Meeting Abstract
The serpulid polychaete Hydroides elegans is a common member of the warm-water marine fouling community. Its calcified tubes can form a layer several centimeters thick on submerged surfaces. The secretion of this tube begins early in metamorphosis and continues throughout the life of the worm. A strong cement is co-secreted with the tube, and both the tube and the cement are produced by a ventrally-positioned pair of “shell glands” located in the first thoracic segment. Little is known about either the composition of this cement or of the genes that encode it. In an attempt to better understand these cements, we used RNA-sequencing to assemble and annotate transcriptomes from both the first (containing putative cement glands) and second thoracic segments (lacking cement glands) of adult worms. We further determined the pool of transcripts that were differentially expressed in the first segment. No marine-invertebrate cement homologs were found in this transcript pool. Because the gene products for the cements are secreted and may be novel, we assembled a group of transcripts that were upregulated in the first segment, did not align with any proteins in NCBI databases, and contained a signaling peptide sequence. We then used whole-mount in situ hybridizations to determine where the 25 most highly expressed transcripts are expressed in competent larvae and in juvenile worms (24h post-induction). Initial results show that some of these transcripts are uniquely expressed in and around the shell glands in both larvae and juvenile worms, and may be components of the tube cement. Assembling a full set of transcripts compromising the cements of H. elegans promises to reveal a novel glue that is secreted and can set in seawater.
