Karyotype of the Indian spiny mouse resulted from tandem fusion of some of the house mouse chromsomes.

Abstract

Chromosomes of the Indian spiny mouse (Mus platythrix) were observed by conventional, G[Giemsa]-, C[chromatin]- and Ag-NOR[nucleolar organizer]-staining methods. This species was characterized by 12 acrocentric autosome pairs in addition to acrocentrix X and Y chromosomes. The comparison of G-banded chromosomes and chromosome length between the spiny mouse and the house mouse (M. musculus) suggested that 8 autosome pairs (1-8) of the former species are derived from the tandem fusion of 2 acrocentric pairs of the latter species. Pairs 9-12 and X and Y in the spiny mouse seemed to correspond in some autosome pairs and X and Y of the house mouse. In this procedure, about 13% of the total chromosome length of the house mouse seemed to be lost to produce the new composites.