Article: Retroviruses reinfect humans

Discussion in 'Health and medical' started by Robert Karl Sto, Mar 23, 2004.

  1. Retroviruses reinfect humans Genomic sequences are
    remnants of repeated reinfections during primate evolution
    By Cathy Holding

    There are 98,000 human endogenous retroviral (HERV)
    sequences in the human genome, most inactivated by
    mutations. A new study in the March 22 PNAS reveals that
    this large number of insertions is most likely the result of
    germline reinfection rather than retrotransposition or
    complementation.

    "What we think is really happening is that in the past 30
    million years, there have been very many of these elements,
    not fixed but just present in a small number of
    individuals," said Robert Belshaw, from the Department of
    Biological Sciences, Imperial College London, and lead
    author of the study.

    These would have been infecting and moving about, possibly
    between individuals, but certainly within individuals, from
    somatic cells back into germline cells. Periodically, one
    would pick up a mutation that would stop it from moving
    about. "Once dead, there would be no selection against it
    from the host. They're just a bit of junk, and they could
    then drift to fixation by chance," Belshaw told The
    Scientist.

    "The idea which some people had held was that a lot of these
    elements, although they come originally from viruses, had
    actually spread around the genome by mechanisms other than
    virological ones," said John M. Coffin, professor of
    molecular biology and microbiology at Tufts University's
    Sackler School of Graduate Biomedical Sciences

    Read the rest at The Scientist.com
    http://www.biomedcentral.com/news/20040323/01

    Posted by Robert Karl Stonjek.
     
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