Johnson Gregory A, Minela Thainá, Seo Heewon, Bazer Fuller W, Burghardt Robert C, Wu Guoyao, Pohler Ky G, Stenhouse Claire, Cain Joe W, Seekford Zachary K, Soffa Dallas R
Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA.
Department of Animal Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX 77843, USA.
Biomolecules. 2025 Jul 17;15(7):1037. doi: 10.3390/biom15071037.
Species have different strategies for implantation and placentation. Much can be learned about general molecular and cellular biology through the examination and comparison of these differences. To varying degrees, implantation in all species includes alterations in epithelial polarity, the transformation of the endometrial stroma, the differentiation of the trophoblast, cell-to-cell and tissue-to-tissue signaling through hormones, cytokines, and extracellular vesicles, and the alteration of the maternal immune system. This review focuses on implantation in pigs, sheep, and cows. These species share with mice/rats and humans/primates the key events of early embryonic development, pregnancy recognition, and the establishment of functional placentation. However, there are differences between the pregnancies of livestock and other species that make livestock unique biomedical models for the study of pregnancy and cell biology in general. Pig, sheep, and cow conceptuses (embryo/fetus and associated placental membranes) elongate prior to implantation, displaying central implantation, extended periods of conceptus attachment to the uterus, and epitheliochorial (pigs) and synepitheliochorial (sheep and cows) placentation. This review will discuss what is understood about how the trophoblast and extraembryonic endoderm of pig, sheep, and cow conceptuses elongate, and how a major goal of current in vitro models is to achieve conceptus elongation. It will then examine the adhesion cascade for conceptus implantation that initiates early placental development in pigs, sheep, and cows. Finally, it will conclude with a brief overview of early placental development in pigs, sheep, and cows, with a listing of some important "omics" studies that have been published.
不同物种具有不同的着床和胎盘形成策略。通过对这些差异进行检查和比较，可以了解到许多关于一般分子和细胞生物学的知识。在不同程度上，所有物种的着床都包括上皮极性的改变、子宫内膜基质的转化、滋养层的分化、通过激素、细胞因子和细胞外囊泡进行的细胞间和组织间信号传导，以及母体免疫系统的改变。本综述聚焦于猪、绵羊和牛的着床过程。这些物种与小鼠/大鼠以及人类/灵长类动物一样，都经历早期胚胎发育、妊娠识别和功能性胎盘形成的关键过程。然而，家畜的妊娠与其他物种存在差异，这使得家畜成为研究妊娠和细胞生物学的独特生物医学模型。猪、绵羊和牛的孕体（胚胎/胎儿及相关胎盘膜）在着床前会伸长，呈现中央着床、孕体与子宫长时间附着，以及上皮绒毛膜（猪）和融合上皮绒毛膜（绵羊和牛）胎盘形成。本综述将讨论关于猪、绵羊和牛孕体的滋养层和胚外内胚层如何伸长的已知信息，以及当前体外模型的一个主要目标是如何实现孕体伸长。然后将研究猪、绵羊和牛孕体着床的黏附级联反应，该反应启动早期胎盘发育。最后，将简要概述猪、绵羊和牛的早期胎盘发育，并列出已发表的一些重要的“组学”研究。
