Figure 4

Expression of Platynereis neural bHLH genes during trunk neurogenesis. Expression of Pdu-NeuroD, Pdu-neurogenin (Pdu-Ngn), Pdu-achete-scute (Pdu-ASH), Pdu-Olig, and Pdu-atonal (Pdu-ATH), as determined by WMISH, on a selection of larval stages is shown. Most of the images are ImageJ projections and all images are ventral views (anterior up). Labels are as in Figure 1. See the main text for the detailed descriptions of the expression patterns. In (B) and (C), arrows point to the groups of cells expressing Pdu-Ngn or Pdu-ASH and whose positions correspond to the neurons that will latter differentiate (compare with Figure 1B,C). In (G) and (H), the arrowheads point to putative PNS precursor cells. In (J), the arrow points to a weak medial expression of Pdu-Olig and arrowheads to its more lateral expression domains that form three bilateral small stripes. In (M, N, O, R, S, T), the arrow points to the medial expression and the arrowheads to the more lateral expression domains that lie outside the VNC. In (W-Y), arrowheads point to expressions in cells associated with the parapodes. Labelling associated with the parapodes in (U) is probably background (as seen at higher magnification).