Chromosomal distribution, genomic feature and functional implication of the HERV-W family in humans

We examined the chromosomal distribution of the human endogenous retrovirus (HERV-W) family in humans. FISH data indicated that the HERV-W probe (fosWE1) derived from the gorilla fosmid library was clearly detected in all chromosomes except for chromosomes 13, 18, 21, and Y. Most of the HERV-W family seems to be proliferated during the course of primate radiation approximately 2545 Myr ago. The sequences of target site duplication (TSD) for the proliferation of HERV-W family were completely different in full length or processed pseudo HERV-W sequences, respectively. The HERV-W LTR elements, having biological roles of alternative promoter, exonization, alternative polyadenylation, were detected in several loci, and those elements are actively expressed in various tissues. Taken together, these data are valuable sources for understanding the biological roles of HERV-W family in humans.