Figure 1. Period Enhancer and Related Sequences in Other CLK/CYC Targets.

(A) Alignment of the central part of the 69-bp enhancer in the Drosophila period gene in the 12 species. Locations of E1 and E2 boxes are indicated.

(B) Similar sequences were found in promoters of the five known CLOCK/CYCLE targets: period, timeless, vri, Pdp1, and cwo (CG17100). Only the two most distant species are shown (D. melanogaster and D. grimshawi), but the elements are found across the full species tree.

(C) Species tree of sequenced Drosophila (from http://rana.lbl.gov/drosophila).