The prion domain spreads between cells and tissues in <i>C. elegans</i> by vesicular transport.

Abstract

<p>(A) Nematode muscle organization: BWM cells are arranged in quadrants, four longitudinal bands that run along the entire worm. Each quadrant is formed by staggered pairs of striated mononucleated cells. (B). Collapsed confocal z-stacks of nematodes expressing R2E2m::RFP and CFP::RAB-5 in BWM cells. RAB-5 does not co-localize with R2E2 containing vesicles, but enables the visualization of distinct cells, which is difficult in R2E2m::RFP only expressing nematodes. Single BWM cells of two quadrants are outlined. Arrows indicate connections between cells of different quadrants. Although muscle arms are extended not only to motor neurons but also to distant muscle cells that could form such connections, gap junctions between these cells allow electrical coupling, but no exchange of cytosolic content. (C) Collapsed confocal z-stacks of nematodes expressing RFPm in BWM cells. Single BWM cells of two quadrants are outlined. (D, E) Collapsed confocal z-stack and brightfield images of <i>C. elegans</i> expressing R2E2m::RFP or RFPm in BWM cells. Boxed region is displayed in higher magnification. BWM (M), intestine (I) and coelomocytes (CC) are outlined. (F) Single-plane confocal micrographs showing intestinally expressed R2E2i::RFP in vesicles located in intestinal and BWM cells. Intestine (I) and BWM cell (M) are outlined. Note the parallel aligned myofilaments (arrowheads) in the brightfield image as a muscle-specific marker. Scale bars: 10 µm.</p