an endogenous foamy-like viral element in the coelacanth genome一个内生foamy-like病毒元素在腔棘鱼基因组中.pdfVIP

An Endogenous Foamy-like Viral Element in the Coelacanth Genome Guan-Zhu Han*, Michael Worobey* Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, United States of America Abstract Little is known about the origin and long-term evolutionary mode of retroviruses. Retroviruses can integrate into their hosts’ genomes, providing a molecular fossil record for studying their deep history. Here we report the discovery of an endogenous foamy virus-like element, which we designate ‘coelacanth endogenous foamy-like virus’ (CoeEFV), within the genome of the coelacanth (Latimeria chalumnae). Phylogenetic analyses place CoeEFV basal to all known foamy viruses, strongly suggesting an ancient ocean origin of this major retroviral lineage, which had previously been known to infect only land mammals. The discovery of CoeEFV reveals the presence of foamy-like viruses in species outside the Mammalia. We show that foamy-like viruses have likely codiverged with their vertebrate hosts for more than 407 million years and underwent an evolutionary transition from water to land with their vertebrate hosts. These findings suggest an ancient marine origin of retroviruses and have important implications in understanding foamy virus biology. Citation: Han G-Z, Worobey M (2012) An Endogenous Foamy-like Viral Element in the Coelacanth Genome. PLoS Pathog 8(6): e1002790. doi:10.1371/ journal.ppat.1002790 Editor: Michael Emerman, Fred Hutchinson Cancer Research Center, United States of America Received February 29, 2012; Accepted May 22, 2012; Published June 28, 2012 Copyright: 2012 Han, Worobey. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medi