Fig. 6.

Series of images from Movie S8 in the supplemental material showing 2 quasisynchronous fusion events (1 and 2) involving three different hyphae. During fusion event 1 between the two FoH1::GFP hyphae (tip to side), a green fluorescent nucleus (black arrow) divides, and one of the daughter nuclei (white arrow) migrates through the fusion bridge to invade the neighboring cell, while the other daughter nucleus (yellow arrow) invades the underlying hyphal cell. After an extended period (156 min), the nucleus that invaded the neighboring hypha moves back through the fusion bridge to its original cell compartment, while the nuclei in the underlying cell compartment are visible as a single fluorescent spot throughout the rest of the movie. Note that the nucleus inside the neighboring recipient cell (red arrows) divides again and that one of the daughter nuclei is immediately degraded. During fusion event 2 between the FoH1-GFP and the FoH1-ChFP hyphae (tip-to-tip VHF), a red fluorescent nucleus (black arrowhead) divides and one of the daughter nuclei (white arrowheads) invades the adjacent FoH1-GFP hypha. After 95 min, the resident green fluorescent nucleus (yellow arrowhead) is degraded and the red fluorescent nucleus persists inside the cell and subsequently divides while the hypha continues to grow.