The effect of Coco MO on asymmetrically expressed genes. Stage 256 embryos were stained by in situ hybridization for Pitx2c (A), Xnr1 (D), and Xlefty-a (G). Left and right sides of the same embryos are shown. Panels G are dorsal views of cleared embryos, showing midline expression of Xlefty-a. Embryos injected in the right dorsal blastomere with 3 ng Coco MO have mostly bilateral expression of Pitx2c (B), Xnr1 (E), and Xlefty-a (H). Coinjection of Mut Coco RNA (10 pg) restores left-side expression in Coco MO-injected embryos (Pitx2c C, Xnr1 F, Xlefty-a I). Panels A, D, G are controls. Embryos in panels A were coinjected with 1 ng LacZ RNA and stained with Red Gal, to show that the right side was correctly targeted.