Fig. 6. Tollo mRNA is expressed in ectodermal cells that surround differentiating neurons. After in situ hybridization (purple), embryos were stained with mAb 22C10 (brown) to visualize the relationship between differentiating neurons and Tollo-expressing ectodermal cells. (A) Segments of the peripheral ectoderm are shown (T2-A4, anterior towards the left, dorsal towards the top of the panel) from an early stage 14 embryo. Neurons differentiate within domains of tollo mRNA expression. (B) Higher magnification of T2 and T3 from A shows the intimate relationship between Tollo-expressing ectodermal cells and differentiating neurons. Scale bar: 60 µm in A; 20 µm in B.