EVOLUTION OF FUCOSYL-TRANSFERASE GENES IN VERTEBRATES

Cloning and expression of chimpanzee FUT3, FUT5, and FUT6 genes confir med the hypothesis that the gene duplications at the origin of the pre sent human cluster of genes occurred between: (i) the great mammalian radiation 80 million years ago and (ii) the separation of man and chim panzee 10 million years ago, The phylogeny of fucosyltransferase genes was completed by the addition of the FUT8 family of alpha(1,6)fucosyl transferase genes, which are the oldest genes of the fucosyltransferas e family. By analysis of data banks, a new FUT8 alternative splice exp ressed in human retina was identified, which allowed mapping the human FUT8 gene to 14q23. The results suggest that the fucosyltransferase g enes have evolved by successive duplications, followed by translocatio ns, and divergent evolution from a single ancestral gene.