• Finding new pathway components
Despite years of intensive study, we are still discovering new molecules that influence Wg/Wnt signaling. We conducted a series of suppressor/enhancer screens using weak wg mutant alleles, and isolated a number of modifiers that may identify new parts of the pathway or new control mechanisms.
Related papers:
• Greer, E. R., Chao, A.T., and Bejsovec, A. (2013) The role of Pebble/Ect2 in regulating Wg/Wnt activity. Development 140: 4937-46. PMID: 24198276
• Jones, W.M., Chao, A.T., Zavortink, M., Saint, R. and Bejsovec, A. (2010) Cytokinesis proteins Tum and Pav have a nuclear role in Wnt regulation. Journal of Cell Science 123: 2179-2189. PMID: 20516152
• Chao, A.T., Jones, W.M. and Bejsovec, A. (2007). The HMG-box transcription factor, Sox-Neuro, acts with Tcf to control Wg/Wnt signaling activity. Development 134: 989-997. PMID: 17267442
• Transport of Wg within the epithelium
Wg is secreted from a single row of cells in each segment, but moves away from that row of cells to stabilize Arm and repress Svb across a broad domain in each embryonic segment. Wg, like other Wnts, has a fatty acyl group attached to it, so it associates with membranes and cannot freely diffuse. Understanding how Wg can move from cell to cell will help reveal how it generates pattern.
Related papers:
• Moline, M. M., Southern, C. and Bejsovec, A. (1999). Directionality of Wingless protein transport is essential for wild-type epidermal patterning in the Drosophila embryo. Development 126, 4375-4384. PMID: 10477304
• Dierick, H. and Bejsovec, A. (1998). Functional analysis of Wingless reveals a link between intercellular ligand transport and dorsal-cell specific signaling. Development 125, 4729-4738. PMID: 9806921
• Generation of cell fate diversity
Low levels of Wg signaling within the denticle-secreting ventral domain generate the distinctive shapes in different rows of the denticle belts. We identified several Wg target genes that regulate production of these different cellular morphologies.
Related papers:
• Rizzo, N.P. and Bejsovec, A. (2017). SoxNeuro and Shavenbaby act cooperatively to shape denticles in the embryonic epidermis of Drosophila. Development 144: 2248-2258. PMID: 28506986
• Bejsovec, A. and Chao, A.T. (2012) crinkled reveals a new role for Wingless signaling in Drosophila denticle formation. Development 139:690-698. PMID: 22219350
• Bejsovec, A. and Wieschaus, E. (1993). Segment polarity gene interactions modulate epidermal patterning in Drosophila embryos. Development 119, 501-517. PMID: 8287799
