The primitive streak and cellular principles of building an amniote body through gastrulation
The primitive streak and cellular principles of building an amniote body through gastrulation
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通过原肠胚形成羊膜体的原始条纹和细胞原理
DOI：
10.1126/science.abg1727
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发表时间：
2021
期刊：
影响因子：
56.9
通讯作者：
Sutherland Ann
中科院分区：
文献类型：
--
作者：
Sheng Guojun;Martinez Arias Alfonso;Sutherland Ann
多能细胞是由受精后不久发生的胚胎分裂产生的。这些细胞通过原肠胚形成过程转化为生物体的可识别轮廓，这赋予它们在新兴坐标系中的谱系和空间身份。在许多灵长类动物的胚胎（如爬行动物、鸟类和哺乳动物）中，原肠胚形成与一种称为原始条纹的短暂结构有关。人类发展也遵循这一模式。在人类中，原始条纹在受精后约14天形成。原始条纹的出现打破了上胚层（一片上皮化的多能细胞）的径向对称性，并被认为象征着人类个性的出现。因此，许多国家已经为受精卵的体外培养建立了14天的法律的限制-这被称为“14天规则”。近年来，多能干细胞已成为研究人类早期发育的细胞和分子机制的一个有前途的体外模型。在这些体外模型中观察到的发育特征的解释需要正确理解动物原肠胚形成的一般和adjacotes原始条纹特别是ADVANCESSIn这篇综述中，我们提供了一个系统发育和个体发育概述的原始条纹及其在介导adjacotes原肠胚形成的作用，我们讨论了基于胚胎干细胞的哺乳动物早期胚胎发生模型对这一标志性结构功能的影响。我们提供的证据表明，原始条纹是不是一个保守的功能，在哺乳动物和鸟类的原始条纹独立进化，通过不同的超细胞机制，导致其形态出现。我们认为，除了介导从多能外胚层的胚层的出现，原肠胚形成主要是一个过程中，胚胎获得一个坐标系来组织其主要细胞的命运和器官和组织的原基相对于彼此在空间。我们强调，这一过程是由一组保守的信号转导和转录网络通过一个小的集合的细胞行为，其中的组织水平的影响是由边界条件的调节。我们认为，不断变化的边界条件，在胚胎外谱系，如滋养外胚层和原始内胚层的进化形式，发挥了关键作用，在改造的胚孔，特征的anabolote胚胎，到原始条纹。这些组织的组织的变异性和胚胎和胚外区域的划分支持了哺乳动物和鸟类原始条纹的形态外观以及爬行动物原始条纹相关结构的观察到的变异。在过去的几年里，胚胎干细胞已被用作模型，以概括早期哺乳动物胚胎发生的几个方面。这些研究表明，胚层，甚至是一个基本的身体计划，可以形成在没有一个原始的streak. OUTLOOK我们的模型预测，最基本的功能，一个原始的条纹状结构在早期胚胎发育不是它的形态表现，而是它的能力，以调解协调细胞命运规范事件的空间。我们的模型还表明，细胞命运的规范和组织水平的形态发生在原肠胚形成过程中独立调节，然后在体内胚胎发育过程中协调。在体外发育模型中，这两个...
BACKGROUNDPluripotent cells are generated by embryonic divisions that occur shortly after fertilization. These cells are transformed into the recognizable outline of an organism through the process of gastrulation, which endows them with lineage and spatial identities in the context of an emerging coordinate system. In many amniote embryos (such as those of reptiles, birds, and mammals), gastrulation has been associated with a transient structure called the primitive streak. Human development also follows this pattern. In humans, the primitive streak forms ~14 days after fertilization. The appearance of the primitive streak breaks the radial symmetry of the epiblast (a sheet of epithelialized pluripotent cells) and has been suggested to symbolize the emergence of human individuality. As such, many countries have established a legal limit of 14 days for the in vitro culture of fertilized human eggs—this is known as the “14-day rule.” In recent years, pluripotent stem cells have become a promising in vitro model for studying the cellular and molecular mechanisms associated with early human development. Interpretation of developmental features observed in these in vitro models requires proper understanding of animal gastrulation in general and of the amniote primitive streak in particular.ADVANCESIn this Review, we offer a phylogenetic and ontogenetic overview of the primitive streak and its role in mediating amniote gastrulation, and we discuss the implications of embryonic stem cell–based models of early mammalian embryogenesis on the function of this iconic structure. We provide evidence that the primitive streak is not a conserved feature in amniote development and that the mammalian and avian primitive streaks have evolved independently through different supracellular mechanisms that led to their morphological emergence. We argue that, in addition to mediating the emergence of germ layers from the pluripotent epiblast, gastrulation is principally a process in which an embryo acquires a coordinate system to organize its primary cell fates and the primordia of organs and tissues relative to each other in space. We highlight that in amniotes this process is regulated by a set of conserved signaling and transcriptional networks through a small collection of cellular behaviors, the tissue-level effects of which are governed by boundary conditions. We suggest that changing boundary conditions, in the form of evolution of extraembryonic lineages such as the trophectoderm and primitive endoderm, have played a key role in the transformation of the blastopore, characteristic of anamniote embryos, into the primitive streak. Variability in the organization of these tissues and the demarcation of embryonic and extraembryonic territories underpins the observed variation in the morphological appearance of the primitive streak in mammals and birds and of primitive streak–related structures in reptiles. Over the past few years, embryonic stem cells have been used as models to recapitulate several aspects of early mammalian embryogenesis. These studies have revealed that the germ layers, and even a rudimentary body plan, can form in the absence of a primitive streak.OUTLOOKOur model predicts that the most fundamental feature of a primitive streak–like structure in early amniote development is not its morphological manifestation but rather its capacity to mediate coordinated cell fate specification events in space. Our model also suggests that cell fate specification and tissue-level morphogenesis are regulated independently during gastrulation and then coordinated during embryonic development in vivo. In developmental models in vitro, these two …
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由形态信号中心组织的干细胞的哺乳动物胚胎模型的构建。
影响因子：
16.6
作者：
Xu PF;Borges RM;Fillatre J;de Oliveira-Melo M;Cheng T;Thisse B;Thisse C
通讯作者：
Thisse C
影响因子：
3.7
作者：
Coolen M;Nicolle D;Plouhinec JL;Gombault A;Sauka-Spengler T;Menuet A;Pieau C;Mazan S
通讯作者：
Mazan S
上皮类型、侵入、胚孔结构和脊索动物中胚层形态发生的进化。
DOI：
10.1002/jez.b.21198
发表时间：
2008
期刊：
Journal of experimental zoology. Part B, Molecular and developmental evolution
影响因子：
--
作者：
Shook,DavidR;Keller,Ray
通讯作者：
Keller,Ray
DOI：
10.1159/000147748
发表时间：
1995
期刊：
Acta anatomica
影响因子：
--
作者：
E. Hay
通讯作者：
E. Hay
DOI：
10.1242/dev.111583
发表时间：
2015-01-01
期刊：
Development (Cambridge, England)
影响因子：
--
作者：
Stankova V;Tsikolia N;Viebahn C
通讯作者：
Viebahn C