Fig. 4

Identification of spinal cord neurons in line 812C at 48 hpf.

(a) Lateral view of three GFP-positive neural cells situated in a non-uniform distribution along the dorsal longitudinal fasiculus (DLF) indicated by a tight grouping of neuronal projections. Axons projecting from neurons located in the contralateral DLF can be seen to rise from the ventral midline before joining the in-focus DLF (arrowheads). (b) Lateral view of a single GFP-positive neuron illustrating the projections originating from the cell. Two projections extend within the DLF – one ascending and one descending – and a third ventrally extending axon turns anteriorly and fades from view as it approaches the ventral midline before ascending in the contralateral DLF (not shown). (c) Two-colour in situ transcript hybridisation indicating that GFP-positive cells (stained red) are not the tbx16-positive dorsal longitudinal ascending interneurons (stained blue). (d) Two-colour in situ transcript hybridisation showing that neurons expressing GFP (stained red) also express mafba (stained blue). All embryos are positioned anterior left and dorsal up. Scale bars indicate 100 μm.