Fig. 4

Expression of left-right asymmetry genes in atp1a1a.1^m883 mutant embryos. A,B: charon is a negative regulator of nodal signaling, expressed around the KV. There is no difference in expression of cha in had^m883 mutant and wild-type embryos at the 14-somite stage. C,D: At the 15-somite stage, southpaw is expressed in left lateral plate mesoderm in wild-type, but bilaterally symmetric in m883 mutants. E,F: lefty1/antivin, another suppressor of nodal signaling, is expressed in the left heart primordium and the left diencephalon in the habenula of wildtype embryos, but reveals a clear isomerism of the heart anlage and the habenula expression domain in the mutant embryos at the 20-somite stage. G: pitx2 is expressed in the left heart anlage and lateral plate mesoderm, as well as a left domain in the diencephalon (I) in wildtype at the 22-somite stage, but is expressed bilaterally symmetric in both domains in atp1a1a.1 mutant embryos (H,J). A: Dorsal view onto the tail primordium (ventral side of embryo) anterior at top; B: lateral view anterior to the left; C-H: dorsal views with anterior at top (E slightly oblique); I,J: posterior-dorsal oblique view of brain with dorsal at top and left at left.