Fig. 6. Enhancement of mlp84B mutant phenotypes by reduction in D-titin activity. (A) Enhancement of pupal lethality at 18°C displayed by mlp84B P-element alleles and sls mutants. Numbers given are the percentage of the number of mutant adults divided by the expected number for the cross. (B) Average axial ratios for pupae of indicated genotype. (^*P>10^–6, compared with the appropriate P-element allele alone.) (C) Representative pupae; bar, 200 µm. (D-H) Muscle fillets of third-instar larvae stained with Alexa Fluor-488 phalloidin. (D) Wild type; bar, 200 µm. (E) mlp84B^P8/Df(3R)dsx2M. (F) sls^j1D7mlp84B^P8/Df(3R)dsx2M; inset highlights torn muscle fibers. (G) sls^g05/sls^e4. (H) sls^j1D7/+. (I) Late-stage embryos labeled with D-titin antiserum to highlight muscle fiber morphology. (J) Single muscle fibers from third-instar larvae stained with Alexa Fluor-488 phalloidin: wild type (upper panel), mlp84B^P8/Df(3R)dsx2M (middle panel), sls^j1D7mlp84B^P8/Df(3R)dsx2M (lower panel); bar, 20 µm.