Cytogenetic aspects of phylogeny in the Bovidae. I. G-banding.

An extensive G-banding study of karyotypes of 12 species of Bovidae has been undertaken in an attempt to trace homologies and patterns of evolution of karyotype phenotypes throughout the family. G-banding profiles revealed a considerable degree of chromosome-arm homology throughout the group, which also extended into the related superfamilies, the Giraffoidea and Cervoidea. The conservation of banding patterns in chromosome arms strongly indicates that Robertsonian translocation type rearrangements have provided the major source of interspecies karyotype differences, with inversions and reciprocal and tandem translocations providing relatively minor contributions. Examples of individuals carrying newly arisen Robertsonian translocations are not infrequent, and in one instance there was evidence that two similar rearrangements had arisen independently in two species. Despite the extensive changes in karyotype organization, subfamilies within the Bovidae were characterized by the presence of common rearrangements, and those involving autosomal pairs 11 and 12 of the ox, as well as the X chromosome, separate the Bovinae from the Caprinae and Hippotraginae.