Meeting Abstract
Growth via molting in crustaceans is regulated by arthropod steroid hormones, ecdysteroids. These hormones are synthesized and released from a pair of molting glands or Y-organs (YO). Molt-inhibiting hormone (MIH), released from X-organ/sinus gland complex in the eyestalk, negatively regulates ecdysteroid biosynthesis and thereby inhibits molting. mTOR and TGFβ signaling pathways control YO activity during molt stage-specific transitions. To further identify the genes involved in the regulation of molting, transcriptome libraries were generated from YO from intermolt and from early, mid, and late premolt animals. RNA-Seq, using the Illumina HiSeq platform, of three intermolt YO biological replicates generated 227,811,829 raw reads. These 100 bp paired end reads were mapped de novo using Trinity assembly software. The assembly generated 288,673 contigs with average length of 872 bp and contig N50 = 1842 bp. Using Bowtie 2.0, 91% of the raw reads were mapped back to the reference transcriptome. Preliminary targeted BLAST analysis of the reference intermolt YO transcriptome identified previously reported genes, as well as new sequences that encode ecdysteroid biosynthetic enzymes and a suite of phosphodiesterases. The reference transcriptome was evaluated by comparing full-length sequences obtained by Illumina sequencing with G. lateralis genes in the GenBank database (e.g., mTOR, Akt, β-actin, EcR, RXR, NO synthase, Elongation Factor-2, E75, myostatin-like, Ras, and NO-insensitive guanylyl cyclase). There were 98% to 100% nucleotide identities and protein similarities. Following annotation of reference transcriptome library, the goal is to identify gene networks that regulate YO activity and sensitivity to MIH through the molt cycle. Supported by NSF (IOS1257732).
