The nuclear receptor seven up functions in adipocytes and oenocytes to control distinct steps of Drosophila oogenesis

RNAi-based screens uncover a potential new role for the orphan neuropeptide receptor Moody in Drosophila female germline stem cell maintenance

“…In accordance, a previous study from our group found that ubiquitous somatic knockdown of seven up (svp, which encodes a nuclear receptor) led to decreased egg laying with effects in GSC maintenance, germline cyst survival, and vitellogenesis [17]. Interestingly, svp knockdown in adipocytes led to increased GSC loss and early germline cyst death, but no measurable effect on egg production, whereas svp knockdown in oenocytes caused degeneration of vitellogenic follicles and a reduction in number of eggs laid [17], indicating that egg count assays may not adequately capture more subtle changes in earlier steps of oogenesis. By contrast, we found that ubiquitous somatic knockdown of moody has a very strong effect on GSC maintenance (Fig 3D-3F) with consistent decreases in egg laying ( Fig 1D).…”

“…To identify novel neuropeptide signaling pathways that might regulate oogenesis, we performed three separate screens using egg counts as a read-out: pan-neuronal neuropeptide knockdown using nSyb-Gal4 [16], ubiquitous somatic neuropeptide receptor knockdown using tub-Gal4 in combination with the temperature-sensitive Gal4 inhibitor Gal80 ts (tub ts ) [17], and germline-specific neuropeptide receptor knockdown using the maternal triple driver MTD, which combines three germline drivers (otu-Gal4::VP16, nos-Gal4::VP16, and Gal4-nos. NGT) expressed in the germarium and throughout oogenesis [18].…”

“…The effect of poor diet on egg production has also been well documented [19]. Egg counting has also been successfully used to identify amino acid transporters necessary in adipocytes and nuclear receptors required in the soma for egg production [17,20]. By contrast, our RNAi-based screens using egg counting as a readout indicate that this assay can have low signal-to-noise ratio and thus be unreliable.…”

“…For pan-neuronal neuropeptide knockdown, control and experimental nSyb>hairpin RNA females were raised at 18˚C to minimize Gal4 expression during development [73]. Ubiquitous somatic knockdown was achieved using tub ts [17], which combines tub-Gal4 [74] with a temperature sensitive allele of the Gal4 inhibitor tub-Gal80 ts [75]. To screen for neuropeptide receptors required in the soma for egg production, females carrying tub ts and UAS-neuropeptide receptor hairpin RNA or UAS-Luciferase JF01355 were raised at 25˚C.…”

The Nuclear Receptor Seven Up Regulates Genes Involved in Immunity and Xenobiotic Response in the AdultDrosophilaFemale Fat Body

“…E78 (FBgn0004865, potential PPAR homolog) is required for follicle development/survival ( Ables and Drummond-Barbosa 2010 ), E75 (FBgn0000568, potential REV-ERB homolog) is cell autonomously required for vitellogenesis ( Buszczak et al 1999 ; Ables and Drummond-Barbosa 2010 ), and HR39 (FBgn0261239, LRH1 homolog) and Ftz-F1 (FBgn0001078, SF1 homolog) are required for ovulation ( Sun and Spradling 2013 ; Knapp et al 2020 ). In addition to having these ovary-intrinsic roles, nuclear receptors can also function in peripheral tissues to control oogenesis, as recent studies show ( Sieber and Spradling 2015 ; Weaver and Drummond-Barbosa 2019 ). For example, EcR is required in the central nervous system to regulate female feeding behavior and thereby support egg production ( Sieber and Spradling 2015 ).…”