Figure 15.

Expression patterns of Pdu-Hes13 and their schematic representations in Platynereis larvae and during posterior elongation (PE). Whole-mount in situ hybridization (WMISH) for the different stages indicated on each panel is shown. Pdu-Hes13 is first expressed in four bilateral patches at 24 h post fertilization (hpf). At 48 hpf, Pdu-Hes13 + cells of the ventral nerve cord (VNC), at the vicinity of the midline, are observed, in addition to few brain cells and stomodeum cells. At 72 hpf, the expression in cells around the midline, in the stomodeum and in the brain are maintained or extended (for the brain cells), and an additional expression in the cone-shaped midgut appears. During PE, this gene is still expressed in cells of the VNC around the midline plus in scattered gut cells. Panels are ventral views (anterior is up) for the larvae and during PE. Deeper ventral views (different focus plane) are highlighted in red for 48 and 72hpf larvae.