Eclosion muscles secrete ecdysteroids to initiate asymmetric intestinal stem cell division in Drosophila

Dev Cell. 2023 Dec 8:S1534-5807(23)00614-7. doi: 10.1016/j.devcel.2023.11.016. Online ahead of print.ABSTRACTDuring organ development, tissue stem cells first expand via symmetric divisions and then switch to asymmetric divisions to minimize the time to obtain a mature tissue. In the Drosophila midgut, intestinal stem cells switch their divisions from symmetric to asymmetric at midpupal development to produce enteroendocrine cells. However, the signals that initiate this switch are unknown. Here, we identify the signal as ecdysteroids. In the presence of ecdysone, EcR and Usp promote the expression of E93 to suppress Br expression, resulting in asymmetric divisions. Surprisingly, the primary source of pupal ecdysone is not from the prothoracic gland but from dorsal internal oblique muscles (DIOMs), a group of transient skeletal muscles that are required for eclosion. Genetic analysis shows that DIOMs secrete ecdysteroids during mTOR-mediated muscle remodeling. Our findings identify sequential endocrine and mechanical roles for skeletal muscle, which ensure the timely asymmetric divisions of intestinal stem cells.PMID:38096823 | DOI:10.1016/j.devcel.2023.11.016

Source: Developmental Cell - December 14, 2023 Category: Cytology Authors: Song Zhang Song Wu Ruining Yao Xueying Wei Benjamin Ohlstein Zheng Guo Source Type: research