Isoprenoid synthesis genes are up-regulated in the head and tail of clo and scl^mo embryos. (A) Expression profile of the genes up-regulated in clo and scl^mo embryos at 36 hpf. Columns represent mutants of which name, tested allele, and the respective developmental stage are given; rows represent genes. Fold changes are shown as log2 (mutant/WT, or morphant/uninjected). Blue and yellow boxes indicate decreased and increased gene expression, respectively, in mutant compared with WT (morphant compared with uninjected) embryos. The expression of genes highlighted in red is further illustrated by in situ hybridization in panels B, C, D and E. (B-D) Expression of cyp51 at 36 hpf. In WT, transcripts are found in germ cells and at low levels in epidermal cells of the forehead and of the tail fin; in clo^m39 embryos, abundant expression of cyp51 is detected primarily in the eye, in the brain, and in epidermal cells of the forehead and the tail fin. Panel B shows lateral view; panel C shows dorsal view. (D) scl^mo embryos at 36 hpf show an expression pattern similar to clo, with transcripts of cyp51 abundant in the eye, in epidermal cells of the forehead and the tail fin, and around the otic placode. (E) WT embryos express only low levels of hmgcs1 in the brain and the eye at 36 hpf. In clo^m39 mutants at 36 hpf, hmgcs1 is highly expressed in the brain, in the eye, and in epidermal cells of the caudal fin.