Mechanisms of neuropeptidergic regulation of larval settlement behavior in the marine worm, Platynereis dumerilii

海洋无脊椎动物幼虫的定居和变态是许多动物门生命周期的重要过渡阶段。虽然在许多情况下，这一过程是由神经肽调节的，但这些分子如何在幼虫体内作用，以一种精心定时的方式影响行为和形态变化，仍然是未知的。在这个项目中，我们将探讨幼虫定居行为是如何由拮抗神经肽调节的。我们将研究海洋蠕虫Platynereis dumerilii，在那里我们发现一种保守的神经肽，肌抑制肽（MIP）诱导幼虫定居行为，这种作用被allatotropin/orexin信号拮抗。初步实验表明，MIP通过游离脂肪酸信号诱导幼体纤毛游动细胞内的钙峰，从而强烈抑制纤毛跳动和快速沉降。Allatotropin在MIP信号通路的一个未知点拮抗，阻断MIP信号诱导沉降的作用。我们建议通过结合脂质组学、转录组学、行为和形态学方法来表征这一信号通路。Platynereis系统使我们能够在整个生物体环境中研究详细的分子信号，将特定分子和行为联系起来。

Marine invertebrate larval settlement and metamorphosis is an important transitional stage in the life cycle of several animal phyla. While in many cases this process is regulated by neuropeptides, how these molecules act within larvae to affect behavioral and morphological changes in a carefully timed manner is still unknown. In this project we will explore how larval settlement behavior is regulated by antagonistic neuropeptides. We will study the marine worm, Platynereis dumerilii, where we found that a conserved neuropeptide, myoinhibitory peptide (MIP) induces larval settlement behavior and this effect is antagonized by allatotropin/orexin signaling. Preliminary experiments suggest that MIP signals by free fatty acids to induce calcium spikes in the ciliated swimming cells of the larvae, resulting in a strong inhibition of ciliary beating and rapid settlement. Allatotropin acts antagonistically at an unknown point in the MIP signaling pathway to block the settlement-inducing effects of MIP signaling. We propose to characterize this signaling pathway through a combination of lipidomics, transcriptomics, behavioral and morphological approaches. The Platynereis system allows us to study detailed molecular signaling in a whole-organism context, linking specific molecules and behavior.