A. Capsule size was examined for the WT and pkr1 strains by growing cells in defined low iron medium at 30°C for 48h and staining with Indian ink. The pkr1 mutant is hyper-capsular compared with the WT strain.
B. Capsule formation by cells defective in ESCRT-I, -II and –III components in the pkr1 strain background. The top panel shows the capsule size for the double mutants upon India ink staining and the bottom panel shows the increase in capsule size detected upon overexpression of the N-terminal region of Rim101 from the RIM1011-628 allele.
C. Fifty cells of each strain were measured from the experiment in B to determine cell diameter and capsule radius. Each bar represents the average of the 50 measurements with standard deviations. The pEF1p designation indicates that the strains were transformed with the empty vector used for overexpression of the RIM1011-628 allele. The differences in capsule size for the pkr1 mutant (double asterisk) and the empty vector transformants (single asterisk) relative to all other strains are statistically significant by the Student t test (P<0.05).