钙调磷酸酶催化亚基A（protein phosphatase 3 catalytic A,PPP3CA）是PPP3C在骨骼肌中的主要亚型,在肌纤维分化中起重要作用.为研究PPP3CA基因在不同品种鸭（Anas platyrhynchos domestica）发育早期肌肉中的表达规律及其与肌纤维特性的相关性,本研究选用生长速度差异较大的金定鸭和高邮鸭,采用实时荧光定量PCR检测鸭13、17、21、25和27胚龄及7日龄胸肌和腿肌中PPP3CA mRNA的表达水平.结果表明,两鸭种同一肌肉组织中PPP3CA mRNA的表达表现出显著的时间特异性,而品种和性别效应并不显著.两鸭品种胸肌和腿肌中PPP3CA mRNA的表达模式虽不同,但均是在13胚龄（13embryonic day,E13 d）时最高,且在出雏后7日龄时极显著高于27胚龄（出雏前）（P＜0.01）.胸肌中PPP3CA mRNA在21胚龄时显著低于其他各胚龄或日龄（P＜0.01）;腿肌中PPP3CA mRNA在21胚龄时表达量较高,27胚龄时降到最低,且极显著低于其他各胚龄或日龄（P＜0.01）.相关性分析结果显示,两鸭品种腿肌PPP3CA mRNA表达量与本研究前期检测的肌纤维类型、直径、面积和密度等肌纤维特性呈现不同程度的线性相关;两鸭品种胸肌和腿肌PPP3CA mRNA表达量与均与本研究前期检测的类胰岛素生长因子（insulin-like grow factor-Ⅰ,IGF-Ⅰ）mRNA表达量呈显著的正相关（P＜0.05或P＜0.01）.初步推测鸭发育早期骨骼肌中PPP3与肌纤维类型和肌纤维生长发育密切相关,与IGF-Ⅰ可能共同参与了对骨骼肌生长发育的调节.本研究结果将有助于了解PPP3在鸭肌肉早期发育中的作用,并为改良鸭肉品质提供理论依据.
Protein phosphatase 3 catalytic A （PPP3CA） is a major isozyme of PPP3C in skeletal muscle and plays an important role in myofiber differentiation. In the present study, expression of PPP3CA mRNA was quantified by absolute quantitative RT-PCR in the peetorale and leg muscle tissues from Jinding ducks and Gaoyou ducks （Anas platyrhynchos domestica） differing in growth rates on days 13, 17, 21, 25, 27 of embryonic development and 7 days post-hatching （PH）. The results showed that there was a significant variation with the age of ducks in the PPP3CA mRNA expression profile of the same muscle tissue in 2 duck breeds, but there was no significant breed and sex effect. In both pectoral and leg muscles, the expression peak ofPPP3CA mRNA appeared at 13 embryonic day （El3 d） and the PPP3CA mRNA expression level at 7 d PH was very significantly higher than that at E27 d （before hatching） （P〈0.01）. In pectoral muscles, the expression of PPP3CA mRNA was firstly declined from El3 d to E21 d, then increased from E21 d to 7 d PH, and the lowest point appeared at E21 d which was very significantly lower than that at other embryonic age or day-old （P〈0.01）. In leg muscles, the expression of PPP3CA mRNA was significantly declined from El3 d to El7 d, then significantly increased to E21 d, then decreased gradually to E27 d, and finally increased to 7 d PH; the lowest point appeared at E27 d which was very significantly lower than that at other embryonic ages or day-old （P〈0.01）, and the expression level was not significantly different among El7 d, E25 d and 7 d PH （P〉0.05）. The correlation analysis showed that varying degrees of linear correlation were found between the expression of PPP3CA mRNA in leg muscles and myofiber types, diameter, cross-sectional area and density the data were detected in former studies in 2 duck breeds; the expression levels of PPP3CA mRNA in pectoral and leg muscles of 2 duck breeds were significantly positively correlated with IGF- I mRNA expression which was d
Journal of Agricultural Biotechnology