Sexually dimorphic genetic architecture of complex traits in a large-scale F2 cross in pigs
Sexually dimorphic genetic architecture of complex traits in a large-scale F2 cross in pigs
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猪大规模 F2 杂交中复杂性状的性别二态性遗传结构
DOI：
10.1186/s12711-014-0076-2
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发表时间：
2014-11-06
影响因子：
4.1
通讯作者：
Huang, Lusheng
中科院分区：
文献类型：
--
作者：
Cui, Leilei;Zhang, Junjie;Huang, Lusheng
背景：人类和模式生物在各种复杂性状中表现出性别二态性是很常见的。然而，这种现象很少在猪身上进行研究。结果：为了研究猪复杂性状性别二态性的遗传贡献，我们对白杜洛克与二花莲F2杂交的921个个体的213个性状进行了性别分层分析。在研究的213个性状中，有102个在两性之间存在显著差异（q值<0.05），这表明性别是影响猪广泛性状的重要因素。我们比较了这213个性状在男性和女性之间的估计遗传力。其中，肉质性状和脂肪酸组成相关性状在两性间存在显著差异，说明遗传因素影响了两性二态性状的变异。接下来，我们分别在男性和女性中进行了全基因组关联研究（GWAS）；与在包括男性和女性的GWAS中鉴定的关联数量相比，这种方法使我们能够鉴定出13.6%以上的显著性状- snp（单核苷酸多态性）关联。通过比较snp在两性中的等位基因效应，我们鉴定出43个显著的两性二态snp，这些snp与22个性状相关；43个基因座中有41个是常染色体。最显著的性二态基因位点位于6号染色体上9.3 - 10.7 Mb之间，与肌肉色相角和Minolta a*值（反映肉的红色的参数）有关。在血红素合成中起重要作用的附近基因NUDT7是一个强有力的候选基因。结论：本研究表明，性别是影响表型值和改变猪复杂性状遗传变异效应的重要因素；它还强调了在实施GWAS时按性别分层的重要性。
Background:It is common for humans and model organisms to exhibit sexual dimorphism in a variety of complex traits. However, this phenomenon has rarely been explored in pigs.Results:To investigate the genetic contribution to sexual dimorphism in complex traits in pigs, we conducted a sex-stratified analysis on 213 traits measured in 921 individuals produced by a White Duroc × Erhualian F2 cross. Of the 213 traits examined, 102 differed significantly between the two sexes (q value <0.05), which indicates that sex is an important factor that influences a broad range of traits in pigs. We compared the estimated heritability of these 213 traits between males and females. In particular, we found that traits related to meat quality and fatty acid composition were significantly different between the two sexes, which shows that genetic factors contribute to variation in sexual dimorphic traits. Next, we performed a genome-wide association study (GWAS) in males and females separately; this approach allowed us to identify 13.6% more significant trait-SNP (single nucleotide polymorphism) associations compared to the number of associations identified in a GWAS that included both males and females. By comparing the allelic effects of SNPs in the two sexes, we identified 43 significant sexually dimorphic SNPs that were associated with 22 traits; 41 of these 43 loci were autosomal. The most significant sexually dimorphic loci were found to be associated with muscle hue angle and Minolta a* values (which are parameters that reflect the redness of meat) and were located between 9.3 and 10.7 Mb on chromosome 6. A nearby gene i.e. NUDT7 that plays an important role in heme synthesis is a strong candidate gene.Conclusions:This study illustrates that sex is an important factor that influences phenotypic values and modifies the effects of the genetic variants that underlie complex traits in pigs; it also emphasizes the importance of stratifying by sex when performing GWAS.