Fig. 2

cxcr4a is indispensable for KV formation and ciliogenesis.

(A–B) Light micrographs at the 10-somite stage showed smaller or even absent KVs in cxcr4a^um20 or cxcl12b^mu100 mutants. Scale bar, 200 μm. Embryo ratios with different KV sizes were shown in (B). Underlying data can be found in  S1 Data. (C) Time-lapse confocal images from the 1-somite stage to the 6-somite stage showed the dynamic formation of KV in WT and cxcr4a-deficient Tg(sox17:GFP) embryos. Scale bar, 20 μm. The ratios of affected embryos were indicated. (D–F) Fluorescent immunostaining of KV using anti-GFP and anti-α-Tubulin antibodies at the 10-somite stage in WT embryos and cxcr4a^um20 mutants. The boxed areas in the images were presented at higher magnification in the relevant insets. Scale bar, 20 μm. Cilia average number and length were quantified from three independent experiments, and the group values were expressed as the mean ± SD (E and F). Student t test, *P < 0.05, **P < 0.01. Underlying data can be found in  S1 Data. (G) Fluorescent bead tracking experiments showed that fluorescent beads moved in a persistent counterclockwise fashion in WT embryos but had no directional flow in cxcr4a^um20 mutants. White spots, yellow spots, and curves mark the start points, the end points, and the tracks of bead movements, respectively. GFP, green fluorescent protein; KV, Kupffer’s vesicle; sox, SRY-box transcription factor; Tg, transgene; WT, wild-type; α-Tubulin, acetylated tubulin.