Isolation and phylogeny of new endogenous retroviral sequences belonging to the HERV-F family

A new human endogenous retroviral family (HERV-F) has been identified from human chromosome 7q31.1-q31.3 that was identical to the XA34 cDNA clone iso lated from a human glioma cDNA library with an ERV-9 env probe. We investig ated pol gene sequences of the HERV-F family from a human monochromosomal D NA panel and analyzed these with HERV-F. The pol gene sequences of the HERV -F family were detected on chromosomes 3, 6, 7, 10, 11, 14, 19, 20, X, and Y as examined by PCR. Thirty-six pol gene sequences identified from the hum an chromosomes have a high degree of sequence similarity (80-99%) with that of the HERV-F. Phylogenetic analysis of pol gene sequences distinctively s howed four groups, indicating that the HERV-F family could be amplified at least four times after the original integration into the human genome or re present integration events separately during hominid evolution. One clone ( HFY-3) on chromosome Y shared 100% sequence identity with a clone (HF19-2) on chromosome 19, and a clone (HF20-6) on chromosome 20 suggests either a r ecent retrotransposition or a chromosomal translocation. The history of end ogenous retroviral sequences may contribute to an understanding of evolutio nary change in human genomes.