BACKGROUND Although retinoic acid (RA) signaling plays a crucial role in the body patterning of chordates, its function in non-chordate invertebrates, other than its mediation of environmental cues triggering metamorphosis in cnidarians, is largely unknown. We investigated the role of RA signaling in the metamorphosis of starfish (Echinodermata). RESULTS We found that exogenous RA treatment induced metamorphosis in starfish larvae. In contrast, inhibitors of RA synthesis and RA receptors suppressed metamorphosis triggered by attachment to a substrate. Gene expressions of the RA signaling component were detected in competent larvae. CONCLUSIONS This study provides insight into the ancestral function of RA signaling, which is conserved in the metamorphosis of cnidarians and starfish.

中文翻译：

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视黄酸信号在海星变态中的作用。

背景尽管视黄酸 (RA) 信号在脊索动物的身体模式中起着至关重要的作用，但它在非脊索动物无脊椎动物中的功能，除了它介导触发刺胞动物变态的环境线索外，在很大程度上是未知的。我们研究了 RA 信号在海星（棘皮动物）变态中的作用。结果 我们发现外源性 RA 处理诱导了海星幼虫的变态。相比之下，RA 合成抑制剂和 RA 受体抑制了由附着于底物引发的变态。在感受态幼虫中检测到 RA 信号成分的基因表达。结论 本研究提供了对 RA 信号的祖先功能的深入了解，该功能在刺胞动物和海星的变态过程中是保守的。