Chrispijn et al., 2019 - Loss of the Polycomb group protein Rnf2 results in derepression of tbx-transcription factors and defects in embryonic and cardiac development. Scientific Reports   9:4327 Full text @ Sci. Rep.

Figure 1

Zygotic rnf2 mutant zebrafish embryos show a pleiotropic phenotype. (a) Lateral view of wildtype embryos (left panel) and rnf2 mutant embryos (right panel) at 3 dpf. The rnf2 mutants show a pleiotropic phenotype, including motility problems, craniofacial defects (arrowheads), lack of pectoral fins, and a pronounced heart edema (arrowheads). Not all phenotypes are visible in the pictures. Scale bar = 1 mm. (b) Expression of tissue-specific markers was assessed by WISH at 3 dpf in wildtype and rnf2 mutant embryos. fabp2: intestinal marker, fabp10: liver marker, try: exocrine pancreas marker (arrowhead indicates pancreatic lobe), and myl7: cardiomyocyte marker. Scale bar is 200 µm.

Figure 4

Zebrafish rnf2 mutant embryos show cardiac looping defects. (a) Fluorescent images of wildtype and rnf2 mutant sibling embryos in a Tg(myl7::GFP) background at 3 dpf. Scale bar is 500 µm. (b) Stills of live-imaging by light sheet microscopy of wildtype and rnf2 mutant hearts in a Tg(myl7::GFP) background starting at 1 dpf. Scale bar is 100 µm.

Figure 6

Cardiac chamber identity is disrupted in rnf2 mutants at 3 dpf. (a) GSEA using the list of cardiac genes reported by Hill et al.38 indicates that the group of transcription factors is significantly enriched in being upregulated in rnf2 mutant hearts at 3 dpf as detected by Single HeartsRNA-seq (FDR q-value = 0.001; NES = 1.96). The leading transcription factors (n = 9) are listed in the zoom of the GSEA plot. (b) GSEA indicates the annotation ‘Structural Group’ genes (n = 23) to be enriched for downregulation upon the rnf2 mutation in hearts at 3 dpf. The leading genes (n = 8) are listed in the zoom of the GSEA plot. FDR q-value = 0.054; NES = −1.67. (c) Normalized counts as found by Single HeartsRNA-seq for nppa, myl7, myh6, and vmhc at 3 dpf in wildtype and rnf2 mutant hearts with their accompanying whole mount in situ hybridizations. Scale bar is 200 µm.

ZFIN wishes to thank the journal Scientific Reports for permission to reproduce figures from this article. Please note that this material may be protected by copyright. Full text @ Sci. Rep.