Project description:Non-canonical microRNAs (miRNAs) are a class of short endogenous RNA molecules with the ability to control development, autophagy, apoptosis and the stress response in eukaryotes by pairing with partially complementary sites in the 3' untranslated regions (UTRs) of targeted genes. Recent studies have demonstrated that miRNAs serve as critical effectors in intricate networks of host-pathogen interactions. Thereforce, the differential expression of miRNAs were evaluated in Madin-Darby bovine kidney (MDBK) cells infected with bovine viral diarrhea virus (BVDV) NADL (100 TCID50/ 0.1 ml) for 6 h compared to normal MDBK cells using Solexa high-throughput sequencing technology (BGI, China). Examination of small RNA populations in BVDV infected MDBK cells compared to MDBK cells
Project description:In vitro maturation (IVM) of the oocytes is a routine method in bovine embryo production. The competence of bovine oocytes to develop into embryo after IVM and in vitro fertilization (IVF) is lower as compared to in vivo preovulatory oocytes. Cumulus cells (CC) that enclose an oocyte are involved in the acquisition of oocyte quality during maturation. Using transcriptomic approach we compared cumulus cells gene expression during IVM with that in vivo preovulatory period.
Project description:With regulatory roles in development, cell proliferation and disease, micro-RNA (miRNA) biology is of great importance and a potential key to novel RNA-based therapeutic regimens. Biochemically based sequencing approaches have provided robust means of uncovering miRNA binding landscapes on transcriptomes of various species. However, a current limitation to the therapeutic potential of miRNA biology in cattle is the lack of validated miRNAs targets. Here, we use cross-linking immunoprecipitation (CLIP) of the Argonaute (AGO) proteins and unambiguous miRNA-target identification through RNA chimeras to define a regulatory map of miRNA interactions in the cow (Bos taurus). The resulting interactome is the deepest reported to date for any species, demonstrating that comprehensive maps can be empirically obtained. We observe that bovine miRNA targeting principles are consistent with those observed in other mammals. Motif and structural analyses define expanded pairing rules with most interactions combining seed-based pairing with distinct, miRNA-specific patterns of auxiliary pairing. Further, miRNA-target chimeras had predictive value in evaluating true regulatory sites of the miR-17 family. Finally, we define miRNA-specific targeting for >5000 mRNAs and determine gene ontologies (GO) for these targets. This confirmed repression of genes important for embryonic development and cell cycle progress by the let-7 family, and repression of those involved in cell cycle arrest by the miR-17 family, but it also suggested a number of unappreciated miRNA functions. Our results provide a significant resource for transcriptomic understanding of bovine miRNA regulation, and demonstrate the power of experimental methods for establishing comprehensive interaction maps.