Ubiquitin-Mediated Response to Microsporidia and Virus Infection in C. elegans
Figure 5
N. parisii cells are almost never targeted by ubiquitin later during infection, but ubiquitin forms clusters that accumulate in the C. elegans intestine.
A,B) C. elegans intestines stained an anti-conjugated-ubiquitin antibody FK2 (green), and DAPI for DNA (blue): Panel B also includes a FISH probe against N. parisii rRNA (red). A) Sections of uninfected and N. parisii-infected C. elegans intestines. In the infected intestine an N. parisii spore labeled with the anti-conjugated-ubiquitin antibody is enlarged in box inset in upper left, and meront (arrowhead), and host nucleus (N) are indicated. Scale bar = 10 µm. B) Sections of uninfected and N. parisii-infected C. elegans intestines (30 hpi) shown with ubiquitin cluster (arrow) and ubiquitin staining within an N. parisii meront (arrowhead) indicated. Scale bar = 10 µm. C) Intestines of uninfected and infected animals expressing an intestinal GFP::ubiquitin transgene (48 hpi, grown at 20°C to prevent construct aggregation) are shown. Small GFP::ubiquitin aggregates are sometimes observed in uninfected animals (arrow). Scale bar = 20 µm. D) Enlarged portion of box in panel C. Oblong N. parisii meronts are visible through the absence of green (arrowhead) and ubiquitin clusters associating with the meronts (arrow) are indicated. Scale bar = 10 µm. E) Animals expressing the intestinal GFP::ubiquitin construct were infected with N. parisii and, together with control uninfected animals, fixed at the indicated times. Fixed animals were stained with a FISH probe against N. parisii rRNA to mark the infection and their intestinal cells were inspected for visible GFP::ubiquitin aggregates (30 transgenic animals were inspected per timepoint and condition). F) Animals expressing the intestinal control GFP::ubiquitinΔGG construct were treated and analyzed as in E.