Fig. 1

Requirement for Ntl and Spt for expression of Nodal ligands and antagonists around Kupffer's Vesicle. A-F: Arrowhead: perinodal regions flanking Kupffer's Vesicle. Arrows: spaw expression in the LPM. s: somites stage. A,B: Wild-type sibs and ntl^b160 homozygotes from a ntl^b160 incross, respectively; 7-10s. Dorsal view of tailbud. Dig-spaw probe. C,D: Wild-type sib and ntl^b160 homozygotes; 16-19 s. Lateral view, tail to bottom left. Dig-spaw probe. E: Sixteen to 18 s. Dorsal view, tailbud to bottom right. Dig-spaw probe. Left: Injected with 12 ng Gene Tool's Negative Control Morpholino (NC-MO). Right: Injected with 8 ng spt MO2. F,G: Sixteen to 19 s. Dig-spaw probe. F: Dorsal view of tailbud. Left: Injected with 4 ng spt MO1. Right: Injected with 8 ng 5-mis-spt MO1. G: Lateral view, tail to left. Left: Injected with 4 ng spt MO1. Right: Injected with 8 ng 5-mis-spt MO1. H-J: Progeny of a ntl^b160 incross; 7-10 s. DNP-ntl (red) + Dig-cha (purple, arrowhead) probes. Dorsal view of tailbud. H: Wild-type sib. I,J: ntl^b160 homozygotes. K: Eleven to 12 s. Dorsal view. Dig-cha probe. Left: Injected with 4 ng ntl-1 MO (high dose ntl-1 MO). Right: Uninjected counterpart. L: Eight to 9 s. Dorsal view of tailbud. Dig-cha probe. Left: 8 ng NC-MO; Middle: 8 ng spt2 MO; Right: Uninjected. M: Eight to 9 s. Dig-cha probe. Left: 4 ng spt MO1. Right: 8 ng 5-mis-spt MO1. N,O: Eight to 11 s. Dig-cha probe. N: Injected with 8 ng spaw-1 MO. O: Injected with 8 ng NC-MO. P: Seventeen to 21 s. Dig-spaw probe. Dorsal view of tail. Arrowhead: perinodal spaw expression. Left: Injected with 1 ng lrdr1 MO. Arrow denotes reversed (right-side) spaw expression in the LPM. Right: Injected with 8 ng NC-MO. Q: Twelve to 15 s. Lateral view, head to top. Dig-krox20 (hindbrain) plus Dig-cha probe (arrowhead). Left: Injected with 1 ng lrdr1 MO. Right: Injected with 8 ng NC-MO.