Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand; Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore, Queensland 4558, Australia.
Department of Anatomy, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
Peptides. 2018 Jan;99:231-240. doi: 10.1016/j.peptides.2017.10.008. Epub 2017 Oct 18.
Neuropeptides synthesized and released by neuronal cells play important roles in the regulation of many processes, e.g. growth, feeding, reproduction, and behavior. In the past decade, next-generation sequencing technologies have helped to facilitate the identification of multiple neuropeptide genes in a variety of taxa, including arthropods, molluscs and echinoderms. In this study, we extend these studies to Holothuria scabra, a sea cucumber species that is widely cultured for human consumption. In silico analysis of H. scabra neural and gonadal transcriptomes enabled the identification of 28 transcripts that encode a total of 26 bilaterian and echinoderm-specific neuropeptide precursors. Furthermore, publicly available sequence data from another sea cucumber, Holothuria glaberrima, allowed a more in-depth comparative investigation. Interestingly, two isoforms of a calcitonin-type peptide precursor (CTPP) were deduced from the H. scabra transcriptome - HscCTPP-long and HscCTPP-short, likely the result of alternative splicing. We also identified a sea cucumber relaxin-type peptide precursor, which is of interest because relaxin-type peptides have been shown to act as gonadotropic hormones in starfish. Two neuropeptides that appear to be holothurian-specific are GLRFA, and GN-19. In H. scabra, the expression of GLRFA was restricted to neural tissues, while GN-19 expression was additionally found in the longitudinal muscle and intestinal tissues. In conclusion, we have obtained new insights into the neuropeptide signaling systems of holothurians, which will facilitate physiological studies that may enable advances in the aquaculture of sea cucumbers.
神经元细胞合成和释放的神经肽在许多过程的调节中发挥着重要作用，例如生长、进食、繁殖和行为。在过去的十年中，下一代测序技术帮助鉴定了多种神经肽基因，包括节肢动物、软体动物和棘皮动物。在这项研究中，我们将这些研究扩展到了海参，这是一种广泛用于人类食用的海参。对海参神经和性腺转录组的计算机分析，使我们能够鉴定出 28 种转录本，这些转录本总共编码 26 种两侧对称动物和棘皮动物特异性神经肽前体。此外，从另一种海参，糙海参，获得的公开可用序列数据允许更深入的比较研究。有趣的是，从海参转录本中推断出两种降钙素型肽前体（CTPP）的同工型 - HscCTPP-long 和 HscCTPP-short，这可能是选择性剪接的结果。我们还鉴定了一种海参松弛素型肽前体，这很有趣，因为松弛素型肽已被证明在海星中作为促性腺激素发挥作用。两种似乎是海参特异性的神经肽是 GLRFA 和 GN-19。在海参中，GLRFA 的表达局限于神经组织，而 GN-19 的表达还存在于纵向肌肉和肠组织中。总之，我们对海参的神经肽信号系统有了新的认识，这将有助于生理研究，这可能会促进海参的水产养殖。
