Pereiro Luisa, Loosli Felix, Fernández Juan, Härtel Steffen, Wittbrodt Joachim, Concha Miguel L
Anatomy and Developmental Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile.
Karlsruhe Institute of Technology, Institute of Toxicology and Genetics, Karlsruhe, Germany.
Dev Dyn. 2017 Nov;246(11):812-826. doi: 10.1002/dvdy.24496. Epub 2017 Mar 24.
Comparative studies beyond the traditional model organisms have been instrumental in enhancing our understanding of the conserved and derived features of gastrulation, a fundamental process in which the germ layers are specified and shaped to form the body axis. Here, we analyzed gastrulation in a vertebrate group with an extreme mode of early development, the annual killifish.
Gastrulation in annual killifish of the genus Austrolebias takes place after the initially dispersed deep blastomeres congregate to form the so-called reaggregate. Cells from the early reaggregate do not appear to form part of any recognizable axial embryonic structure and are possibly extraembryonic. In contrast, later reaggregate cells become engaged in morphogenetic transformations indicative of a process of gastrulation and axis formation. The expression of brachyury and goosecoid suggests that gastrulation takes place in a compressed blastopore-like structure with an organizer region displaced to one end. No collective cell internalization proper of blastopore architecture is observed, though, and it appears that gastrulation primarily involves the reorganization of individual cells.
The unique mode of gastrulation in annual killifish demonstrates that a process so ancient and fundamental to ontogenesis can have striking morphogenetic variations nonpredicted from the sole examination of model species. Developmental Dynamics 246:812-826, 2017. © 2017 Wiley Periodicals, Inc.
超越传统模式生物的比较研究有助于增进我们对原肠胚形成过程中保守特征和衍生特征的理解，原肠胚形成是一个基本过程，在此过程中胚层得以确定并塑形以形成身体轴线。在此，我们分析了一种具有极端早期发育模式的脊椎动物——一年生鳉鱼的原肠胚形成过程。
澳大利亚鳉属一年生鳉鱼的原肠胚形成发生在最初分散的深层卵裂球聚集形成所谓的再聚集物之后。早期再聚集物中的细胞似乎并未形成任何可识别的轴向胚胎结构的一部分，可能是胚外细胞。相比之下，后期再聚集物中的细胞参与了形态发生转变，这表明存在原肠胚形成和轴线形成过程。短尾相关蛋白（brachyury）和类鹅膏蛋白（goosecoid）的表达表明原肠胚形成发生在一个类似胚孔的压缩结构中，组织者区域位于一端。不过，未观察到胚孔结构特有的集体细胞内陷现象，原肠胚形成似乎主要涉及单个细胞的重组。
一年生鳉鱼独特的原肠胚形成模式表明，这样一个对个体发育如此古老且基本的过程可能具有从仅对模式物种的研究中无法预测的显著形态发生变异。《发育动力学》246:812 - 826，2017年。© 2017威利期刊公司。
