Figure 5
From: Myogenesis in the basal bilaterian Symsagittifera roscoffensis (Acoela)
Musculature of juvenile S. roscoffensis shortly before (A, B) and after (C, D) hatching. All images except B, which is a CLSM micrograph, are 3D reconstructions based on CLSM image stacks. Anterior is up in all aspects. Dorsal and ventral surfaces show different muscle patterns with longitudinal (lm), circular (cm) and diagonal (dm) muscles. A, B. Dorsal views. C, D. The ventral side of the animal contains additional U-shaped muscles (um), ventral crossover muscles (com) and antero-lateral accessory muscles (amm). D. A groove (pink) is formed in the region of the mouth (m). The dorsoventral musculature (dvm) is visible. Filaments of sensory receptor cells are marked with an arrow. E. Close-up of the mouth region, showing the ring muscle around the mouth opening (cmm) and accessory muscles emerging from there. F. Dorsal view of the anterior part showing the complex dorsoventral musculature. Scale bars: 50 μm (A-D), 10 μm (E), 25 μm (F).