Construction of the recombinant B. sphaericus strains by homologous recombination. The genes were introduced either upstream from the binary toxin (cry11A) or at the protease locus (cry11A, cry11Ba, and aphA3). E1, EcoRI. Probes used in Southern blot analysis were the 5′ end of the binary toxin (BamHI/BglII fragment from pHT560) (), the 5′ end of the protease gene (BamHI/SalI fragment from pPS408) (▪), the internal part of cry11Ba (PstI/HpaI fragment from pJEG80.2) (□), and the 5′ end of cry11A (BamHI/SphI fragment from pPS401) ().