Fig. 4. Mash1 and Dll1 are upregulated in sympatho-adrenal precursor cells of Insm1 mutant mice. Analysis of Mash1 expression by in situ hybridization and immunohistochemistry at E10.5 (A,B,E-H) and E12.5 (I,J), and of Dll1 expression at E10.5 (C,D) by in situ hybridization of Insm1^lacZ/+ and Insm1^lacZ/Insm1^lacZ mice. In situ hybridization using a probe specific for Mash1 (A,B,I,J) and Dll1 (C,D). Immunohistochemistry using antibodies against (E,F) β-galactosidase (red) and Mash1 (green); (G,H) Phox2a (red) and Mash1 (green). Scale bars: 100 µm in A,I; 50 µm in E.