Figure 3
Localisation and quantification of PbBSMT mRNA in P. brassicae. (a–c) Diagrammatic overview of the P. brassicae structures, (d–f) the P. brassicae structures seen in the brightfield images, (g–i) and in the FISH images. (j) Signal maxima per cell. (a) The cell that is fully pictured in (a) shows a plasmodium which is at the onset of spore formation (orange polygon) inside a hypertrophied host cell (cell walls are indicated by the green lines). At the onset of spore formation round, spore like aggregations of the plasmodium become visible (orange circles). During this development stage high numbers of mRNAs can be detected (see image g) which are randomly distributed when no structures are visible in the plasmodium, but appear aggregated around the spore like structures. When the differentiation of the plasmodium progresses (b) these spore like, aggregated areas become more distinct until they have developed into individual resting spores which are not connected via the plasmodium anymore (orange dots). Signals peak around areas which already start to be recognisable as individual portions and get less in areas where resting spores are formed. Finally, the whole plasmodium has developed into resting spores (c, orange dots), that fill the entire host cell. The mRNA signals decrease further in number and brightness before disappearing completely. Bars = 10 µm. (j) Signal maxima µm-3 of smFISH PbBSMT signals (n = 37) highlighting a peaking of PbBSMT mRNAs during spore formation. Labelling on the x-axes corresponds to the life cycle stages in images (a–c). No significant correlation was identified. One extreme outliner at 0.088 signals µm-3 is not displayed to improve figure layout.
