MYH16 (myosin, heavy chain 16 pseudogene)

MYH16 is abbreviation of myosin heavy chain 16.  Stedman et al. (2004) found that this gene is nonfunctional in human, but chimpanzee and other non-human primate species seem to have functional MYH16 gene.  Because human has MYH16 pseudogene, its localized expression in masticatory muscle in non-human primates is lost, causing marked size reduction in human.  They estimated time of nonfunctionalization of MYH16 to be approximately 2.4 million years ago.  Perry et al. (2005), however, comparing larger nucleotide sequence data between human and chimpanzee, reestimated nonfunctionalization date as 5.3 million years ago.

Contributed by Saitou Naruya, Genetics domain leader.