| Yak(Bos gruniens) is distributed in the Qinghai-Tibet Plateau and adjacent areas. Influenced by high altitudes and special climatic, the muscle and adipose tissue of yaks grow rapidly owing to plenty of pasture in warm season, while in cold season, the muscle and adipose tissue of yaks suffered severe weight loss under shortage of pasturage. In this study, high-throughput sequencing technology was used to build micro RNA library of yak subcutaneous fat and longissimus muscle in cold-season and warm-season separately, late to identify differential expressed micro RNAs and analyze their functions so as to study the roles of micro RNA in yak fat and muscle metabolism under nutrient stress. The results are as follows:1. Four small RNA libraries of yak were successfully constructed, including subcutaneous fat from cold and warm season, longissimus muscle from cold and warm season separately. Clean reads with 24 M reads were obtained from each library, and the highest percentages of detected s RNAs were 22-nt length small RNA.2. In library of yak subcutaneous fat, 450 micro RNA were identified, 70 micro RNA of which expressed significantly different in tissues of two seasons. Among differential expressed micro RNA, mi R-335, mi R-378, mi R-378 b, mi R-200 a, mi R-200 b, mi R-200 c and mi R-210 played roles in yak fat metabolism.3. In library of yak longissimus muscle, 344 micro RNA were identified, 79 micro RNA of which expressed significantly different in tissues of two seasons. mi R-133 b, mi R-378, mi R-378 c, mi R-29 a, mi R-29 b and mi R-29 c played roles in yak muscle metabolism.4. There were 815 target genes were predicted in yak subcutaneous fat, KEGG pathway annotation results showed that target genes were significantly enriched in 77 pathways that played important role in fat metabolism(P<0.05). In longissimus muscle, there were 1,315 target genes were predicted, which were significantly enriched in 99 pathways related to muscle metabolism.In conclusion, high-throughput sequencing technology were used in this study to identify micro RNAs of yak subcutaneous fat and longissimus muscle collected from warm and cold season. The results showed that micro RNAs played important roles in regulating fat and muscle metabolism of yak under nutritional stress, and to provide a scientific basis and theoretical support for future study. |
