Meeting Abstract

S3-1.7  Jan. 4  Molecular controls of axis specification and cell determination in marine invertebrate embryos and larvae HENRY, Jonathan/Q*; PERRY, Kimbely/J; MARTINDALE, Mark/Q; University of Illinois-Urbana; University of Illinois-Urbana; University of Hawaii, PBRC Kewalo Marine Laboratory

Recent advances in cell and molecular biology have permitted an understanding of cell interactions and molecular signalling pathways that control early development, more specifically those relating to the establishment of specific cell fates and axial properties that define larval and adult morphologies. Comparative work reveals a tremendous level of conservation, but also interesting differences between representative species. For instance, data suggests that beta catenin plays a key role in the transduction of signals involved in establishing cell fates along the animal-vegetal axis particularly related to the establishment of the endomesodermal lineages (e.g., gut) in the larvae and adults of various metazoans. New studies, including our own, indicate that this role is also conserved within representative protostome (lophotrochozoan) phyla. On the other hand, there are some significant differences found in certain species, even between members of the same phyla (e.g., Mollusca). All metazoan embryos set aside cells that serve as key inductive signaling centers ("organizers") that specify the fates of adjacent cells and entrain various axial properties. The establishment of the dorsal (D) organizer in the spiralian phyla (annelids, molluscs, etc.) relies on MAPK signal transduction, but there are interesting evolutionary differences related to the spatial and temporal activation of MAPK in the dorsal cell lineage of various spiralians. This report considers the evolution and function of these signal transduction pathways in metazoan development.