Department of Biochemistry, Showa University School of Medicine, Shinagawa-ku, Tokyo 142-8555, Japan,
Department of Bioengineering, School of Engineering, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan.
Zoolog Sci. 2023 Feb;40(1):7-12. doi: 10.2108/zs220058.
Relaxin-like gonad-stimulating peptide (RGP) is a hormone with gonadotropin-like activity in starfish. This study revealed that spawning inducing activity was detected in an extract of brachiolaria larvae of . Spawning inducing activity in the extract was due to RGP (PpeRGP), not 1-methyladenine. The expression of PpeRGP mRNA was also found in brachiolaria. Immunohistochemical observation with specific antibodies for PpeRGP showed that PpeRGP was distributed in the peripheral adhesive papilla of the brachiolaria arms. In contrast, PpeRGP was not detected in the adult rudiment or ciliary band regions, which are present in the neural system. These findings strongly suggest that RGP exists in the larvae before metamorphosis. Because gonads are not developed in starfish larvae, it seems likely that RGP plays another role other than gonadotropic action in the early development of starfish.
类松弛素性腺刺激肽（RGP）是一种在海星中具有促性腺激素样活性的激素。本研究表明，在短腕幼虫提取物中检测到了产卵诱导活性。提取物中的产卵诱导活性归因于 PpeRGP（PpeRGP），而不是 1-甲基腺嘌呤。PpeRGP mRNA 的表达也在短腕幼虫中发现。用 PpeRGP 的特异性抗体进行免疫组织化学观察表明，PpeRGP 分布在短腕幼虫臂的外周黏附乳头中。相比之下，在神经系中存在的成虫原基或纤毛带区域中未检测到 PpeRGP。这些发现强烈表明 RGP 存在于变态前的幼虫中。由于海星幼虫中没有性腺发育，因此 RGP 在海星的早期发育中可能发挥着除促性腺作用以外的其他作用。
