Fig. 1

Serial Glafenine exposure results in IEC delamination. (A) Schematic of dosing regimen used for serial Glafenine (Glaf.) exposure. (B) Representative brightfield and AO fluorescence images of 6 dpf DMSO- and Glafenine-treated larvae (arrowhead points to AO⁺ material in the intestinal lumen). (C) Glafenine dose–response for quantified intestinal AO fluorescence (left y axis, blue, 3-parameter least-squares fit) and survival (right y axis, maroon). (D) Kinetics of intestinal AO response with 30 μM Glafenine (n = 20 larvae per condition per time point; significance was determined between treatment groups within each time point by unpaired 2-sided Student’s t test; **P < 0.01, ****P < 0.0001). (E) Flow cytometry analysis of relative abundance of viable (7-AAD⁻) Tg(fabp2:DsRed)⁺ enterocytes from DMSO- and Glafenine-treated larvae (each point is a pool of 20 larvae; significance was determined in by unpaired 2-sided Student’s t test). (F) Sequential frames from live confocal imaging of Tg(fabp2:DsRed) larvae at 40 h into the treatment regimen. (G) Representative images of dissected larval zebrafish intestines exposed to DMSO or Glafenine ex vivo at 0 and 4 h (arrow points to mass of apoptotic cells in the intestinal lumen). (H) Quantification of seca5-tdTomato fluorescence in larval intestinal explants (n = 6 DMSO-treated and 5 Glafenine-treated intestines; 4-parameter least-squares fit; comparison of t_1/2: P = 0.0002 [extra sum-of-squares F test]).