Fig. 6. tsp mutant muscles interact with neighboring muscles and not with tendon cells. Wild-type embryos (A-E) and tsp mutant embryos (F-J) labeled for ßPS integrin (A,F, red) and Myosin heavy chain (B,G, MHC, green) are shown as well as their merged images (C,H). Arrowheads in F and H indicate sites of ectopic muscle-muscle interactions. The bracket in F and H indicates the sites of attachment of the lateral transverse muscles, showing significantly reduced PSß staining at the muscle-tendon attachment sites of two lateral transverse muscles and positive PSß staining when the third lateral transverse muscle is attached to other muscles (arrowheads in F,H). (D-J) High magnification of the ventral-longitudinal muscles of embryos stained for ßPS (red, D-J), MHC (green, D,I) and Stripe (blue, D-J). Arrowhead in I and J shows ßPS staining between the ventral-longitudinal muscle that is not associated with tendons; the arrowhead in D and E shows the parallel normal association of ßPS staining with tendons in wild type.