Hemocyanin synthesis in the blue crab Callinectes sapidus

1. The synthesis of hemocyanin in the blue crab, Callinectes sapidus, was investigated by molecular techniques. 2. Polyadenylated mRNA was prepared from the hepatopancreas and translated in rabbit reticulocyte lysate. 3. Translation products were immunoprecipitated with immobilized antihemocyanin IgG. Analysis of the IgG-bound polypeptides by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed two polypeptides comigrating with authentic Callinectes hemocyanin. 4. A synthetic degenerate 17-mer oligonucleotide mixture derived from the amino acid sequence of the "copper B" binding site of crustacean hemocyanins was prepared. Northern blotting showed the probe to hybridize with one major 2.3 kb RNA species. 5. These results indicate that the hepatopancreas is the site of hemocyanin synthesis.