Left-right asymmetry in the level of active Nodal protein produced in the node is translated into left-right asymmetry in the lateral plate of mouse embryos

► Nodal activity in node is asymmetric although Nodal mRNA is bilateral. ► Target of Nodal produced in the node is not node itself but lateral plate. ► Successful detection of Nodal activity (phosphorylated Smad2/3) in histology.