A New Cytotype of the Iranian House Mouse, Mus musculus Linnaeus, 1758 (Rodentia: Muridae), in Birjand Region, Eastern Iran: Implications for the Evolution of Sex- Autosome Translocations

The highly conserved morphology and chromosomal structures of house mouse, Mus musculus, provides a good model for chromosomal studies. Sex-autosome translocations is one of the rarest chromosomal rearrangements among mammals and therefore sex-autosome translocations has been offered as accurate taxonomic markers to identify species with similar morphological traits. In this study, we described the outcome of a comprehensive cytogenetic survey of the house mouse, Mus musculus, in the eastern Iran using G banding method. Interestingly, results showed the presence of a new cytotype of X-autosome translocation of house mouse which was found in 18 specimens of Birjand region in the eastern Iran. Larger size of choromosomal translocation was observed in Chromosome X. We used karyotype asymmetry method as a powerful statistical parameter to extract coefficient of variation of chromosome length. Based on the data of this study, the results, Birjand population did not show asymmetry in all Asymmetry indexes (AI, DI, As%, A, A2, A1 and Syi %), and this result confirmed translocations in Birjands' chromosomes as well.