The present study was undertaken to produce monoclonal antibodies (MAbs) against immunoglobulin (Ig) purified from black rockfish (Sebastes schlegeli Higendorf) serum using protein A, mannan binding protein, and goat IgG affinity columns. These three different ligands were found to possess high affinity for black rockfish serum Ig. All of the Igs purified eluted at only 0.46 M NaCl concentration in anion exchange column chromatography and consisted of two bands at 70 kDa and 25 kDa in SDS-PAGE; they also had similar antigenicity for MAbs to Ig heavy chain in immunoblot assays. Therefore, black rockfish Ig is believed to exist as a single isotype within serum. The MAbs produced against Ig heavy chain reacted specifically with spots distributed over the pI range from 4.8 to 5.6 with a molecular weight of 70 kDa on two dimensional gel electrophoresis immunoblot profiles.
Animals ; Antibodies, Monoclonal/*biosynthesis/immunology ; Chromatography, Affinity/veterinary ; Electrophoresis, Gel, Two-Dimensional/veterinary ; Immunoblotting/veterinary ; Immunoglobulin Heavy Chains/immunology ; Immunoglobulin Light Chains/immunology ; Immunoglobulins/blood/*immunology ; Perciformes/blood/*immunology

Black rockfish (Sebastes schlegeli) is an important mariculture species in Korea. The production of this fish is drastically declined due to bacterial diseases, particularly streptococcosis caused by Lactococcus garvieae. The bacterial surface characteristics of SJ7 and TY6 were found to have capsule but not NB13 and YS18. The experiential evaluation of L. garvieae pathogenicity, the capsular isolates showed high cumulative mortality i.e. SJ7 (100%) and TY6 (60%) compared to non-capsular isolates. Based on this result the capsular isolates L. garvieae were highly suspected as the causative agent of streptococcosis in rockfish.
Agglutination Tests/veterinary ; Animals ; Bacterial Capsules ; DNA, Bacterial/genetics/isolation&purification ; Fish Diseases/*microbiology/mortality ; Fishes ; Fluorescent Antibody Technique, Indirect/veterinary ; Gram-Positive Bacterial Infections/microbiology/mortality/*veterinary ; Lactococcus/*pathogenicity ; Polymerase Chain Reaction/veterinary