An article from MIT:TR in the early 2000s always stuck with me as an example of how intricate and interconnected genes really are. Researchers using fruit flies

An article from MIT:TR in the early 2000s always stuck with me as an example of how intricate and interconnected genes really are. Researchers using fruit flies found one born with white eyes, and they narrowed the mutation to a specific gene. They were able to modify it in vivo to reliably produce white eyes, but the change had an unexpected second outcome, which was that white-eyed males would only attempt to mate with other males. Years later, there was a group who cited that fruit fly paper when they proposed the same methodology to control mosquito populations, but I'm not sure if they ever recreated the male preference. The mosquito gene editing did pan out, but the method is different in that it doesn't allow females to survive, while males will go on to mate with other non-edited populations and spread the female-killing gene.