Figure 2. FKH-9 is expressed in both neuronal and intestinal tissues. (A) Confocal microscopy image of the head of a
fkh-9(
qd327) L2 larva, germline-edited with gfp inserted at the 3' end of the endogenous
fkh-9 locus. Open arrow heads point to unidentified neurons expressing FKH-9::GFP. Scale bar is 50 microns. (B) Confocal microscopy image of the intestine of a
fkh-9(
qd327) L2 larva. Filled-in arrow heads point to intestinal nuclei with FKH321 9::GFP expression. Scale bar is 50 microns. (C)
fkh-9(
qd327) does not confer
xbp-1-mutant larval resistance to P. aeruginosa, suggesting it encodes a functional protein. (D) Fosmid rescue, intestinal re-expression (using the Pges-1 promoter), and neuronal re-expression (using the Prab 3 promoter) of FKH-9 are all sufficient to sensitize
xbp-1 mutant animals to P. aeruginosa PA14 exposure during larval development. Error bars indicate S.D. of three plates in panels C-E. (E) Overexpression of FKH-9 from an extrachromosomal array carrying either fosmid, plasmid encoding intestine-specific expression (Pges-1::
fkh-9), or plasmid encoding neuron-specific expression (Prab-3::
fkh-9) is not sufficient to perturb ER homeostasis of
xbp-1 mutant animals on E. coli OP50. Significance in panels C and D was assessed by one-way ANOVA followed by Dunnett's multiple comparisons test. ***- P<0.0001, ***- P<0.001, n.s.- not significant (P>0.05) compared to
xbp-1(
tm2482) (panel C) and compared to
xbp-1(
tm2482);
fkh-9(
ok1709) (panel D).