Expression trends for genes that peak at each Drosophila melanogaster embryonic stage. Panels (1) to (12) correspond to the 12 successive developmental stages. Each panel displays the fitted expression trends for the top ten genes that achieve their peak expression during that stage. In particular, panel (1) shows genes that are most highly expressed at the first stage and panel (12) shows genes most highly expressed at the last stage. Panels (7) and (8) are notable because they show genes with marked peaks at 12–14 hours and 14–16 hours respectively.