Fig. 1. Hes1 and Hes5 expression in the developing nervous system. In-situ hybridization for Hes1 and Hes5 was performed with mouse embryos at E9.5 or indicated stages. (A-E) Hes1 and Hes5 exhibit mostly complementary expression patterns. Hes1 is expressed in the isthmus (A, arrowhead) and the optic vesicles (C,D, arrows) whereas Hes5 is not (B, arrowhead and E, arrow). (F) In the Hes1-null embryo, Hes5 is expressed in the optic vesicles (arrow). (G-J) Hes1 and Hes5 exhibit complementary expression patterns in the spinal cord. Hes1 and Hes5 expression is expanded in Hes5-null (H, arrows) and Hes1-null spinal cord (J, arrow), respectively. The dorsal is up in G-J. Scale bar: 50 µm in G-J.