Orangutan fetal globin genes: nucleotide sequences reveal multiple gene conversions during hominid phylogeny

The authors have determined the nucleotide sequences of the linked gamma - super(1)- and gamma super(2)-fetal globin genes from a single orangutan (Pongo pygmaeus)) chromosome and compared them with the corresponding genes of other simian primates ( gamma super(1)- and gamma super(2)-genes of human, chimpanzee, gorilla, and the single gamma -gene of the spider monkey). To explain these different evolutionary histories and also hominid relationships, the authors provide evidence for the occurrence of sequence conversions which affect region 1 (120 base pairs 5'-flanking through exon 2) in all hominid species and extend to varying degrees into region 2 (intron 2 through exon 3). Close examinations of the proposed conversions further suggest that 12 of the 13 conversions identified involved gamma super(1) converting gamma super(2).