(A) Schematic of the two-photon ablation experiment. (B) Gross morphology at 80 hpf was comparable between control and ablated fish. (C–D) Tg(elavl3:Gal4-VP16); Tg(UAS:EGFP-CAAX); Tg(sst2:RFP) zebrafish mounted in 0.5% agarose with tricaine were subjected to two-photon laser ablation. The detached neuron clusters were ablated between 31 and 33 hpf. The control was mock ablation of cells adjacent to the leading edge of the migrating neurons using the same laser intensity. Pre-ablation, short time-lapse immediately following ablation, and post-ablation images are displayed. Orange and pink boxes outline the regions of ablation; arrowheads point to ablated cells. (E–J) Whole mount immunostaining at 80 hpf for acetylated Tubulin (nerves), Insulin (beta cells), RFP (delta cells), and DAPI (DNA). Quantification of islet nerve density (G), primary islet mass (H), beta cell number (I), and delta cell number (J), mean ± SEM, n = 18–25 animals, p-values from t tests are presented.