Effects Of PHGDH Gene On Meat Traits And Proliferation And Differentiation Of Myogenic Cells In Heying Black Chicken

Muscle is an important part of livestock and poultry products,and it is regulated and affected by a series of genes from embryonic stage to adulthood.It is very important for livestock and poultry production to understand the mechanism of regulating muscle growth and development.The regulation of muscle growth and development is mainly due to changes in the expression of some genes,which will be constantly changing with the growth of animals from embryonic stage to adulthood.In the previous phase,our research group screened out differentially expressed genes related to muscle growth and development using RNA-seq technology.On this basis,in this study,we used PHGDH as the key gene and Heying Black Chicken as the research material to study the effects of PHGDH gene on the proliferation and differentiation of chicken myoblasts as well as the screening of mutation sites using DNA-seq technology and the expression patterns of PHGDH gene in different tissues and different growth stages of Heying Black Chicken by fluorescence quantitative method.The main research results are as follows:1.The results showed that a total of six mutation sites were found in the exons of PHGDH gene in Heying Black Chicken.The association analysis results showed that,for carcass traits,g.G193C locus had significant(P<0.05)or very significant(P<0.01)effects on leg muscle weight and liver weight,respectively.g.C415T locus had a significant effect on abdominal fat weight(P<0.05);The g.A559G locus had significant or extremely significant effects on live weight,leg muscle weight,full bore weight,abdominal fat weight(P<0.05 or P<0.01),respectively.The g.G1612 A locus showed significant effects on liver weight(P<0.05).The g.G1635A locus showed significant effects on full bore weight,liver weight and abdominal fat weight(P<0.05).The g.A1681G locus had a significant effect on liver weight(P<0.05).For growth traits,g.G193C locus had significant effects on 4-week-old(W)and 16-W body weight(P<0.05);g.C415T locus had a significant effect on body weights at 8W and 16W(P<0.05).The g.A559G locus had a very significant effect on the body weights of both 12 W and 16W(P<0.01).g.G1612 A locus had a significant(P<0.05)or very significant effect on 16W body weight(P<0.01),respectively.g.G1635A locus had a very significant effect on body weight of 16W(P<0.01).The g.A1681G locus had either a significant(P<0.05)or very significant effect on the body weights of 12W and 16W,respectively(P<0.01).2.We used 4 W Heying Black Chicken to study the expression of PHGDH gene in different tissues and growth stages of Heying Black Chicken.The results showed that PHGDH was highly expressed in chest muscle,leg muscle,liver and kidney of Heying Black Chicken,and the difference was very significant with that in spleen(P<0.01).The expression patterns of PHGDH in Heying Black Chick en at different stages were detected again.The results showed that the expression levels of each tissue were higher at birth for both rooster and hen,and then showed different high and low trends.In roosters,the expression patterns of chest and leg muscles were basically the same,the highest was 0 W,which was lower at 4 W;the gene expression was at a high level from 8W to 12 W,and it was the lowest at 16 W;In hens,the expression levels of chest and leg muscles were different to a certain extent.The expression level of leg muscle was higher than that of chest muscle at 0 W,and both expression levels of chest and leg muscles were significantly decreased at 4 W;the expression level of leg muscle then decreased slowly;the expression level of chest muscle increased at 8 W and decreased at 12 W.3.With the prolongation of myoblast differentiation and the obvious thickening of the myotube,the expression of PHGDH gene also gradually increased.After interfering with PHGDH gene,we found that it extremely significantly reduced the proliferation level of myoblasts(P<0.01),significantly or extremely significantly(P<0.05 or P<0.01)inhibited the expression of differentiation marker genes MYOD and MYOG,and extremely significantly up-regulated the expression of MSTN gene(P<0.01),and simultaneously inhibited the expression of MYHC gene protein,significantly reducing the myotube area after differentiation(P<0.01),and inhibiting the proliferation and differentiation of myoblasts.After overexpression of PHGDH gene,we found that it extremely significantly increased the proliferation of myoblasts(P<0.01),significantly(P<0.05)or extremely significantly(P<0.01)increased the expression of differentiation marker genes MYOG and MYOD,and extremely significantly down-regulated the expression of MSTN gene(P<0.01).At the same time,it significantly promoted the expression of MYHC gene protein,significantly increased the myotube area after differentiation(P<0.05),and promoted the proliferation and differentiation of myoblasts.In summary,PHGDH gene promotes the proliferation and differentiation of myoblasts and can be used as an important regulatory factor in the process of muscle growth and development.