Ecdysone-induced protein 93 (E93) is a metamorphic determinant involved in crosstalk between 20-hydroxyecdysone (20E) and juvenile hormone (JH) during the insect molting process. The present study identified the E93 gene from the swimming crab, P. trituberculatus, and found it was widely distributed in adult tissues. PtE93 mRNA levels in Y-organ and epidermis fluctuated during the molt cycle, suggesting its involvement in juvenile molting. In vitro and in vivo treatments with 20E led to an induction of PtE93 expression in Y-organ and epidermis, while we found the opposite effect for methyl farnesoate (MF) treatments, a crustacean equivalent of insect JH. We also observed that two genes for ecdysteroid biosynthesis, Spook (Spo) and Shadow (Sad), were suppressed by 20E and induced by MF, showing a negative correlation between PtE93 and ecdysteroid biosynthesis. PtE93 RNA interference (RNAi) induced Spo and Sad expression levels, elevated ecdysteroid content in culture medium, and relieved the 20E inhibitory effect on ecdysteroid synthesis, indicating an inhibitory role of PtE93 on ecdysteroid synthesis. Overall, our results suggest that E93 may be involved in the crosstalk between 20E and MF during crustacean molting, and its presence in Y-organ is closely related to ecdysteroid synthesis.

蜕皮激素诱导蛋白 93 (E93) 是一种变态决定因子，参与昆虫蜕皮过程中 20-羟基蜕皮激素 (20E) 和保幼激素 (JH) 之间的串扰。本研究从三疣梭子蟹中鉴定出E93基因，并发现它广泛分布于成体组织中。Y 器官和表皮中的PtE93 mRNA 水平在蜕皮周期中波动，表明其参与幼年蜕皮。在体外和体内用 20E 处理导致Y 器官和表皮中PtE93表达的诱导，而我们发现法呢酸甲酯 (MF) 处理的效果相反，法尼索酸甲酯 (MF) 是甲壳类动物的昆虫 JH 的等价物。我们还观察到两个蜕皮类固醇生物合成基因Spook ( Spo ) 和Shadow ( Sad ) 被 20E 抑制并被 MF 诱导，显示 PtE93 和蜕皮类固醇生物合成之间呈负相关。PtE93 RNA干扰(RNAi)诱导Spo和Sad表达水平，升高培养基中蜕皮激素含量，并解除20E对蜕皮激素合成的抑制作用，表明PtE93对蜕皮激素合成具有抑制作用。总的来说，我们的结果表明E93可能参与了甲壳类动物蜕皮过程中20E和MF之间的串扰，并且它在Y器官中的存在与蜕皮类固醇的合成密切相关。