Fig. 7. Lhx5 regulates Sfrps that antagonize Wnt signaling in zebrafish forebrain. At gastrula stages, Wnt genes are expressed in the posterior paraxial mesoderm and Wnt signaling activates axin2 expression. Rostral ectodermal cells express Lhx5, which activates the expression of Sfrps. Sfrps in turn antagonize Wnt activity in the rostral ectoderm and axin2 expression is prevented. Similar events are likely to also occur in the presumptive forebrain at segmentation stage. Question mark denotes that other unknown Lhx5 downstream factors may also contribute to the antagonism of Wnt signaling.