不同品种猪肌内脂肪合成代谢相关基因表达水平的研究

Study of intramuscular fat synthesis metabolism related genes expression level in the different varieties of pigs

为了研究肌内脂肪与脂类合成代谢相关基因的关系,试验采用荧光定量PCR的方法检测了8头乌金猪和6头长白猪背最长肌脂肪酸合成酶（FAS）、固醇调节元件结合蛋白1c（SREBP-1c）和硬脂酰CoA去饱和酶（SCD）基因mRNA相对表达量,同时采用索氏提取法检测背最长肌肌内脂肪含量,并对两者进行相关性分析。结果表明：乌金猪FAS基因mRNA相对表达量极显著高于长白猪（P〈0.01）;SCD基因mRNA相对表达量显著高于长白猪（P〈0.05）;SREBP-1c基因mRNA相对表达量虽然高于长白猪,但差异不显著（P〉0.05）。乌金猪背最长肌肌内脂肪含量高于长白猪,且差异显著（P〈0.05）。乌金猪和长白猪的FAS和SCD基因mRNA相对表达量都与肌内脂肪含量呈极显著正相关（P〈0.01）;乌金猪SREBP-1c基因mRNA相对表达量与肌内脂肪含量呈极显著正相关（P〈0.01）,长白猪SREBP-1c基因mRNA相对表达量与肌内脂肪含量呈显著正相关（P〈0.05）。说明脂肪酸合成关键基因的mRNA相对表达量在乌金猪和长白猪间存在品种差异,这种差异可能是肌内脂肪含量不同的主要原因之一。

The aim of the present study was to investigate the relationship between intramuscular fat （IMF） and lipid metabolism related genes. The relative expression levels of fatty acid synthase （ FAS）, sterol regulatory element binding protein 1c （ SREBP- 1c ） and stearoyl -CoA desaturase （SCD） mRNA in longissimus dorsi muscle of 8 Wujin pigs and 6 Landrace pigs was detected by real-time PCR. At the same time, the IMF content of longissimus dorsi muscle was detected by Soxhlet extraction method, and the correlation between them was analyzed. The results showed that the relative expression level of FAS mRNA in Wujin pig was significantly higher than that in Landrace pig （ P〈0. 01 ）. The relative expression level of SCD mRNA was significantly higher than that of Landrace （P〈0.05）. The relative expression level of SREBP-1 c mRNA was higher in Wujin pigs than that in Landrace pigs, but the difference was not significant （P〉0. 05）. The intra muscular fat content of longis- simus dorsi in wujin pigs was higher than that in Landrace pigs, and the difference was significant （P〈0. 05）. The mRNA expression levels of FAS and SCD genes in Wujin and Landrace pigs were positively correlated with IMF content （P〈0. 01 ）. The relative expression level of SREBP-1c mRNA in Wujin pig was positively correlated with IMF content （P〈 0.01 ）. There was a significant positive correlation between SREBP-1c mRNA expression level and IMF content in Landrace pigs （P〈0. 05 ）. The results indicated that the relative mRNA expression level of the key genes of fatty acid synthesis was different between Wujin and Landrace pigs, and the difference might be one of the main reasons for the difference of IMF content.