Tc. Hodgman et al., IDENTIFICATION OF A CRYPTIC GENE ASSOCIATED WITH AN INSERTION-SEQUENCE NOT PREVIOUSLY IDENTIFIED IN BACILLUS-THURINGIENSIS, FEMS microbiology letters, 114(1), 1993, pp. 23-29
After screening several Bt strains with a cryII toxin probe, clones fr
om two strains were found to contain a cryptic cryIIB gene associated
with an insertion sequence element belonging to the IS2/IS3 family. Th
e lack of expression of this gene appears to result from mutation of t
he upstream orf2 gene which has been shown to be necessary for cryII e
xpression.