Filamentation assays on various media. (A) Overnight cultures were spotted onto weak-inducing media such as M199 agar plates, Spider agar, and BSA plates, and monitored daily. Overnight cultures were also spotted onto YPD containing 10% (v/v) fetal calf serum (FCS), a strong inducer of filamentation. Representative figures at the indicated times and incubation temperatures are shown. (B) Filamentation was also assayed in liquid media. Inoculums of 5 × 106 cells ml-1 were incubated at 37°C with constant shaking at 200 rpm. The time of germination, extent of elongation, and overall hyphal morphology were observed and compared between each strain at given time points using standard light microscopy. Results from growth in weak-inducing medium (Spider medium) are shown here at 2 and 4 hours where aberrant branching is evident at the latter timepoint. Standard light microscopy was performed using a 60× and 40× objective for the 2 and 4 hour timepoint, respectively.