Fig. 2. Oncopeltus even-skipped blastoderm expression. (A-F,J1-K3) stained with probe made to Of'eve. (A) Blastoderm at 20-24 hours. Of'eve transcript appears on the posterior two-thirds of the blastoderm surface. At this stage, transcript is evenly distributed around the blastoderm, without dorsal or ventral differences. (B) Blastoderm at 32-36 hours; dorsal aspect. The anterior boundary has refined to become the first stripe. (C) Embryo at a slightly later stage than in B; dorsal aspect. The first three stripes of Of'eve have already formed with the fourth stripe just becoming visible (arrowhead). (D) Embryo with four stripes visible. (E) Embryo with five stripes visible. Arrowheads bracket the remainder of the initial broad domain. (F) Lateral view of 36- to 40-hour-old embryo with all six Of'eve stripes visible on blastoderm surface. Posterior patch of transcript remains during germband invagination. Arrow indicates invagination site. (G) Blastoderm at 36-40 hour stained for Oncopeltus engrailed. Six vertical stripes of engrailed, corresponding to the mandibular (Mn) through third thoracic segments (T3) are present on blastoderm surface. Arrow indicates site of germband invagination. (H) Embryo at 36-40 hours stained for both hunchback (orange) and even-skipped (purple). Central band of Of'hb expression spans first three Of'eve stripes. Arrow indicates germband invagination. (I) Embryo at 36-40 hours stained for both Krüppel (orange) and even-skipped (purple). Of'Kr expression spans Of'eve stripes 4-6. Arrow indicates germband invagination. (J1-J3) The same 40-44 hour embryo as in I undergoing germband invagination stained for eve. (J1) Lateral aspect showing that first Of'eve stripe has faded, while stripe 6 is no longer visible on blastoderm surface. (J2) Ventral aspect. Stripe 6 in process of migrating to contribute to the germband. (J3) Higher magnification of embryo shown in J2. (K1-K3) Embryo during germband invagination, at a later stage than in J. (K1) Lateral aspect of blastoderm surface, showing that all Of'eve stripes on the blastoderm have faded. (K2) Embryo with ventral region of yolk removed to show underlying early germband. (K3) Higher magnification of same embryo. Expression of Of'eve can be seen in early germband and in three stripes (arrows). Scale bars: 200 µm.