lacz Fusion Used to find regulatory genes that control expression of virulence gene lac fusion strain is mutagenized(chemical or another transposon) Resulting colonies screened for aberrant regulation BIOL 533 Lecture 4BIOL 533 6 Lecture 4 lacZ Fusion • Used to find regulatory genes that control expression of virulence gene – lacZ fusion strain is mutagenized (chemical or another transposon) – Resulting colonies screened for aberrant regulation