Fig. 5: Folinic acid stimulates β-cell regeneration in juvenile zebrafish.

a–d Single-plane and maximum projection confocal images of pancreata in control (a–a”) or folinic acid-treated (b–b”) 1-month-old juvenile zebrafish on the Tg(ins:H2BGFP);Tg(ins:flag-NTR);Tg(tp1:H2BmCherry) background, following β-cell ablation. Quantification showed an increase in the number of regenerating β-cells in the secondary islets upon treatment with folinic acid (c) as well as an increase in the number of ins:H2BGFP⁺tp1:H2BmCherry⁺ cells (d). The dashed line outlines the pancreas. Arrowheads point to ins:H2BGFP⁺ cells in the secondary islets. Scale bar, 20 μm. n = 8 (control) and n = 9 (folinic acid) biologically independent zebrafish were used for the quantification of this experiment. Data are presented as mean values ± SEM. Unpaired two-tailed Student’s t test was used to assess significance for (c) and (d). c *P = 0.0264; d *P = 0.0319.