Transcriptomics of rat born to dams fed a diet deficient in methyl group donors

It is clearly established that the maternal diet during pregnancy can induce physiological and metabolic adaptations in the developing fetus which determine its susceptibility later in life to develop diabetes, obesity... The molecular and genomic mechanisms underlying the programming of the metabolic syndrome remain largely unknown but may involve resetting of epigenetic marks and fetal gene expression. We analyzed the profile of the liver transcriptome in 21-day-old rats born to mothers fed with a standard diet or a diet lacking methyl donor nutrients (Vitamin B12 and folates) during gestation and lactation. From a total of 44,000 probes for 26,456 genes, we found two gene clusters whose expression levels had statistically significant differences between control and deficient rats: 3,269 up-regulated and 2,841 down-regulated genes. Bioinformatics analysis revealed that these genes are mainly involved in glucose and lipid metabolism, nervous system, coagulation, endoplasmic reticulum (ER) stress and mitochondrial function.已有明确研究证实，孕妇妊娠期的饮食可对发育中的胎儿产生生理与代谢层面的适应性改变，进而决定其成年后罹患糖尿病、肥胖症等疾病的易感性。介导代谢综合征编程效应的分子与基因组机制目前仍未完全阐明，但其可能涉及表观遗传标记与胎儿基因表达的重编程过程。本研究对21日龄大鼠的肝脏转录组（liver transcriptome）谱进行了分析，受试大鼠的母鼠在妊娠期与哺乳期分别饲喂标准饲料或缺乏甲基供体营养素（维生素B12与叶酸）的饲料。本次分析针对26456个基因共设计了44000个探针，最终发现对照组与营养素缺乏组大鼠存在两个表达水平具有统计学显著差异的基因簇，其中包含3269个上调表达基因与2841个下调表达基因。生物信息学（Bioinformatics）分析显示，上述差异基因主要参与糖脂代谢、神经系统功能、凝血过程、内质网（ER）应激以及线粒体功能相关的生物学过程。