Loss of ABC transporters, White, Brown, and Scarlet, prevents increase in mitotic divisions of germline stem cells in response to mating in Drosophila melanogaster.

The replenishment of specialized cells depends on the activity of stem cells. Recent advances in stem cell research have shown that the germline stem cells (GSCs) in Drosophila melanogaster can increase their mitotic activity in response to mating. Here, we show that this ability to respond to mating is eliminated if the males are mutant for either of the ABC transporters, White (W), Brown (Bw) or Scarlet (St), which are known for their role in eye pigmentation and amine production. However, reducing the expression of w specifically from the germline cells also caused a failure to increase GSC mitotic activity upon mating, suggesting that w is required intrinsically in the stem cells. The w gene is a common genetic background for genetic experiments and frequently used as a control. Our findings underline the importance of careful experimental design and control choice.