Meeting Abstract

P2.91  Saturday, Jan. 5  Determining the Potential Activity of Wnt Signaling in Zebrafish Oocyte Maturation Through Examination of β-catenin and Dishevelled mRNA Concentrations PINCUS, NB*; DEMARAIS, AA; Univ. of Puget Sound; Univ. of Puget Sound npincus@pugetsound.edu

During oocyte maturation, the oocyte progresses from prophase I to metaphase II of meiosis, and a multitude of other cellular changes occur. The mechanism for oocyte maturation is not yet fully characterized. We are examining the role of Wnt signaling pathways in oocyte maturation in zebrafish ovaries. Specifically we are examining two Wnt signaling pathway components: β-catenin (ctnnb1) and Dishevelled (dvl2). β-catenin is a an interesting protein to study because it plays a dual role as both a cell adhesion protein when attached to membrane-bound complexes, and a coactivator for transcription by the Wnt pathway when free in the cytoplasm. Dishevelled is the “hub” of Wnt signaling and plays a key role in relaying external signals to internal pathway components. β-catenin protein appears to increase in relative cytoplasmic concentration after maturation; however, this change is not the result of migration from cytoskeleton associated membrane-bound complexes. We conducted analyses of mRNA levels of Wnt pathway genes during zebrafish oocyte maturation using RT-qPCR. We examined β–actin, GAPDH and ef1-α as potential reference genes for oocyte maturation, since these were found to have constant expression during zebrafish embryo development or bovine oocyte development. We then examined the changes in mRNA concentrations for β-catenin and Dishevelled over the course of oocyte maturation. It appears that levels of β-catenin and Dishevelled mRNA increase during maturation. The results of our research will contribute to our understanding of the cellular processes which occur during oocyte maturation, and the importance of signaling pathways such as the Wnt pathway in these processes.