Key Laboratory of Swine Genetics and Breeding, Ministry of Agriculture and Key Lab of Agriculture Animal Genetics, Breeding and Reproduction, Ministry of Education, Beijing, People's Republic of China.
Mol Biol Rep. 2011 Apr;38(4):2619-32. doi: 10.1007/s11033-010-0403-9. Epub 2010 Nov 17.
Six1 belongs to the Six gene family that includes six members in mammals (from Six1 to Six6). It has been demonstrated that Six1 homeodomain transcription factor is implicated in myogenesis. However, the molecular characteristics of Six1 in pigs have not been reported. In this study, we isolated and characterized the porcine Six1 gene full-length cDNA, genomic DNA and proximal promoter sequence. Semi-quantitative RT-PCR results confirmed that porcine Six1 was highly expressed in skeletal muscle. Real-time quantitative PCR results showed that porcine Six1 was highly expressed in embryonic stage and no significant expression differences is observed between Meishan and Yorkshire pigs. Furthermore, Six1 expression was significantly different among different developmental stages in Yorkshire pigs and the expression trend was up-regulated from 3 days to 180 days, reaching its highest expression level at 180 days. In addition, the data of Six1 expression in different muscles demonstrated that Six1 was a fast-twitch muscle high expression gene. PCR-HindII-RFLP was established to detect a C/T mutation and an A/G mutation which were present in promoter and intron, respectively. Meanwhile, their associations with economic traits were assessed in Meishan × Yorkshire F2 reference family. The statistical results revealed that the two HindII polymorphisms of porcine Six1 had significant associations with several meat quality traits (P<0.05). Taken together, these studies suggest that porcine Six1 may play an important role in skeletal muscle growth and meat quality.
Six1 属于 Six 基因家族，该家族在哺乳动物中包含六个成员（从 Six1 到 Six6）。已经证明 Six1 同源结构域转录因子与肌发生有关。然而，猪 Six1 的分子特征尚未报道。在这项研究中，我们分离并鉴定了猪 Six1 基因全长 cDNA、基因组 DNA 和近端启动子序列。半定量 RT-PCR 结果证实，猪 Six1 在骨骼肌中高度表达。实时定量 PCR 结果表明，猪 Six1 在胚胎期表达量较高，梅山猪和约克夏猪之间没有显著的表达差异。此外，约克夏猪不同发育阶段的 Six1 表达存在显著差异，表达趋势从 3 天到 180 天呈上调趋势，在 180 天达到最高表达水平。此外，Six1 在不同肌肉中的表达数据表明，Six1 是一种快肌高表达基因。建立了 PCR-HindII-RFLP 来检测启动子和内含子中分别存在的 C/T 突变和 A/G 突变。同时，在梅山猪×约克夏 F2 参考家系中评估了它们与经济性状的关联。统计结果表明，猪 Six1 的两个 HindII 多态性与几种肉质性状显著相关（P<0.05）。综上所述，这些研究表明猪 Six1 可能在骨骼肌生长和肉质方面发挥重要作用。
