Comparative Gene Mapping in Baboon (Papio) Species

Gene mapping in nonhuman mammalian species is a field of increasing importance in man's efforts to understand genome organization, to develop animal models for human genetic diseases, and to investigate phylogenetic relationships and evolutionary mechanisms. The primates are of particular interest in these studies because of their morphological and physiological similarities to man. The availability and convenient size of the baboons (Papio species) make them the primates of choice for various areas of research having applications to man. The baboons also appear to have many chromosomal and genetic homologies to man as well as to the other primates, although their precise taxonomic relationship to some of these other primates is not yet clear.

In order to evaluate some of the proposed chromosomal homologies between the baboons and other species, to shed additional light on the taxonomic relationships, and to further explore the baboons as models for human disease, this study sought to develop or extend the gene maps of two species of baboons, Papio papio and P. hamadryas. Baboon x mouse or Chinese hamster somatic cell hybrids segregating baboon chromosomes were analyzed for baboon gene and chromosome content using enzyme electrophoresis and chromosome banding techniques. Eighteen genes were assigned to chromosomes in P. hamadryas and four in P. papio by their concordant segregation with the chromosomes or with previously assigned gene markers. Several other independently segregating gene markers or syntenic groups were also identified in these species. The gene maps of the two baboon species were found to be the same where they can be compared. These maps are compared with those available for man and other species, particularly the rhesus monkey (Macaca mulatta), which is considered to be closely related to the baboons. A possible primate model for human lymphoid disease is also discussed.