Figure 1

Fins are elongated in the adult zebrafish mutant Dhi2059. (A) WT fish with normal-sized fins. (B and C) Both one- and two-copy transallelic mutants of Dhi2059 possessed elongated paired and median fins. Bars, 50 mm in (A–C). (D) The lengths of caudal fins in Dhi2059 mutants are significantly longer compared to WT siblings. Fish were generated by kcnj13^Dhi2059/+ incrossing. For each group, n = 40 (20 males and 20 females). * P < 0.0001 by ordinary one-way ANOVA test (Tukey’s multiple comparisons) based on mean difference and SD. (E and F) Normal fin ray segments in WT fish. (G and H) In the Dhi2059 mutant, the fin ray segments of the caudal fins are increased. The number of fin ray joints are barely noticeable. Black/white arrowheads indicate natural ray joints. Red arrows indicate the healing scars of broken bone structures. (E–H) Tg (col2a1a: EGFP-CXXC) labeled WT and Dhi2059 mutant fish. Bars, 25 mm in (E–H). (I) Allometric growth of caudal fins in kcnj13^Dhi2059/+ mutants (n = 39; k = 1.5) compared to isometric WT siblings (n = 23, k = 1.0), reflected by linear regression analysis on the lengths of caudal fins and standard body lengths (measured from the tips of the snouts to the posterior ends of the last vertebrae). k = allometric coefficient. The slopes are significantly different, P = 0.002, F-test of general linear model analysis. All fish were generated by incrossing of kcnj13^Dhi2059/+ fish. WT, wild-type.