Meeting Abstract
Embryonic organizers are signaling centers that coordinate developmental events within an embryo. Localized to either an individual cell or group of cells, embryonic organizing activity induces the specification of other cells in the embryo and can influence formation of the body axes. In the spiralian Capitella teleta, organizing activity is localized to a single cell, 2d. Previous cell deletion studies have shown that 2d induces the formation of the dorsal-ventral axis. In this study, we attempt to identify the signaling pathway responsible for the organizing activity seen in 2d. Embryos at stages when organizing activity is occurring were exposed to various small molecule inhibitors, raised to larval stages, and scored for axial anomalies analogous to previously described phenotypes. We also examined the expression patterns of candidate genes to determine whether expression is restricted solely to the organizer cell or its precursor. Our preliminary results suggest that the MAPK, Notch, and ADMP pathways do not play a role in 2d’s dorsal-ventral axis formation. However, the TGF Beta and Noggin pathways have yielded promising results. These and further investigations will shed light on the identity of the 2d signaling pathway involved with Capitella axes formation, and contribute to our understanding of the evolution of body plan diversity.
