Translation components in adult Drosophila melanogaster adipocytes regulate the ovarian germline stem cell lineage

Adult stem cells, which support tissue homeostasis and damage repair, are influenced by whole organism physiology. Dietary input has a major impact on the stem cell supported ovary in Drosophila melanogaster females, appropriately matching reproductive output to nutrient availability. Previous work has shown that inter-organ communication plays a role in modulating the ovarian response to diet. Specifically, amino acid sensing by the adipose tissue remotely controls germline stem cells and their progeny. While we have shown that activation of the amino acid response pathway, a part of the integrated stress response, and mTOR signaling in adipocytes impacts germline stem cell maintenance and ovulation, it is unclear how downstream signaling mediates these responses. Here, using a combination of genetic and cell biological tools, we show that regulation of translation in adult adipocytes impacts the ovarian germline stem cell lineage, from stem cell maintenance to ovulation of mature oocytes. This work strongly suggests that the adipose tissue produces specific factors to control stem cell activity in the ovary and highlights how inter-organ communication underlies organismal physiological responses to diet.