Karyotypic variation in populations of deer mice (Peromyscus maniculatus) from eastern Canada and the northeastern United States

Abstract

The karyotypes of deer mice (Peromyscus maniculatus) from populations of five subspecies from the northeastern United States and eastern Canada were analyzed by G- and C-banding. Within an invariant diploid number of 48, intra- and inter-populational variation in the number of autosomal arms (80-86) was attributable to a pericentric inversion (chromosome 8) and (or) the presence of heterochromatic short arms (chromosomes 8, 10, 12, and 19). The plesiomorphic (noninverted) condition of chromosome 10 in these five populations is unique among deer mice; previous chromosome-banding studies of P. maniculatus report data for geographically central or western populations and indicate only the derived (inverted) condition of chromosome 10. As the plesiomorphic condition of chromosome 10 is apparently restricted to the northeastern forest form of P. maniculatus, the morphology of this chromosome potentially represents a simple and discrete character for resolving the historically problematic question of the specific status of the eastern grassland and forest morphotypes of deer mice.