The second general area of interest in the lab is to understand how timing of developmental processes is regulated. In many organisms systemically delivered steroid hormones modulate developmental transitions, including metamorphosis in insects and puberty in humans. Our previous work has identified the neuroendocrine signals that trigger steroid production and release in Drosophila melanogaster (Shimell et al. 2018; Yamanaka et al.2015), as well as characterized the cell biology of steroid production and secretion in endocrine cells and determined how biosynthetic intermediates are trafficked between the mitochondria and the ER. More recently, we have characterized inputs into the critical weight checkpoint and their effects on developmental timing and body size (Shimell and O’Connor 2023, Pan and O’Connor 2021, Pan et al. 2019)
We are currently looking into the mechanism responsible for a prolonged development program in Drosophila harboring a mutation in the Trus gene and examining the subcellular localization of steroid biosynthetic enzymes.