Development of a DNA Microarray-Based Identification System for Commercially Important Korean Oyster Species

The correct identification of oyster species is essential for both aquaculture and taxonomic study, but it has often been a challenging task due to enormous morphological variation in shell morphs with ecophenotypic origins. The difficulty of species identification based entirely on shell characters has raised the need for developing an accurate, rapid tool for the identification and discrimination of oyster species. In this study, a DNA microarray-based identification system was established for eight commercially important oyster species (Crassostrea ariakensis, Crassostrea gigas, Crassostrea sikamea, Crassostrea nippona, Crassostrea angulata, Ostrea circumpicta, Ostrea denselamellosa, and Saccostrea kegaki). Sixteen species-specific probes developed in this study unambiguously distinguished eight target oyster species with no false-positive or false-negative signals. Of the eight oyster species examined, three Crassostrea species, C. angulata, C. gigas, and C. sikamea, which are indistinguishable by morphology, could be precisely identified using species-specific hybridization probes. The DNA microarray-based identification system developed in this study offers a very effective and reliable tool for eight oyster species, most of which are of commercial value and/or ecological significance in the macrobenthic community of offshore marine environments.