Fig. 3. Embryonic expression of cv-c. cv-c RNA in situ hybridisation in wild-type (A-E) or cv-c^J17 (F) embryos. (A) Expression is not detected in blastoderm embryos, indicating a lack of maternal contribution. (B) Expression in stage 8 embryos is seen in the head (arrow) and head mesoderm, at the tip of the cephalic furrow, in the amnioserosa (arrowhead), and within distinct regions of the hindgut and midgut primordia. (C) At stage 11, cv-c transcripts are detected at high levels in the tracheal pits and in the epidermal cells that will later form the leading edge cells during dorsal closure (arrowhead). (D) At stage 13, cv-c is expressed in many tissues, including the MpTs (arrowhead), the longitudinal visceral muscle (LVM) of the midgut (black arrow), lymph glands, peripheral nervous system and regions of the head. (E) At stage 16, the highest level of cv-c is in the gut visceral musculature (arrowhead). (F) cv-c transcripts in cv-c^J17 mutant embryos are detected in the LVM of the midgut but are either absent or considerably reduced in other tissues (stage 13 embryo shown). In this, and all subsequent figures, embryos are orientated with anterior towards the left.