Generation of poly- and mono-clonal antibodies against trout fibronectin (FN) and their use in FN immunodetection in teleost fishes.

Immunization of rats with gelatin-affinity column purified fibronectin (FN) from rainbow trout (Oncorhynchus mykiss) plasma produced a polyclonal antiserum that reacts specifically with FN in immunoblotted protein extracts and cultured cells, not only from trout but also from swordtails (Xiphophorus helleri). Most importantly, this antiserum specifically stains FN-containing structures in sections from embryos, as well as skin and dorsal fin of swordtails and platyfish (Xiphophorus maculatus), allowing, e.g., correlation of the distribution of FN with neural crest cell development in Xiphophorus. The antiserum also cross-reacts with FN in sections from embryos of the Japanese medaka (Oryzias latipes) and coho salmon (Oncorhynchus kisutch). In addition to the polyclonal antibodies, monoclonal anti-trout FN antibodies were produced in rats. These did not exhibit reactivity on sections, but stained the cultured fish cells and FN in immunoblots. Both types of antibodies may be of interest to the fish industry for marking the level of FN as an indicator, not only for infectious diseases, but also for certain developmental stages such as smoltification and spawning.