Messenger RNA from allotype-defined rabbits directing the cell-free synthesis of immunoglobulin heavy and light chains.

In vitro synthesis studies were performed utilizing polyA(+)-RNA and lymphocytes from the spleens of rabbits hyperimmunized with Micrococcus luteus or Streptococcus pneumoniae (type III). PolyA(+)-RNA isolated after 4 M guanidinium thiocyanate extraction and oligo(dT)-selection appeared to be undegraded on CH3HgOH-agarose gel electrophoresis and demonstrated biological activity when translated in a rabbit reticulocyte cell-free system. The electrophoretic patterns of the specifically immunoprecipitated cell-free products were compared with those of Nonidet-P40 extracts (lysates) and secretions (supernatants) from rabbit spleen lymphocyte cultures and serum proteins. Kappa light chains with specific b allotypes, as well as immunoglobulin heavy chains, were identified. The efficient translation of mRNA of defined allotypes was a necessary prerequisite for production of characterized cDNA clones and identification of genomic sequences for rabbit immunoglobulin heavy and light chains.