Polyubiquitin is not essential in C. albicans.A. The genotype of C. albicans ubi4/ubi4 mutants was confirmed by Southern blotting of HindIII digested C. albicans genomic DNA with PCR-amplified probes against the UBI4, ARG4 and URA3 open reading frames: UBI4/UBI4 (BWP17); UBI4/ubi4 (MLC35 and MLC36); ubi4/ubi4 (MLC40, MLC41, MLC42) (Table 1).B. Growth of C. albicans ubi4/ubi4 mutants in liquid YPD at 30°C: UBI4/UBI4, grey diamonds (BWP17); UBI4/ubi4, open squares (MLC35); ubi4/ubi4, closed triangles and closed squares (MLC40, MLC41).C. Colonial growth of C. albicans ubi4 mutants: UBI4/UBI4 (BWP17); UBI4/ubi4 (MLC35); ubi4/ubi4 (MLC40). Images were taken with the same magnification.