Department of Animal Science, College of Agriculture and Natural Resources, Michigan State University, East Lansing, MI 48824, USA.
Department of Animal Science, College of Agriculture and Natural Resources, Michigan State University, East Lansing, MI 48824, USA; Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA.
Domest Anim Endocrinol. 2021 Jan;74:106577. doi: 10.1016/j.domaniend.2020.106577. Epub 2020 Oct 8.
Changes in maternal nutrition during pregnancy can result in profound effects on placental function and fetal development. Although the preconceptional period holds the potential to reprogram embryonic and placental development, little is known regarding the effects of premating nutritional manipulation on placental function and fetal and postnatal offspring growth. To test this, Polypay-Dorset sheep (n = 99) were assigned to 1 of 3 nutritional treatments (n = 33/treatment) receiving 50% (UN: undernutrition), 100% (C: control), or 200% (ON: overnutrition) of maintenance energy requirements for 21 d before mating during April-May (increasing photoperiod). Thereafter, diets were the same across groups. We evaluated maternal reproductive variables and maternal and offspring weight and body mass index through weaning. Maternal plasma was collected through pregnancy until postnatal day 1 to assay pregnancy-associated glycoproteins (PAGs) and progesterone. Fertility rate was similar among treatments, but ON females had a higher reproductive rate (UN: 82%; C: 100%, ON: 145%). When correcting by total birth weight, twin pregnancies had lower PAGs and progesterone versus singleton pregnancies (P < 0.001). At birth, UN lambs were heavier than C lambs regardless of birth type (P < 0.01). Growth velocity, daily gain, and weaning weight were similar, but UN and ON females grew faster and were heavier at weaning versus C females. We demonstrated that a 3-wk preconceptional maternal undernutrition or overnutrition, when correcting by total birth weight, results in lower endocrine capacity in twin pregnancies. Preconceptional maternal undernutrition and overnutrition increased postnatal female lamb growth, suggestive of reprogramming of pathways regulating growth before conception. This highlights how preconceptional nutrition can result in marked sex-specific differences.
妊娠期间母体营养的变化可能会对胎盘功能和胎儿发育产生深远影响。虽然受孕前阶段有可能重新编程胚胎和胎盘的发育，但对于配种前营养干预对胎盘功能以及胎儿和产后后代生长的影响知之甚少。为了检验这一点，我们将 99 只 Polypay-Dorset 绵羊（n = 99）分配到 3 种营养处理组中的 1 种（n = 33/处理组），在 4-5 月（光照时间增加）配种前 21 天接受 50%（UN：营养不良）、100%（C：对照）或 200%（ON：营养过剩）的维持能量需求。此后，各组的饮食相同。我们通过断奶评估了母体生殖变量以及母羊和后代的体重和体重指数。在妊娠期间直至产后第 1 天采集母体血浆，以测定妊娠相关糖蛋白（PAG）和孕酮。在处理组中，受孕率相似，但 ON 组的繁殖率更高（UN：82%；C：100%，ON：145%）。当按总出生体重校正时，双胎妊娠的 PAG 和孕酮低于单胎妊娠（P < 0.001）。在出生时，UN 羔羊的体重比 C 羔羊重，无论出生类型如何（P < 0.01）。生长速度、日增重和断奶体重相似，但 UN 和 ON 组的母羊在断奶时比 C 组的母羊生长更快、体重更重。我们表明，在按总出生体重校正时，受孕前 3 周的母体营养不良或营养过剩会导致双胎妊娠的内分泌能力降低。受孕前母体营养不良和营养过剩增加了产后雌性羔羊的生长，表明在受孕前重新编程了调节生长的途径。这突出表明受孕前的营养可以导致明显的性别特异性差异。
