Adaptive evolution and loss of function of a primate intrinsic immunity gene
The evolution of retroviral elements and their hosts is inextricably tied together throughout the animal kingdom. Retroviral elements selfishly unleash an onslaught of tactics to replicate themselves within host cells while the host must fight back with an arsenal of weaponry that has been honed over hundreds of millions of years to protect host genomes from invasion by these selfish retroviral elements. Host and virus are perpetually locked in this evolutionary arms race that leaves distinct footprints on both genomes that can be "read" using molecular evolution techniques. Here I present an in depth study of one such host gene, APOBEC3H, that has dutifully served its primate hosts to limit retroviral replication for millions of years. Most humans, however, have recently lost the services of this retroviral defense gene, leaving these individuals more susceptible to several retroviral pathogens with large current-day impacts on human health and evolution, including HIV-1, LINE-1 and Alu elements.