Netrins are unnecessary for CaP axons to extend to intermediate targets.
Projected confocal stacks of GFP-expressing motor axons in living Tg(mnx1:GFP) embryos injected with various MOs. A–C. In standard control MO-injected embryos CaP axons extend to the second intermediate target by 24 hpf (A), the third intermediate target by 30 hpf (B), and by 36 hpf have extended past the third intermediate target and wrap around the ventral aspect of the myotome (C). In ntn1a SBMO (D–F), ntn1b SBMO (G–I), and ntn2 SBMO (J–L) injected embryos the time course of CaP axon outgrowth was the same as in controls (A–C). Scale bar = 20 μm.