USE OF AN ENHANCED ESCHERICHIA-COLI OPAL SUPPRESSOR STRAIN TO SCREEN A MYCOPLASMA-HYOPNEUMONIAE LIBRARY

Many mycoplasma genes contain internal UGA (opal) codons because of th eir use as tryptophan coding codons. This results in a lack of express ion of many cloned mycoplasma antigenic epitopes in Escherichia coli. It has been shown that opal suppressors can be used to enhance express ion of defined mycoplasma gene sequences, but no studies have been pub lished using E. coli suppressor strains to screen mycoplasma gene libr aries for immunoreactive epitopes. The E. coli suppressor strain ISM61 2 was used to screen a Mycoplasma hyopneumoniae Lambda gene library. T his strain contained an inducible opal suppressor, trpT, as well as th e release factor 2 mutation prfB3. Strain ISM612 was shown to enhance antibody recognition of cloned mycoplasmal gene sequences.