Fig. 2
aTUB-LIR and 5HT-LIR in early-stage C. teleta larvae (stages 4 – 6). Images are z-stack confocal images of larvae labeled with anti-acetylated-α-tubulin (green), anti-serotonin (red) and nuclear stain (blue). Panels labeled with an apostrophe (e.g., a') are single-channel images of either aTUB-LIR (’) or 5HT-LIR (”) from the merged image without an apostrophe (e.g., a) except where otherwise noted. The z-stack in g” is of the same animal, but includes more superficial focal planes in order to show cell bodies with 5HT-LIR. Panels a and c are cropped views of the brain. The two forming brain lobes (br) are indicated in a. The scale bar in e is 50 μm, and all images are to approximately the same scale. Open arrowheads in a, b’, c, d’, e’ indicate scac+. In b”, closed arrowheads point to a faint pair of neuronal cell bodies with 5HT-LIR and open arrows point to neurites with 5HT-LIR that run along the ventral side of the prototroch. The position of the prototroch (pt) and telotroch (tt) is indicated in e, f and g. The circumesophageal connectives (cc) and main connectives (mc) of the ventral nerve cord are indicated in e’. Open arrows in e” point to neurites with 5HT-LIR that run along the prototroch and telotroch. In f, f’, g and g’, lines mark the posterior boundary of segments three and four. In f’, closed arrows point to the right pair of ventral-lateral neurites that run from anterior to posterior. In f”, the open arrow indicates an aberrant neurite. Closed arrowheads in g” point to peripheral neurons with 5HT-LIR. Stage is indicated in the lower-left corner, and view is indicated in the lower-right corner, except for a and c, which are dorsal views. Anterior is to the left in all ventral views, and ventral is down in all anterior views. ant, anterior; cc, circumesophageal connectives; mc, main connectives; pt, prototroch; tt, telotroch; vent, ventral