Karyotype of the Indian Spiny Mouse Resulted from Tandem Fusion of Some of the House Mouse Chromosomes

Abstract

Chromosomes of the Indian spiny mouse (Mus platythrix) were observed by conventional, G-, C and Ag-NOR-staining methods. This species was characterized by 12 acrocentric autosome pairs in addition to acrocentric X and Y chromosomes. The comparison of G-banded chromosomes and chromosome length between the spiny mouse and the house mouse (M. musculus) had led the assumption that 8 autosome pairs (nos. 1 to 8) of the former species had been derived from the tandem fusion of two acrocentric pairs of the latter species. Pair nos. 9 to 12 and X and Y in the spiny mouse seemed to correspond in some autosome pairs and X and Y of of the house mouse. In this procedure, about 13 percent of the total chromosome length of the house mouse seemed to be lost to produce the new composites.