FIG 4.

Phenotypic analyses of Mucor deletion mutants in selected genes during phagocytosis and mouse infection. (A) Spore fitness of strains with the indicated mutations after 5 h of macrophage phagocytosis, assessed by their ability to develop healthy colonies on MMC medium. Control plates contain spores obtained after growing in cell culture medium for 5 h without macrophages. R7B was used as the wild-type (WT) strain. All MMC plates were incubated for 48 h. (B) Polarity index measures after phagocytosis for all deletion strains generated compared to those of the wild-type control (R7B). Error bars correspond to the standard errors of the means (SEM) from technical replicates (n = 50 spores), and statistical significance was analyzed by the unpaired t test. (C) Virulence assays with immunosuppressed mice. Each color shows the survival curve for a group of 10 mice infected with 1 × 10⁶ spores from one of the deletion mutant strains. Survival rates were compared to the results for mice infected with a virulent control strain (R7B) and statistically analyzed by a Mantel-Cox test. NRRL3631 was used as an avirulent control strain. Asterisks (*) indicate a significant difference determined by the unpaired t test (*, P ≤ 0.05; **, P ≤ 0.005; ***, P < 0.0001).