Meeting Abstract
Cell signaling is a critical process in animal development. Functional studies of cell signaling can shed light on the varied developmental patterns across the animal kingdom. Additionally, by comparing how these functions differ between organisms one can glean insight into the evolution of animal diversity. In this study, a MAPK inhibitor (U0126) was used to block the MAPK signaling cascade for 2-3 hours during early development of the annelid Chaetopterus sp. Immunohistochemical and morphological analyses reveal that after drug exposure, an abnormal mesoderm and endoderm phenotype was observed in three day old larvae (L3). The phenotypic responses observed in this study were graded and varied directly with the concentration of the MAPK inhibitor. We hypothesize that the MAPK cascade may be activated during gastrulation, evidenced by the presence of an abnormal phenotype when embryos were exposed during gastrulation. The phenotype observed in Chaetopterus shows similarities to that observed in two other annelid species: Platynereis dumerilii and Capitella teleta suggesting that there may be a conserved role for MAPK signaling during morphogenesis of mesoderm in annelids.
