FIG 6.
Deletion of ump2 eliminates filamentation when either rho1 or rac1 is overexpressed. (A and B) Haploid cells with ump2 deleted in the ½ WT (A) or Pcrg rho1 (B) background were grown on SLAA, and colony morphology was observed after 4 days. While rho1 overexpression strains exhibit reduced filamentation, ump2 deletion completely eliminates filamentation in all backgrounds examined. (C through F) Strains with rac1 overexpression (C and E) or ump2 deletion in the rac1 overexpression background (D and F) were grown on SLAD (C and D) or YEPS (E and F) medium, and colony morphology was observed after 4 days. ump2 deletion abolishes the filamentation of the rac1 overexpression strains. (G) The rac1 overexpression strain with the ump2 deletion, complemented with a plasmid-borne ump2 gene, displayed an intermediate level of filamentation on SLAD medium, comparable to that seen in the ½ WT strain alone (Fig. 4A) or with an empty vector (Fig. 4C). Magnification, ×4. Colony edges for the strains depicted in panels C, D, and G are shown at ×10 magnification in Fig. S4 in the supplemental material. For each strain, the ratio of the filamentation area, extended from the edge of a colony, to the colony area is given as the mean ± standard deviation for a minimum of 12 independent measurements.