DEVELOPMENT OF MICROSATILLITES FOR PARENTAGE ANALYSIS IN BAY SCALLOPS Argopecten irridians SPAWNED FOR RESTORATION

The bay scallop Argopecten irridians is a filter feeding bivalve that lives in seagrass beds. In Florida, this species supports a culturally and economically important recreational fishery. The scallop population has declined due to various factors and aquaculture-based restoration efforts have historically occurred and are ongoing in many areas of the state at a variety of scales. To document the success of restoration and the genetic diversity of cultured scallop larvae, we worked to develop a method for parentage analysis using microsatellites. Such a system would also be valuable for analyses of population-level genetic structure.

Development of the microsatellite system included trial and error determination of field sampling methods. Methods for non-lethal broodstock sampling evolved from the tedious practice of clipping tentacles to sterile cotton swabs of the adductor muscle (Fig. 1). Tissue storage agents evolved from ethanol to LoTEPA buffer, which requires prompt DNA extraction but greatly reduces processing time. Critically for parentage analysis, we established that individual bay scallop larvae can provide sufficient DNA for PCR amplification as early as 7 days post fertilization. Only a handful of the dozen-plus published bay scallop microsatellite loci (target n = 9) have proven suitable for analysis. Others produced numerous spurious bands after capillary electrophoresis, making interpretation difficult. Thus, an NCBI-available draft genome for the species was assembled to identify primers. As of November 2017, the new primers are being verified to complete a set suitable for parentage analysis.