Figure 1. Fungal infection of adult worms does not induce a UPR. (A) RT-PCR analysis of xbp-1 splicing. Under standard culture conditions (control), a 220 bp amplicon from an unspliced (us) xbp-1 transcript is detected, together with very low levels of a 197 bp amplicon from a spliced (s) transcript. The abundance of this smaller band does not increase after infection with D. coniospora (infection) or PMA treatment (PMA), but is clearly increased upon UPR-induction with tunicamycin (Tu). (B) The green fluorescence in transgenic worms carrying a pnlp-29::GFP (strain IG274; left column) or a phsp-4::GFP (IG1320; right column) reporter was observed after infection, exposure to tunicamycin, or high salt. While infection and osmotic stress induced high level of pnlp-29::GFP expression, tunicamycin induced phsp-4::GFP.