A once-maligned genetic parasite may actually be essential for survival.
Mouse embryos need that genetic freeloader — a type of jumping gene, or transposon, called LINE-1 — to continue developing past the two-cell stage, researchers report in the July 7 Cell.
Many scientists “charge that these are nasty, selfish genetic elements” that jump around the genome, making mutations and wreaking havoc, says study coauthor Miguel Ramalho-Santos, a developmental and stem cell biologist at the University of California, San Francisco. But the new research suggests that the jumping gene is more helpful to development than previously thought.