How invading jumping genes are thwarted

"Since Carnegie Institution's Barbara McClintock received her Nobel Prize on her discovery of jumping genes in 1983, we have learned that almost half of our DNA is made up of jumping genes -- called transposons. Given their ability of jumping around the genome in developing sperm and egg cells, their invasion triggers DNA damage and mutations. This often leads to animal sterility or even death, threatening species survival. The high abundance of jumping genes implies that organisms have survived millions, if not billions, of transposon invasions. However, little is known about where this adaptability comes from.

Now, a team of Carnegie researchers has discovered that, upon jumping gene invasion, reproductive stem cells boost production of non-coding RNA elements (piRNA) that suppress their activity and activates a DNA repair process allowing for normal egg development. The results are published in the November 1, 2018, issue of Developmental Cell.

The researchers studied jumping genes in the fruit fly Drosophila melanogaster -- a classic model to study jumping genes in developing sperm and egg cells. To set up a powerful system studying jumping gene adaptation, the researchers needed a tool to control their activity. It has been known for four decades that environmental temperature influences the severity of sterility in the fruit fly upon jumping gene invasion. At temperatures of 77 degrees F (25 degrees C) offspring have sterile ovaries, while at 64 degrees F (18 degrees C) offspring have fully developed and fertile ovaries..." | Learn More >>