Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Passeig Marítim de la Barceloneta, 37-49, 08003 Barcelona, Spain
Departament de Genètica, Microbiologia i Estadística, Institut de Recerca de la Biodiversitat, Universitat de Barcelona, Avinguda Diagonal 643, 08028 Barcelona, Spain.
Development. 2020 Dec 3;147(23):dev192575. doi: 10.1242/dev.192575.
Almost all animals undergo embryonic development, going from a single-celled zygote to a complex multicellular adult. We know that the patterning and morphogenetic processes involved in development are deeply conserved within the animal kingdom. However, the origins of these developmental processes are just beginning to be unveiled. Here, we focus on how the protist lineages sister to animals are reshaping our view of animal development. Most intriguingly, many of these protistan lineages display transient multicellular structures, which are governed by similar morphogenetic and gene regulatory processes as animal development. We discuss here two potential alternative scenarios to explain the origin of animal embryonic development: either it originated concomitantly at the onset of animals or it evolved from morphogenetic processes already present in their unicellular ancestors. We propose that an integrative study of several unicellular taxa closely related to animals will allow a more refined picture of how the last common ancestor of animals underwent embryonic development.
几乎所有动物都经历胚胎发育，从单细胞受精卵发育为复杂的多细胞成体。我们知道，发育过程中的模式形成和形态发生过程在动物界中是高度保守的。然而，这些发育过程的起源才刚刚开始被揭示。在这里，我们关注的是动物姐妹原生生物如何重塑我们对动物发育的看法。最有趣的是，许多这些原生生物谱系表现出短暂的多细胞结构，这些结构受类似于动物发育的形态发生和基因调控过程的控制。我们在这里讨论了两个潜在的替代方案来解释动物胚胎发育的起源：它要么是在动物出现的同时起源的，要么是从它们单细胞祖先中已经存在的形态发生过程进化而来的。我们提出，对几种与动物密切相关的单细胞分类群进行综合研究，将使我们更清楚地了解动物的最后共同祖先是如何经历胚胎发育的。
