Dr. Susan G. Ernst

Biography

During embryogenesis, a developmental program encoded in the genome orchestrates the formation of a three-dimensional organism. Our interest is in informational molecules and mechanisms that direct and regulate this process. Using the sea urchin, a model developmental system, we ask a broad range of questions focusing on oogenesis, early development and cell differentiation, and how cell lineages are established. Current investigations include: Endo16, a gene we isolated for its endoderm specific expression encodes an extracellular protein on the surface of cells of the invaginating gut during the dramatic morphogenetic movements of gastrulation. Results suggest that Endo16 functions in cell adhesion through an RGD tripeptide positioned between two calcium-binding regions. We are currently testing several aspects of Endo16 function. Endo16 is a large modular glycoprotein that contains an unusual cysteine pattern similar to that found in the serum albumin protein family. Computational analysis and comparison of Endo16 protein with other invertebrate and vertebrate proteins is underway to decipher the evolutionary relationships of this complex protein. We have demonstrated that very young sea urchin oocytes maintain an asymmetrically localized Microtubule Organizing Center (MTOC) that will become the animal vegetal axis of the embryo. Investigations are underway to establish when during oogenesis the MTOC first appears and is localized.

Research Interest

Developmental Biology and Genetics and Molecular Biology