Abstract：
In pigs, meat quality depends markedly on the fatty acid (FA) content and composition of the intramuscular fat, which is partly determined by the gene expression in this tissue. The aim of this work was to identify the link between muscle gene expression and its FA composition. In an (Iberian × Duroc) × Duroc backcrossed pig population, we identified modules of co-expressed genes, and correlation analyses were performed for each of them versus the phenotypes, finding four relevant modules. Two of the modules were positively correlated with saturated FAs (SFAs) and monounsaturated FAs (MUFAs), while negatively correlated with polyunsaturated FAs (PUFAs) and the omega-6/omega-3 ratio. The gene-enrichment analysis showed that these modules had over-representation of pathways related with the biosynthesis of unsaturated FAs, the Peroxisome proliferator-activated receptor signalling pathway and FA elongation. The two other relevant modules were positively correlated with PUFA and the n-6/n-3 ratio, but negatively correlated with SFA and MUFA. In this case, they had an over-representation of pathways related with fatty and amino acid degradation, and with oxidative phosphorylation. Using a graphical Gaussian model, we inferred a network of connections between the genes within each module. The first module had 52 genes with 87 connections, and the most connected genes were ADIPOQ, which is related with FA oxidation, and ELOVL6 and FABP4, both involved in FA metabolism. The second module showed 196 genes connected by 263 edges, being FN1 and MAP3K11 the most connected genes. On the other hand, the third module had 161 genes connected by 251 edges and ATG13 was the top neighbouring gene, while the fourth module had 224 genes and 655 connections, and its most connected genes were related with mitochondrial pathways. Overall, this work successfully identified relevant muscle gene networks and modules linked with FA composition, providing further insights on how the physiology of the pigs influences FA composition.
摘要：
在猪中,肉质明显取决于肌内脂肪的脂肪酸（FA）含量和组成，这部分是由该组织中的基因表达决定的。这项工作的目的是确定肌肉基因表达与其FA组成之间的联系。在（伊比利亚×杜洛克）×杜洛克回交的猪种群中，我们确定了共表达基因的模块，并对它们中的每一个与表型进行了相关性分析，找到四个相关模块。其中两个模块与饱和脂肪酸(SFAs)和单不饱和脂肪酸(MUFA)呈正相关,而与多不饱和脂肪酸（PUFA）和omega-6/omega-3比率呈负相关。基因富集分析表明，这些模块与不饱和脂肪酸的生物合成相关的通路过度表达，过氧化物酶体增殖物激活受体信号通路和FA延伸。其他两个相关模块与PUFA和n-6/n-3比值呈正相关,但与SFA和MUFA呈负相关。在这种情况下,他们过度表达了与脂肪和氨基酸降解有关的途径，和氧化磷酸化。使用图形化高斯模型，我们推断了每个模块中基因之间的连接网络。第一个模块有52个基因和87个连接，最相关的基因是ADIPOQ，这与FA氧化有关，ELOVL6和FABP4均参与FA代谢。第二个模块显示了由263条边连接的196个基因，FN1和MAP3K11是最相关的基因。另一方面,第三个模块有161个基因由251个边缘连接，ATG13是顶部相邻基因，第四个模块有224个基因和655个连接，其最相关的基因与线粒体途径有关。总的来说,这项工作成功地确定了与FA组成相关的相关肌肉基因网络和模块，提供有关猪的生理如何影响FA组成的进一步见解。
