Figure 8

Leg musculature associated with the ventral and preventral organs. Confocal laser-scanning micrographs of Euperipatoides rowelli (Peripatopsidae). (A)  Vibratome cross-section of an adult specimen, double-labelled with phalloidin-rhodamine (f-actin; red) and a DNA marker (Bisbenzimide; blue) showing the prominent musculature associated with the ventral organ. Dorsal is up. Arrowheads point to ventral leg depressor muscles that attach to the ventral organ. (B) Musculature in an early stage VII embryo in ventral view (same embryo as in Figure 2I), double-labelled with phalloidin-rhodamine (f-actin; red) and a DNA marker (Bisbenzimide; blue). Anterior is up. Note that the presumptive anterior and posterior limb depressor muscles extend to the anlagen of the ventral (arrows) and preventral organs (arrowheads). (C) Limb musculature in a newborn juvenile in ventral view, labelled with phalloidin-rhodamine (f-actin; glow scale). Anterior is up. Note the anterior leg depressor, which connects to the preventral organ, whereas the posterior leg depressor attaches to the ventral organ. Abbreviations: ad, anterior leg depressor muscle; dp, dermal papilla; lg, presumptive leg; lm, longitudinal musculature; pd, posterior leg depressor muscle; pv, preventral organ; vo, ventral organ. Scale bars: 50 μm.