The central role of septa in the basidiomycete Schizophyllum commune hyphal morphogenesis

Publication date: Available online 22 May 2019Source: Fungal BiologyAuthor(s): Marjatta RaudaskoskiAbstractThe purpose of the present research was to observe in the filamentous basidiomycete Schizophyllum commune, the connection between the nuclear division and polymerization of the contractile actin ring with subsequent formation of septa in living hyphae. The filamentous actin was visualized using Lifeact-mCherry and the nuclei with EGFP tagged histone 2B (H2B). Time-lapse fluorescence microscopy confirmed that both in monokaryotic (haploid) and dikaryotic hyphae, the first signs of the contractile actin ring occur at the site of the nuclear division, in one to two minutes after division. At this stage, the telophase nuclei have already separated and moved tens of micrometers from the division site. The actin ring is replaced by the septum in six minutes. Before division, the actin cytoskeleton occurs in the monokaryotic and dikaryotic apical cells at the site where the forward nuclear movement stops for division. Actin filaments also occur between the closely located sister nuclei in very early telophase, suggesting that the components necessary for arranging the contractile actin ring are present at the site of nuclear division throughout the division process. The apical cells treated with filamentous actin disrupting drug latrunculin A, had swollen tips but the cells were longer than in control samples due to the absence of the contractile actin rings, and as a consequen...

Source: Fungal Biology - May 24, 2019 Category: Biology Source Type: research