瘦素受体对苏钟猪脂肪沉积调控的影响

Role of leptin receptor in the regulation of fat deposition in Suzhong pigs

[目的]研究瘦素受体(leptin receptor,LEPR)的mRNA表达和编码序列单核苷酸多态性(c SNPs)对猪脂肪沉积性状的影响。[方法]本文旨在利用实时荧光定量PCR(RT-q PCR)方法和免疫印迹方法检测了该基因在高脂猪和低脂猪背最长肌、背膘、心、肝和肾共5种组织样中的mRNA和蛋白表达量,利用直接测序方法检测了LEPR第18外显子c SNPs,并对LEPR表达量、编码序列单核苷酸多态位点与苏钟猪脂肪沉积相关性状进行了关联分析。[结果]RT-q PCR结果表明:LEPR mRNA在这5种组织中均有表达,且差异显著(P<0.05),其中背膘组织中的表达量显著高于其他组织(P<0.05),其次为背最长肌中的表达量,高脂猪的mRNA表达量显著高于低脂猪(P<0.05)。Western blot结果表明,LEPR蛋白在背膘和背最长肌中显著表达,且高脂猪的蛋白表达量显著高于低脂猪(P<0.05),说明猪脂肪沉积量越高,LEPR mRNA和蛋白表达量越高。PCR-sequencing结果表明,在LEPR c DNA的c.2841C>T位点处,T等位基因为脂肪沉积的优势等位基因。[结论]LEPR的表达对苏钟猪脂肪沉积调控有显著影响,其c.2841C>T位点可作为苏钟猪脂肪沉积肉质性状改良育种的分子标记。

[Objectives]The aim of the paper is examine the effect of LEPR mRNA expression and coding single nucleotide polymorphisms on fat deposition traits in Suzhong pigs. [Methods]LEPR mRNA and protein expression was detected in five tissues of longissimus dorsi muscle,backfat,heart,liver and kidney by real-time quantitative PCR（RT-qPCR）and Western blot,cSNPs within exon 18 of LEPR were detected by PCR-sequencing,and association of LEPR expression,polymorphism with fat deposition related traits was analyzed in Suzhong populations. [Results]RT-qPCR results indicated that LEPR mRNA was expressed in all the five tissues with significant differences（P〈0.05）,expression in backfat was higher than expression in any other tissue（P〈0.05）,followed by the expression in longissimus dorsi muscle. LEPR mRNA expression in high-fat pigs was significantly higher than that in low-fat pigs（P〈0.05）. Western blot results demonstrated that LEPR protein was highly expressed in backfat and longissimus dorsi muscle,and LEPR protein expression in high-fat pigs was significantly higher than that in low-fat pigs（P〈0.05）. This suggests that pigs with higher fat deposition have higher LEPR expression of mRNA and protein. In addition,LEPR polymorphism results revealed that T allele seems to have advantageous effects on fat deposition at c.2841C〉T locus. [Conclusions]There is important effect of LEPR expression on fat deposition in Suzhong pigs,and LEPR c.2841C〉T could be a molecular marker for improving fat deposition related pork traits in Suzhong pigs.