Impaired caudal fin regeneration in Shp2 deficient, but not Rptpα deficient embryos. Zebrafish embryos from a ptpn11a ^+/− ptpn11b ^−/− in-cross and a ptpra ^+/− in-cross were amputated at 2 dpf and caudal fin regeneration was assessed at 3 dpa (i.e. 5dpf, 3 dpa). Equivalent uncut embryos were monitored as controls (i.e. 5dpf, uncut). (a, d) Representative images of embryo caudal fins are shown. (b,c) Means of caudal fin growth of embryos lacking Shp2 (ptpn11a ^−/− ptpn11b ^−/−) embryos following amputation and uncut controls are depicted relative to caudal fin growth of uncut ptpn11a ^+/+ ptpn11b ^−/− embryos. (e,f) Means of caudal fin growth of embryos lacking Rptpα (ptpra ^−/−) following amputation and uncut controls are depicted relative to caudal fin growth of uncut ptpra ^+/+ embryos. Regeneration was quantified by measuring the distance from the tip of the notochord to the edge of the caudal fin as indicated. Means of amputated ptpn11 ^−/− ptpn11b ^−/− or ptpra ^−/− embryos were compared to amputated ptpn11a ^+/+ ptpn11b ^−/− or ptpra ^+/+ embryos, respectively, using a Mann-Whitney U-test with a confidence level of 99%. Significance: ***p < 0.001; n.s. not significant; error bars indicate standard error of the mean. All embryos were genotyped.