Highly conserved chromosomes in an Asian squirrel (Menetes berdmorei, Rodentia: Sciuridae) as demonstrated by ZOO-FISH with human probes.

The chromosomes of Menetes berdmorei (Rodentia, Sciuridae, Sciurinae) were studied by ZOO-FISH using whole human chromosome probes. All homoeologies between M. berdmorei and human chromosomes were determined, except for two small chromosome segments. Twelve human chromosomes are conserved in a unique block of synteny; ten are split into two and one into three blocks. Thus, a small number of interchromosomal rearrangements, about twenty, separates human from this squirrel karyotype. Homoeologies between human and the presumed ancestral chromosomes of Sciurinae could also be deduced, as well as those with the presumed ancestral chromosomes of eutherian mammals. Sciurinae chromosomes appear to be much closer to those of non-rodent mammals than those of Muridae and Cricetidae species studied so far. Thus, they provide an interesting tool to link the rodent genome to those of other mammals.