INRA-ENVA, UMR 1198 Biologie du Développement et Reproduction, Domaine de Vilvert, Jouy en Josas, France.
Reproduction. 2011 Jan;141(1):79-89. doi: 10.1530/REP-10-0174. Epub 2010 Oct 6.
Axis specification in mouse is determined by a sequence of reciprocal interactions between embryonic and extra-embryonic tissues so that a few extra-embryonic genes appear as 'patterning' the embryo. Considering these interactions as essential, but lacking in most mammals the genetically driven approaches used in mouse and the corresponding patterning mutants, we examined whether a molecular signature originating from extra-embryonic tissues could relate to the developmental stage of the embryo proper and predict it. To this end, we have profiled bovine extra-embryonic tissues at peri-implantation stages, when gastrulation and early neurulation occur, and analysed the subsequent expression profiles through the use of predictive methods as previously reported for tumour classification. A set of six genes (CALM1, CPA3, CITED1, DLD, HNRNPDL, and TGFB3), half of which had not been previously associated with any extra-embryonic feature, appeared significantly discriminative and mainly dependent on embryonic tissues for its faithful expression. The predictive value of this set of genes for gastrulation and early neurulation stages, as assessed on naive samples, was remarkably high (93%). In silico connected to the bovine orthologues of the mouse patterning genes, this gene set is proposed as a new trait for embryo staging. As such, this will allow saving the bovine embryo proper for molecular or cellular studies. To us, it offers as well new perspectives for developmental phenotyping and modelling of embryonic/extra-embryonic co-differentiation.
在老鼠中，轴的规范是由胚胎和胚胎外组织之间的一系列相互作用决定的，以至于一些胚胎外基因似乎“塑造”了胚胎。考虑到这些相互作用是必不可少的，但在大多数哺乳动物中缺乏，我们使用了在老鼠和相应的模式突变体中使用的基因驱动方法，检查了源自胚胎外组织的分子特征是否与胚胎本身的发育阶段相关，并预测它。为此，我们在着床前阶段（发生原肠胚形成和早期神经胚形成时）对牛胚胎外组织进行了分析，并通过使用先前报道的用于肿瘤分类的预测方法分析了随后的表达谱。一组六个基因（CALM1、CPA3、CITED1、DLD、HNRNPDL 和 TGFB3），其中一半以前与任何胚胎外特征都没有关联，表现出明显的可区分性，并且主要依赖于胚胎组织来实现其准确表达。这组基因对原肠胚形成和早期神经胚形成阶段的预测价值（在未经验证的样本上评估）非常高（93%）。通过与老鼠模式基因的牛同源物进行计算机分析，该基因集被提议作为胚胎分期的新特征。因此，这将允许保存牛胚胎本身进行分子或细胞研究。对我们来说，它还为胚胎/胚胎外共分化的发育表型和建模提供了新的视角。
