Comparison of banded karyotypes between two subspecies of the red and white giant flying squirrelS Petaurista albomfus (Mammalia, Rodentia)

Banded karyotypes of two related subspecies of Petaurista alborufus castaneus from southern China and Petaurista alborufus lena from Taiwan are presented and compared. Both subspecies had 2n=38 with a fundamental number of FN=72, and shared the gross chromosomal similarity and G-band homology.However, the size of their X chromosomes, C-band patterns and the number and sites of Ag-NORs revealed gross differences. These cytogenetic information suggest that each subspecies developed independently from the common ancestral form. Robertsonian mechanism was absent for their karyotype evolution. With regard to the number of NORs, the P. alborufus lena karyotype seemed to be primitive. The present findings suggest that P. alborufus lena could be categorized as a distinct species.