Insulin-like Growth Factors and Myostatin expression in Pejerrey during starved/refeeding periods

SIMÓ, I; BOTTA, P; FERNÁNDEZ, DANIEL A.; ARRANZ, S

Buenos Aires

Simposio; 7th International Symposium on Fish Endocrinology? (7ISFE), Buenos Aires, 2012.; 2012

<!-- @page { margin: 2cm } P { margin-bottom: 0.21cm; direction: ltr; color: #000000; widows: 2; orphans: 2 } P.western { font-family: "Times New Roman", serif; font-size: 12pt; so-language: es-ES } P.cjk { font-family: "Times New Roman", serif; font-size: 12pt } P.ctl { font-family: "Times New Roman", serif; font-size: 12pt; so-language: ar-SA } --> Insulin-like growth factors (IGFs) are crucial in the formation and maintenance of skeletal muscle. Myostatin is a key negative regulator of skeletal muscle growth acting as an inhibitor of myoblast cell cicle progression. Here we have examined the gene expression changes in muscle of juvenils pejerrey (Odontesthes bonariensis) under fasting and re-feeding conditions. As a result of gene expression-analysis by real time PCR we observed decresed levels of IGF-I and myostatin in starved fish compared to control group. After refeeding IGF-II levels were significantly lower than controls but IGF-I and myostatin did not differ from controls.To gain insigth into muscle growth parameters, a comparison of the number and fibre size in starved and normal fish was performed. A significant increase in the percentage of new fibres was observed after starving. The data showed that IGF-I and IGF-II act in different stages of muscle growth in response to starved/refeeding periods. A significant decreased in myostatin levels during starvation could be associated with muscle progenitor cell proliferation.