Fig. 4

Ct-syt1 expression in early-stage stage C. teleta larvae (stages 4 – 6). Panels show DIC images of animals after whole mount in situ hybridization for the synaptotagmin1 homolog Ct-syt1. In panels d, g, j and k, DIC images from multiple focal planes were merged in Helicon Focus to show more of the Ct-syt1 expression pattern. Open arrowheads in A and D indicate Ct-syt1 ⁺ cells along the ventral edge of the developing brain. The position of the prototroch (pt) and telotroch (tt) is indicated in b, c, e, f, h, i, k and l. Open arrowheads in E mark Ct-syt1 ⁺ cells around the mouth. Closed arrowheads in H and I point to Ct-syt1 ⁺ cells in the ganglia of the ventral nerve cord. Asterisks mark the position of the mouth. Stage is indicated in the lower-left corner, and view is indicated in the lower-right corner. All lateral views are of the left side. Anterior is to the left in all ventral, dorsal and lateral views, and ventral is down in all anterior views. ant, anterior; dors, dorsal; lat, lateral; pt, prototroch; tt, telotroch; vent, ventral