In this study, Altay sheep and Turpan black sheep were used for the main research object. The meatproduction and meat quality were studied in molecular level. In DNA level, its genetic polymorphism wasdetected using SSCP and DNA sequencing technology. The association between genetic variations andweight were analyzed by software.The aim was to find molecular markers about weight traits. In RNA level,the mRNA expression of MyoG, H-FABP and LPL genes were detected in muscular tissue of Altay sheepand Turpan black sheep by using Real-time Quantitative PCR (RQ-PCR). The aim was to study theregulatory effect of MyoG gene for meat production, H-FABP and LPL for intramuscular fat content (IMF)and fatty acids composition.The research results will provide basis of selecting breeding and molecularmarker assisted selection. The significant results are as follows:1. Genetic variation of Myogenic Differentiation Antigen gene family and their association betweenweight traitsThe polymorphism of MyoD gene family was detected in two sheep breeds. MyoG gene has geneticpolymorphism in two sheep breeds. DNA sequencing revealed that in exon3(1600delete A), it createdthree genotypes: AAã€AB and BB, the B allele was the dominant allele. The association between geneticvariations and weight traits were analyzed, in Altay sheep, genotype AA was much lower than genotype ABtype and BB type (P <0.05) in average weight. In Turpan black sheep, genotype AA was significantlyhigher than genotype AB type and BB type (P <0.01) in average weight. As the varieties vary, the genemutation leads the different effect. In general, there is an influence between gene mutation and weight inAltay sheep and Turpan black sheep.2. The correlation analysis between MyoG expression in different muscles and meat production intwoXinjiang sheep breeds.The expression of MyoG were detected in different muscles, the study found that, the expression ofMyoG in different muscles were significant difference in Altay sheep and Turpan black sheep (P<0.05), thecorrelation analysis between MyoG expression and meat production showed that, MyoG expression werevery significantly positive correlated with the meat weight(P<0.01, r=0.982)in longissmus, and inquadriceps it were significantly positive correlated with the meat weight in Altay sheep(P<0.05, r=0.290).In Turpan black sheep, MyoG expression were significantly positive correlated with the meat weight inlongissmus (P<0.05, r=0.755). Thereby it is proved that MyoG gene has regulator to meat productionpositively in Altay sheep and Turpan black sheep.3. The correlation analysis between H-FABP, LPL expression in different muscles and intramuscular fatcontent, fatty acids in twoXinjiang sheep breeds.The expressions of H-FABP, LPL were detected in different muscles, the study found that, the expressionof H-FABP in arm triceps were significantly higher than it in quadriceps femoris (P<0.05) and verysignificantly higher in longissimus dorsi (P<0.01) in Altay sheep. The expressions of H-FABP in armtriceps and longissimus dorsi were significantly higher than it in quadriceps femoris in Turpan black sheep(P<0.05). The correlation analysis with intramuscular fat content showed that the expression of H-FABPfene were have significantly negative correlated with the IMF (P<0.05, r=-0.18), the correlation analysisbetween IMF and meat tenderness indicated they were positive correlation in longissimus dorsi in Altaysheep and quadriceps femoris in Turpan black sheep (P<0.05, r=0.798,r=0.769), thereby it is provedpreliminarily that the expression of H-FABP have negative regulator to meat tenderness in5months sheep. The expression of LPL in arm triceps and quadriceps femoris were significantly higher than it inlongissimus dorsi (P<0.01), the correlation analysis with the fatty acids showed that the expression of LPLin arm triceps were positive correlated to total fatty acids (P<0.05, r=1.00) and negative correlation withunsaturated fatty acids, saturated fats in Altay sheep (P<0.05, r=-1.00,r=-0.99). In Turpan black sheep theexpression of LPL were correlated to saturated fats in arm triceps, quadriceps femoris and longissimusdorsi(P<0.05, r=0.83,r=0.91,r=0.85). The saturated fatty acids has a positive correlated to the smell ofmeat, so it is proved that the LPL gene has positively regulator to the aroma-forming reactions in Turpanblack sheep.In this study, Genetic variation of Myogenic Differentiation Antigen gene family and the expression ofMyoG, H-FABP, LPL in different muscles were detected. In general, there is an influence between genemutation and weight in Altay sheep and Turpan black sheep, MyoG gene has regulator to meat productionpositively in Altay sheep and Turpan black sheep, H-FABP gene has negative regulator to intramuscular fatcontent, LPL gene has regulator to TFAC in Altay sheep and saturated fatty acid content in Turpan blacksheep. |