e indicated that RIC8 is required for the maintenance of Gi levels and its localization to the plasma membrane. Moreover, RIC8 also acts as a biosynthetic chaperone at the G subunit folding 
and participates in their subsequent proper membrane targeting. Analogously, we demonstrated that the inhibition of Ric8 synthesis during oocyte maturation interfered with the correct localization of PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19704093 Gi1/2 and reduced its level in the cell PF-562271 site cortex region. However, the localization pattern of Gi1/2 in the cytoplasm and the localization of LGN were not influenced by the Ric8 siRNA treatment of oocytes. Although the downregulation of Ric8 expression had no statistically relevant effect on the morphology of maturing oocytes, we observed a tendency for some oocytes to divide abnormally. Furthermore, meiosis I lasted longer in Ric8 siRNA treated cells and some oocytes could not maintain the correct positioning of chromosomes in the metaphase arrests. In addition, RIC8 functionally also interacts with the Gi-GDP:RGS14 signaling complex and regulates its activation state. Interestingly, in mammalian oogenesis, RGS14 is initially expressed in oocytes, but is degraded at the second meiotic arrest. Prior to the first mitosis, RGS14 is de novo expressed by the activated embryonic genome and it co-localizes with anastral mitotic apparatus of the zygote. Remarkably, in exponentially proliferating cell culture RGS-14 localizes in the nucleus during interphase and is distributed to the centrosomes and astral microtubules during mitosis, and alteration of RGS-14 levels leads to cell growth arrest. The similar expression profile of RIC8 protein during oogenesis, and in early zygote with expression and localization of its interaction partners, suggests that RIC8 might function in concert with Gi, LGN, NuMA and RGS14 to regulate meiosis and mitosis. After fertilization oocyte completes meiosis and the genetic material of mature gametes forms the paternal and maternal pronucleus. We found that RIC8 localized to the female and male pronucleus and accumulated in the nucleolus precursor bodies. RIC8 also concentrated in NPBs of the second polar body and blastomeres PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19704080 of two-cell embryos. Whereas nucleolus of growing oocyte is active and mainly responsible for ribosome biogenesis, in analogy with nucleoli of somatic cells, transcription largely ceases in the nucleoli of fully grown oocytes and blastomeres of early cleavage embryos until the transition from the maternal to embryonic genome. The function of these “inactive” nucleoli in mature oocytes and blastomeres is not clear yet, but mouse embryos lacking nucleoli fail to develop past the first few cleavages. Although the oocyte nucleolus is not needed for the progression of meiosis to the second metaphase, it is indispensable in further early development. Accumulation of RIC8 in the rim region of NPBs, where methylated DNA and centromeres assemble to nucleoli, suggests that RIC8 may also be involved in the maintenance of nucleolar function or architecture. We also found RIC8 expression in several regions of mouse reproductive tract, like epithelium of Fallopian tube and uterus. Interestingly, RIC8 accumulated in the basal layer of cilia in the ciliated epithelium of ampulla region. Two types of cilia, motile and primary are present in 16 / 19 Dynamics of RIC8 in Oogenesis mammalian cells. The motile cilia cooperatively beat in a wave-like pattern to generate fluid flux, which is essential for pickup and transport of the ovul