Karyotypes, nucleolus organizer region (NOR) and C-band peculiarities of Spalax from Northern Ankara

This work was performed for the characterization of chromosomal features of samples belonging to the Spalax species (blind mole rat) collected from northern region of Ankara (Kızılcahamam, Çubuk, Akyurt, Kalecik) by cyogenetic studies (karyotype, nucleolus organizer region-NOR and C-banding).In recent years, Spalax of Turkey have been the subject of extensive karyotype studies. The main goal of these studies was to contribute to the overcoming of cytogenetic problems. Such studies have shown that Spalax species living in Turkey have at least 26 different chromosomal forms. Members of Spalax species are almost living underground ecological niche with limited mobility capabilities. For these reasons, populations may display highly variable karyological features even if they do not have important geographical barriers. Any spontaneous mutation may remain in the population leading to generation of karyological variations. The aim of our thesis is to demonstrate such variations.Our study was realized with samples that we have collected between 20.04.2006 and 12.05.2007 in Ankara?s northern towns. We used a total of 9 mole rats (2 females, 9 males) in the study.Bone morrow technique described by Yuksel (1984) was used for karyotype analysis. The a-1 step technique of Black (1980) was used for silver staining of sample preparations, whereas the technique of Sumner (1972) was applied for C-banding.Our observations showed that the diploid chromosome number (2n) is 60. Of those, 9 pairs had subtelocentric and 20 pairs acrocentric morphologies and big submetacentric X chromosome, subtelocentric Y chromosome, respectively. We identified 3 NOR-positive chromosomes in all (both male and female) samples. C-banding showed that chromosome centromers stain darker with differeance of concentrasion. It is observed that during C-banding due to the density difference between chromosomes the centromeres are darker. The stained regions on the chromosomes are observed as pericentric, metacentric and distal according to the localization of centromeres. The presence of double bands on the 4th, 11th and 13th chromosomes are significant. Any morphological difference is obtained during C-band karyotyping for all the samples.Taken together, our study did not show any chromosomal form variation between the samples analyzed.