phoA Gene Fusions Virulence genes are small subset of total genes, so random mutagenesis will affect many more non-vIrulence genes Way to optimize number of virulence gene mutations takes advantage of fact that most virulence genes are on bacterial surface or excreted into medium BIOL 533 Lecture 4BIOL 533 9 Lecture 4 phoA Gene Fusions • Virulence genes are small subset of total genes, so random mutagenesis will affect many more non-virulence genes • Way to optimize number of virulence gene mutations takes advantage of fact that most virulence genes are on bacterial surface or excreted into medium