AGE-DEPENDENT CHANGES IN BOVINE SKELETAL MUSCLE TRANSCRIPTOMIC PROFILE

The postnatal growth of muscle tissue occurs by hypertrophy comprising satellite cells proliferation, differentiation and protein turnover. The highest rate of skeletal muscle gains and protein synthesis in bulls occurs in the period between 180 and 360 days of postnatal life. However, genes which are responsible for quantitative and qualitative changes in skeletal muscle during this period are not identified up to date. The aim of our study was to compare the changes in transcriptomic profile of skeletal muscle (m. semitendinosus) in 12 Polish Black and White bulls between 6 and 12 month of life. For experimental purposes we used bovine cDNA microarray (the NBFGC EST collection) which contains 18,263 unique genes, derived from many different tissue types and various physiologically important states within these tissues. Our results revealed 53 genes which expression changed in the same manner depending on age of all examined pairs of animals. Thirty two of these genes showed at least 2-fold difference in expression between two analyzed age points. Age-dependent up-regulation was the most pronounced in the case of following genes: similar to MAD2L1 binding protein, similar to thymocyte potein thy28 isoform 1, similar to type I inositol-1,4,5-triphosphate 5-phosphatase, similar to nucleoside diphosphate kinase 6, proline rich 14, similar to transcription factor E2-alpha and phospholipase C gamma 1. The highest age-dependent decrease of the transcript was observed in the case of: similar to ubiquitin carboxy-terminal hydrolase L1, similar to latent TGF-beta binding protein 3 precursor, phospho-mannomutase 2, CD74 antigen, simlar to BCL6 co-represor-like 1, plateled/endothelial cell adhesion molecule (PECAM1), necdin, zygin, tight junction protein 3, ankyrin and apolipoprotein-L3. Although the role of the most of above genes and interactions between products of their expression is not clear at the moment, the significance of their response between 6 and 12 month of age may indicate their involvement in growth, development and metabolic changes in bovine skeletal muscle during the first year of postnatal life.