ZFIN is incorporating published figure images and captions as part of an ongoing project. Figures from some publications have not yet been curated, or are not available for display because of copyright restrictions.

Expression analysis of mvp during zebrafish organ regeneration. (A) Schematic illustration of transgenic constructs for mvp reporter strain. (B–D) mvp:EGFP expression in heart, spinal cord and fin at designated time points. Arrowheads in B indicate expression in compact layer of ventricle wall. Arrows in B indicate expression in primordial layer of myocardium. Asterisks in C indicate injury epicenter. Dotted line in D indicate the approximate resection plane. A to C, scale bar = 100 μm.

Generation of mvp knockout zebrafish line. (A) The zebrafish mvp genomic locus and Cas9/sgRNA targeting site. Deletions in Δ22,490 allele are shown as dashes. (B) In situ hybridization and qPCR results showing the absence of mvp mRNA in mvp knock out embryos. Data are mean ± SEM. ∗∗∗∗P < 0.0001. (C) Live images of control and mvp^−/− zebrafish at designated time points. Lateral view, anterior to the left. For embryos and larvae, scale bar = 200 μm. For animal from 30 dpf to 60 dpf, scale bar = 2 mm. (D) Representative Kaplan-Meier plot for mvp^−/− fish and clutchmates from one of three independent experiments. In each experiment, 60 mvp^−/− animals and 60 total siblings were followed. n.s, not significant, Mantel-Cox test. (E) Fecundity (measured by clutch size) and mating efficiency (measured by percentage of fish laid embryos) in control and mvp^−/− zebrafish. 30 mvp^−/− fish and 30 age-matched control fish out-crossed with age-matched wild-type fish.

Heart regeneration in mvp KO fish. (A) Visualization of epicardial cells in control and mvp^−/− fish. Epicardial cells proliferate by 7 dpi and are incorporated into the regenerating myocardial wall. Inset shows enlarged view of boxed area. Bar graph showing the density of epicardial cell at surface of hearts from control and mvp^−/− fish. Data are mean ± SEM. For each group, eight samples were assessed. n.s, not significant. (B) Cardiomyocyte proliferation at 7 days post-amputation (dpa) in ventricular sections from control and mvp^−/− animals, assessed by Mef2 and PCNA staining. Arrowheads, the PCNA positive. Scale bar = 100 μm. Bar graph showing cardiomyocyte proliferation indices on 7 dpa in control (n = 8) and mvp^−/− (n = 8) fish. Proliferation data were collected for 4–6 sections per heart and averaged to generate each data point. Data are mean ± SEM. n.s, not significant. (C) Section images of ventricles at designated time points, assessed for myocardium (MHC) recovery and scar tissue (fibrin, collagen) removal. In A, B and C, dashed line indicates approximate resection plane.

Spinal cord regeneration in mvp KO fish. (A) Proliferation of neural cells in control and mvp^−/− animals on 7 day post-injury (dpi), assessed by PCNA staining. Bar graph showing percentage of proliferating neural cells in control (n = 6) and mvp^−/− (n = 6) fish. epi, injury epicenter. (B) Upper panel, spinal cord structure of transected site by 30 dpi. Lower panel, retrograde tracing of axonal projections using Fluoro-Ruby (FR). Regenerating axons spanned the transection injury in both control fish (6/6) and mvp^−/− fish (4/5; p < 0.05). Asterisks indicate injury epicenter. In A and B, scale bars = 100 um. (C) Representative swim tracking of individual animals. (D) Quantification of total distance (mean ± SEM, n = 6 for each group) and speed in (C). n.s, not significant.

Fin regeneration in mvp KO fish. (A) Left panel, representative hematoxylin-stained sections of caudal fin regenerates (blastemal region) at 48 h post-amputation (dpa). Arrowheads indicate the plane of amputation. Middle panel, blastemal proliferation revealed by PCNA staining. Scale bar = 50 μm. Bar graph, cell proliferation (PCNA + cells) quantified in the blastema. PCNA + cell number was averaged among all sections spanning the entire fin width, and normalized to DAPI counts in the image. n.s, not significant. (B) Live images of fin regeneration in control and mvp^−/− zebrafish at designated time points. Scatter plot with mean ± SEM to show the length of regenerated tissue at 14 dpa (n = 9 for each group). (C) Representative images of bone structure (revealed by Alizarin red staining) of caudal fin in control and mvp^−/− fish on 14 dpa. Left lower panel, scatter plot with mean ± SEM to show the bifurcations in regenerated tissue (n = 9 for each group). Right lower panel, scatter plot with mean ± SEM to show the segment number in regenerated tissue (n = 9 for each group). n.s, not significant. In B and C, dashed line indicates approximate resection plane.

The effects of loss of mvp on injury-induced cell dearth and transcriptome landscape. (A) At 6 h post-surgery, cell death in heart and spinal cord was assessed with TUNEL staining. Bar graph showing number of TUNEL + cells, data are mean ± SEM. ∗∗P < 0.001, ∗P < 0.05. Data were collected for 6–8 sections per experiment set. Scale bar = 100 μm. (B) Principal component analysis (PCA) plots from the whole transcriptome of hearts from control and mvp^−/− fish. (C) Heat maps of selected gene sets. The colour intensity represents the log2 fold change of the gene expression.