Campo-Paysaa Florent, Marlétaz Ferdinand, Laudet Vincent, Schubert Michael
Institut de Génomique Fonctionnelle de Lyon, CNRS UMR5242-INRA 1288-ENS-UCBL, IFR128 BioSciences Lyon-Gerland, Ecole Normale Supérieure de Lyon, Lyon, France.
Genesis. 2008 Nov;46(11):640-56. doi: 10.1002/dvg.20444.
Retinoic acid (RA) is a vitamin A-derived morphogen important for axial patterning and organ formation in developing vertebrates and invertebrate chordates (tunicates and cephalochordates). Recent analyses of genomic data have revealed that the molecular components of the RA signaling cascade are also present in other invertebrate groups, such as hemichordates and sea urchins. In this review, we reassess the evolutionary origins of the RA signaling pathway by examining the presence of key factors of this signaling cascade in different metazoan genomes and by comparing tissue-specific roles for RA during development of different animals. This discussion of genomic and developmental data suggests that RA signaling might have originated earlier in metazoan evolution than previously thought. On the basis of this hypothesis, we conclude by proposing a scenario for the evolution of RA functions during development, which highlights functional gains and lineage-specific losses during metazoan diversification.
视黄酸（RA）是一种源自维生素A的形态发生素，对发育中的脊椎动物和无脊椎动物脊索动物（被囊动物和头索动物）的轴向模式形成和器官形成至关重要。最近对基因组数据的分析表明，RA信号级联的分子成分也存在于其他无脊椎动物类群中，如半索动物和海胆。在这篇综述中，我们通过检查不同后生动物基因组中该信号级联关键因子的存在情况，并比较RA在不同动物发育过程中的组织特异性作用，重新评估RA信号通路的进化起源。对基因组和发育数据的讨论表明，RA信号可能在动物进化中起源的时间比之前认为的更早。基于这一假设，我们通过提出一个RA在发育过程中功能进化的设想来得出结论，该设想突出了后生动物多样化过程中的功能获得和谱系特异性丧失。
