RNA-binding proteins function in a diversity of ways to regulate RNA metabolism, including RNA translation, stability, and subcellular localization. Increasingly, it has become clear that many of these regulatory processes occur in compartmentalized regions of the cytoplasm, including RNP (ribonucleoprotein) structures such as stress granules and P bodies (processing bodies). We have been investigating RNPs that are induced in C. elegans oocytes in response to extended meiotic arrest or stress. Based on their composition, the hypothesis for the function of the RNP granules is to regulate mRNA stability and/or translation during periods of extended meiotic arrest or stress. The Schisa lab has identified 59 genes as required for RNP granule assembly in an RNAi screen. To investigate the role of RNP granules in regulating mRNA stability, qRT-PCR is being performed. We are currently comparing levels of
pos-1 mRNA, an mRNA at high levels in RNP granules, in arrested
fog-2 oocytes with levels in arrested
fog-2 oocytes after RNAi inhibits assembly of RNP granules. The goal is to determine whether failure to assemble RNP granules affects RNA stability. We are using
pgk-1 as our control RNA. We are planning to assay several mRNAs known to localize to RNP granules in arrested oocytes, and have a large number of RNAi targets to use to interfere with RNP granule assembly. We hope that this approach will address part of our hypothesis for the function of RNP granules in meiotically-arrested oocytes.