Insights into shell deposition in the Antarctic bivalve Laternula elliptica: gene discovery in the mantle transcriptome using 454 pyroseqeuencing

The Antarctic clam, Laternula elliptica, is a stenothermal bivalve mollusc which morphologically resembles the soft-shelled clam Mya arenaria, the major ingredient of clam chowder. Previous studies have shown that this mollusc displays a high level of plasticity with regard to shell deposition and damage repair against a background of genetic homogeneity. The Southern Ocean has amongst the lowest present-day CaCO3 saturation rate of any ocean region, and therefore will be among the first to become undersaturated under current ocean acidification scenarios. This is the first 454 data from an Antarctic marine invertebrate. Sequencing of mantle tissue from this species has considerably increased resources for the investigation of the processes of shell deposition and repair in molluscs in a changing environment. A number of promising candidate genes were identified for functional analyses, not only in this species, but also for comparative studies in economically important model aquaculture species, such as Crassostrea gigas and Mytilus edulis.