Chromosome Study of Yulong Vole (Eothenomys proditor).

A first description of the karyotype of Yulong vole (Eothenomys proditor) is presented. Karyotype studies were carried out using conventional staining, G-banding, C-banding and silverstaining. Yulong vole was sharp different from other allied voles on karyotype. The diploid number is 2n=32, with the fundamental number of 56. The autosomes consist of 13 pairs of meta-/submetacentric elements and two pairs of arcrocentric elements. The X chromosome is medium sized and submetacentric, whereas the Y chromosome is small and subacrocentric. The G-banding allows to identify chromosome pairing and to detect the chromosome rearrangements intervening in karyotypic differentiation. In the C-banded karyotype, the centromeric heterochromatin is observed in Nos. 2, 4 and 12 chromosomes, the terminal C-band is found in No. 13 and X chromosomes. Y chromosome is completely C-band-positive, moreover, the interstial distribution of C-bands has been demonstrated on the biarm of No. 2 chromosome pair and the long arm of Nos. 2, 9 and 10 chromosomes respectively. Nucleolus organizer regions (NORs) appeared in the long arm of Nos. 1, 2 and 4 chromosomes and short arm of No. 11 chromosome.