Laboratorio de Endocrinología y Metabolismo Animal, Universidad de la República, Montevideo, Uruguay.
Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana, IL, United States.
Theriogenology. 2020 Apr 1;146:14-19. doi: 10.1016/j.theriogenology.2020.01.047. Epub 2020 Jan 28.
This study investigated the effects of undernutrition and the presence of the conceptus at the time of maternal recognition of pregnancy on the expression of uterine indicators of metabolism in ewes. Adult Rasa Aragonesa ewes were allocated to one of two planes of nutrition for 28 days: maintenance energy intake (control; 5 cyclic and 6 pregnant ewes) providing 7.8 MJ of metabolisable energy, and 0.5 maintenance intake (undernourished; 6 cyclic and 7 pregnant ewes) providing 3.9 MJ of metabolisable energy per ewe. RNA from intercaruncular uterine tissue was harvested at slaughter on Day 14 of estrous cycle or pregnancy, and hybridized to the Agilent 15K Sheep Microarray chip. Functional bioinformatics analyses were performed using PANTHER (Protein ANalysis THrough Evolutionary Relationships) Classification System. The presence of the embryo upregulated expression of genes encoding peptide and monocarboxylate transporters regardless of nutritional treatment, although the degree of gene expression was lower in undernourished ewes. Genes encoding enzymes involved in glycolysis were downregulated both in pregnant control and undernourished ewes, probably as a compensatory mechanism for the increased glucose transport to the uterus. Compared with control cyclic ewes, control pregnant ewes had greater expression of genes involved in oxidation of fatty acids, suggesting increased uterine energy demands. This was not observed in undernourished pregnant animals when compared to undernourished cyclic ewes; nevertheless, those animals had lower uterine expression of enzymes involved in fatty acid biosynthesis. The presence of the embryo upregulated genes involved in electron transport probably as a result of increased energy demands for pregnancy. Overall, the data indicate that depending on the nutritional status of ewe, pregnancy alters gene expression of metabolic pathways related to energy generation in the uterus. An impairment in nutrient transport and metabolism in the uterus of pregnant undernourished ewes may explain the greater embryo mortality associated with undernutrition.
本研究旨在探讨母体识别妊娠时营养不良和胎儿存在对绵羊子宫代谢指标表达的影响。成年拉沙罗萨母羊被分配到两种营养水平中的一种进行 28 天的实验：维持能量摄入（对照组；5 只发情和 6 只妊娠母羊）提供 7.8 MJ 可代谢能量，以及 0.5 维持摄入（营养不良组；6 只发情和 7 只妊娠母羊）提供每只羊 3.9 MJ 可代谢能量。在发情周期或妊娠第 14 天屠宰时采集间子宫组织的 RNA，并与安捷伦 15K 绵羊微阵列芯片杂交。使用 PANTHER（通过进化关系进行蛋白质分析）分类系统进行功能生物信息学分析。无论营养处理如何，胚胎的存在都上调了编码肽和单羧酸转运蛋白的基因表达，尽管在营养不良的母羊中基因表达的程度较低。参与糖酵解的酶基因在妊娠对照组和营养不良组的母羊中均下调，这可能是为了增加葡萄糖向子宫的转运而产生的补偿机制。与对照组发情母羊相比，对照组妊娠母羊中与脂肪酸氧化相关的基因表达更高，这表明子宫对能量的需求增加。然而，在与营养不良的发情母羊相比时，在营养不良的妊娠动物中没有观察到这种情况；尽管如此，这些动物的脂肪酸生物合成相关酶在子宫中的表达较低。胚胎的存在上调了参与电子传递的基因，这可能是由于妊娠对能量的需求增加所致。总的来说，这些数据表明，根据母羊的营养状况，妊娠会改变与子宫能量生成相关的代谢途径的基因表达。妊娠营养不良母羊子宫中营养物质转运和代谢的受损可能解释了与营养不良相关的胚胎死亡率增加的原因。
