Department of Animal Science, University of Connecticut, Storrs, CT 06269, USA.
Department of Animal Sciences, North Dakota State University, Fargo, ND 58105, USA.
J Anim Sci. 2021 Dec 1;99(12). doi: 10.1093/jas/skab299.
Maternal nutrient restriction during gestation adversely affects offspring growth and development of liver and skeletal muscle tissues. Realimentation following nutrient restriction may alleviate these negative impacts on development but may alter metabolism and tissue composition. Forty-eight ewes, pregnant with singletons, were fed to meet 100% National Research Council (NRC) recommendations starting at the beginning of gestation. On day 50 of gestation, seven ewes were euthanized (BASE), and fetal liver, skeletal muscles, and blood samples were collected. The remaining animals were fed either 100% of NRC recommendations (CON) or 60% NRC recommendations (RES), a subset were euthanized at day 90 of gestation (n = 7/treatment), and fetal samples were collected. Remaining ewes were maintained on the current diet (CON-CON, n = 6; RES-RES, n = 7) or switched to the alternate diet (CON-RES, RES-CON; n = 7/treatment). On day 130 of gestation, the remaining ewes were euthanized, and fetal samples were collected. At day 130 of gestation, maternal nutrient restriction during late-gestation (RES-RES and CON-RES) decreased fetal liver weight (P < 0.01) and cross-sectional area in triceps brachii (P = 0.01; TB), longissimus dorsi (P = 0.02; LM), and semitendinosus (P = 0.05; STN) muscles. Maternal nutrient restriction during mid-gestation increased hepatocyte vacuole size at day 130 of gestation. Late-gestational maternal nutrient restriction increased mRNA expression of insulin-like growth factor (IGF) binding protein-1 (P < 0.01), glycogen synthase 2 (P = 0.01; GYS2), and pyruvate dehydrogenase kinase 1 (P < 0.01; PDHK1) in the liver and IGF receptor 1 (P = 0.05) in the LM. Lipid concentration in the LM was decreased by late-gestational nutrient restriction (P = 0.01) and increased by mid-gestational nutrient restriction in STN (P = 0.03) and TB (P < 0.01). Principal component analysis of lipidomics data demonstrated clustering of principal components by day of gestation and elastic net regression identified 50, 44, and 29 lipids that classified the treatments in the fetal liver, LM, and blood, respectively. In conclusion, restricting maternal nutrition impacts fetal liver and muscle morphology, gene expression, and lipid metabolism, whereas realimentation attenuated some of these effects. Therefore, realimentation may be a viable strategy to reduce the impacts of nutrient restriction, but can lead to alterations in lipid metabolism in sheep.
孕期母体营养限制会对后代的肝脏和骨骼肌组织的生长和发育产生不利影响。营养限制后的再营养可能会减轻对发育的这些负面影响，但可能会改变代谢和组织组成。48 只怀孕单胎的母羊从妊娠开始就按照 100%的国家研究委员会（NRC）建议进行喂养。在妊娠第 50 天，7 只母羊被安乐死（BASE），并采集胎儿肝脏、骨骼肌和血液样本。其余动物分别喂食 100%NRC 推荐量（CON）或 60%NRC 推荐量（RES），一部分在妊娠第 90 天被安乐死（n = 7/处理），并采集胎儿样本。其余母羊继续按当前饮食喂养（CON-CON，n = 6；RES-RES，n = 7）或切换到替代饮食（CON-RES，RES-CON；n = 7/处理）。在妊娠第 130 天，其余母羊被安乐死，并采集胎儿样本。在妊娠第 130 天，晚期妊娠期间的母体营养限制（RES-RES 和 CON-RES）降低了胎儿肝脏重量（P < 0.01）和三头肌（P = 0.01；TB）、背最长肌（P = 0.02；LM）和半腱肌（P = 0.05；STN）的横截面积。妊娠中期的母体营养限制增加了妊娠第 130 天的肝细胞空泡大小。晚期妊娠期间的母体营养限制增加了肝脏中胰岛素样生长因子（IGF）结合蛋白-1（P < 0.01）、糖原合酶 2（P = 0.01；GYS2）和丙酮酸脱氢酶激酶 1（P < 0.01；PDHK1）的 mRNA 表达，以及 LM 中的 IGF 受体 1（P = 0.05）。晚期妊娠期间的母体营养限制降低了 LM 中的脂质浓度（P = 0.01），并增加了 STN（P = 0.03）和 TB（P < 0.01）中的中期妊娠期间的母体营养限制。脂质组学数据的主成分分析表明，主成分按妊娠天数聚类，弹性网络回归确定了 50、44 和 29 种脂质，分别在胎儿肝脏、LM 和血液中对处理进行分类。总之，限制母体营养会影响胎儿肝脏和肌肉的形态、基因表达和脂质代谢，而再营养则减轻了这些影响。因此，再营养可能是减轻营养限制影响的可行策略，但会导致绵羊脂质代谢的改变。
