Expression pattern of candidates for patterning genes. (A) Heat map of the relative expression level of 67 regulatory genes (transcription factors and signal transducers). Red indicates positive values and green indicates negative values (color spectrum bar is shown to the right; N.D., not detected). Red circles indicate the genes examined by whole-mount in situ hybridization in (B). Stage and marking of each sample is shown above. The stage-specific co-expression cluster and marking specificity of each gene are also shown. See also Figures 2 to 4. (B) Spatial expression patterns of spalt and E75 (probe designed at the common region of E75A and E75B) mRNA in P. xuthus larva during the fourth molt. Numbers in each panel indicate molt stage-hours after head capsule slippage. Black arrows indicate the position of 20E application.