Sequencing of rhesus macaque Y chromosome clarifies origins and evolution of the DAZ (Deleted in AZoospermia) genes

Abstract

Studies of Y chromosome evolution often emphasize gene loss, but this loss has been counterbalanced by addition of new genes. The DAZ genes, which are critical to human spermatogenesis, were acquired by the Y chromosome in the ancestor of Old World monkeys and apes. We and our colleagues recently sequenced the rhesus macaque Y chromosome, and comparison of this sequence to human and chimpanzee enables us to reconstruct much of the evolutionary history of DAZ. We report that DAZ arrived on the Y chromosome about 38 million years ago via the transposition of at least 1.1megabases of autosomal DNA. This transposition also brought five additional genes to the Y chromosome, but all five genes were subsequently lost through mutation or deletion. As the only surviving gene, DAZ experienced extensive restructuring, including intragenic amplification and gene duplication, and has been the target of positive selection in the chimpanzee lineage. Editor's suggested further reading in BioEssays Should Y stay or should Y go: The evolution of non-recombining sex chromosomes Abstract The DAZ genes, which are critical to spermatogenesis, are the sole survivors of a massive autosomal transposition to the primate Y chromosome. We reconstruct the evolutionary history of DAZ over 25 million years through a comparison of the complete Y chromosome sequences of human, chimpanzee, and rhesus macaque. © 2012 WILEY Periodicals, Inc.