Fig. 6. Summary of Oncopeltus even-skipped evolution, expression and function. (A) Summary of even-skipped expression within the insects. Species where functional data for eve is known are listed in red. Some species with derived modes of embryogenesis such as polyembryony or complete early cleavage, have altered eve expression and may therefore represent secondarily derived conditions. The early broad domain of eve expression has been reported in several insects, but no function has ever been attributed to it. +, expression present in this species; –, expression not present in species;?, neither presence nor absence of expression was reported. Coleopteran, hymenopteran and dipteran phylogenies based on previous work (Lawrence, 1982; Dowton, 1994; Yeates, 1999). (B) Oncopeltus eve may occupy both upstream and downstream positions in the segmentation hierarchy. The early broad blastoderm expression (red) is required for activation of the blastoderm expression of the central hunchback and Krüppel domains. These gap genes may then in turn regulate striped Of'eve expression. (C) Summary of putative roles for Of'eve. The early broad blastoderm domain (red) is most likely responsible for regulation of hunchback and Krüppel. The eve stripes (blue) seen on blastoderms and germbands may regulate engrailed. The growth zone expression (red) may be required for proper growth of the posterior. The deleted region in Of'eve RNAi embryos is shown in purple.