1. The ΔsimA strain shows less cellular proliferation during macrophage infection and ruptured yeast cells.
The ΔsimA strain shows less cellular proliferation during macrophage infection and ruptured yeast cells. (A) Macrophages infected with simA+, ΔsimA, and ΔsimA simA+ conidia 48 h postinfection. After 48 h, numerous yeast cells dividing by fission were observed in macrophages infected with wild-type (simA+) or ΔsimA simA+ conidia. The ΔsimA strain showed less cellular proliferation within macrophages than the wild-type (simA+) and ΔsimA simA+ strains. Some ΔsimA conidia remained ungerminated (black arrowhead), but a number had germinated into yeast cells (black double arrowhead). Yeast cells appeared ruptured and to be releasing cellular contents (black double arrowhead). (B) Unlike wild-type (simA+) and ΔsimA simA+ yeast cells, ΔsimA yeast cells were often ruptured (white arrowhead) and leaking their cellular contents (black arrowhead). Cells were not clearly visible under DIC conditions (black double arrowhead), and degraded fungal cellular material was observed (white double arrowhead). Images were captured using differential interference contrast (DIC) or with epifluorescence to observe calcofluor-stained fungal cell walls (CAL). Scale bars, 10 µm.
Kylie J. Boyce et al. mSphere 2018; doi: /mSphere