Figure 7.

L-R asymmetric expression of Nodal and Lefty in the mouse embryo. Cluster analysis (top) shows the relations among members of the TGFβ superfamily of proteins. In situ hybridization (bottom) reveals the L-R asymmetric expression of Nodal (which encodes a left-side determinant) and Lefty (which encodes a feedback inhibitor of Nodal) in the E8.0 mouse embryo. Note that Nodal and Lefty are expressed in the LPM on the left side, whereas Lefty is also expressed at the midline (left side of the floor plate). There are actually two Lefty genes, with Lefty2 being preferentially expressed in the LPM and Lefty1 at the midline. Modified with permission from Shiratori and Hamada.¹⁵⁷⁾