FIGURE SUMMARY
Title

Ewing Sarcoma Ewsa Protein Regulates Chondrogenesis of Meckel's Cartilage through Modulation of Sox9 in Zebrafish

Authors
Merkes, C., Turkalo, T.K., Wilder, N., Park, H., Wenger, L.W., Lewin, S.J., Azuma, M.
Source
Full text @ PLoS One

4 dpf MZ ewsa/ewsa mutants display an aberrant angle of Meckel’s cartilage and palatoquadrate.

A. Lateral views (anterior to the left) of wt/wt (left) and MZ ewsa/ewsa (right) and ventral views of adult zebrafish. The calcified bones were visualized by alizarin red staining. B. Lateral views (anterior to the left) of (a) wt/wt and (b) MZ ewsa/ewsa and ventral views of (c) wt/wt and (d) MZ ewsa/ewsa chondrocytes from 4 dpf zebrafish embryos visualized with alcian blue. (e and f) Angle formed by Meckel’s cartilage showing that the palatoquadrate is wider in the MZ ewsa/ewsa mutant than wt/wt at 4 dpf and 7 dpf. bh: basihyal, d: dentary, m: Meckel’s cartilage, pq: palatoquadrate, ch: ceratohyal, cb: ceratobranchial.

Prehypertrophic chondrocytes of Meckel’s cartilage in MZ ewsa/ewsa fails to differentiate into hypertrophic chondrocytes.

A. Flat mounted Meckel’s cartilage of 4 dpf (left) wt/wt and (right) MZ ewsa/ewsa. B. Number of cells of Meckel’s cartilage of 4 dpf wt/wt and MZ ewsa/ewsa zebrafish (P = 0.0002). C. Lateral views (anterior to the left, dorsal to the top) of 4dpf (Left) wt/wt and (Right) MZ ewsa/ewsa visualized by in situ hybridization using probe for ihha (top panel) and colX (bottom panel). m: Meckel′s cartilage. D. Ventral views (anterior to the left) of Meckel′s cartilage of (Left) wt/wt and (Right) MZ ewsa/ewsa visualized by immunohistochemistry using (top) anti-IHH antibody (green), and anti-Collagen type II antibody (Red) (4dpf), and (bottom) anti-Collagen X antibody (green) and anti-Collagen type II antibody (Red) (5dpf).

MZ ewsa/ewsa mutants display altered expression domains of Sox9 target genes.

27hpf of (Left) wt/wt and (Right) MZ ewsa/ewsa visualized by in situ hybridization using antisense RNA probe for A. sox5, B. noggin1, C. noggin2, D. bmp4, E. ctgfa, F. ctgfb, G. col2a1a and H. col2a1b. Top panel: low magnification images, middle and bottom panel: high magnification images.

Ewsa binds to ctgfa and ctgfb target genes.

A. Lateral views (anterior to the left, dorsal to the top) of 4dpf of (Left) wt/wt and (Right) MZ ewsa/ewsa visualized by in situ hybridization using probe for ctgfa (tom panel) and ctgfb (bottom panel). m: Meckel′s cartilage. B. Ventral views (anterior to the left) of 4dpf Meckel′s cartilage of (Left) wt/wt and (Right) MZ ewsa/ewsa visualized by immunohistochemistry using anti-Ctgf antibody (green), and anti-Collagen type II antibody (Red). C. (left) Schematics of ctgfa and ctgfb genes. Black circle: Sox9 binding site, black square: exon, arrows: PCR primer for ChIP assay. (right) ChIP assays were performed using 27 hpf zebrafish embryos. IgG: negative control of ChIP, anti-Ewsa: ChIP sample using EWSa antibody, input: 4.5% of DNA from total lysates was subjected to PCR, dw: negative control for PCR reaction.

The MZ ewsa/ewsa mutant displays normal patterning.

The MZ ewsa/ewsa mutant displays normal patterning of craniofacial chondrocytes.

The Sox9 antibody recognizes zebrafish Sox9a.

EXPRESSION / LABELING:
Antibodies:
Fish:
Anatomical Terms:
Stage: Prim-5
Acknowledgments
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