A genetic mosaic screen identifies genes modulating Notch signaling in Drosophila

Abstract

Notch signaling is conserved in most multicellular organisms and plays critical roles during animal development. The core components and major signal transduction mechanism of Notch signaling have been extensively studied. However, our understanding of how Notch signaling activity is regulated in diverse developmental processes still remains incomplete. Here, we report a genetic mosaic screen in Drosophila melanogaster that leads to identification of Notch signali ng modulators during wing development. We discovered a group of genes required for the formation of the fly wing margin, a developmental process that is strictly dependent on the balanced Notch signaling activity. These genes encode transcription factors, protein phosphatases, vacuolar ATPases and factors required for RNA transport, stability, and translation. Our data support the view that Notch signaling is controlled through a wide range of molecular processes. These results also provide foundations for further study by showing that Me31B and Wdr62 function as two novel modulators of Notch signaling activity.

Investigation of Isoform Specific Functions of the V-ATPase a Subunit During Drosophila Wing Development

“…Our results strongly support a model that V-ATPases might exist as multiple subtypes composed by diverse subunit isoforms in the same cells to meet the diversified demands. The accumulation of signaling molecules and alteration of signaling activities are not always fully penetrant in Vha100 mutant cells, which is also noticed in previous studies on other V-ATPase subunits (Yan et al, 2009;Vaccari et al, 2010;Ren et al, 2018). During tissue development, the V-ATPase regulates acidification of cellular organelles which are necessary for protein sorting, trafficking, and turnover (Forgac, 2007).…”

“…The following fly stocks were used: hh-Gal4, UAS-mCD8-gfp/TM6B (Ren et al, 2018); Vha100-2 RNAi (TH04790.N; TsingHua Fly Center); FRT42D, Vha44 KG00915 /Cyo (#111534; Kyoto Stock Center); FRT42D, Vha44 K 05440 /Cyo (#111081; Kyoto Stock Center); FRT82B, Vha100-1 1 /TM3, Sb (#39669; Bloomington Drosophila Stock Center); w;Sco/Cyo (#2555; Bloomington Drosophila Stock Center); and w;TM3/TM6B (#2537; Bloomington Drosophila Stock Center). The Ubx-FLP; FRT82B, Ubi-RFP/TM6B, Ubx-FLP; FRT42D, Ubi-RFP/Cyo, and Ubx-FLP; FRT42D, Ubi-GFP/Cyo stocks were used to generate mosaic mutant clones in the wing disks (Ren et al, 2018). The sens−GFP reporter was described before (Sarov et al, 2016) and obtained from Bloomington Drosophila Stock Center (#38666).…”

“…Two mutants of the regulatory C subunit Vha44 were tested (Supplementary Figure S3A) and both of them resulted in various developmental defects including loss of wing marginal bristles and nicking of wing margin ( Supplementary Figures S3B-D). We then investigated whether Vha44 regulates Notch (N) and Wingless (Wg) signaling activity, two major signaling pathways that were affected by mutations of other V-ATPase subunits (Vaccari et al, 2010;Kobia et al, 2013;Gleixner et al, 2014;Portela et al, 2018;Ren et al, 2018). In the wild type imaginal wing disk, the N target gene cut is produced in a narrow stripe of cells along the dorsal/ventral (D/V) boundary (Supplementary Figure S3E).…”

“…In Drosophila melanogaster, mutations that dampen the V-ATPases activity are reported to disrupt the formation of eye, wing and egg chambers (Yan et al, 2009;Buechling et al, 2010;Hermle et al, 2010;Vaccari et al, 2010). Further studies demonstrated that V-ATPases are involved in regulation of cell proliferation, cell fate determination and tissue patterning through modification of key developmental signaling pathways (Kobia et al, 2013;Gleixner et al, 2014;Portela et al, 2018;Ren et al, 2018).…”

The ATPase TER94 regulates Notch signaling duringDrosophilawing development

“…We have performed a genetic mosaic screen to identify modifiers of Notch signaling in the Drosophila wing (Ren et al, 2018). During the screen we found that fly wings harboring homozygous TER94 k15502 mutant clones displayed wing margin nicking phenotypes (Fig.…”