Fig. 4. In vivo time-lapse analysis of the early stages of growth in the wild type and the wal1 mutant. Spores were germinated in liquid YPD or YPD supplemented with G418 for selection of the wal1 mutant for 8 hours at 30°C and then transferred to microwell-containing slides for further observation. Representative frames from Movies 1 and 2 (see supplementary material) are shown at the indicated time points (hours:minutes). Arrowheads point to hyphal tips that ceased growth and asterisks mark positions where contact inhibition occurred. Scale bars, 40 µm (A), 20 µm (B).