FIG 6.

Pdr802 is a negative regulator of Titan cell formation. (A) The indicated strains were subjected to in vitro conditions that induce Titan cell formation and imaged with India Ink. All images are to the same scale; bar, 10 μm. Images were selected so that each shows multiple examples of Titan cells, not to reflect abundance of this morphotype. (B) The percentage of Titan cells in each culture was quantified using flow cytometry, gated as indicated by the red square. FSC-A, forward scatter; SSC-A, side scatter. (C) DNA content of cells after staining with propidium iodide (PI) and analysis by flow cytometry. (Top) 1C and 2C gates determined using control cultures of KN99α grown in YNB without or with benomyl, which traps cells at 2C. (Middle) Profiles of the indicated strains after growth under Titan cell-inducing conditions, showing an increased polyploid tail in mutant cultures relative to wild-type cells. (Bottom) DNA content profiles for only the Titan cells (gated as for panel B, red box) for each strain, showing their polyploid nature.