Fig. 5: Dilp8-Lgr3 pathway is required for glue expulsion and spreading behavior.

a dilp8 and Lgr3 mutants do not perform GSB. Shown is the percentage of animals of the depicted genotypes that perform GSB. b Photo time-series of GSB and its two phases (ventral tetanus and visible GSB) in a larva expressing the salivary gland glue protein Sgs3::GFP (green) as a marker for glue (arrow, and descending white arrowhead marking progression of glue spreading towards the larval posterior, bottom). Representative images of 3 animals (see also Supplementary Videos 3, 5-7). c Dot blots showing the duration of GSB and d post-GSB in control animals of the depicted genotypes. e dilp8 and Lgr3 mutants do not perform post-GSB. Shown is the percentage of animals of the depicted genotypes that perform post-GSB. f Knockdown of Lgr3 in R18A01 > neurons or R18A01 > alone, but not in R19B09 > , impedes GSB. Shown is the percentage of animals of the depicted genotypes that perform GSB. g Expression of UAS-Lgr3 (>Lgr3) in R18A01 > neurons partially rescues the GSB defect of Lgr3 mutants. Shown is the percentage of animals of the depicted genotypes that perform GSB. h GSB is rescued in dilp8 mutants by expression of Dilp8 after the midthird instar transition. Shown is the percentage of animals of the depicted genotypes that perform GSB. i RNAi knockdown of dilp8 using combined epidermal drivers (A58 > + Eip71CD > ), but not each one alone, disrupts GSB in a fraction of animals. Shown is the percentage of animals of the depicted genotypes that perform GSB. j dilp8 and Lgr3 mutants fail to expulse glue (Sgs3::GFP, green). k Quantification of j. Shown is the percentage of animals of the depicted genotypes that perform glue expulsion. Statistics (full details in Supplementary Table 2): a, e-i, k Binomial tests with Bonferroni correction. f Fisher’s Exact Test (magenta line). c, d Dots, one larvae. Horizontal bar, median. Error bars, 25-75%. *P < 0.05. ns, non-significant (P > 0.05). (N) Number of animals (orange). Scale bar, 1 mm.