A newly identified allele of dnmt1 is similar to uhrf1 and displays elevated TgBAC(tnfa:GFP) expression. (A) cc39.3pd1093 (Middle), a mutant recovered from our forward genetic screen, had a similar phenotype to uhrf1pd1092 and failed to complement (Top) with dnmt1s872 (Bottom). (B) Confocal images of crosssections through WT and dnmt1pd1093 mutants revealed excessive cell shedding (arrows), luminal debris, and a flattened epithelium in mutants. (C and D) Elevated TgBAC(tnfa:GFP) expression was observed in the intestinal epithelium (encircled by a red dotted line) of dnmt1pd1093 mutants (Upper and Lower Right) but not WT larvae at 120 hpf. Red arrows point to the intestinal epithelium. The yellow frame indicates the plane of section for C and D, Lower. Crosssections (Lower) through WT (C) and dnmt1pd1093 mutants (D) revealed up-regulation of TgBAC(tnfa:GFP) in the intestinal epithelium of mutants. (E) dnmt1pd1093 mutants have increased TgBAC(tnfa:GFP) epithelial fluorescence (measured in arbitrary units, a.u.), decreased cell height, and increased cell shedding, similar to uhrf1pd1092 mutants. ***P < 0.001, ****P < 0.0001.