Transcriptomic analysis of crustacean molting gland (Y-organ) regulation via the mTOR signaling pathway

• Published in: Scientific reports 2018-05, Vol.8 (1), p.7307-17, Article 7307
• Main Authors: Shyamal, S., Das, S., Guruacharya, A., Mykles, D. L., Durica, D. S.
• Format: Article
• Language: English
• Subjects: 38/39; 38/91; 45/90; 631/114/2114; 631/337/2019; 631/45/776/812; 82/51; 96/95; AKT protein; Animals; Biosynthesis; Brachyura - cytology; Brachyura - drug effects; Brachyura - genetics; Brachyura - growth & development; Crustaceans; Ecdysteroids - biosynthesis; Ganglia; Gecarcinus lateralis; Gene Expression Profiling; Gene Expression Regulation, Developmental - drug effects; Growth factors; Hemolymph; Humanities and Social Sciences; Kinases; Molt-inhibiting hormone; Molting; Molting - drug effects; Molting - genetics; multidisciplinary; Rapamycin; Science; Science (multidisciplinary); Signal transduction; Signal Transduction - drug effects; Signal Transduction - genetics; Sirolimus - pharmacology; TOR protein; TOR Serine-Threonine Kinases - metabolism; Transcription activation; Transforming growth factor-b; Wnt protein
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-018-25368-x

The intermolt crustacean Y-organ (YO) maintains a basal state mediated by pulsatile release of molt inhibiting hormone (MIH), a neuropeptide produced in the eyestalk ganglia, inhibiting YO ecdysteroidogenesis. Reduction of MIH results in YO activation and the animal enters premolt. In the crab, Gecarcinus lateralis , molting was induced by eyestalk ablation (ESA). ESA animals were injected with either rapamycin, an mTOR inhibitor, or DMSO vehicle at Day 0. YOs were harvested at 1, 3, and 7 days post-ESA and processed for high throughput RNA sequencing. ESA-induced increases in mRNA levels of mTOR signaling genes (e.g., mTOR , Rheb , TSC1 / 2 , Raptor , Akt , and S6 kinase ) declined following rapamycin treatment. In concert with mTOR inhibition, mRNA levels of ecdysteroid biosynthesis genes (e.g., Nvd , Spo , Sad , Dib , and Phm ) were decreased and accompanied by a decrease in hemolymph ecdysteroid titer. By contrast, rapamycin increased the mRNA level of FKBP12 , the rapamycin-binding protein, as well as the mRNA levels of genes associated with Wnt and insulin-like growth factor signaling pathways. Many MIH and transforming growth factor-β signaling genes were down regulated in ESA animals. These results indicate that mTOR activity either directly or indirectly controls transcription of genes that drive activation of the YO.