In crabs, ecdysteroid hormones are synthesized and released from a pair of molting glands called the Y-organs (YO), which mediate growth and development. As a first step in defining developmental changes in gene expression over the molt cycle in this important organ, a transcriptome was generated from three biological replicates from the Y organ of the blackback land crab, Gecarcinus lateralis. The library was constructed from intermolt stage animals. Illumina sequencing of cDNA libraries generated 227,811,829 100-base pair (bp) paired-end reads, following assembly, approximately 20% of the contigs could be assigned using BLAST, Trinotate, TMHMM, SignalP or HMMER.  Functional and pathway annotations were carried out via gene ontology (GO) and KEGG orthology (KO) analyses; 58% and 44% of the contigs with BLASTx hits were assigned to GO and KO terms, respectively. The gene expression profile was similar to a crayfish YO transcriptome database, and the relative abundance of each contig was highly correlated among the three G. lateralis replicates. Signal transduction pathway orthologs were well represented, including those in the mTOR, TGFβ, cyclic nucleotide, MAP kinase, calcium, VEGF, phosphatidylinositol, ErbB, Wnt, Hedgehog, Jak-STAT, and Notch pathways.

We have recently conducted a transcriptomic analysis examining the role of the mTOR signaling pathway in the control of  ecdysteroid synthesis as the YO transitions from intermolt to early premolt. This work has been recently published and the manuscript link is available here.  We have also examined changes in gene expression through RNA-seq analysis as the YO transitions through the molt cycle as triggered by multiple limb autotomy. Access to this study will be made available once this research has been reviewed and accepted for publication.

Access to the Illumina raw data sets has been deposited in CyVerse Discovery Environment.

The information containing trinity assembly and annotations is available here.

Venn diagram illustrates the distribution of unique contigs annotated to one or combination of the three GO categories. Many of the contigs were assigned to two or all three categories.

Dr. Mykles’ website can be found here

Dr. Donald Mykles, our collaborator in the YO transcriptome project