FIG. 6.

Morphology of the wild-type S. griseus strain IFO13350 containing extra copies of dasA. (A) S. griseus IFO13350 harboring pES1 shows a wrinkled colony morphology on YMPD agar medium, as does mutant NP4, and forms substrate spores, as examined by scanning electron microscopy. Photographs were taken after growth at 28°C for 4 days. Bars, 1 μm. (B) The morphological defect of S. griseus IFO13350 harboring pES1 depends on glucose as a carbon source, because on YMP medium containing other sugars at a concentration of 1% instead of glucose, the wild-type strain harboring pES1 shows normal sporulation. Photographs were taken after growth at 28°C for 5 days. (C) Sporulation in the substrate mycelium of agar-grown S. griseus IFO13350 harboring pES1. Bars, 1 μm. An ultrathin section containing substrate mycelium penetrated into agar after growth at 28°C for 2 days was examined at different magnifications (left panel). A substrate spore chain of the wild type harboring pES1 is shown, together with the substrate (SM) and aerial (AM) mycelium of the wild-type strain as controls (right panel). (D) Ectopic, substrate spores of S. griseus IFO13350 harboring pES1, together with the aerial spore of the wild-type strain as a control, is shown. The samples were prepared after growth at 28°C for 4 days. Bar, 0.1 μm.