Inhibition Of MSTN Expression By Fertilized Egg Yolk Extract Complex Promotes Skeletal Muscle Growth

Skeletal muscle is one of the most important organs of organisms and an important part of the production of animal products.The development of skeletal muscle is regulated by complex mechanisms in animals.The growth and development of skeletal muscle is closely related to the meat production rate and meat quality of animals.Studies have shown that the number of skeletal muscle fibers has become a fixed pattern during embryonic development.According to the purpose of production,the factors and signaling pathways in the regulation of skeletal muscle growth and development can change the muscle regeneration capacity and yield.Myostatin(MSTN)is a very important negative regulator during development,the yolk complex from fertilized eggs(YCFE)can effectively antagonize the expression of MSTN and then promote skeletal muscle growth..Purpose:1.To study whether it inhibits MSTN by feeding the fertilized egg yolk extract complex to mice,which has a positive effect on mouse skeletal muscle development and affects the expression of Peroxisome proliferator-activated receptor gamma coactivator(PGC-1?)and Fibronectin domain 5(FNDC5);2.To study the knockdown of MSTN gene,the expression of PGC-1? and FNDC5 in mouse skeletal muscle;3.To reveal the mechanism of the skeletal muscle development of the fertilized egg yolk extract complex,and to lay the foundation for the study of the different pathways of PGC-1?-FNDC5 after affecting the expression of MSTN.Method:1.Establish a mouse model of fertilized egg yolk extract complex,collect circulating blood and skeletal muscle,apply real-time quantitative PCR(q RT-PCR),immunofluorescence staining,enzyme-linked immunosorbent assay(Elisa)and Western blot analysis.The expression of MSTN in skeletal muscle determines the effect of fertilized egg yolk extract complex on skeletal muscle.2.Analysis of PGC-1? and FNDC5 expression in skeletal muscle of MSTN-/-mice by MSTN knockout(MSTN-/-)mouse skeletal muscle by immunohistochemistry,Western blot and real-time quantitative PCR(q RT-PCR).Result:1.The fertilized egg yolk extract complex has a positive regulatory effect on the bone development of mice: it is confirmed that there is a compound that antagonizes MSTN in the fertilized egg yolk extract complex;the mouse is infused with the fertilized egg yolk extract complex,and the mouse skeletal muscle is larger than the sham group;the expression of MSTN decreased in skeletal muscle and circulating blood.The expression of Myogenic differentiation factor 1(Myo D)was significantly increased in skeletal muscle,and the expression of Muscle ring finger protein 1(Mu RF-1)and Muscle-specific E3 ligase dystrophin Fbox-1(Atrogin-1)was decreased,Protein kinase B(p-Akt/t-Akt)and p-Smad2/3/t-Smad2/3 ratio increases;the fertilized egg yolk extract complex is added to the C2C12 cell,and the cell proliferation and differentiation function is enhanced;the expression levels of PGC-1? and FNDC5 were significantly increased in skeletal muscle,and the content of Irisin was significantly increased in serum.2.The protein expression levels of PGC-1? and FNDC5 in skeletal muscle of MSTN-/-mice were significantly higher than those in the control mice.Conclusion:The fertilized egg yolk extract complex inhibits MSTN,and the positive regulation of skeletal muscle growth and development is mainly through the Akt pathway.The complex composition may affect the expression levels of PGC-1? and FNDC5 and the PSC-after knockdown of the MSTN gene.There is an inconsistency in the influence paths of 1? and FNDC5,but their influence trends are consistent.