The marine rocky intertidal is one of the most variable environments with respect to the prevailing abiotic factors. Depending on the particular tidal and climatic conditions, inhabitants can be submerged in cool seawater part of their day, but then suffer heat and desiccation stress during aerial exposure on sunny afternoon low tides. These variable and unpredictable conditions mean that intertidal organisms will have evolved unique capabilities to survive in this extreme environment.

A number of attributes make mussels particularly appropriate for investigating the physiological rigors and adaptive processes that allow life to flourish in an unpredictable environment. In particular, being sessile, means that the same assemblage of animals can be sampled repeatedly over periods of days, weeks, and even years, thus allowing their phenotype to be interpreted within the context of prior abiotic events.

We are constructing an encylopedia of cDNAs for the California ribbed mussel, Mytilus californianus. The DOE's Joint Genome Institute is sequencing these cDNAs as a collaboration in the 2006 Community Sequencing Project. Our goal is to curate a set of 15,000 non-redundant cDNAs from gill and adductor muscle tissue. This should represent a significant proportion of their transcriptome and will open the way to functional genomics investigations of adaptive responses. We are particularly interested in understanding the mechanisms that underpin short-term or dynamic adaptations which are manifest over an hourly, tidal, or diurnal timescale.

Mussels are an important 'sentinel' organism for ecotoxicological monitoring and our cDNA collection is being probed to identify biomarkers for a range important pollutants, e.g. heavy metals, polyaromatic hydrocarbons, etc.