Fig. 1

Combined loss of zebrafish Stag1b and Stag2b phenocopies the null cohesin mutation rad21. (A-C) Lateral views of representative wild-type (A), stag1b−/−; stag2b−/− (B) and rad21−/− (C) embryos at 48 h post-fertilization (hpf). Arrowheads indicate developmental anomalies: magenta for a small head, yellow for pericardial edema, and cyan for a kinked tail. (D-F) Expression of runx1 at 12 somites in wild-type (D), stag1b−/−; stag2b−/− (E) and rad21−/− (F) embryos. Lateral and posterior views are shown. White arrowheads indicate the loss of runx1 expression in PLM. The numbers in the lower left-hand corners of A-F indicate the number of embryos with similar expression patterns. (G-J) Confocal images of cell cycle progression in wild-type (G,I) and stag1b−/−; stag2b−/− (H,J) embryos at 48 hpf stained with anti-α-tubulin (cyan; main panel and left-hand insets), anti-phH3 (yellow; main panel and middle insets) antibodies and Hoechst (magenta; main panel and right-hand insets). Images are maximum intensity projections of three (0.15 μm) optical sections taken from the tail region of 48 hpf embryos. Scale bars: 500 μm (A-F); 5 μm (G-J).