Analysis Of Expression And Polymorphism Of Meat Cadidate Genes And Lts Correlation With Meat Traits In Two Inner Mongolia Sheep Breeds

Bamei and Sunit sheep in Inner Mongolia was famous for their super meat quality. Meat quality was an import ecnomic trait. MyoG, Myf5, Myf6, CAST and MSTN gene were impoetant candidate genes for meat quality. Correlation of the expression and Polymorphism with meat quality had been investigated. It may offer genetic theory for further development and utilization for Bamei and sunit sheep.Real-time PCR was used to investigate the expression of cadidate genes (MyoG, Myf5, Myf6, CAST, MSTN) in longissimus dorsi, triceps and biceps femoris in40Bamei and42sunit sheep of defferenet month age. The shear force, pH, colour, loin area were investigated after slaughter. The expression of the cadidate genes was detected. The correlation between the expression and meat quality traits were analyzed.The results show as follows:1.(1) The expression of Myf5of4,6month was significant difference with the expression of12month in longissimus dorsi in Bamei sheep, the order was12month>4month>6month. The expression of Myf5of8month in longissimus dorsi in Sunit sheep was highest and it was significant difference with the expression of5month. The expression of Myf5in6and8month in triceps in Bamei sheep was significant higher than in Sunit sheep.(2) The expression in triceps in Bamei sheep of12month was significant higher than in Sunit sheep.(3) The expression of CAST in Sunit sheep was higher than in Bamei sheep in three muscles of of6,8,12month. The expression of CAST of8month in triceps in Sunit sheep was significant higher than in Bamei sheep.(4) The expression of MSTN show as follows:?The expression of MSTN in longissimus dorsi and biceps femoris of6month in Sunit sheep was significent higher than in Bamei sheep. The expression of MSTN in longissimus dorsi of12month in Sunit sheep was significent lower than in Bamei sheep.?In Bamei sheep, the expression of MSTN in triceps and biceps femoris is highest of4month age, the expression of MSTN in iongissimus dorsi was increasing with the growth of month age. In three muscles investigated, the expression of MSTN was nearly same of12month age.?In Sunit sheep, there was a similar variation trend of the expression of MSTN in three musles investigated. It was highest of6month age and lowest of12month age.It was higer in triceps than in the other two muscles.2. The correlation between the expression and meat quality traits show as following: ?In Sunit sheep, the expression of Myf5in triceps had significant positive correlation with shear force (r=0.985, p=0.015), In Sunit sheep, the expression of Myf6in triceps had greatly signifieant negative correlation with pH2, in biceps femoris, it had significant negative correlation with pH2.?In Bamei sheep, the expression of CAST in biceps femoris had signifieant positive correlation with shear force.In Sunit sheep, in longissimus dorsi, it had signifieant negative correlation with red/green colours.?In Bamei sheep, the expression of MSTN in longissimus dorsi had signifieant positive correlation with loin area, it had signifieant negative correlation with lightness.3. The correlation between the cadidate genes:(1) In Bamei sheep, the expression of MyoG in longissimus dorsi had signifieant negative correlation with the expression of Myf6.(2) The expression of Myf5had positive correlation with the expression of Myf6in three muscles investigated in two breeds and in triceps in Bamei sheep, the positive correlation was signifcent.(3) The expression of Myf6had positive correlation with the expression of MSTN in three muscles investigated in two breeds.Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) method was used to determine the polymorphism of exon6of CAST gene in101Bamei sheep and107Sunit sheep, the correlation between CAST gene and meat quality traits were analyzed. The result show as follows:4.There was two mutation have been found in the exon6of CAST gene (A56G, A184C) in the research.Three genotypes were identified as AA, AB and AC. Polymorphism information content was0.30in Bamei sheep. Polymorphism information content was0.28in Sunit sheep.5. The correlation between genotype and meat quality:In6-month Bamei sheep, there was significant difference of red/green colours (a*) in longissimus dorsi of three genotypes, red/green colours (a*) of AB genotype was better. In12-month Bamei sheep there was significant difference of lightness (L*) of three genotypes in both triceps and biceps femoris.