Evolution of DNA on Y-chromosome in hominoid primates as examined by PCR

Every species of non-human primates, especially those of hominoids, has a variety of reproductive structures and accompanying male traits, such as sexual dimorphism and relative size of testis to body weight, which may be at least partly triggered by DNA on the Y-chromosome. Recently, a panel of PCR (Polymerase Chain Reaction) primer sets were designed to amplify various DNA segments spread over the human Y-chromosome. We applied these primer sets for amplification of DNA segments on the Y-chromosome of hominoid species: chimpanzee, bonobo (Pygmy chimpanzee), gorilla, orangutan, whitehanded gibbon, agile gibbon, and Japanese monkey as an out group. The DNA segments including SRY, testis determining factor, and ZFX/ZFY could be amplified clearly in males of all species examined. These highly conserved genes may serve important biological functions. However, as the phylogenic distance from humans increased, some of the DNA segments could not be amplified. For example, DYZ1 (SY160) could be amplified only using human DNA as a template, and DYF60S1 (SY61), DYZ217 (SY126) and DYS233 (SY148) could be amplified only using human and African great ape DNA. It is interesting to note that locus DYS250 (SY17) could not be amplified in chimpanzee and bonobo but amplified in gorilla and orangutan. Locus DYS251 (SY18) was amplified in all species except the white-handed gibbon. These results indicate that a variety of evolutionary events including mutation, deletion, insertion, and rearrangement occurred in Y-chromosome DNA during primate evolution.