Fig. 1

Increased HP1a-mediated heterochromatin formation in the fat body promotes resistance against systemic P. aeruginosa PA14 infection. A Systemic P. aeruginosa PA14 infection was achieved through surgical wound via needle pricking of the Drosophila thorax. The immune organ (fat body) is located in the abdomen. B, C The survival curve and median survival of flies with fat body-specific C564-driven HP1a overexpression, compared to control, after PA14 infection. D, E The survival curve and median survival of flies with RU486-inducible fat body specific HP1a overexpression after PA14 infection. Control and treated flies received food with either EtOH (vehicle) or RU486, respectively, for 4 days upon eclosion. F Exposure to RU486 did not reduce, but rather increased, susceptibility and reduced survival of S106-GS>+ expressing flies after PA14 infection. For survival curves, n = 40 flies/group and *p < 0.05, ***p < 0.001 by log-rank test. For median survival, data are shown as mean ± SD from 4-5 independent experiments and *p < 0.05 by Student’s t-test. Inoculum of OD600 = 0.1