University of California - San Francisco. (2018, June 21). Not junk: 'Jumping gene' is critical for early embryo: Gene that makes up a fifth of the human genome is not a parasite, but key to the first stages of embryonic development. ScienceDaily Citat: "...Only about 1 percent of the human genome encodes proteins, and researchers have long debated what the other 99 percent is good for...For example, fully half of our DNA is made up of "transposable elements," or "transposons," virus-like genetic material that has the special ability of duplicating and reinserting itself in different locations in the genome, which has led researchers to dub them genetic parasites...Now UCSF scientists have revealed that, far from being a freeloader or parasite, the most common transposon, called LINE1, which accounts for 20 percent or more of the human genome, is actually necessary for embryos to develop past the two-cell stage...The team tried eliminating LINE1 from fertilized eggs and found that the embryos completely lost their ability to progress past the two-cell phase..."We now think these early embryos are playing with fire but in a very calculated way," Ramalho-Santos said. "This could be a very robust mechanism for regulating development."..."
