Identification of Mytilus galloprovincialis larvae from the Galician rı́as by mouse monoclonal antibodies

Abstract

The larvae of different species of bivalves are very similar in appearance during the early stages of development (D-shaped larvae). The method available today for an accurate identification of these larvae, based on the study of several ultrastructural morphological traits of the larval hinge, is impractical when the rapid identification and sorting of the larvae of bivalves are required for the numerous and complex plankton samples that field investigations generate. Therefore, in recent years, new methods such as molecular biology, biochemical, or immunological techniques are being used for efficient and accurate identification of those larvae. Here, we follow this trend and have attempted to produce specific monoclonal antibodies (mAbs) that could be used in immunological techniques for the identification of the larvae of the mussel Mytilus galloprovincialis in plankton samples from the Galician rı́as (NW of Spain). Mice were immunized with different amounts of D-shaped larvae of mussels and with larvae treated in different ways, then mouse spleen cells were fused with myeloma tumoral cells to obtain specific hybrids. We have obtained 12 mAbs against the immunizing larvae, and two of them, M2 and M3, showed a high specific recognition to M. galloprovincialis. These two antibodies do not show any cross-reaction when tested with the larvae of some other abundant species of bivalves coexisting in the area, such as Cerastoderma edule, Ostrea edulis, Aequipecten opercularis, Tapes decussatus, and Tapes philippinarum. Furthermore, each antibody displays a different pattern of staining in the larvae of mussels visualized by confocal microscope, indicating that they are directed against different antigen epitopes. The mAbs obtained, either used alone or in combination, could be very useful for the specific identification of the larvae of M. galloprovincialis, which is the only mussel species present in the area.