A karyological study of the spiny mouseAcomysGeoffroy 1838 (Rodentia Muridae) along the Ethiopian Rift Valley

Descriptions are provided of chromosomal sets and comparative analyses of C-banded chromosomes of the spiny mice from the genus Acomys Geoffroy 1838, which were collected from five localities in Ethiopia (Gamo-Gofa province: Konso area, Arba Minch; upper part of Awash valley: Koka area; middle part of Awash valley: Awash National Park and 70 km North from Awash National Park). Two karyotypic forms were discovered: one, as expected A. cahirinus Desmarest 1819 (2n = 36, NF = 68) and one new for the Ethiopian fauna 68-chromosomal Acomys sp. The distribution of these forms is discussed. Details of the C-banded chromosomes of Acomys cahirinus and Acomys sp. are given for the first time. It was shown that both these karyotypes possess mainly pericentromeric heterochromatin and have insignificant differences in their quantities. It is possible that heterochromatin variations did not make a contribution to the karyotypic evolution of Acomys. Apparently, chromosomal evolution in this genus was determined by Robertsonian or tandemic type translocations.