ZFIN ID: ZDB-FIG-200318-28
Ren et al., 2019 - Canonical Wnt5b Signaling Directs Outlying Nkx2.5+ Mesoderm into Pacemaker Cardiomyocytes. Developmental Cell   50(6):729-743.e5 Full text @ Dev. Cell
ADDITIONAL FIGURES
EXPRESSION / LABELING:
Gene:
Fish:
Anatomical Term:
Stage: Day 4
PHENOTYPE:
Fish:
Observed In:
Stage Range: Long-pec to Day 4

Fig. 4 apc Loss-Of-Function Mutant (apcsd58) Displays Constitutively Activated Canonical Wnt Signaling and Ectopic Pacemaker Formation (A) Sequence analysis of sd58 mutants reveals a C to T nonsense mutation at amino acid 1,018 in the apc gene, thus resulting in a putative premature truncation. (B and C) Bright-field microscopy of the lateral view of (B) wild-type (n = 12 embryos) and (C) apcsd58 mutant (n = 10 embryos) embryos shows that apcsd58 mutants display an upward curved tail and edema at 48 hpf. Confocal images of (D, D’, F, F’, and H) wild-type and (E, E’, G, G’, and I) apcsd58 mutant embryos at 48 hpf reveal that apcsd58 mutant hearts display (E and E’) increased canonical Wnt-activation as detected by TCF:nlsmCherry (n = 8 embryos) and (G and G’) increased number of Isl1+/myl7+ pacemaker cardiomyocytes (n = 7 embryos) but (I) no appreciable change in overall cardiomyocyte numbers (n = 14 embryos) when compared to (D, D’, F, F’, and H) respective wild-type control hearts (n = 7, 9, and 15 embryos). Images in (D’–G’) are single channels from (D–G) merged images, respectively. Green, (D–G) myl7:eGFP and red, (D–E′) TCF:nlsmCherry, (F–G′) anti-Isl1 immunostaining, and (H and I) myl7:H2A-mCherry. (J and K) Bar graphs show the average number of (J) Isl1+/myl7+ pacemaker cardiomyocytes (CMs) from (F–G’) or (K) total cardiomyocytes from (H and I). (L and M) Optical-mapping of the propagation of calcium activation in (L) control (n = 9 embryos) and (M) apcsd58 mutant (n = 7 embryos) hearts at 48 hpf reveals retrograde cardiac conduction from ventricle to atrium in apcsd58 mutants. Numbers at each isochronal line (60-ms intervals) indicate temporal sequence of calcium activation in the heart. At, atrium and V, ventricle. Scale bar, 50 μm. Mean ± SEM. ∗p < 0.05 by Student’s t test. n.s., not significant. See also Figure S3.

Gene Expression Details
Gene Antibody Fish Conditions Stage Anatomy Assay
mCherry apcsd58/sd58; ia5Tg; twu277Tg control Day 4 heart IFL
ia5Tg; twu277Tg control Day 4 heart IFL
Antibody Labeling Details No data available
Phenotype Details
Fish Conditions Stage Phenotype
apcsd58/sd58 control Long-pec caudal fin curved dorsal, abnormal
Long-pec pericardial region edematous, abnormal
apcsd58/sd58; ia5Tg; twu277Tg control Day 4 heart canonical Wnt signaling pathway increased occurrence, abnormal
Day 4 heart mCherry expression increased amount, abnormal
Day 4 heart mCherry expression increased distribution, abnormal
apcsd58/sd58; sd12Tg control Long-pec heart cardiac muscle cell amount, normal
apcsd58/sd58; twu277Tg control Long-pec cardiac conduction system cardiac muscle cell increased amount, abnormal
Acknowledgments:
ZFIN wishes to thank the journal Developmental Cell for permission to reproduce figures from this article. Please note that this material may be protected by copyright.

Reprinted from Developmental Cell, 50(6), Ren, J., Han, P., Ma, X., Farah, E.N., Bloomekatz, J., Zeng, X.I., Zhang, R., Swim, M.M., Witty, A.D., Knight, H.G., Deshpande, R., Xu, W., Yelon, D., Chen, S., Chi, N.C., Canonical Wnt5b Signaling Directs Outlying Nkx2.5+ Mesoderm into Pacemaker Cardiomyocytes, 729-743.e5, Copyright (2019) with permission from Elsevier. Full text @ Dev. Cell