A 304 bp insertion/deletion mutation in promoter region induces the increase of porcine IDH3β gene expression
A 304 bp insertion/deletion mutation in promoter region induces the increase of porcine IDH3β gene expression
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DOI：
10.1007/s11033-011-0876-1
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发表时间：
2012-02-01
影响因子：
2.8
通讯作者：
Xiong, Yuanzhu
中科院分区：
文献类型：
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作者：
Ren, Zhuqing;Liu, Wanghong;Xiong, Yuanzhu
肥胖猪和瘦肉猪在脂肪代谢/脂肪沉积方面存在明显差异，但表型差异的分子机制尚不清楚。为了了解这一点，我们分析了梅山猪(一个典型的中国地方肥胖品种)和大白猪(一个西方瘦肉猪品种)背脂基因表达的差异。在此，我们克隆了猪IDH3β亚基(IDH3B)和该基因的2447bp5‘-侧翼序列，并测定了其基因组结构。猪IDH3B含有IDH3B(1)、IDH3B(2)和IDH3B(3)三种异构体。实时荧光定量RT-PCR结果显示，西方商品猪、大白猪、长白猪和杜洛克猪背脂中这三种亚型的表达普遍上调，而中国地方猪品种梅山猪和通城猪的背脂中这三种亚型的表达水平较高。在5‘-侧翼区发现了一个304bp的插入/缺失变异。双荧光素酶报告基因分析表明，IDH3B基因的启动子在体外具有比野生型更高的荧光素酶活性。在西方商品猪中检测到AA、AB和BB等位基因，其中A等位基因在西方商品猪中占优势，而在中国地方猪中则以B等位基因占优势。与大白猪一样，AA型梅山猪的IDH3B基因表达水平高于AB型和BB型猪。此外，还对大白9号眉山F2资源群体中的317头猪进行了遗传多样性检测。关联分析表明，AA型猪的臀部背脂厚度高于AB型猪(P<；0.05)或BB型猪。这些结果表明，猪IDH3β基因启动子区域304个碱基的插入突变增加了猪IDH3β转录本的表达，该突变可能成为猪育种中标记辅助选择的候选标记。
Obese and lean pig breeds show obvious differences in adipose metabolism/fat deposition; however, the molecular mechanism underlying phenotype variation remains unknown. In order to understand it, we analyzed the differences of gene expression in backfat between Meishan (a typical Chinese indigenous obese breed) and Large White (a lean Western breed) pigs. Here, we cloned porcine beta subunit of IDH3 (IDH3B) and 2447 bp 5'-flanking sequence of this gene, and determined the genomic structure. Porcine IDH3B contains three isoforms, IDH3B(1), IDH3B(2) and IDH3B(3). Real-time RT-PCR revealed that these three isoforms were prevalently up-regulated in backfat of western commercial pigs, Large White, Landrace and Duroc, compared with Chinese indigenous breeds, Meishan and Tongcheng pigs. A 304 bp insertion/deletion variant was found in the 5'-flanking region. Dual-luciferase reporter assays showed that in vitro the promoter of IDH3B gene with the insertion had higher luciferase activity as compared with the wild type. Three genotypes AA, AB and BB, due to this insertion, were detected, and the frequency of allele A was dominant in western commercial pigs, whereas allele B predominated in Chinese indigenous breeds. IDH3B mRNA expression in Meishan pigs was more abundant with genotype AA than with genotype AB or BB, as in Large White pigs. In addition, the polymorphism was detected in 317 pigs of a Large White 9 Meishan F2 resource population. Association analysis showed that pigs with genotype AA possessed higher backfat thickness at buttocks than those with genotype AB (P < 0.05) or BB. These data suggested that the 304 bp insertion mutation in promoter region increased the expression of porcine IDH3 beta transcripts and this mutation might be a candidate marker for marker assistant selection in swine breeding.