207 - Satellite Cells Participate in the wnt/ca2+ Pathway Controlled Porcine Myofiber Determination

The type of myofiber is important for porcine meat quality. Meanwhile, the nt/Ca²⁺ pathway has been showed multiple roles in skeletal muscle formation; however, the distinct mechanism is still unclear. In this study, the weaned piglets and satellite cells were designed into the control group, lysine deficiency group and lysine rescue group to investigate the function of Wnt/Ca²⁺ pathway in governing skeletal muscle typing. After we confirm the growth of weaned piglets was controlled by lysine, the isobaric tag for relative and absolute quantification (iTRAQ) analysis of skeletal muscle detected that Wnt/Ca²⁺ pathway was involved in the transition of fast and slow fiber. Then, we found the ratio of type Ⅰ myofiber in Semimembranous (fast muscle) was significantly increased after lysine deficiency (P < 0.05), and decreased by lysine rescue (P < 0.05). In contrast, the ratio of type Ⅰ myofiber in Semitendinous muscle (slow muscle) was significantly decreased in the lysine deficiency group, and increased in the lysine rescue group (P < 0.05). Furthermore, the Wnt/Ca²⁺ pathway was significantly increased in Semimembranous muscle, while decreased in Semitendinous muscle with lysine deficiency, and this phenomenon was inversed after lysine rescue (P < 0.05). Meanwhile, the Wnt/Ca²⁺ pathway was stronger in satellite cells isolated from Semitendinous muscle (StSCs) than that of Semimembranous satellite cell (SmSCs) (P < 0.05). And we also found the StSCs enter in differentiation is more easily than SmSCs (P < 0.05). Besides, the ratio of type Ⅰ myofiber originated from StSCs showed greater than StSCs (P < 0.05). In summary, we conclude that satellite cells participate in the Wnt/Ca²⁺ pathway controlled porcine myofiber determination.