Cytogenetic analysis on Turkonalassus quercanus Keskin, Nabozhenko et Alpagut-Keskin, 2017 (Coleoptera: Tenebrionidae: Helopini)

Abstract

Cytogenetic features of the endemic Western Anatolian tenebrionid species Turkonalassus quercanus Keskin, Nabozhenko et Alpagut-Keskin, 2017 were analyzed using conventional and differential staining. Chromosome preparations were obtained from the gonads of both males and females. The karyotype of T. quercanus was found to be 2n = 20 (9 + Xyp), which is considered the modal number for Tenebrionidae. The heteromorphic sex chromosomes of T. quercanus form a parachute like bivalent at metaphase I (MI) of male meiosis. Both conventional and differential staining have shown that predominantly metacentric chromosomes of T. quercanus exhibit a typical pericentromeric heterochromatin pattern. As per results of the silver staining, the existence of a prominent nucleolus at prophase I and a highly impregnated area associated with Xyp at MI are indicated the sex chromosomal location of NOR. In comparison with previously published cytogenetic data on other species of the tribe Helopini which are presenting the same karyotype formula, our results suggest that a series of chromosomal rearrangements may have been involved in their karyotype evolution.

Keywords

• cytogenetics
• tenebrionidae
• helopini
• turkonalassus
• nalassus
• sex chromosomes
• nor
• heterochromatin