Gecarcinus lateralis breed:Eukaryote | cultivar:Consejo Dominicano de Pescay Acuicultura, Dominican Republic Assembly

The intermolt crustacean Y-organ (YO) maintains a basal state mediated by high circulating levels of molt inhibiting hormone (MIH), a neuropeptide inhibiting YO ecdysteroidogenesis. During early premolt, the YO undergoes activation, characterized by reduced circulating MIH. mTOR signaling pathway genes are up-regulated in the early premolt YO, and rapamycin, an mTOR inhibitor, inhibits YO ecdysteroid biosynthesis.In the crab, G. lateralis, molt cycle entry was induced via MIH removal by eyestalk ablation (ESA). ESA animals were injected with either rapamycin or DMSO carrier. YO tissues were harvested at 1, 3, and 7 days post-ESA and processed for RNA-seq. mRNAlevels for mTOR pathway genes were elevated over intermolt animals, but declined following rapamycin treatment. In concert with mTOR inhibition, ecdysteroid pathway genes decreased in mRNA expression, accompanied by decreases in ecdysteroid titer. On entering premolt, decreases in mRNA abundance were also observed in cyclic nucleotide gene pathway components, supporting earlier work indicating these regulatory pathways mediate MIH signaling. In contrast, rapamycin inhibition increased transcript abundance for FKBP12, the rapamycin-binding protein and genes associated with Wnt and Insulin-like signaling pathways, suggesting both inhibitory and stimulatory transcriptional effects mediated by YO mTOR pathway inhibition.