Project description:In the present study, Bovine transcriptome was characterized in order to identify a set of candidate genes potentially useful for rapid detection of illegal use of some growth promoters (GPs) as dexamethasone (DEX) alone or in combination with the B2-agonist clenbuterol (CLEN). A bovine oligo microarray platform (GPL7053) was used to profile gene expression from twelve (12) bovine biceps brachii samples. Isolated and purified total RNAs were individually hybridized to the Agilent bovine V1 4x44k DNA microarray. The comparison of untreated and treated bovine transcriptomes revealed a set of differentially expressed genes. After functional analysis and qPCR validation, 16 genes were found to be differentially expressed among groups (15 downregulated genes & 1 upregulated gene between CTR and DEX and CTR and DEX CLEN groups, respectively).
Project description:In the present study, Bovine transcriptome was characterized in order to identify a set of candidate genes potentially useful for rapid detection of illegal use of some growth promoters (GPs) as dexamethasone (DEX) alone or in combination with the B2-agonist clenbuterol (CLEN). A bovine oligo microarray platform (GPL7053) was used to profile gene expression from twelve (12) bovine biceps brachii samples. Isolated and purified total RNAs were individually hybridized to the Agilent bovine V1 4x44k DNA microarray. The comparison of untreated and treated bovine transcriptomes revealed a set of differentially expressed genes. After functional analysis and qPCR validation, 16 genes were found to be differentially expressed among groups (15 downregulated genes & 1 upregulated gene between CTR and DEX and CTR and DEX CLEN groups, respectively). A total of 24 animals was used in this study. Animals were randomly divided into three groups of 8 animals each. The first group was used as a control (CTRL), the second was treated with dexamethasone (DEX) administered via feed 0.75 mg per capita for 42 days (group DEX), and the third one was treated with an increasing dose of Clenbuterol (CLEN) via feed 2 mg per capita during the first week, 4 mg per capita during the second week, and 6 mg per capita during the third and the fourth weeks (28 days in total), in combination with DXM 0.66 mg per capita for 21 days (group DEX+ CLEN).Twelve samples (4/group) out of the 24 were chosen for the microarray analysis based on the highest isolated RNA quality.
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.