The Mystery Genes That Are Keeping You Alive

When it came to the substantial number that were unknown, the team conducted one more study, using the best understood (at the genetic level) organism of all: Drosophila melanogaster. These fruit flies have been the subject of research for more than a century because they are easy and inexpensive to breed, have a short life cycle, produce lots of young, and can be genetically modified in numerous ways.

The team used gene editing to dial down the use of around 300 low-scoring genes found in both humans and fruit flies. “We found that one-quarter of these unknown genes were lethal—when knocked out, they caused the flies to die, and yet nobody had ever known anything about them,” says Freeman. “Another 25 percent of them caused changes in the flies—phenotypes—that we could detect in many ways.” These genes were linked with fertility, development, locomotion, protein quality control, and resilience to stress. “That so many fundamental genes are not understood was eye-opening,” Freeman says. It’s possible that variation in these genes could have very big impacts on…