Li Qinggang, Wang Zhixiu, Zhang Bo, Lu Yunfeng, Yang Yuzeng, Ban Dongmei, Wu Changxin, Zhang Hao
National Engineering Laboratory For Animal Breeding, China Agricultural University, No. 2 Yuanmingyuan West Rd., Beijing, 100193, China,
Lipids. 2014 Oct;49(10):1047-55. doi: 10.1007/s11745-014-3928-1. Epub 2014 Jul 9.
Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A) is a candidate gene for lean meat production because it plays a key role in lipid metabolism. In this study, SNPs within the porcine PPARGC1A gene were investigated using PCR-sequencing and PCR-RFLP. Quantitative real-time PCR and Western blot were then used to analyze mRNA and protein expression in longissimus dorsi muscle (LM), liver, and backfat tissues of Dianna small-ear pigs (DSP, n = 6), Tibetan pigs (TP, n = 6), and large white pigs (LW, n = 6). Five novel SNPs (g.-1269A>G in the 5'-upstream regulatory region; g.190C>T, g.218C>A and g.234C>A in exon 8; and g.20C>T in intron 10) and three previously identified SNPs (g.417A>T in exon 8; g.56C>A in exon 9; and g.34G>A in intron 9) were found. Of these, only two, g.-1269A>G and g.234C>A, had three different genotypes in the three breeds (DSP, n = 63; TP, n = 51; and LW, n = 52). Expression was highest in LM, modest in the liver, and minimal in backfat. In LM tissue, LW had higher mRNA and protein levels than DSP and TP (P < 0.05), and there was a negative correlation between gene expression and intramuscular fat (IMF) content. LW had numerically higher expression in liver and backfat tissues than DSP and TP, and the differences in protein levels were significant (P < 0.05 in liver, P < 0.01 in backfat). In conclusion, PPARGC1A may play a key role in down-regulating lipid deposition, and the SNPs with differential genotype distribution among the three pig breeds may be related to gene expression and fat deposition.
过氧化物酶体增殖物激活受体γ共激活因子1α（PPARGC1A）是瘦肉生产的候选基因，因为它在脂质代谢中起关键作用。在本研究中，使用PCR测序和PCR-RFLP技术对猪PPARGC1A基因内的单核苷酸多态性（SNP）进行了研究。然后，采用定量实时PCR和蛋白质印迹法分析了滇南小耳猪（DSP，n = 6）、藏猪（TP，n = 6）和大白猪（LW，n = 6）的背最长肌（LM）、肝脏和背膘组织中的mRNA和蛋白质表达。发现了5个新的SNP（5'-上游调控区的g.-1269A>G；外显子8中的g.190C>T、g.218C>A和g.234C>A；以及内含子10中的g.20C>T）和3个先前已鉴定的SNP（外显子8中的g.417A>T；外显子9中的g.56C>A；以及内含子9中的g.34G>A）。其中，只有g.-1269A>G和g.234C>A在三个品种（DSP，n = 63；TP，n = 51；LW，n = 52）中具有三种不同的基因型。表达在LM中最高，在肝脏中适中，在背膘中最低。在LM组织中，LW的mRNA和蛋白质水平高于DSP和TP（P < 0.05），并且基因表达与肌内脂肪（IMF）含量之间存在负相关。LW在肝脏和背膘组织中的表达在数值上高于DSP和TP，并且蛋白质水平的差异具有显著性（肝脏中P < 0.05，背膘中P < 0.01）。综上所述，PPARGC1A可能在下调脂质沉积中起关键作用，并且在三个猪品种中具有不同基因型分布的SNP可能与基因表达和脂肪沉积有关。
