sisterless A is required for activation of Sex lethal in the Drosophila germline.

According to a preprint abstract from biorxiv.org, the activation of the switch gene Sex lethal (Sxl) is crucial for the correct sexual identity and gametogenesis in both somatic cells and germ cells in Drosophila. While the mechanism for counting X chromosomes in the germline is different from somatic cells, the X chromosome gene sisterless A (sisA) is essential for Sxl activation in the germline. Loss of sisA leads to defects in Sxl expression, ovarian tumors, and germline loss. However, additional factors regulating female-specific expression of Sxl in the germline are yet to be discovered. This research has not been peer-reviewed. [Extracted from the article]