Figure 6.

Frictional force between hypha and substratum is required for acute tip reorientation.A. Adhesion of wild-type C. albicans cells on PDMS samples with differentially modified surface chemistries. Modified PDMS samples were inoculated with standardized cell concentrations and the number of cells adhered per mm² per PDMS surface was determined. Bars = standard error of the mean (SEM), n = 3.B. Hyphal reorientation assays were carried out by adhering wild-type cells to the same series of PDMS surface chemistries and incubating in Petri dishes, where hyphae were free to grow in X, Y and Z planes. The response to ridges 1 μm high was expressed as the percentage of hypha-ridge interactions that resulted in hyphal reorientation. Bars = SEM, n = 3.C. Time lapse of immobilized hypha reorienting on contact with a barrier in an enclosed imaging chamber 1 μm in height (Movie S1). Bar = 5 μm.D. Time lapse of a non-immobilized hypha contacting a barrier in an enclosed chamber 1.5 μm in height (Movie S5). Bar = 5 μm.E. Plot of the hyphal tip angles relative to the barrier for the immobilized hypha in panel C (arrows) and the non-immobilized hypha in panel D (arrows). The time of contact with the barrier is designated as t = 0 min. Error bars = SEM, n = 17.