A HML-2 locus in human chromosome 5q15 once formed by L1-mediated retrotransposition of
mRNA. (A) Multiple sequence alignments of relevant regions of the HERV-K(HML-2.HOM) proviral sequence (GenBank acc. no. AF074086; ref. ), a rec mRNA sequence (GenBank acc. no. X72790; ref. ), a recently described retrotransposed rec mRNA in human chromosome 2q32.1 , and the HML-2 locus in human chromosome 5q15 are shown, depicting target site duplications, rec-typical intron/exon boundaries and poly-A tails immediately upstream of the 3′TSD of the chromosome 2q32.1 and 5q15 loci. See ref.  for a more detailed description of the chromosome 2q32.1 locus. (B) A dot plot matrix comparison of the chromosome 5q15 locus sequence (reverse complemented) with the HERV-K(HML-2.HOM) reference sequence is shown with proviral regions indicated for the latter, likewise depicting the rec-typical proviral regions present for that HML-2 locus. (C) Presence of the HML-2 locus in the homologous regions of human chromosome 5q15 in the genomes of chimpanzee, gorilla, orangutan, gibbon, and lack in rhesus monkey (the homologous HML-2 locus also lacking in baboon is not shown). Marmosets, as new world monkeys, generally lack HERV-K(HML-2) homologous sequences. LTR, long terminal repeat; SA, splice acceptor; SD, splice donor; TSD, target site duplication.