Vkorc1 gene polymorphisms confer resistance to anticoagulant rodenticide in Turkish rats.

Mutations in Exon 1, 2 and 3 of the vitamin K epoxide reductase complex subunit 1 (Vkorc1) gene are known to lead to anticoagulant rodenticide resistance. In order to investigate their putative resistance in rodenticides, we studied the genetic profile of the Vkorc1 gene in Turkish black rats (Rattus rattus) and brown rats (Rattus norvegicus). In this context, previously recorded Ala21Thr mutation (R. rattus) in Exon 1 region, Ile90Leu mutation (R. rattus, R. norvegicus) in Exon 2 region and Leu120Gln mutation (R. norvegicus) in Exon 3 region were identified as "missense mutations" causing amino acid changes. Ala21Thr mutation was first detected in one specimen of Turkish black rat despite the uncertainty of its relevance to resistance. Ile90Leu mutation accepted as neutral variant was detected in most of black rat specimens. Leu120Gln mutation related to anticoagulant rodenticide resistance was found in only one brown rat specimen. Furthermore, Ser74Asn, Gln77Pro (black rat) and Ser79Pro (brown rat) mutations that cause amino acid changes in the Exon 2 region but unclear whether they cause resistance were identified. In addition, "silent mutations" which do not cause amino acid changes were also defined; these mutations were Arg12Arg mutation in Exon 1 region, His68His, Ser81Ser, Ile82Ile and Leu94Leu mutations in Exon 2 region and Ile107Ile, Thr137Thr, Ala143Ala and Gln152Gln mutations in Exon 3 region. These silent mutations were found in both species except for Ser81Ser which was determined in only brown rats.

Determination of genetic variations in the genus Dryomys Thomas, 1906 (Rodentia: Gliridae) distributed in Turkey using NADH dehydrogenase 1 (ND1) gene.

Genetic diversity and phylogeny of Dryomys nitedula and Dryomys laniger from Turkey was described in the present study by using mitochondrial DNA NADH dehydrogenase 1 gene (ND1). Genetic variation in ND1 gene was determined by two model-based phylogenetic analyses and a network analysis revealed 27 haplotypes of D. nitedula constructing four main lineages (Thrace, Anatolia, North-eastern Anatolia and Savsat) that have non-overlapping geographic distributions and no shared haplotypes, but on the other hand, three haplotypes were detected in four samples of D. laniger from Turkey. It was determined that nucleotide diversity was low but haplotype diversity was high in D. laniger, whereas, D. nitedula has both high level of haplotype and nucleotide diversity. Characterization of Thrace lineage of D. nitedula with low nucleotide diversity and determination of the total nucleotide diversity of Anatolian lineages (Anatolia + North-eastern Anatolia+Savsat) to be approximately four times higher than that of Thrace lineage indicated that Anatolia may have served as a refuge for D. nitedula. Divergence times and high level of nucleotide differences between D. nitedula lineages showed that diversification of the lineages may have occurred before and during ice ages in Turkey, thought to be a refuge for post-glacial colonization and biodiversity resource of Europe. Additionally, estimated divergence times and calculated genetic distances yielded compatible results with the previous paleontological and genomic data for the diversification time of two species in the genus.

Genetic variations of Turkish bank vole, Myodes glareolus (Mammalia: Rodentia) inferred from mtDNA.

The bank vole, Myodes glareolus, lives in deciduous forests throughout the Palearctic region. In Turkey, this species is distributed only in northern Anatolia (the Black Sea region) where these forests exist. This study reveals genetic differentiation among bank vole populations based on two regions of mitochondrial DNA (cytochrome b and D-loop). Populations in northern Anatolia are divided into two genetic lineages (the "eastern" and "western Black Sea" lineages) by the Kizilirmak Valley. While the western Black Sea lineage is close to the Balkan lineage, in accordance with their geographical proximities, surprisingly, the Uludag lineage, also situated in Western Turkey appears related to the eastern Black Sea population. The divergence time analyses suggest a separation between the Balkan and Turkish groups around 0.26 Mya, whereas the split between the eastern and western Black sea lineages appeared a little bit later (0.20 Mya). Our results suggest that regional refuges existed for this species in Turkey and that small-scale habitat fragmentations led to genetic differentiations between Myodes populations.

Golden hamsters are nocturnal in captivity but diurnal in nature.

Daily activity rhythms are nearly universal among animals and their specific pattern is an adaptation of each species to its ecological niche. Owing to the extremely consistent nocturnal patterns of activity shown by golden hamsters (Mesocricetus auratus) in the laboratory, this species is a prime model for studying the mechanisms controlling circadian rhythms. In contrast to laboratory data, we discovered that female hamsters in the wild were almost exclusively diurnal. These results raise many questions about the ecological variables that shape the activity patterns in golden hamsters and the differences between laboratory and field results.

Molecular phylogeny of the Cricetinae subfamily based on the mitochondrial cytochrome b and 12S rRNA genes and the nuclear vWF gene.

Despite some popularity of hamsters as pets and laboratory animals there is no reliable phylogeny of the subfamily Cricetinae available so far. Contradicting views exist not only about the actual number of species but also concerning the validity of several genera. We used partial DNA sequences of two mitochondrial (cytochrome b, 12S rRNA) and one partial nuclear gene (von Willebrand Factor exon 28) to provide a first gene tree of the Cricetinae based on 15 taxa comprising six genera. According to our data, Palaearctic hamsters fall into three distinct phylogenetic groups: Phodopus, Mesocricetus, and Cricetus-related species which evolved during the late Miocene about 7-12MY ago. Surprisingly, the genus Phodopus, which was previously thought to have appeared during the Pleistocene, forms the oldest clade. The largest number of extant hamster genera is found in a group of Cricetus-related hamsters. The genus Cricetulus itself proved to be not truly monophyletic with Cricetulus migratorius appearing more closely related to Tscherskia, Cricetus, and Allocricetulus. We propose to place the species within a new monotypic genus. Molecular clock calculations are not always in line with the dating of fossil records. DNA based divergence time estimates as well as taxonomic relationships demand a reevaluation of morphological characters previously used to identify fossils and extant hamsters.