Dendrogram of various classes of endogenous retrovirusesWIKIMEDIA, FGRAMMENRemnants of retroviruses that entered the human genome millions of years ago can regulate some innate immune responses. These viral sequences have previously been linked to controlling early mammalian development and formation of the placenta, among other things. A study published today (March 3) in Science establishes that one such endogenous retrovirus in human cells can also regulate the interferon response, which helps organisms quickly respond to infections. The work is one of the first reports to show that human cells could have adopted retroviral sequences to regulate their genes.
“Before we started this project . . . we knew our genomes were full of these elements and many of them are activated during normal development in cells,” said study coauthor Edward Chuong, a postdoc at the University of Utah in Salt Lake City. “Our motivation was: How can we take the next step and figure out their potential biological consequences?”
Chuong and his University of Utah mentors Nels Elde and Cédric Feschotte began by scanning the sequences around interferon-induced genes, finding at least 27 transposable elements that likely originated from the long repeats at the ends of retroviral sequences. One such element, known as MER41, comes from a virus that invaded the genome approximately 45 million to 60 million years ago; the team found ...
