Fig. 3

FMRF-LIR in early-stage C. teleta larvae (stages 4 – 6). Images are z-stack confocal images of larvae labeled with anti-FMRF (red) and Hoechst nuclear stain (green). Panels labeled with an apostrophe (e.g., a') are single-channel images of FMRF-LIR from the merged image without an apostrophe (e.g., a). Panels a – c are cropped images of the brain. The scale bar in g is 50 μm, and all images are approximately the same scale. Open arrowheads in a’ and g’ indicate flask-shaped cells in the brain. The open arrowhead in d’ points to a cluster of cells with 5HT-LIR in the brain. The open arrow in d’, e’, f’ and i’ points to F-AMC. Closed arrowheads in e’ and h’ mark flask-shaped cells in the head. The position of the prototroch (pt) and telotroch (tt) is indicated in g, h and i. Closed arrows in h’ point to the right pair of ventral-lateral neurites that run from anterior to posterior. In h’ and i’, open arrowheads mark neurons in the ventral nerve cord with FMRF-LIR, anterior closed arrows point to cells with FMRF-LIR positioned lateral to the mouth, and lines indicate the posterior boundary of segments four and five. In i’, two closed arrowheads point to cells near the mouth. Stage is indicated in the lower-left corner, and view is indicated in the lower-right corner, except for a – c, which are dorsal views. Anterior is to the left in all ventral and dorsal views, and ventral is down in all anterior views. ant, anterior; dors, dorsal; pt, prototroch; tt, telotroch; vent, ventral