Kawamura / Poster

Red/green visual pigment gene organization of owl monkeys and common marmosets

Kawamura S¹, Hirai M¹ and Takenaka O^2
1Graduate School of Frontier Sciences, University of Tokyo, Tokyo, Japan,
²Primate Research Institute, Kyoto University, Inuyama, Japan

     Many species of New World primates show significant individual variations in color vision. To explain this unique polymorphism, "triallelic single-locus X-chromosome theory" has been proposed for their red/green visual pigment genes. Their genomic organizations of the genes, however, have not been directly investigated. To assess the validity of the theory, we employed Southern blotting, genomic-library screening, and fluorescence in situ hybridization (FISH) methods for several species of New World primates.
     We isolated two and five genes from a male marmoset and owl monkey, respectively. Genes were mapped on the long arm tip of X-chromosomes in both species by FISH. From a family study, however, we concluded that presence of two genes in male marmosets is due to hematopoietic chimerism caused by blood exchange between dizygotic twin embryos. As for owl monkey, only one gene appeared functional among the five. These results demonstrate that the single-locus X-chromosome theory is valid in many species of New World primates as far as functional genes are concerned.