Figure 3.
Meis1 and Meis2 are expressed in prospective lens placode ectoderm. (A) Whole-mount mRNA in situ hybridization shows strong Meis1 expression in the eye in E10.5 mouse embryos. Note that the Meis1 ocular expression domain extends beyond the Pax6 expression domain, while Meis2 is expressed at much lower levels in the eye at this developmental stage. (B) Meis1 and Meis2 proteins are expressed in the lens ectoderm of wild-type and Sey1Neu/Sey1Neu embryos at both E9.5 and E10.5 (yellow immunofluorescence). Optic vesicle and optic cup expression of Meis1 and Meis2 is also retained in Sey1Neu/Sey1Neu embryos. (oc) Optic cup; (ov) optic vesicle; (le) prospective lens ectoderm; (lv) lens vesicle. (C) Specificity of the Meis1 and Meis2 antibodies. Antibodies directed against Meis1 and Meis2 were tested on adjacent E10.5 mouse cryosections by immunohistochemistry. Meis1 but not Meis2 is strongly expressed in hindbrain, whereas Meis2 but not Meis1 is strongly expressed in nasal placode. These and other results (Toresson et al. 2000) support the specificity of these antibodies. (hb) Hindbrain; (np) nasal placode.