Regulation of Metamorphosis by Environmental Cues and Retinoic Acid Signaling in the Lecithotrophic Larvae of the Starfish Astropecten latespinosus
Regulation of Metamorphosis by Environmental Cues and Retinoic Acid Signaling in the Lecithotrophic Larvae of the Starfish Astropecten latespinosus
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环境信号和视黄酸信号对海星卵磷脂幼虫变态的调节
DOI：
10.1086/706039
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Wada Hiroshi
中科院分区：
文献类型：
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作者：
Yamakawa Shumpei;Morino Yoshiaki;Honda Masanao;Wada Hiroshi
海星（棘皮动物）的共同祖先被认为有浮游营养的幼虫，尽管一些物种显示有卵磷脂营养的幼虫，它们在变态之前不进食。此外，一些卵泡营养的paxillosidan幼虫，如Astropecten latespinosus的幼虫，缺乏腕骨臂，这是浮游营养幼虫接受环境信号的感觉器官。在本研究中，我们发现，用栖息地的天然沙子培养晚棘棘刺槐的幼虫，可以促进其变态。我们还发现维甲酸信号通路介导了环境刺激下的变态过程，如浮游营养型幼虫。我们用原位杂交法检测了试剂处理和基因表达分析。外源性视黄酸处理诱导变态，而视黄酸合成抑制剂或视黄酸受体拮抗剂抑制变态。维甲酸信号相关基因在幼芽中表达。综上所述，我们认为接受特定的环境信号对于食油营养幼虫的变态是必需的。许多海洋无脊椎动物有两阶段的生命周期，浮游幼虫和固定的成虫阶段(1)。由于无根成虫的活动受限，在变态过程中，幼虫在合适的环境中定居是至关重要的(2)。因此，浮游生物幼虫通常具有对特定环境线索作出反应的感觉装置(2)。
Common ancestors of starfish (echinoderms) are believed to have planktotrophic larvae, although some species show lecithotrophic larvae, which do not feed before metamorphosis. Furthermore, some lecithotrophic paxillosidan larvae, such as those of Astropecten latespinosus, lack brachiolar arms, the sensory apparatus for the reception of environmental cues in planktotrophic larvae. In this study, we found that the metamorphosis of A. latespinosus was stimulated when larvae were cultured with natural sand from their habitat. We also found that retinoic acid signaling mediated the metamorphosis process upon environmental stimulation, as in planktotrophic larvae. We examined reagent treatments and gene expression analysis by in situ hybridization. Exogenous retinoic acid treatment induced metamorphosis, whereas retinoic acid synthesis inhibitor or antagonist for retinoic acid receptors suppressed metamorphosis. Retinoic acid signalingrelated genes were expressed in juvenile rudiments. In conclusion, we propose that the reception of particular environmental cues is required for the metamorphosis of lecithotrophic larvae.Many marine invertebrates have biphasic life cycles, with planktonic larval and sessile adult phases (1). Because sessile adults have restricted motility, the settling of larvae in suitable environments during metamorphosis is of critical importance (2). Therefore, planktonic larvae usually possess sensory apparatuses to respond to specific environmental cues (2).