Dr. Gary M Wessel
Fertilization and the block to polyspermy: Sperm-egg interactions result in a cascade of responses including exocytosis of cortical granules. This secretory event functions in the permanent block to polyspermy, important for fertilization, and in the formation of a protected environment for early embryonic development. We study the function of cortical granules in the modification of the egg cell surface and extracellular matrix using a molecular analysis of the protease and peroxidase activities, the structural proteins of the fertilization envelope, and the major protein of the extraembryonic matrix, hyalin. Signaling Mechanisms in Oogenesis, Meiotic Maturation, and Fertilization: We examine the signal transduction pathways leading to normal cell function. These pathways target the release of free calcium into the cytoplasm, the generation of nitric oxide, and resumption of the cell cycle. We find a network of interacting molecular machines that include heterotrimeric G-proteins, and use yeast two-hydrid approaches to identify new components of each pathway. Oocyte-Specific Transcriptional Mechanisms: Oocytes make several organelles specific to their cell type and transcribe a host of genes not active in any other cell. Some of these genes make the most abundant transcripts in the cell, which are then degraded selectively at maturation of the cell. Using GFP reporter gene constructs, we examine the gene's cis-elements, and through use of bioinformatic approaches, have cloned and are testing specific transcription factors found greatly enriched in oocytes for their contribution to this cell's phenotypic development.
Lab MembershipsWessel Lab (Principal Investigator/Director)
Department of Molecular and Cellular Biology and Biochemistry
185 Meeting Street