Tarkan Yorulmaz

A new cytotype (2n=46) of Nannospalax xanthodon from Turkey

A new cytotype was found in a population of mole rats Nannospalax xanthodon from south-eastern Anatolia, Turkey. The karyotype contained 46 chromosomes and 66 autosomal arms (11 biarmed and 11 acrocentric autosomal pairs). The X chromosome was submetacentric and the Y chromosome small subtelocentric. Distinct dark C-bands were observed on all the biarmed chromosomes and on three pairs of acrocentric autosomes. The NORs were detected on the short arms of two subtelocentric pairs of autosomes. The published data indicate considerable chromosomal variation between populations of mole rats in south-eastern Anatolia. The finding of a karyotype with a unique chromosomal number in the karyologically well-studied region of south-eastern Anatolia indicates that the karyotype structuring between mole rat populations may be even more complex than previously realised.

C-banding and Ag-NOR distribution patterns in Euphrates jerboa, Allactaga euphratica (Mammalia: Rodentia), from Turkey

Abstract A chromosomal study of Allactaga euphratica from the Şanlıurfa Province in Southeast Anatolia, Turkey, was performed. The diploid number of 48 chromosomes was found in all four specimens examined. The C-band-positive regions were distributed in centromeric areas of all the autosomal pairs and the X chromosome. Extensive C-positive heterochromatin intercalary blocks were observed in the largest pair of autosomes. The small Y chromosome was stained uniformly and C-negatively. The active nucleolus organizer regions (NORs) were localized in two pairs of small bi-armed autosomes. The C-heterochromatin distribution and localization of the secondary constrictions bearing NORs apparently differ between karyotypes of the related jerboa species A. euphratica and Allactaga williamsi. This cytogenetic difference may be implied as a suitable marker in further studies of the relationships in contact zones and possible hybridization between these two taxa.

C-heterochromatin variation and NOR distribution in the karyotype of water vole, Arvicola terrestris (Mammalia, Rodentia)

Abstract A chromosomal study of populations of Arvicola terrestris from Anatolia in Turkey and from Central Europe was performed. The diploid number of 36 chromosomes was found in all the specimens examined. The autosomal complement consisted of 12 meta- and submetacentric pairs, two large or medium-sized subtelocentric pairs, and three small acrocentric (Turkey) or subtelocentric (Central Europe) pairs (FNa = 62–68). The X chromosome was medium-sized submetacentric, the Y chromosome was small acrocentric or subtelocentric. All the chromosomes could be reliably identified by their unique G-banding patterns. The C-banding analysis revealed variation in the amount of constitutive heterochromatin in centromeric regions and in short arms of certain autosomes. A unique feature of the C-banded karyotype of individuals from Anatolia was the absence of dark positive regions in most chromosomes. Populations of water vole from Anatolia resemble in their C-band pattern those studied previously in Azerbaijan, and possibly also in the Balkan peninsula, and they are different in this respect from populations in Central Europe and the other parts of the species range. The X chromosome was stained uniformly and C-negatively in populations from Anatolia, whereas a faint dark centromeric C-band was observed in individuals from Central Europe. The Y chromosome was stained C-positively. The active nucleolar organizer regions (NORs) were localized in one pair of small metacentric and two acrocentric autosome pairs in the karyotype of individuals from Anatolia.

C-heterochromatin and NORs distribution in karyotypes of three vespertilionid bat species from Turkey

Abstract The chromosomal banding analysis of the karyotypes of Turkish populations of Eptesicus serotinus, Nyctalus lasiopterus and Barbastellus barbastellus was performed with the use of C-banding and Ag-NOR staining. The results obtained in E. serotinus and N. lasiopterus were congruent with previous data reported from other regions. The karyotype of E. serotinus (2n = 50, NF = 52) contained a moderate amount of centromeric C-heterochromatin and a single NOR was localized in an acrocentric autosomal pairs. The karyotype of N. lasiopterus (2n = 42, NF = 54) contained a higher amount of centromeric C-heterochromatin and the NORs were localized in two autosomal pairs. The karyotype of B. barbastellus was standard in its general characteristics (2n = 32, NF = 54, low amount of C-heterochromatin) but the NOR was localized in only one acrocentric autosomal pair. In studies from other regions, the NORs were recognized in all five acrocentric autosomal pairs of the complement of B. barbastellus.