Fig. 2

Activation of tnfa⁺ macrophages in (tnfa:eGFP-F/mpeg1:mCherry-F) transgenic larvae upon E. coli infection.

(A) Diagram showing the site where Crimson E. coli or non-fluorescent E. coli (blue) were injected in the muscle of 3 dpf Tg(mpeg1:mCherryF/tnfa:eGFP-F) larvae. The red dotted box represents the region imaged by confocal microscopy. (B) Tg(mpeg1:mCherryF/tnfa:eGFP-F) larvae were infected with crimson-expressing E. coli (blue) at 3 dpf in the muscle and imaged from 30 min pi to 10 hr 30 min pi every 3 min 30 s. Representative time-lapse maximum projections show the expression of tnfa (green) induced in myeloid-like cells at the infection site from 3 hpA. The time pA is shown on top right corner, scale bar = 25 µm. (C) Maximum projections of confocal analysis of GFP-F (green) and mCherryF (red) expressions in Tg(mpeg1:mCherryF/tnfa:eGFP-F). Larvae were previously infected with E. coli at 3 dpf in the muscle and imaged at 6 hpi. Arrowheads show macrophages expressing tnfa. Scale bar on left panels = 20 µm and on right panels = 10 µm.