猪背最长肌肌纤维类型的发育性变化及其品种和性别特点  

The Developmental Changes of Myofibre Types in LD Muscle of Erhualian and Large White Pigs

作　　者：杨晓静[1] 赵茹茜[1] 陈杰[1] 胥清富[1] 韦习会[1] 陈杰 

机构地区：[1]南京农业大学农业部动物生理生化重点开放实验室,江苏南京210095

出　　处：《中国兽医学报》2005年第1期89-94,共6页Chinese Journal of Veterinary Science

基　　金：国家自然科学基金重点资助项目 (3 983 0 2 90 ) ;江苏省重点课题 (BK2 0 0 2 2 0 4)

摘　　要：4种肌球蛋白重链的异构体 (My HC 、My HC2 a、My HC2 x、My HC2 b)分别特征性地对应 4种不同类型的肌纤维( 、2 a、2 x和 2 b)。选用生长速度快 ,但肉质较差的瘦肉型猪大白猪和生长速度慢 ,但肉质较好的肥胖型猪二花脸作为实验动物 ,采用相对定量 RT- PCR方法 ,测定了背最长肌中 、2 a、2 x和 2 b4种 My HC m RNA基因的表达 ,以探讨二花脸猪和大白猪背最长肌中 、2 a、2 x和 2 b 4种肌纤维类型比例的发育性变化 ,并分析了其品种和性别特点。结果表明 :(1) 3日龄 My HC 型和 2 a型肌纤维的比例较高 ,2 b型几乎没有分化 ;(2 )从 3日龄到 2 0日龄 ,肌纤维组成发生了急剧的变化 ,My HC 型和 2 a型表达下调 ,比例下降 ,2 b型肌纤维显著上升 (P<0 .0 5 ) ,且品种间无显著差异 ;(3) 90日龄以后 ,二花脸公猪背最长肌中 My HC 型和 2 a型的比例均显著高于大白猪 ,同时 ,大白猪背最长肌中酵解型肌纤维 2 b的比例增加迅速 ,显著地高于二花脸 (P<0 .0 5 ) ;(4)性别间比较 ,My HC 型纤维的比例无显著差异 ,90日龄和180日龄 ,二花脸母猪的 My HC2 b的比例显著高于二花脸公猪 (P<0 .0 5 )。以上结果提示 ,大白猪和二花脸猪背最长肌肌纤维类型的差异主要表现在 90日龄后 ,大白猪 型纤维比例的显著下降和2b型纤维比例的显著增加与其肌肉的快速沉积有关;而二花脸猪背最长肌较高比例的MyHC I型和2a型纤维与其优良的内质相关。Four isoforms(MyHCⅠ、MyHC2a、MyHC2b、MyHC2x) of myosin heavy chain(MyHC) represent characteristically four types of myofibre(1,2a,2x,2b).In present study,the developmental patterns of myofibre in longissimus dorsi(LD) muscle were compared between Erhualian and Large White pigs by determining the ratios of mRNA abundances of four isoforms of MyHC with semi-quantitative RT-PCR.The results indicated that:(1)the proportion of MyHCⅠ and 2a fibres were high at 3 days of age,and MyHC 2b fibres were almost not differentiated;(2)from D3 to D20,the composition of myofibres changed dramatically,the MyHCⅠ and 2a fibres decreased significantly(P<0.05),and MyHC2b fibres increased remarkably(P<0.05),no difference between breeds was observed during early postnatal growth;(3)after D90,the content of MyHC 2b in-creased rapidly and the strain difference was displayed with significantly higher proportion of MyHCⅠ and 2a fibres in Erhulian pigs as compared with Large White pigs at the same age;(4)no sex differences in the developmental pattern of the proportion of MyHCⅠ in Erhualian pigs were found in general,except D90 and D180,when the proportion of MyHC2b fibres was higher in females than in males at the same age(P<0.05).The results suggest that the strain differences in the composition of myofibres in LD muscle appear after D90,the remarkably decreased MyHCⅠ fibres and increased MyHC2b fibres contributes to the fast muscle deposition as well as the accelerated body growth in Large White pigs,while the higher proportion of MyHCⅠ and 2a fibres corresponds to better meat quality in Erhulian pigs.

关 键 词：大白猪 日龄 背最长肌 二花脸猪 发育性变化 品种 肌纤维 HC 性别特点 表达 

分 类 号：R739.91[医药卫生—肿瘤] S828[医药卫生—临床医学]