Sally Horne-Badovinac (University of Chicago)
MolBio Seminar Series
Dr. Horne-Badovinac has had a long standing interest in the dynamic cell behaviors that shape tissue and organs during development. This focus began in Didier Stainier’s lab at UCSF during her graduate work, where she identified the process that initiates the leftward bending of the zebrafish intestine. Wanting to pursue this interest in a simpler organ system, she then trained in Drosophila genetics with David Bilder at UC Berkeley. It was there that she began working on the little-studied question of how the initially spherical egg chamber is transformed into an elongated egg. Since joining the Department of Molecular Genetics and Cell Biology at the University of Chicago in 2008, her lab has used this system to elucidate mechanisms of collective cell migration, polarized basement membrane secretion and basement membrane remodeling. In the long term, her lab will combine the best experimental attributes of flies and fish for a highly synergistic approach to the study of organ morphogenesis.
Round and Round: Planar polarity and collective migration in elongating egg chambers
Complex organ shapes arise from the coordinate actions of individual cells. The Drosophila egg chamber is an initially spherical, organ-like structure that lengthens along its anterior-posterior axis as it grows. This morphogenesis depends on an unusual form of planar polarity in the organ’s outer epithelial layer, the follicle cells. Concurrent with their planar polarization, the follicle cells undergo a dramatic collective migration that causes the entire egg chamber to rotate within an external ECM. This migration is unusual, in that the follicle cells form a continuous epithelium with no leading edge. It is therefore possible that the planar polarity in this tissue coordinately aligns the cells’ front-rear axes to set the direction for collective movement. In this seminar, I will discuss how a series of genetic and chemical perturbations of follicle cell migration have suggested that the opposite scenario is true – that follicle cell planar polarity is, in fact, an emergent property of individual cell migratory behaviors.
Free and open to the university community and the public