Figure 6

Development of the anterior two trunk ganglia in Hypsibius dujardini. Confocal z-series micrographs of embryos labeled for acetylated α-tubulin in ventral view. Anterior is up in all images. Contralateral and longitudinal pioneering axons are indicated by hollow and solid arrowheads, respectively. Asterisks (in (A) and (B)) indicate cells that will provide fibers to the central commissure of the first trunk ganglion. (A-F) Embryos of subsequent developmental stages. Each hemiganglion projects one longitudinal and one commissural pioneering axon (in (C)). Later in development, contralateral commissures grow toward the anterior adjacent segment (in (E)). Abbreviations: av, anteroventral cells; c1, c2, commissures of trunk ganglia 1 and 2; g1 to g3, anlagen of trunk ganglia 1 to 3; ic, inner connectives. Scale bars: (A-F), 5 μm.