INRA, UMR 1198 Biologie du Développement et Reproduction, F-78352 Jouy-en-Josas, France.
Anim Reprod Sci. 2012 Sep;134(1-2):19-28. doi: 10.1016/j.anireprosci.2012.08.007. Epub 2012 Aug 11.
In ruminants, more than 30% of the embryonic loss observed after artificial insemination has an early origin that is coincident with the marked elongation of the conceptus that occurs before implantation. During this developmental phase, physiological interactions are established between the conceptus and the uterus which are essential for the establishment of pregnancy and the elongation process. Our molecular knowledge of elongating conceptuses in cattle has long been focused on its analysis in view of its interactions with the uterus with the elongating stages being defined, like the uterus stages, by days post insemination or conception. The gene clusters reported so far indicate important pathways, some being shared by the non-elongating conceptuses of other mammals. However, to identify the key components of the elongation process - that could be specific to ungulates - new models are needed. Somatic nuclear transfer could be one of them as it provides complementary insights on differentiation beyond the blastocyst stage. Nonetheless, other models are necessary to convert gene lists or networks in elongating phenotypes. This review partly summarizes information on these topics, but data on the impact of the uterus on the elongation process or on the differentiation of the embryonic tissues are reviewed elsewhere.
在反刍动物中，人工授精后观察到的胚胎损失超过 30%，其早期起源与胚胎在着床前明显延长同时发生。在这个发育阶段，胚胎和子宫之间建立了生理相互作用，这对于妊娠的建立和伸长过程至关重要。我们对牛伸长胚胎的分子知识长期以来一直集中在其与子宫的相互作用分析上，伸长阶段与子宫阶段一样，通过授精或受孕后天数来定义。迄今为止报道的基因簇表明了重要的途径，其中一些途径与其他哺乳动物的非伸长胚胎共享。然而，要确定伸长过程的关键组成部分——可能是有蹄类动物特有的，需要新的模型。体细胞核移植可能是其中之一，因为它提供了超越囊胚阶段的分化的补充见解。尽管如此，还需要其他模型来将基因列表或网络转化为伸长表型。这篇综述部分总结了这些主题的信息，但有关子宫对伸长过程或胚胎组织分化影响的数据在其他地方进行了综述。
