Research Summary

During development, discrete organs and entire body plans emerge from the coordinate actions of individual cells. These complex morphogenetic events require dynamic regulation of cell shape, polarity and adhesion across cell populations. Our lab seeks to understand how these cellular behaviors are orchestrated to produce an organ’s final shape.

To address this question we are investigating the morphogenetic mechanisms that create the elliptical shape of the Drosophila egg. Each fly egg arises from a multi-cellular follicle, in which the germ cells are surrounded by a somatic epithelium. Initially spherical, follicles lengthen dramatically along their A-P axes during oogenesis. We have identified a large collection of mutations that disrupt follicle elongation, thus providing an unprecedented opportunity to dissect the molecular mechanisms governing this poorly understood process. Two questions in which we are particularly interested are outlined below.

How is planar polarity established in the follicular epithelium?
Follicle elongation depends on the precise, planar arrangement of cytoskeletal and extracellular matrix molecules at the basal surface of the follicular epithelium. Interestingly, this example of planar polarity does not depend on the well studied Frizzled-PCP signaling pathway, suggesting that an unconventional regulatory mechanism operates in this tissue. We are using genetic, cell biological and biochemical approaches to investigate the molecular mechanisms controlling this novel planar polarity system.

What are the cellular behaviors that drive follicle elongation?
Planar polarity is used to coordinate individual cellular behaviors within the epithelium during follicle elongation, but the nature of these cellular behaviors is mysterious. We are employing dynamic live imaging techniques, in both wild-type and mutant contexts, to better understand the polarized cell behaviors that drive this morphogenesis.

Selected Publications

Horne-Badovinac, S. and Bilder, D. (2008). Dynein regulates epithelial polarity and the apical localization of stardust A mRNA. PLoS Genetics, 4(1), 40-51. (PubMed)

Horne-Badovinac, S. and Bilder, D. (2005). Mass Transit: epithelial morphogenesis in the Drosophila egg chamber. Developmental Dynamics, 232(3), 559-574. (PubMed)

Horne-Badovinac, S., Rebagliati, M. and Stainier, D.Y. (2003). A cellular framework for gut looping morphogenesis in zebrafish. Science, 302(5645), 662-665. (PubMed)

Horne-Badovinac, S., Lin, D., Waldron, S., Schwarz, M., Mbamalu, G., Pawson, T., Jan, Y.N., Stainier, D.Y.R., Abdelilah-Seyfried, S. (2001). Positional cloning of heart and soul reveals multiple roles for PKC-gamma in zebrafish organogenesis. Current Biology 11, 1492-1502. (PubMed)