Lambo Colleen A, Edwards Ashley K, Bazer Fuller W, Dunlap Kathrin, Satterfield M Carey
1Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences Texas A&M University, College Station, TX 77843 USA.
2Department of Animal Science, Texas A&M University, 2471 TAMU, College Station, TX 77843 USA.
J Anim Sci Biotechnol. 2020 May 14;11:48. doi: 10.1186/s40104-020-00454-1. eCollection 2020.
In recent decades, there has been a growing interest in the impact of insults during pregnancy on postnatal health and disease. It is known that changes in placental development can impact fetal growth and subsequent susceptibility to adult onset diseases; however, a method to collect sufficient placental tissues for both histological and gene expression analyses during gestation without compromising the pregnancy has not been described. The ewe is an established biomedical model for the study of fetal development. Due to its cotyledonary placental type, the sheep has potential for surgical removal of materno-fetal exchange tissues, i.e., placentomes. A novel surgical procedure was developed in well-fed control ewes to excise a single placentome at mid-gestation.
A follow-up study was performed in a cohort of nutrient-restricted ewes to investigate rapid placental changes in response to undernutrition. The surgery averaged 19 min, and there were no viability differences between control and sham ewes. Nutrient restricted fetuses were smaller than controls (4.7 ± 0.1 kg vs. 5.6 ± 0.2 kg; < 0.05), with greater dam weight loss (- 32.4 ± 1.3 kg vs. 14.2 ± 2.2 kg; < 0.01), and smaller placentomes at necropsy (5.7 ± 0.3 g vs. 7.2 ± 0.9 g; < 0.05). Weight of sampled placentomes and placentome numbers did not differ.
With this technique, gestational studies in the sheep model will provide insight into the onset and complexity of changes in gene expression in placentomes resulting from undernutrition (as described in our study), overnutrition, alcohol or substance abuse, and environmental or disease factors of relevance and concern regarding the reproductive health and developmental origins of health and disease in humans and in animals.
近几十年来，孕期不良影响对产后健康和疾病的作用日益受到关注。众所周知，胎盘发育的变化会影响胎儿生长以及成年后患疾病的易感性；然而，尚未有在不影响妊娠的情况下，在孕期收集足够的胎盘组织用于组织学和基因表达分析的方法。母羊是研究胎儿发育的成熟生物医学模型。由于其子叶型胎盘，绵羊有可能通过手术切除母胎交换组织，即胎盘小叶。在营养良好的对照母羊中开发了一种新的手术程序，以在妊娠中期切除单个胎盘小叶。
对一组营养受限的母羊进行了一项随访研究，以调查其对营养不良的快速胎盘变化。手术平均耗时19分钟，对照母羊和假手术母羊之间的生存能力没有差异。营养受限的胎儿比对照组小（4.7±0.1千克对5.6±0.2千克；P<0.05），母羊体重减轻更多（-32.4±1.3千克对14.2±2.2千克；P<0.01），尸检时胎盘小叶更小（5.7±0.3克对7.2±0.9克；P<0.05）。采样胎盘小叶的重量和胎盘小叶数量没有差异。
通过这项技术，绵羊模型中的妊娠研究将深入了解营养不良（如我们研究中所述）、营养过剩、酒精或药物滥用以及与人类和动物生殖健康及健康与疾病发育起源相关且令人关注的环境或疾病因素导致的胎盘小叶基因表达变化的起始和复杂性。
