Fig. 7. Activity of the Xena/XVASP proteins controls the formation of branches at retinal axon terminals. Branching parameters in control GAP-GFP-expressing and FP4-Mito-RFP+GAP-GFP-expressing neurons. The total number of branches, the total number of nodes, the number of primary and secondary branches, the length of primary branch segments, and the length of the total arborization are shown at the time of tectum entry (t0h), or at 1, 2 and 3 hours (t1h, t2h and t3h, respectively) after the retinal ganglion cell (RGC) axons have invaded the tectum (mean±s.e.m. from a sample of 20 retinal axons). ^*P<0.05, ^**P<0.01 and ^***P<0.001, FP4-Mito-expressing axons compared with corresponding control axons. °P<0.05 and °°P<0.01, axons at 1, 2 and 3 hours compared with axons at 0 hours.