Fig. 6. Hip1r epsin double-mutant cells display developmental phenotypes similar to those of Hip1r single-mutant cells. Wild-type (WT), epsin-null (epsin-), Hip1r-null (Hip1r-) and Hip1r epsin (Hip1r-/epsin-) double-mutant cells were harvested and inoculated onto non-nutrient agar plates to induce spore formation. Spores were examined by DIC microscopy. Wild-type spores (A) are ovoid, whereas epsin-null spores (B) are less oblong, with some round spores. Hip1r-null spores (C) and Hip1r epsin double-null spores (D) are completely round. Bar, 5 µm. (E) When treated with detergent or heat, Hip1r-null and Hip1r epsin double-mutant spores show decreased viability. Wild-type, epsin-null, Hip1r-null and Hip1r epsin double-mutant spores were harvested and left untreated, subjected to washes with the detergent NP40 or heat treated for 10 minutes. Spores were then plated on a bacterial lawn, where they germinated and grew. Cleared plaques were counted as a measure of spore germination. Error bars represent the s.e. (n=1000 spores, seven experiments).