Systematic comparison of sea urchin and sea star developmental gene regulatory networks explains how novelty is incorporated in early development.
Systematic comparison of sea urchin and sea star developmental gene regulatory networks explains how novelty is incorporated in early development.
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DOI：
10.1038/s41467-020-20023-4
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发表时间：
2020-12-04
影响因子：
16.6
通讯作者：
Hinman VF
中科院分区：
文献类型：
--
作者：
Cary GA;McCauley BS;Zueva O;Pattinato J;Longabaugh W;Hinman VF
动物分类群中广泛的形态多样性是数百万年进化的产物。形态学是发育的产物，因此表型进化源于控制胚胎发生高度协调过程的基因调控网络（grn）拓扑结构的变化。理解动物多样性起源的一个特殊挑战在于确定grn如何在保持网络整体稳定性的同时结合新颖性，从而保持胚胎生存能力。在这里，我们收集了海星从受精卵到原肠胚形成的内胚层规范的综合GRN，对应于海胆发育的等效区域和阶段的GRN。grn的比较确定了新颖性是如何被纳入早期开发的。我们展示了GRN如何适应转录因子pmar1的引入，pmar1的包含导致两种稳定的Delta-Notch信号模式之间的切换。信号通路可以在多种模式下发挥作用，我们提出导致模式切换的GRN变化可能是胚胎发生变化的共同进化机制。我们的数据还提出了一个模型，其中进化上保守的网络基序或内核可能在整个发育过程中发挥作用，以稳定这些信号转换。目前尚不清楚基因调控网络（GRN）如何在保持整体稳定性的同时整合新颖性。在这里，作者提供了海星从合子阶段到原肠胚形成的内胚层规范的全面GRN，表明保守的网络核稳定了信号模式的进化变化。
The extensive array of morphological diversity among animal taxa represents the product of millions of years of evolution. Morphology is the output of development, therefore phenotypic evolution arises from changes to the topology of the gene regulatory networks (GRNs) that control the highly coordinated process of embryogenesis. A particular challenge in understanding the origins of animal diversity lies in determining how GRNs incorporate novelty while preserving the overall stability of the network, and hence, embryonic viability. Here we assemble a comprehensive GRN for endomesoderm specification in the sea star from zygote through gastrulation that corresponds to the GRN for sea urchin development of equivalent territories and stages. Comparison of the GRNs identifies how novelty is incorporated in early development. We show how the GRN is resilient to the introduction of a transcription factor, pmar1, the inclusion of which leads to a switch between two stable modes of Delta-Notch signaling. Signaling pathways can function in multiple modes and we propose that GRN changes that lead to switches between modes may be a common evolutionary mechanism for changes in embryogenesis. Our data additionally proposes a model in which evolutionarily conserved network motifs, or kernels, may function throughout development to stabilize these signaling transitions. It is unclear how a gene regulatory network (GRN) incorporates novelty whilst still maintaining overall stability. Here, the authors provide a comprehensive GRN for endomesoderm specification in the sea star from zygote stage to gastrulation, showing conserved network kernels stabilize evolutionary changes in signaling modes.