Maternal RNA complexes in oocytes

点击翻译按钮获取中文摘要

Our research examines an important transfer of genetic information that occurs between the mother's egg and the developing embryo. Before fertilization, the egg undergoes a process called oogenesis. The oocyte, which eventually becomes the egg, is a highly specialized single cell of the female germline that carries out certain processes, quite different that those of sperm, for the purposes of reproduction. The oocyte expresses a large amount of genes from the maternal genome of the mother that get passed onto the next generation embryo. The embryo receives genetic information from both male (sperm) and female (egg). However, in oocytes, there is a key difference in the normal information transfer process of cellular gene expression that usually involves trancription of DNA information in genes into messenger RNA molecules, and subsequent translation into proteins that carry out the bulk of cellular processes. In oocyes, many genes are expressed as RNA molecules but they are stored for very long periods and not released for translation until after fertilization in the embryo (thus, the mother's genes are expressed as proteins in the offspring). It has been known for over 20 years that maternal RNAs are stored in multi-protein storage particles called mRNPs, however very little is known about how mRNPs are assembled, the proteins and mRNAs of which they are composed, and the mechanisms by which certain RNAs are selectively translated into proteins in the embryo. We examine this, focussing on a protein called YY1, that we identified as a novel mRNP protein. We use frog oocytes and embryos as a model system to examine the basic biology of mRNPs with hope of advancing our knowledge of the fundamental processes of life. Specific aims: A variety of biochemical and molecular techniques will be employed to determine how YY1 interacts with RNAs in YY1-mRNP complexes, what RNAs and other proteins are in these complexes, what is the actual function of YY1 in mRNPs and what role it plays in the mechanism of development.