Fig. 1. stripeA and stripeB mRNAs show distinct expression profiles during embryonic development. Upper panel: schematic representation of the coding sequences of StripeA and StripeB isoforms, and the genomic region of the stripe gene (non-coding exons are shown in black and coding exons in white). Lower panel: whole embryo staining of stage 14 embryo, before muscle-tendon interaction (A-D), stage 15 (E-H), where part of the muscles are attached, or stage 17 embryos, where muscle-tendon interaction has been established (I-L). Staining was with anti-StripeA (red, A,E,I); anti-Stripe (blue, B,F,J; an antibody recognizing both Stripe isoforms); and anti-Myosin heavy chain (MHC, green, C,G,K). D,H and L are the corresponding merged images. Arrowheads in I point to the three muscle-bound tendon cells expressing high StripeA levels. The inset in L represents high magnification of the bracket showing about 14 blue-labeled tendon precursor cells, from which only three cells that are in close proximity with the three lateral transverse muscles express StripeA. NLS, nuclear localization signal; ZF, zinc finger.