PMC

Differences in the patterns of infection shown by wild type and ΔMcl1. Manduca larvae were injected with conidia and bled at 10-h intervals. (A) Wild-type germ tubes emerging from encapsulation 30 h after injection. (B) Heavy encapsulation of ΔMcl1 mutant cells 30 h after injection. The arrows show the emergence of fungal hyphae (note that the center of the capsule is melanized). (C) Wild-type hyphal bodies 50 h after injection unhindered by hemocytes. (D) Encapsulation of ΔMcl1 hyphal body 50 h after injection. (E) Wild-type hyphal body labeled with FITC-conjugated poly(l-lysine) to demonstrate negative charge. (F) Calcofluor staining of wild-type hyphal body. (G) Calcofluor staining of ΔMcl1 hyphal body. (Scale bar, 5 μm.)

Fungal hyphal body production in G. mellonella hemocoel. The 3rd instar larvae of G. mellonella were topically inoculated with fungal spores (10⁷ conidia/ml) in 0.05% Tween 80. (A) Hyphal bodies observed at 84 h postinoculation using light microscopy. Arrows, hyphal bodies. (B) Time course of hyphal body proliferation postinoculation of wild-type and Bb::S43Ac-1 spores. Hyphal body concentrations were determined by direct counting using a hemocytometer over the indicated time course. The experiment was repeated three times, and each treatment contained four replicates. Error bars indicate SDs.

Cell morphologies of Cordyceps militaris and Calcarisporium cordycipiticola during infection observed by TEM. Cross sections of the infected fruiting body of C. militaris (3 dpi) were shown. (A), (C) Hyphal cells of C. cordycipiticola and C. militaris. (E) Hyphal cell of C. cordycipiticola. (B–D,F) Hyphal cells of C. militaris after being infected by C. cordycipiticola. Red arrow indicated cells of C. cordycipiticola, yellow indicated empty hyphal cells of C. militaris without organelles, and blue indicated the deformed cells. Scale bar = 1 µm.

Growth is not confined to the hyphal tip in ΔatmA mutants. Hyphae were stained with FITC-conjugated wheat germ agglutinin to localize sites of active cell-wall deposition. Growth occurs at the tips of wild-type hyphae (A, arrow). In ΔatmA mutants (B), growth is also observed in the spore body (arrow). In wild-type hyphae that were germinated in the presence of 5 μg/ml benomyl, growth is largely confined to the spore body (C). Bars, 10 μm.