Cell movements controlled by the Notch signalling cascade during foregut development inDrosophila

Abstract

Notch signalling is an evolutionarily conserved cell interaction mechanism,the role of which in controlling cell fate choices has been studied extensively. Recent studies in both vertebrates and invertebrates revealed additional functions of Notch in proliferation and apoptotic events. We provide evidence for an essential role of the Notch signalling pathway during morphogenetic cell movements required for the formation of the foregut-associated proventriculus organ in the Drosophila embryo. We demonstrate that the activation of the Notch receptor occurs in two rows of boundary cells in the proventriculus primordium. The boundary cells delimit a population of foregut epithelial cells that invaginate into the endodermal midgut layer during proventriculus morphogenesis. Notch receptor activation requires the expression of its ligand Delta in the invaginating cells and apical Notch receptor localisation in the boundary cells. We further show that the movement of the proventricular cells is dependent on the short stop gene that encodes the Drosophila plectin homolog of vertebrates and is a cytoskeletal linker protein of the spectraplakin superfamily. short stop is transcriptionally activated in response to the Notch signalling pathway in boundary cells and we demonstrate that the localisation of the Notch receptor and Notch signalling activity depend on short stop activity. Our results provide a novel link between the Notch signalling pathway and cytoskeletal reorganisation controlling cell movement during the development of foregut-associated organs.

The adult Drosophila gastric and stomach organs are maintained by a multipotent stem cell pool at the foregut/midgut junction in the cardia (proventriculus)

“…Several signal transduction pathways, including those of Hh, Wg, Decapentaplegic (Dpp), N, and Janus kinasesignal transducer and activator of transcription (JAK-STAT), are required for this epithelial cell sheet movement. [32][33][34] In this study, we identified a multipotent stem cell pool at the F/M junction in adult Drosophila. These cells differentiated into gastric and stomach cells.…”

Mouse ACF7 andDrosophilaShort stop modulate filopodia formation and microtubule organisation during neuronal growth

“…Accordingly, the range of its reported phenotypes is wide, and Shot plays structural roles and/or mediates signalling events in these contexts. Reported shot mutant phenotypes comprise structural and adhesion defects in the epidermis (Prokop et al, 1998;Röper and Brown, 2003), developmental aberrations of foregut and tracheal tubes (Fuss et al, 2004;Lee et al, 2003), and failed association of microtubules with the fusome during oogenesis (Röper and Brown, 2004).…”

Drosophila melanogaster as a Model Organism for Bluetongue Virus Replication and Tropism

“…In line with previously published data regarding BTV replication in Culicoides (26), we observed clear infection of fat bodies, salivary glands, and the foregut-midgut junction (proventriculus). BTV-1/NS3mCherry replication in the proventriculus was restricted to ectodermal cells (foregut origin), while the endodermal cells (midgut origin) were uninfected (27,42). These data imply that BTV can enter from the basement membrane (e.g., membrane directly in contact with the hemocoel) of foregut cells but not midgut cells.…”