Brad Davidson, Swarthmore College: "Mitotic Tuning: Cell Division Modulates Inductive Signals During Early Heart Development"
– 5:00 PM
Druckenmiller Hall, Room 020
About 40,000 children are born with heart defects every year. In order to treat these conditions we must gain a comprehensive understanding of heart formation, including the very first steps taken by heart cells in early embryos.
Currently, our research is focused on revealing the precise function of FGF in early heart development. We have demonstrated that FGF signaling causes a group of four founder cells to undergo an asymmetric division. The smaller daughters of this division respond to continued FGF signaling by activating heart genes and migrating towards the site of future heart formation while the larger daughter form tail muscle. Through transgenic manipulations, we can disrupt FGF signaling specifically in these four cells, blocking heart development. Conversely, we can activate downstream factors and cause the entire group of cells to migrate and form extra heart tissue. We are also able to isolate Ciona heart cells and examine lineage-specific gene expression. This analysis employs micro-arrays designed to probe all predicted coding regions in the Ciona genome.
Through these techniques we have identified an extensive set of heart genes up-regulated by FGF. Future studies will focus on determining the role of these FGF target genes in heart development as well as identifying the precise transcriptional mechanisms by which FGF and downstream factors co-ordinate heart gene expression.
Davidson is assistant professor of developmental biology at Swarthmore College, Swarthmore, Pennsylvania.