Karyotype and sex chromosome differentiation in two species (Coleoptera, Tenebrionidae).

Cytogenetic features of Nabozhenko & Keskin, 2010 and Küster, 1850 were analysed using conventional and differential staining. Mitotic and meiotic chromosomal analysis revealed the diploid number as 2n = 20 (9+Xy) in both species. Besides the general resemblance of two Mulsant, 1854 karyotypes, important differences related to variations in the number of metacentric/submetacentric chromosomes, localization of highly impregnated regions which are considered as NOR and heterochromatin distribution are clearly observed. The most prominent difference between two species is found related to the X chromosome which is clearly larger in and has a conspicuous secondary constriction on the long arm. As a result of silver staining, the existence of highly impregnated areas associated with Xy of in both prophase I and metaphase I, suggests that NORs are seemingly located on sex chromosomes. On the other hand, the potential NORs of were observed only in prophase I nuclei. With the application of fluorescence dye DAPI, the AT rich chromosome regions and Xy which forms the parachute configuration were shown in both species.