Growth Regulatory Pathway collaborates with Axial Patterning Genes to regulate Patterning and Growth in Drosophila Eye
In all the multicellular organisms, organogenesis requires axial patterning to determine Antero-Posterior (AP), Dorso-Ventral (DV), Proximo-Distal (PD) axes. Any deviation in these axes during development leads to congenital birth defects. In our model system, Drosophila melanogaster (a.k.a fruit fly), Dorso-Ventral (DV) patterning marks first lineage restriction event. We have identified defective proventriculus (dve), an ortholog of SATB homeobox 1 (special AT-rich sequence binding protein 1), as a new member of DV patterning genes hierarchy. We have shown that dve acts downstream of pannier (pnr, a GATA-1 transcription factor), and upstream of wingless (wg) in dorsal gene hierarchy. Loss-of-function (LOF) of dve or pnr results in dramatic dorsal eye enlargements, whereas Gain-of-function (GOF) of dve, pnr suppresses eye specific fate. We have demonstrated that Wingless (Wg), (1) is downstream target of Hippo growth regulatory pathway (highly conserved) in eye, (2) acts downstream of dve, (3) exhibits similar eye enlargement and suppression phenotypes (upon LOF, GOF respectively), and has been shown to play a role in growth. Here, we present that, DV patterning genes interacts with Hippo signaling to regulate their common downstream target, Wg during developing Drosophila eye. Our data (using GOF, LOF) states that (1) These two unrelated pathways are related and interacts antagonistically, (2) Activating Hippo signaling suppresses dve, pnr expressing cells, downregulates Wg and changes head, antennae specific fate to an eye, (3) Blocking cell death activity of hpo (using UAS-p35, anti-apoptotic) doesn’t affects its ability to undergo differentiation, (4) Growth regulatory pathway regulates the expression of DV patterning genes (dve, pnr acts downstream of Hippo pathway), and that (5) GOF/LOF of dve, pnr does not affect the expression of Hippo downstream reporters diap1 and expanded in developing eye of Drosophila. These studies present new genetic interaction between two unrelated pathways to regulate growth and patterning of an organ.
Madhuri Kango-Singh, Amit Singh
Primary Advisor's Department
Stander Symposium project
"Growth Regulatory Pathway collaborates with Axial Patterning Genes to regulate Patterning and Growth in Drosophila Eye" (2018). Stander Symposium Projects. 1270.