Project description:The selection of cattle with high feed efficiency is of paramount importance with regard to reducing feed costs in the beef industry. Global gene expression patterns in metabolically important tissues can be used to identify genes that are potentially involved in regulating feed efficiency. We identified 5 genes (p<0.001;FDR <0.1) to be differentially expressed in skeletal skeletal muscle between high and low residual feed intake heifers with all 5 transcripts being upregulated in the low residual feed intake phenotype. Among these differentially expressed genes, all transcripts were related to oxidative phosphorylation and mitochondrial homeostasis. A total of 11 genes (p<0.001;FDR <0.1) were differentially expressed in hepatic tissue tissue between high and low residual feed intake bulls with 8 transcripts being upregulated and 3 being downregulated in the low residual feed intake phenotype. These differentially expressed genes were related to oxidative response, protein mediation and cell signalling. Pathway analysis on the RNAseq data indicates a relationship between oxidative phosphorylation and residual feed intake in skeletal muscle and aldosterone signalling and NRF2 mediated oxidative stress in hepatic tissue.
Project description:The biological mechanisms associated with the residual feed intake in ruminants have been harnessed immensely via transcriptome analysis of liver and ruminal epithelium, however, this concept has not been fully explored using whole blood. We applied whole blood transcriptome analysis and gene set enrichment analysis to identify key pathways associated with divergent selection for low or high RFI in beef cattle. A group of 56 crossbred beef steers (average BW = 261.3 ± 18.5 kg) were adapted to a high-forage total mixed ration in a confinement dry lot equipped with GrowSafe intake nodes for period of 49 d to determine their residual feed intake (RFI). After RFI determination, weekly whole blood samples were collected three times from beef steers with the lowest RFI (most efficient; low-RFI; n = 8) and highest RFI (least efficient; high-RFI; n = 8). Prior to RNA extraction, whole blood samples collected were composited for each steer. Sequencing was performed on an Illumina NextSeq2000 equipped with a P3 flow. Gene set enrichment analysis (GSEA) was used to analyze differentially expressed gene sets and pathways between the two groups of steers. Results of GSEA revealed pathways associated with metabolism of proteins, cellular responses to external stimuli, stress, and heat stress were differentially inhibited (false discovery rate (FDR) < 0.05) in high-RFI compared to low-RFI beef cattle, while pathways associated with binding and uptake of ligands by scavenger receptors, scavenging of heme from plasma, and erythrocytes release/take up oxygen were differentially enriched (FDR < 0.05) in high-RFI, relative to low-RFI beef cattle. Taken together, our results revealed that beef steers divergently selected for low or high RFI revealed differential expressions of genes related to protein metabolism and stress responsiveness.
Project description:To identify transcriptional markers for beef traits related to meat tenderness and moisture, we measured the transcriptome of the Longissimus dorsi skeletal muscle in 10 Korean native cattle (KNC). We analyzed the correlation between the beef transcriptome and measurements of four different beef traits, shear force (SF), water holding capacity (WHC), cooking loss (CL), and loin eye area (LEA). We obtained non-overlapping and unique panels of genes showing strong correlations (|r| > 0.8) with SF, WHC, CL, and LEA, respectively. Functional studies of these genes indicated that SF was mainly related to energy metabolism, and LEA to rRNA processing. Interestingly, our data suggested that WHC is influenced by protein metabolism. Overall, the skeletal muscle transcriptome pointed to the importance of energy and protein metabolism in determining meat quality after the aging process. The panels of transcripts for beef traits may be useful for predicting meat tenderness and moisture. Experiment Overall Design: Gene expression profiles were correlated with beef traits measured at the same cattle.
Project description:Wandong cattle are an autochthonous Chinese breed used extensively for beef production. The breed tolerates extreme weather conditions and raw feed and are resistant to tick-borne diseases. However, the genetic basis of testis development and sperm production as well as breeding management is not well established in local cattle. In this study, we performed total RNA-Seq and comprehensively analyzed the circ-RNA expression profiling of the testes samples of six bulls at 3 years and 3 months of developmental age. In total, 17 013 circ-RNAs were identified, of which 681 circRNAs (P-adjust < 0.05) were differentially expressed (DE). Among these DE circ-RNAs, 579 were upregulated and 103 were downregulated in calf and bull testes. The Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses revealed that the identified target genes were classified into three broad functional categories, including biological process, cellular component, and molecular function, and were enriched in the lysine degradation, cell cycle, and cell adhesion molecule pathways.