Differentially expressed genes in genetically divergent Nellore steers for calcium content in the Longissimus dorsi muscle

• Published in: Journal of animal science 2016-10, Vol.94, p.435-435
• Main Authors: Afonso, J, Tizioto, P C, Oliveira, P S N, S Diniz, W J, Lima, A O D, Souza, M M D, Rocha, M I P, Silva, J V D, Buss, C E, Gromboni, C F, Mourão, G B, Nogueira, A R, Coutinho, L L, Regitano, L C A
• Format: Article
• Language: English
• Subjects: Adhesion; Animals; Beef cattle; Binding; Bovidae; Breeding; Calcium; Calcium-binding protein; Carbohydrates; Cartilage; Cattle; Collagen; Extracellular matrix; Gene expression; Genes; Genetics; Genomics; Integrins; Mammals; Meat; Metals; Morphogenesis; Muscle contraction; Muscles; Neurological system; Proteins; Ribonucleic acid; RNA; Skeleton; Troponin
• ISSN: 0021-8812; 1525-3163
• DOI: 10.2527/jam2016-0903

Calcium is an important mineral for mammals, because it is involved in muscle contraction and neuro impulse transmission and controls the flow of substances in the cellular environment. Calcium is the major part of the mammal skeleton; it is found in great amount in milk and can be found in beef. In addition, the calcium content in bovine muscle can influence meat quality traits, such as meat tenderness, due to its importance for calcium-dependent proteases. Although calcium functions in the organism have been extensively studied, a lack of knowledge of the mechanisms regulating calcium content is still observed. In this study, we identified differentially expressed (DE) genes in genetically divergent Nellore steers for calcium content in the Longissimus dorsi (LD) muscle using an RNA-seq approach. From an initial population of 120 animals presenting genomic breeding value (GEBV) estimates for calcium content, we chose 10 animals in two groups selected for their extremely low or high GEBV. The analysis of RNA-seq samples using the Tuxedo suit pipeline revealed 43 DE genes, 32 upregulated in the group with low calcium content. A functional gene enrichment analysis performed by DAVID software indicated 10 functional clusters involved in membrane and extracellular matrix proteins, cell and tissue adhesion, skeleton, neurological system and cartilage development, calcium, carbohydrate and metal binding, and sensorial and sound perception. Gene functions, such as cell and tissue adhesion, and calcium, carbohydrate, and metal binding are related to meat tenderness due to their role in the rigor mortis process and in muscle contraction through the interaction with troponin. Among the upregulated genes in the low calcium content group, we found the collagen genes COL11A1 and COL11A2 involved in skeletal morphogenesis and associated with several genetic syndromes related to abnormal calcium deposits in humans. COL11A1 is downregulated in female Quinchuan cattle, which might explain part of the higher tenderness in this sex, since there is a negative correlation between this trait and collagen. In Bos taurus coreanae both genes are upregulated in intramuscular fat in comparison with subcutaneous fat, along with integrins, calcium dependent proteins that are related to cellular adhesion. These are intermediate results and further experiments will allow the exploration of the genetic findings influencing muscle calcium concentration in Nellore cattle. The results will