Expression of Nvi-Hox5 (top row, panels A, B,C) and Nvi-antiHox5 (bottom row D, E, F). The anterior end is to the right on all panels. All views are ventral. Asterisks mark a background. (A, D) Expression in small worms (5 or 6 segments). (B, E) Expression in juvenile worms (overview). (C, F) Posterior ends at higher magnification are shown. Expression domains of Nvi-Hox5 (C) and Nvi-antiHox5 (F) are complementary. See text for details.