A, phenotypes generated by increasing doses of tbx5a mRNA. The percentage of embryos with the indicated defects was averaged across multiple independent experiments. The total number of embryos analyzed was as follows: mRNA-Tbx5a (35 pg) n = 48; mRNA-Tbx5a (100 pg) n = 199; mRNA-Tbx5a (200 pg) n = 131;. B, qRT-PCR analysis of miR-218a relative expression in 24 and 34 hpf embryos injected with 100 pg of tbx5a mRNA compared with embryos injected with 100 pg of GFP mRNA. C, phase-contrast and confocal images of representative transgenic Tg(cmlc2:eGFP) embryos at 72 hpf showing eye, heart and fin morphological defects induced by the injection of 100 pg (b,b′–c-c′) or of 200 pg (d,d′) of tbx5a mRNA. Arrowheads indicate eye alteration, arrows show fin absence. Labels: A, atrium, V, ventricle. Dotted lines encircle ventricle (white) and atrium (red). Scale bars: black 100 µm, red 25 µm.