Fine mapping of a swine quantitative trait locus for number of vertebrae and analysis of an orphan nuclear receptor, germ cell nuclear factor (NR6A1)
Fine mapping of a swine quantitative trait locus for number of vertebrae and analysis of an orphan nuclear receptor, germ cell nuclear factor (NR6A1)
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DOI：
10.1101/gr.6085507
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发表时间：
2007-05-01
期刊：
影响因子：
7
通讯作者：
Awata, Takashi
中科院分区：
文献类型：
--
作者：
Mikawa, Satoshi;Morozumi, Takeya;Awata, Takashi
猪的椎骨数量各不相同，与产肉量有关。野猪是家猪的祖先，有19根脊椎。相比之下，欧洲商业品种的脊椎骨有21-23个，可能是因为为了增加体型而进行的选择性繁殖。我们以前在猪阴囊染色体(SSC)1和7上发现了两个控制椎骨数量的数量性状基因座(QTL)，这些QTL可以解释两个以上椎骨的增加。在这里，我们进行了一项基于图谱的研究，以确定SSC1上的QTL区域。利用3个F-2实验家系进行区间定位和重组分析，确定了1.9 cM区间内的QTL。然后，我们分析了这一区间内微卫星标记的连锁不平衡，发现在欧洲商业品种中，300kb区域内的10个相邻标记几乎是固定的。这些标记的遗传变异在亚洲地方品种或野猪中观察到。该区域编码一种孤儿核受体--生殖细胞核因子(NR6A1，以前称为GCNF)，它含有与QTL一致的氨基酸替换(Pro192Leu)。这种替换改变了NR6A1与其辅阻遏物、核受体相关蛋白80(RAP80)和核受体辅阻遏物1(NCOR1)的结合活性。此外，小鼠胚胎的体节细胞也表达了NR6A1蛋白。综上所述，这些结果表明NR6A1是影响猪椎骨数量的一个QTL的有力候选者。
The number of vertebrae in pigs varies and is associated with meat productivity. Wild boars, which are ancestors of domestic pigs, have 19 vertebrae. In comparison, European commercial breeds have 21-23 vertebrae, probably owing to selective breeding for enlargement of body size. We previously identified two quantitative trait loci (QTL) for the number of vertebrae on Sus scrofa chromosomes (SSC) 1 and 7. These QTL explained an increase of more than two vertebrae. Here, we performed a map-based study to define the QTL region on SSC1. By using three F-2 experimental families, we performed interval mapping and recombination analyses and defined the QTL within a 1.9-cM interval. Then we analyzed the linkage disequilibrium of microsatellite markers in this interval and found that 10 adjacent markers in a 300-kb region were almost fixed in European commercial breeds. Genetic variation of the markers was observed in Asian local breeds or wild boars. This region encoded an orphan nuclear receptor, germ cell nuclear factor (NR6A1, formerly known as GCNF), which contained an amino acid substitution ( Pro192Leu) coincident with the QTL. This substitution altered the binding activity of NR6A1 to its corepressors, nuclear receptor-associated protein 80 (RAP80) and nuclear receptor corepressor 1 (NCOR1). In addition, somites of mouse embryos demonstrated expression of NR6A1 protein. Together, these results suggest that NR6A1 is a strong candidate for one of the QTL that influence number of vertebrae in pigs.