生长抑素基因在猪胃组织中表达发育性变化及品种比较

 选用生长速度快的瘦肉型猪大白猪和生长速度慢的肥胖型猪二花脸作为试验动物 ,用相对定量RT PCR方法 ,研究猪胃体部组织中生长抑素 (somatostatin ,SS)基因表达发育性变化并进行品种间比较。结果表明 ,(1)出生当天两品种猪胃体部组织中SSmRNA表达水平较高 ,但出生后第 3天均出现显著下降 (P <0 .0 5 ) ;(2 )从 3日龄到 30日龄胃体部组织中SSmRNA表达在二花脸猪和大白猪均表现为上升 ,二花脸猪在 90日龄时达到高峰 ,随后下降。而大白猪在 30日龄之后保持相对稳定 ;(3)二花脸猪胃体组织中SSmRNA表达从出生到 90日龄均显著高于大白猪 (P <0 .0 5 ) ,二花脸猪胃体组织中SS表达自 12 0日龄下调 ,12 0～ 180日龄期间大白猪和二花脸猪胃体部SSmRNA表达没有间差异 (P >0 .0 5 )。以上结果提示 ,猪胃体部组织中SS基因表达调控有特定的时序性 ,并且呈现显著的品种差异 ,这是否与胃结构和功能的发育有关 ,还有待进一步研究。

The Developmental Changes of Somatostatin Gene Expression in Gastric Tissue of Erhualian and Largewhite Pigs

In present study, the developmental changes of somatostatin gene expression in gastric tissue were compared between Erhualian and Largewhite pigs. A semi quantitative RT PCR was applied to determine the levels of SS mRNA. The gastric SS mRNA expression was high at birth, followed by a significantly decrease (P<0.05) at 3 days of age (D3) in both breeds of pigs. From D3 to D30, the expression of SS mRNA in gastric tissue exhibited remarkable up regulation in both breeds, after which a strain differnce in the developmental changes of SS mRNA expression was observed: in Erhualian pigs, SS mRNA expression reached a peak at D90, declined thereafter towards D180, in Largewhite pigs, however, the expression of SS mRNA remained constant from D30 onwards. In general, Erhualian pigs expressed higher levels of SS mRNA in gastric tissue compared with Largewhite pigs at the same age. The strain difference were significant from birth to D90, and vanished at D120 and D180. The results suggest that the gastric expression of SS in the pig is regulated following an instinct timetable in a strain specific manner, its relationship with the development of gastric function as well as its interactions with environmental factors needs to be further studied.