P1-2 Sat Jan 2 The Crustacean juvenile hormone: Characterization of the methyl farnesoate signaling genes in the Gecarcinus lateralis Y-organ transcriptome Bentley, VL*; Mykles, DL; Department of Biology, Colorado State University, Fort Collins, CO Vanessa.Bentley@colostate.edu
The antagonistic interaction between 20-hydroxyecdysone and juvenile hormone (JH) control insect molting and development, respectively. Methyl farnesoate (MF), the precursor to the insect JH-III, stimulates ecdysteroidogenesis in vitro in the Dungeness crab (Metacarcinus magister) Y-organ (YO). Components of the JH synthetic pathway, including farnesoic acid O-methyltransferase (FAMeT), are expressed in the blackback land crab (G. lateralis) YO, suggesting that the YO secretes MF. The components of the MF/MEKRE93 signaling pathway were identified using the G. lateralis de novo assembled multiple leg autotomy (MLA) and eyestalk ablation (ESA) transcriptomes, including Methoprene-tolerant (Met), Steroid receptor coactivator (Src), Krüppel homolog 1 (Kr-h1a and Kr-h1b), E93, and Hsp90. It is hypothesized that Kr-h1 mediates the control of ecdysteroidogenesis by MF. Kr-1a was differentially expressed over the molt cycle in MLA individuals and its relative expression by ESA was not mediated by mTOR activity. Kr-h1b was expressed at low levels and not affected by MLA or ESA. RNAi and in vitro experiments will determine the effects of methoprene and MF on YO ecdysteroid secretion and the effects of molt induction on the expression of MF/MEKRE93 pathway genes. Supported by NSF (IOS-1922701).
