Genetic complementation rescued protoperithecial development in all three MAP kinase mutants.

<p>(<b>A</b>) Young protoperithecium of a rescued Δ<i>os-2</i> transformant (NCAL020) enwrapped by enveloping hyphae. Granulated ECM depositions as seen on Δ<i>os-2</i> hyphae (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042565#pone-0042565-g007" target="_blank">Figure 7A</a>) could no longer be observed in the rescued Δ<i>os-2</i> transformants, which showed smooth hyphal surfaces evenly covered in ECM (compare to wild type in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042565#pone-0042565-g007" target="_blank">Figure 7E</a>). Scale bar, 20 µm; in inset 5 µm. (<b>B</b>) Mature protoperithecium of the rescued Δ<i>os-2</i> transformant. Scale bar, 20 µm. (<b>C</b>) VHF (arrowheads) undergone in the rescued Δ<i>mak-1</i> transformant (NCAL010). Scale bar, 20 µm. The inset shows an ascogonial coil of this strain from which a straight hypha emerges which resembles a trichogyne initial (arrowhead). Scale bar, 5 µm. (<b>D</b>) Mature protoperithecium of the rescued Δ<i>mak-1</i> transformant. Scale bar, 20 µm. (<b>E</b>) CAT-mediated cell fusion (arrowheads) in a rescued Δ<i>mak-2</i> transformant (NCAL043). Scale bar, 20 µm. (<b>F</b>) Mature protoperithecium of a rescued Δ<i>mak-2</i> transformant. Scale bar, 20 µm.