Presence and phylogenetic analysis of HERV-K LTR on human X and Y chromosomes: evidence for recent proliferation.
The K group of human endogenous retroviruses (HERV-K) has been suggested to have a role in disease and has recently been shown to include long terminal repeat (LTR) elements that are human specific. Here we investigated the presence of HERV-K LTRs on the human X and Y chromosomes with the use of PCR on a monochromosomal somatic cell hybrid DNA panel. We report twelve such sequences on the X chromosome and ten sequences on the Y chromosome. Phylogenetic analysis reveals that clones X2, 4, 5, 6, 7, 11, 15 from the X chromosome and clones Y4, 5, 7, 10 from the Y chromosome are closely related to the human-specific members of Medstrand and Mager's cluster 9. The sequence of clone Y7 from the Y chromosome is identical with human-specific HERV-K LTR element (AC002350) from chromosome 12q24. The findings suggest recent proliferation and transposition of HERV-K LTR elements on these chromosomes. Such events may have contributed to structural change and genetic variation in the human genome. We draw attention to evolutionarily recent changes in homologies between X and Y chromosomes as a method of further investigating such transpositions.
Kim
H S
HS
Department of Psychiatry, Warneford Hospital, University of Oxford, United Kingdom.
Crow
T J
TJ
D004279:DNA, Viral / Q000032:analysis; D020077:Endogenous Retroviruses / Q000235:genetics*; D014644:Genetic Variation; D006801:Humans; D006822:Hybrid Cells; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D014960:X Chromosome; D014998:Y Chromosome
D004279:DNA, Viral