Notes on the karyotype of Tachyoryctes splendens (Rüppell 1836) (Rodentia Rhizomyidae) from Ethiopia

Abstract

The new karyotypic form of Tachyoryctes splendens (Rüppell 1836) from Ethiopia is described. It consists of 48 chromosomes, of which three pairs (1, 2, 4) are subtelocentric with very short additional arms, 17 pairs are acrocentric and three pairs are metacentric. The sex pair is composed of the largest submetacentric X-chromosome and large metacentric Y-chromosome. The fundamental number is 62. C-banding reveals pericentromeric heterochromatin in almost all autosomes and X- chromosome, additional heterochromatic blocks at the short arms of subtelocentric autosomes, telomeric blocks of X-chromosome and fully heterochromatinized Y-chromosome. The Ag-NORs are localized at the telomeric ends of the short arms of the first and the second autosomal pairs. The data on T. splendens of Ethiopia are compared with those from earlier studies of the karyotypes of representatives of the family Rhizomyidae to which T. splendens belongs.

Key Words:

• Rodentia
• Tachyoryctes splendens
• systematics
• karyotype
• banding
• Ethiopia