HUMORAL IMMUNOGLOBULINS OF THE WHITE STURGEON, ACIPENSER-TRANSMONTANUS - PARTIAL CHARACTERIZATION OF AND RECOGNITION WITH MONOCLONAL-ANTIBODIES

White sturgeon (Acipenser transmontanus) immunoglobulin (Ig) was purif ied from serum by two methods, ion-exchange chromatography and gel fil tration and precipitation of the euglobulin fraction, The purity of th ese immunoglobulin preparations was confirmed by gel electrophoresis. Sequence analysis of the N-terminal amino acids confirmed that the pur ified protein was immunoglobulin. The major portion of the immunoglobu lin preparation consisted of two proteins with estimated molecular wei ghts (m.w.) of 870 and 170 kDa. The m.w. of the H- and L-chains of the purified Ig were 73 and 27-30 kDa, respectively, as determined by SDS -PAGE. Ion-exchange purified Ig was used to immunize mice for the prod uction of monoclonal antibodies. This resulted in the production of si x stable hybrids that recognized sturgeon Ig, two specific for heavy c hain and four specific for light chain. The kDa mab two anti-H-chain m abs were highly specific for white sturgeon Ig while all four anti-L-c hain mabs cross reacted with Ig from green sturgeon (A. medirostris), Atlantic sturgeon (A. oxyrhynchus oxyrhynchus), shovelnose sturgeon (S caphirhynchus platorynchus), and paddlefish (Polyodon spathula), (all Chondrosteans), but not with channel catfish (Ictalurus punctatus), ra inbow trout (Oncorhynchus mykiss) or striped bass (Morone saxatilis). The mabs were used to enumerate the percentage of sIg(+) lymphocytes i n the peripheral blood of white sturgeon by flow cytometry. The percen tage of cells positively stained with the mabs ranged from 12 to 28%. In a comparison of mabs with polyclonal rabbit anti-sturgeon Ig serum by ELISA the mabs produced a larger signal and less background than th e polyclonal serum. Copyright (C) 1996 Published by Elsevier Science L td.