Genetic Variation And Effect On Proliferation And Differentiation Of Myoblasts Of IGF1R Gene In Cattle

One of the important factors affecting the development of beef cattle industrialization is the growth and development of muscles,so it has always been the key to genetic improvement research.However,the weak molecular basis of muscle development has bound the molecular breeding of cattle.The insulin-like growth factor 1 receptor(IGF1R)gene plays a crucial role in immune regulation,muscle and bone growth.With a wide range of biological functions,it is an important candidate for studying muscle development.Therefore,this study used PCR-based typing and real-time PCR to study the polymorphism of InDel and CNV of Chinese yellow cattle IGF1 R gene and its effects on growth and development.The molecular mechanism of IGF1 R gene on proliferation and differentiation of bovine muscle cells was studied by using interference technology,CCK-8,EdU,flow cytometry,real-time fluorescent quantitative PCR and Western Blot.Get the following main results:1.Polymorphism of InDel locus in IGF1 R gene of yellow cattle and its correlation with growth traitsIn this study,a total of 537 cows from Qinchuan cattle,Jinnan cattle,Xia Nan cattle and Nanyang cattle were selected for InDel locus.PCR analysis was used to analyze the growth traits of yellow cattle.The traits showed three genotypes of II,ID and DD.In Jinnan cattle and Nanyang cattle,InDel polymorphism was significantly associated with some growth traits(P<0.05).2.Distribution of IGF1 R gene CNV in four yellow cattle populations and its association with phenotypeIn this study,422 cows from Qinchuan cattle,Jinnan cattle,Xia Nan cattle and Nanyang cattle were used to study the distribution of relative copy number of IGF1 R gene,which was more discrete in Jinnan cattle,Qinchuan cattle and Nanyang cattle.In Jinnan cattle,Qinchuan cattle and Nanyang cattle,CNV polymorphism was significantly associated with some growth traits(P<0.05);Bioinformatics analysis revealed that the bovine CNV region is highly similar to the human genome CNV,and there are a large number of transcription factors,DNase I hypersensitive sites and high levels of histone acetylation.3.Interfering with IGF1 R gene inhibits proliferation and differentiation of bovine myocytesUsing RT-qPCR assay,it was found that the IGF1 R gene showed significant differences in muscle expression during fetal and adult cattle.Using CCK-8,EdU and flow cytometry experiments,it was found that interference with the IGF1 R gene attenuated cell proliferation activity.Using RT-qPCR and Western Blot assays,it was found that interference with IGF1 R gene significantly decreased the expression of PCNA and CyclinE1,indicating that the interference of IGF1 R gene can inhibit myocyte proliferation;interference with IGF1 R gene can significantly reduce the expression of MYOD gene,demonstrating interference with IGF1 R.The gene is able to inhibit myocyte differentiation.In summary,the IGF1 R gene can promote muscle cell proliferation and differentiation.This study revealed the effect of IGF1 R gene on the growth and development of yellow cattle,and provided new molecular markers for the preservation of Chinese yellow cattle and the genetic improvement of beef cattle.