Figure 10. A CaP/VaP-derived signal is not required for expression of the muscle pioneer-derived Netrin signal.

This image shows an 18 hpf embryo from which CaP/VaPs were removed before axogenesis from the two segments right of the dotted line, whereas CaP/VaPs were not removed from the segment left of the dotted line. The zn1 and znp1 antibodies used to label the motoneuron axons recognize both motoneuron somata and the somata of some other neurons in the ventral spinal cord [66], [71]. The segment on the left shows a CaP/VaP soma (dot) and its axon (arrow) labeled by the antibodies. The two segments on the right show somata of other neurons, but no CaP/VaP somata or motor axons. ntn1a mRNA (blue) was expressed in the muscle pioneers (*) whether CaP/VaPs were present (left) or absent (right). Scale bar  = 20 µm.