samples) with Fennoscandia as the northern apex. We inferred that bank voles colonized Fennoscandia multiple times by two different routes; with three separate colonizations via a southern land-bridge route deriving from a "Carpathian" glacial refugium and one via a north-eastern route from an "Eastern" glacial refugium near the Ural Mountains. Clustering of genome-wide SNPs revealed high diversity in Fennoscandia, with eight genomic clusters: three of Carpathian origin and five Eastern. Time estimates revealed that the first of the Carpathian colonizations occurred before the Younger Dryas (YD), meaning that the first colonists survived the YD in Fennoscandia. Results also indicated that introgression between bank and northern red-backed voles (Myodes rutilus) took place in Fennoscandia just after end-glacial colonization. Therefore, multiple colonizations from the same and different cryptic refugia, temporal and spatial separations and interspecific introgression have shaped bank vole genetic variability in Fennoscandia. Together, these processes drive high genetic diversity at the apex of the northern expansion in this emerging model species.

• Klíčová slova
• Clethrionomys glareolus, approximate Bayesian computation, climate change, cryptic refugia, genotyping-by-sequencing, population genomics,
• MeSH
• Arvicolinae * genetika   MeSH
• fylogeneze MeSH
• genetická variace * MeSH
• genomika MeSH
• refugium * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Evropa MeSH

During the Late Pleistocene, narrow-headed voles (Lasiopodomys gregalis) inhabited Eurasia's vast territories, frequently becoming the dominant small mammal species among steppe-tundra communities. We investigated the relationship between this species' European and Asiatic populations by sequencing the mtDNA genomes of two extant specimens from Russia and 10 individuals from five Central European sites, dated to the post-LGM period. Phylogenetic analyses based on a large portion of mtDNA genomes highly supported the positioning of L. gregalis within Arvicolinae. The phylogeny based on mtDNA cytochrome b sequences revealed a deep divergence of European narrow-headed voles from Asiatic ones and their sister position against the extant L. gregalis and L. raddei. The divergence of the European lineage was estimated to a minimum 230 thousand years ago. This suggest, contrary to the current biogeographic hypotheses, that during the interglacial periods narrow-headed vole did not retreat from Europe but survived the unfavourable conditions within the refugial areas. Based on this result, we propose to establish a cryptic species status for the Late Pleistocene European narrow-headed vole and to name this taxon Lasiopodomys anglicus.

• MeSH
• Arvicolinae klasifikace   genetika   MeSH
• cytochromy b genetika   MeSH
• fylogeneze MeSH
• fylogeografie metody   MeSH
• genetická variace * MeSH
• lesy MeSH
• mitochondriální DNA genetika   MeSH
• sekvence nukleotidů MeSH
• sekvenční analýza DNA MeSH
• tundra MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Rusko MeSH
• Názvy látek
• cytochromy b MeSH
• mitochondriální DNA MeSH

Current species distributions at high latitudes are the product of expansion from glacial refugia into previously uninhabitable areas at the end of the last glaciation. The traditional view of postglacial colonization is that southern populations expanded their ranges into unoccupied northern territories. Recent findings on mitochondrial DNA (mtDNA) of British small mammals have challenged this simple colonization scenario by demonstrating a more complex genetic turnover in Britain during the Pleistocene-Holocene transition where one mtDNA clade of each species was replaced by another mtDNA clade of the same species. Here, we provide evidence from one of those small mammals, the bank vole (Clethrionomys glareolus), that the replacement was genome-wide. Using more than 10 000 autosomal SNPs we found that similar to mtDNA, bank vole genomes in Britain form two (north and south) clusters which admix. Therefore, the genome of the original postglacial colonists (the northern cluster) was probably replaced by another wave of migration from a different continental European population (the southern cluster), and we gained support for this by modelling with approximate Bayesian computation. This finding emphasizes the importance of analysis of genome-wide diversity within species under changing climate in creating opportunities for sophisticated testing of population history scenarios.

• Klíčová slova
• Clethrionomys glareolus, Myodes glareolus, approximate Bayesian computation, genome admixture, postglacial colonization, single-nucleotide polymorphism,
• MeSH
• Arvicolinae genetika   fyziologie   MeSH
• fylogeneze MeSH
• genom * MeSH
• jednonukleotidový polymorfismus * MeSH
• migrace zvířat * MeSH
• rozšíření zvířat * MeSH
• sekvenční analýza DNA MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Anglie MeSH
• Skotsko MeSH
• Wales MeSH