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.
Project description:Sexual dimorphism is one of the important topic in mammal species because appearance of males and females is obvious different in all mammal species. In addition to this, molecular mechanisms also very different each other. Furthermore, it is important to employ a variety of tissues in RNA-seq experiment because recent studies imply gene expression pattern are highly tissue specific. Although previous related studies discovered numerous sexually dimorphic mechanism in mammal species, but still, many mechanisms are undiscovered in case of non-model organisms. One of the representative mammal organism is a cattle which is less researched about sexual dimorphism. For investigate bovine sexual dimorphism, we generated two-way factorial designed 40 samples RNA-seq data composed with two factors such as gender and tissues. Two statistical approaches are employed for identifying bovine sexually dimorphic genes using such two-way factorial designed RNA-seq data. As a result, we observed that detected sexually dimorphic genes exhibited strong tissue specific pattern, but fat tissue showed relatively small tissue specificity than the others. In addition, we observed that sex-related genes are shared in two mammal species such as cattle and rat through qRT-PCR experiments. Finally, we investigated pros and cons of two statistical approaches for complex structured RNA-seq analysis.
Project description:Sexually dimorphic gene expression in bovine conceptuses at the initiation of implantation is not reflected in the changes in the endometrial transcriptome.
Project description:Genome-wide identification of copy number variations in Holstein cattle from Baja California, Mexico, using high-density SNP genotyping arrays