Project description:Liver takes multifunctional important roles and the prediction of its function is hard issue. Detecting methods of gene expression profiles like microarray provide functional information of tissues. Liver and peripheral white blood cells (PBLs) were collected from two different feeding conditioned Holstein cows; estrus cycle and middle of gestation. Also PBLs were fractionated with gradient cells separation. The RNA was applied to oligo-microarray and qRT-PCR. It revealed a group of stable bovine liver genes in constant physiological feeding condition. When they applied to different cows fed in different status, the profiles of some specific genes in liver coincided with those in PBLs. Microarray data were applied to a principal component analysis (PCA). It was found that the liver gene expression profiles were more coincided those in granulocytes than other PBLs fraction by PCA. The relationship between gene profiles in liver and granulocytes was confirmed by qRT-PCR and Hierarchical cluster analysis. Granulocytes gene profile is more reliable than those in mononuclear cells in reflection of liver metabolic function. These results suggest that expressed genes in PBLs, especially granulocytes, may be convenient bio-indicators for diagnosis of clinical disorder and/or detecting aberration of liver function in different feeding condition of cows.
Project description:The liver of dairy cows naturally displays a series of metabolic adaptation during the periparturient period in response to the increasing nutrient requirement of lactation. The hepatic adaptation is partly regulated by insulin resistance and it is affected by the prepartal energy intake level of cows. We aimed to investigate the metabolic changes in the liver of dairy cows during the periparturient at gene expression level and to study the effect of prepartal energy level on the metabolic adaptation at gene expression level.B13:N13
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.