Enriched¹ Gene Ontology molecular functions from SNPs detected by the bivariate uni-SNP analysis.

1<p>P-value <0.0001.</p

SNPs selected¹ for the multi-SNP models, corresponding gene, and model adequacy indicator.

1<p>P-value <0.0001;</p>2<p>Root mean square errors (RMSE) for the models using the training (T) and validation (V) data sets;</p>3<p>Root means square covariance (RMSC) for the bivariate model using the training (T) and validation (V) data sets;</p>4<p>MA, Model adequacy as defined in Eqs. 3 and 4, for the univariate and bivariate analyses, respectively.</p

Number (proportion) of steers by breed and diet in the training and validation data sets.

<p>Number (proportion) of steers by breed and diet in the training and validation data sets.</p

P-values and estimates¹ of the SNPs detected² by the uni-SNP univariate analysis of feed efficiency.

1<p>Additive estimate relative to the minor allele;</p>2<p>P-value <0.0001;</p>3<p>Estimate ± standard error;</p>4<p>T, training data set; V, validation data set;</p><p>*Minor allele.</p

Network of genes affiliated to enriched molecular functions based on SNPs associated with feed efficiency.

<p>Connection between genes affiliated with enriched (P-value <0.0001) functional categories. Genes corresponding to detected (target genes; P-value <0.01) are represented by pink nodes, and intermediate (not-detected) genes are represented by blue nodes. Red edges represent in direct interaction with target genes with any other gene, and golden edges represent interactions between intermediate genes. The size of the network nodes from the target genes is a function of the P-values from the association analyses, in which larger nodes indicate more significant P-values.</p

Description of the diets received by the beef cattle steers analysed.

<p>TNE, Total net energy; NDF, Non-degradable fiber; DM, Dry matter; CP, Crude protein; ADF, Acid detergent fiber; TDN, Total digestible nutrient.</p

Number of detected SNPs and corresponding genes across P-value thresholds by analysis.

1<p>Unique SNPs and genes.</p

SNPs detected¹ bymultiple analyses using uni-SNP models.

1<p>P-value <0.0001.</p

P-values and estimates¹ of the SNPs detected² by the uni-SNP bivariate analysis of feed efficiency.

1<p>Additive estimate relative to the minor allele;</p>2<p>P-value <0.0001;</p>3<p>Estimate ± standard error;</p>4<p>T, training data set; V, validation data set;</p><p>*Minor allele.</p

Molecular Factors Underlying the Deposition of Intramuscular Fat and Collagen in Skeletal Muscle of Nellore and Angus Cattle

<div><p>Studies have shown that intramuscular adipogenesis and fibrogenesis may concomitantly occur in skeletal muscle of beef cattle. Thus, we hypothesized that the discrepancy of intramuscular fat content in beef from Nellore and Angus was associated with differences in intramuscular adipogenesis and fibrogenesis during the finishing phase. To test our hypothesis, longissimus muscle samples of Nellore (<i>n</i> = 6; BW = 372.5 ± 37.3 kg) and Angus (<i>n</i> = 6; BW = 382.8 ± 23.9 kg) cattle were collected for analysis of gene and protein expression, and quantification of intramuscular fat and collagen. Least-squares means were estimated for the effect of Breed and differences were considered at <i>P</i> ≤ 0.05. A greater intramuscular fat content was observed in skeletal muscle of Angus compared to Nellore cattle (<i>P</i>≤0.05). No differences were observed for mRNA expression of lipogenic and lipolytic markers <i>ACC</i>, <i>FAS</i>, <i>FABP4</i>, <i>SERBP–1</i>, <i>CPT–2</i>, <i>LPL</i>, and <i>ACOX</i> (<i>P</i> > 0.05) in skeletal muscle of Nellore and Angus cattle. Similarly, no differences were observed in mRNA expression of adipogenic markers <i>Zfp423</i>, <i>PPARγ</i>, <i>and C/EBPα</i> (<i>P</i>>0.05) However, a greater PPARγ protein content was observed in skeletal muscle of Angus compared to Nellore cattle (<i>P</i>≤0.05). A greater abundance of adipo/fibrogenic cells, evaluated by the PDGFRα content, was observed in skeletal muscle of Angus than Nellore cattle (<i>P</i>≤0.05). No differences in fibrogenesis were observed in skeletal muscle of Angus and Nellore cattle, which is in accordance with the lack of differences in intramuscular collagen content in beef from both breeds (<i>P</i>>0.05). These findings demonstrate that difference in intramuscular fat content is associated with a slightly enhanced adipogenesis in skeletal muscle of Angus compared to Nellore cattle, while no difference in fibrogenesis.</p></div