Study The Regularity Of CAPN1, CAST, H-FABP Genes Expression And Their Effects On Poultry Meat Quality Trait In Different Rearing Systems

With the improvement of people living standard meat quality become highlighted issue affecting consumers’acceptance of poultry products. So this study chosen CAPN1、 CAST and H-FABP, the important candidate genes of meat quality, to further study. Healthy chicks (S02♂×S03♀) were selected after postnatal and feeded together, and then divided into three groups [cage group (C), indoor floor group (I), free range group (F)] on43th day. Ten chickens (the ratio of male to female is1:1) of each treatment were chosen randomly as experimental materials at Ow,2w,4w,6w and8w,10w,13w in different rearing systems. Samples (breast muscle, leg muscle, subcutaneous fat and abdominal fat) were collected for doing real-time qPCR from each chicken after butchered. At the time points of8w, lOw and13w in different rearing systems, body weight were measured and venous blood were collected from wing for measuring biochemical indicator; after butchered, two pieces of breast muscle were collected for measuring IMF, myofiber diameter and density; sebum thick and abdominal weight were measured also. The aim of this study was to explore the regularity of CAPN1, CAST, H-FABP genes expression and their effects on poultry meat quality trait in different rearing systems.The results showed that the profile of CAPN1、CAST gene expression in breast and leg muscle exhibited a "rise-decline-rise-decline" developmental change, with the peak of2w-♂and10w-♀. The profile of H-FABP gene expression in breast and leg muscle were decline from0w-♀gradually. The peak of CAPN1、CAST and H-FABP gene expression in subcutaneous fat or abdominal fat showed up after8w. The difference of genes expression in different issues were showed that CAPN1gene expression was higher in abdominal fat of female chicken than leg muscle of male chicken (P<0.05) at10w and higher in muscle than in fat at other weeks. CAST gene expression was higher in fat issue than in muscle issue significantly at some time points and no significantly at other time points. H-FABP gene expression was higher in leg muscle than fat issues at2w; but at other weeks it was higher in subcutaneous fat or abdominal fat.In breast muscle, the expression of CAPN1was higher in F group than in I group (P <0.05); CAST and myofiber diameter were higher at13w than at8w (P<0.05); H-FABP and myofiber density were higher in F group than in I group (P<0.05); CAPN1/H-FABP was "13w,10w>8w"(P<0.01), larger in male chicken than female chicken (P<0.05); H-FABP/CAST was "8w>10w、13w"(P<0.01), larger in female chicken than male chicken (P<0.05); IMF was higher in F group and C group than in I group(P<0.01), higher at13w than8w (P<0.01); myofiber diameter was "13w>10w>8w"(P<0.01), larger in male chicken than female chicken (P<0.05); myofiber density was "8w>10w>13w"(P<0.01). The results of correlation analysis showed that IMF was negatively correlated with the H-FABP/CAST (P<0.05) and trend to positively with CAPN1/H-FABP (P=0.06); Myofiber diameter was positively correlated with CAST gene expression level (P<0.01) and CAPN1/H-FABP (P<0.05), but negatively with H-FABP/CAST(P<0.01). Myofiber density was positively correlated with H-FABP/CAST and H-FABP gene expression level (P<0.01), but negatively with CAST gene expression and CAPN1/H-FABP (P<0.01). These results upstairs suggested that there were concordant between the regularity of gene expression and IMF, myofiber diameter and density in different rearing systems, ages and sexes. So we conclude that rearing system, age and sex may affect IMF, myofiber diameter and density via affecting the expression of CAPN1、CAST、H-FABP gene.In abdominal fat, the expression of CAPN1gene was higher at10w than at8w, higher in female chicken than male chicken(P<0.01); the expression of H-FABP gene was higher at10w and13w than8w (P<0.05), higher in female chicken than male chicken (P<0.01).The abdominal fat percentage was higher at10w and13w than at8w, higher in female chicken than male chicken (P<0.01). The results of correlation analysis showed that the abdominal fat percentage was positively correlated with H-FABP gene expression (P<0.05) and trend to positively with CAPN1/H-FABP (P=0.06). These results upstairs suggested that there were concordant between the regularity of CAPN1, H-FABP gene expression and abdominal fat percentage in different ages and sexes. So we conclude that age and sex may affect abdominal fat percentage via affecting the expression of CAPN1and H-FABP gene.The results of correlation analysis between the expression of CAPN1、CAST H-FABP in subcutaneous fat or abdominal fat and blood biochemical indicator showed that gene expression or their ratio were correlated with leptin, insulin and Triglyceride which play an important role in lipometabolism. So we conclude that CAPN1、CAST、 H-FABP genes played an important role in lipometabolism of subcutaneous fat and abdominal fat, and may have some contacts in subcutaneous fat.