It’s time for our Gene of the Month, and this time it’s Shriveled. First described in a paper published in May 2016 by Karen Chang and her team at the University of Southern California in Los Angeles, it’s yet another of those fruit fly genes named after the appearance of unfortunate insects carrying a faulty version of the gene. In this case, male flies with faulty Shriveled are infertile, and also have testes that shrink and shrivel with age. The reason lies in the stem cells responsible for keeping them fuelled with sperm. Although a lot is known about the genes and molecules responsible for setting up these stem cells in the first place, much less is known about the way in which they’re maintained over time. The healthy version of Shriveled seems to play a vital part in that process, keeping male flies firing on all cylinders as they age.