Fig. 1. Expression of prep1.1 transcripts during development. (A) Dendrogram, obtained using the ClustalW program, of zebrafish Meis1.1, Meis2.1, Meis3.1 and Prep1.1, human PREP1 and PREP2 (hPREP1 and hPREP2), and Drosophila Homotorax (drHTH) protein sequences. (B) RT-PCR amplifies prep1.1 transcripts in zebrafish embryos at all stages from 2-16 cells to 4 dpf, and in ovaries of mature females. (C-I) RNA in situ hybridization of wild-type embryos. (C-F) prep1.1 transcripts are distributed ubiquitously up to 18 hpf. Arrows in E indicate head mesoderm. (G-I) From 24 hpf onwards prep1.1 transcripts concentrate in the head and become restricted to the region rostral to the otic vesicles (ov) at 72 hpf. Embryo in D is in lateral view with ventral to the left. Embryo in E is in frontal view. Embryos in F-H are in dorsal view and embryo in I is in lateral view. e, eye; m, midbrain; h, hindbrain; t, telencephalon.