Fig. 7.

Replica plating and phenotyping. One 384-well plate of phoA transposon-containing strains was replica plated onto three conditions: rich medium plus indicator (Top), minimal medium (Middle), and minimal medium plus supplemented nutrients (Bottom). (Top) Colony A (arrow) represents a twitch^- phenotype; thus, the mutant is deficient in the gene pilY1, a type-4 fimbrial biogenesis protein. Colony B (circled) is an auxotrophic mutant (showing growth on LB and supplemented, but not minimal, media) and carries an argG (argininosuccinate synthetase) insertion.