Fig. 8. Effects of the 1.6MO on ventrally projecting SMN axons are non cell-autonomous. In wild-type embryo mosaics (A,B), the presence of the 1.6MO (B) or ConMO (A) in ventrally projecting SMNs did not produce abnormally projecting axons. The lineage tracer fluorescein-conjugated dextran (green) was co-injected with the MO. SMN axons were revealed by zn8 immunocytochemistry (red). Ventrally projecting axons (arrows) are both zn8⁺ (red) and GFP⁺ (green), indicating that they contain axons of neurons derived from the MO-injected cell. (C,D) In embryos of the Tg(gata2:GFP) line, GFP⁺ (green) axons were abnormal even though they did not contain the lineage tracer rhodamine-conjugated dextran (red). However, other spinal neurons were positive for the lineage tracer (red), indicating that the 1.6MO had non cell-autonomous effects of ventrally projecting SMNs. Each panel contains a projection of six consecutive confocal sections. Scale bar: 40 µm.