Ca gup1 Δ null mutation causes residual filamentous growth in liquid hyphae inducing medium. (A) Young cell cultures were incubated in liquid YPD with 10% FBS at 37°C. Light microscope samples were photographed at increasing time points. (B) Chitin assembly by CFW staining of the 4 h samples, revealing distinct filament types, hyphae - wt and CF-Ca001 - and pseudohyphae - Cagup1 Δ null mutant strain. Arrows indicate the localization of the septa. The gup1Δ photos are representative of the results obtained with the several clones (3-5) of Cagup1Δ null mutant strain tested.