Fig. 2

Single-cell DSCAM knockdown increases the branching and growth of tectal neurons in vivo. a Sample neurons of stage 45 tadpoles transfected with Alexa 488 dextran and lissamine-tagged Control MO or DSCAM MO and imaged in vivo by two-photon confocal microscopy over the course of 3 days. b Dendritic arbors were digitally reconstructed in three-dimensions using the Neuromantic tracing software. Filopodia, processes of less than 5 μm were manually measured and highlighted in red. c Dendritic arbors of neurons with DSCAM MO had significantly a higher number of branches than controls at each imaging time point, (d) and a higher total arbor length at 28-h and 48-h after initial imaging compared to controls. e Quantifying the rate of branch addition and the increase in total dendritic arbor length reveals that tectal neurons with DSCAM MO grow at a more robust and faster rate than controls (Student’s-t-test). b, f Tectal neurons had significantly more filopodia compared to controls by 48 h after initial imaging only. g, h Tectal neurons with DSCAM MO also extended significantly more axons (marked by the white arrows) than controls. Control MO (n = 31), DSCAM MO (n = 31). In c-e, comparisons are by Two-way ANOVA and Student’s t-test. * p ≤ 0.05, ** p ≤ 0.005, *** p ≤ 0.001. In h, statistical comparison was by Fisher’s Exact Test, p = 0.0192. Scale bars: 20 μm in (a & g); 10 μm in (b)