猪肌红蛋白基因表达的发育性变化及品种、性别特点

试验动物选用生长速度慢的肥胖型猪二花脸猪与生长速度快的瘦肉型猪大白猪，分别于3、20、90、120和180日龄随机屠宰大白猪公猪和二花脸公、母猪各4头，采集背最长肌样品。采用反转录―聚合酶链式反应（RT-PCR）法，以18S rRNA为内标，定量分析背最长肌中肌红蛋白（myoglobin，MB）基因表达的发育性变化，并进行品种和性别间比较。结果显示，两品种猪背最长肌MB mRNA的表达呈现不同的发育模式。3日龄时，MB mRNA 表达无论在大白公猪还是二花脸公猪均处在较低水平，之后两品种出现分歧。大白猪3日龄后MB mRNA 表达无显著变化；而二花脸在20日龄有显著的升高（P<0.01），之后维持此高水平表达。因此，两品种3日龄时MB mRNA水平无显著差异，20到180日龄，二花脸公猪显著高于大白公猪（P<0.01或P<0.05）。性别间，二花脸公猪和母猪MB mRNA水平在120日龄前无显著差异，180日龄时二花脸公猪极显著高于母猪（P<0.01）。

Developmental Changes of Myoglobin Gene Expression in Longissimus Dorsi Muscle of Erhualian and Large White Pigs

In present study, the developmental patterns of myoglobin (MB) mRNA expression were compared between Erhualian and Large White boars, Gender difference was also examined in Erhualian pigs. Semi-quantitative RT-PCR was applied to determine the level of MB mRNA. Different developmental patterns were observed in two breeds of pigs. MB mRNA expression was low in both breeds at D3, while divergent trends were followed by different breed of pigs thereafter. No significant changes in MB mRNA expression were observed in Large White boars over the period of investigation, although a higher level was seen at D120. In Erhualian boars, however, the level of MB mRNA increased significantly (P<0.01) from D3 to D20 and stayed high consistently afterwards. As a result, Erhualian boars expressed higher level of MB mRNA in Longissimus Dorsi muscle compared with Large White boars on 20, 90, 120 and 180 days of age. Similar patterns of MB mRNA expression were found in both sexes of Erhualian pigs, except at D180, a remarkable decrease occured to females (P<0.01), resulting in a significant (P<0.01) gender difference at D180 with higher level of MB mRNA expressed in Erhualian boars.