Department of Food and Animal Science, Veterinary School, Universitat Autònoma de Barcelona, Bellaterra, 08193 Spain.
Genet Sel Evol. 2011 Jul 25;43(1):28. doi: 10.1186/1297-9686-43-28.
Endocrine tissues play a fundamental role in maintaining homeostasis of plasma metabolites such as non-esterified fatty acids and glucose, the levels of which reflect the energy balance or the health status of animals. However, the relationship between the transcriptome of endocrine tissues and plasma metabolites has been poorly studied.
We determined the blood levels of 12 plasma metabolites in 27 pigs belonging to five breeds, each breed consisting of both females and males. The transcriptome of five endocrine tissues i.e. hypothalamus, adenohypophysis, thyroid gland, gonads and backfat tissues from 16 out of the 27 pigs was also determined. Sex and breed effects on the 12 plasma metabolites were investigated and associations between genes expressed in the five endocrine tissues and the 12 plasma metabolites measured were analyzed. A probeset was defined as a quantitative trait transcript (QTT) when its association with a particular metabolic trait achieved a nominal P value < 0.01.
A larger than expected number of QTT was found for non-esterified fatty acids and alanine aminotransferase in at least two tissues. The associations were highly tissue-specific. The QTT within the tissues were divided into co-expression network modules enriched for genes in Kyoto Encyclopedia of Genes and Genomes or gene ontology categories that are related to the physiological functions of the corresponding tissues. We also explored a multi-tissue co-expression network using QTT for non-esterified fatty acids from the five tissues and found that a module, enriched in hypothalamus QTT, was positioned at the centre of the entire multi-tissue network.
These results emphasize the relationships between endocrine tissues and plasma metabolites in terms of gene expression. Highly tissue-specific association patterns suggest that candidate genes or gene pathways should be investigated in the context of specific tissues.
内分泌组织在维持非酯化脂肪酸和葡萄糖等血浆代谢物的体内平衡方面发挥着重要作用，这些代谢物的水平反映了动物的能量平衡或健康状况。然而，内分泌组织的转录组与血浆代谢物之间的关系尚未得到充分研究。
我们测定了 27 头猪（包括 5 个品种）的 12 种血浆代谢物的血液水平，每个品种既有雌性又有雄性。还测定了这 27 头猪中的 16 头猪的 5 种内分泌组织（下丘脑、腺垂体、甲状腺、性腺和背脂组织）的转录组。研究了性别和品种对 12 种血浆代谢物的影响，并分析了这 5 种内分泌组织中表达的基因与所测量的 12 种血浆代谢物之间的关联。当与特定代谢特征相关联的探针集的关联达到名义 P 值<0.01 时，定义为定量性状转录物（QTT）。
在至少两种组织中，非酯化脂肪酸和丙氨酸氨基转移酶的 QTT 数量超过预期。这些关联具有高度的组织特异性。组织内的 QTT 分为共表达网络模块，这些模块富含京都基因与基因组百科全书或基因本体论类别中的基因，这些类别与相应组织的生理功能相关。我们还使用来自这 5 种组织的非酯化脂肪酸的 QTT 探索了一个多组织共表达网络，发现一个模块，富含下丘脑的 QTT，位于整个多组织网络的中心。
这些结果强调了内分泌组织与血浆代谢物在基因表达方面的关系。高度组织特异性的关联模式表明，候选基因或基因途径应该在特定组织的背景下进行研究。
