Effect Of A Chicken C-Myc Gene Novel Transcript On Proliferation,differentiation And Apoptosis Of Myoblasts

The growth and development of skeletal muscle directly affects the meat production of broilers.c-Myc is an important factor regulating embryonic development and cell growth,and it plays an important role in the growth and development of skeletal muscle,while the specific mechanism is not yet clear.In this study,three novel transcripts of chicken c-Myc were cloned in myoblasts and embryonic muscle tissue,named c-Myc-2,c-Myc-3,and c-Myc-4 successively,in which c-Myc-2 lacks the whole second exon of chicken c-Myc.Tissue expression analysis revealed that c-Myc-2 was highly expressed in middle and late embryonic leg muscle.Using protein expression labeling test,we confirmed that c-Myc-2 is a long non coding RNA.After overexpression of c-Myc-2 in myoblasts,the effects of c-Myc-2 on myoblasts were detected through EdU assay,flow cytometry and qRT-PCR.It was found that c-Myc-2 not only inhibits the proliferation and differentiation of myoblast but also promotes its apoptosis.We further analyzed the c-Myc-2 gene interaction network using digital gene expression profiling of chicken myoblasts.A total of 294 differentially expressed genes were screened for c-Myc-2 overexpressing and control group by differential gene analysis(Fold Change ? 2,The corrected P value ? 0.05),of which 204 were up-regulated and 90 were down-regulated.These differentially expressed genes were significantly enriched in some pathways related to chicken growth and development,such as cell cycle,p53 signaling pathway and growth factor activity.The partial differential genes in cell cycle pathways were verified,and the results are consistent with the sequencing results.In addition,this study screened the SNPs of c-Myc and performed correlation analysis in the F2 full sibs of Xinghua chicken and White Recessive Rock.The results showed that the SNP site g.1215C>A and g.1834T>C locus were significantly related to multiple growth traits.In general,we discovered three novel transcripts of c-Myc,and revealed the role of novel transcript c-Myc-2 in chicken myoblasts and the molecular regulatory pathways involved in this study.This further makes clear the role of c-Myc in the development of chicken skeletal muscle,and provides a theoretical basis for molecular breeding of chicken growth traits.