Ventral nerves of Tg(Xla.Tubb:DsRed), Tg(sox10:NLS-Eos) double transgenic larvae treated with DMSO for control (A-D), or with the topoisomerase inhibitor 10-HCT (E-H); untransected controls (A,B,E,F) or laser nerve transected (C,D,G,H) at different time points: before transection (A,C,E,G) or 48 hours post transection (B,D,F,H). Graphical representation of the number of Schwann cells for the different conditions and time points (I). In DMSO controls, the number of Schwann cells was only non-significantly marginally reduced after laser nerve transection (C,D). Similarly, in untransected control nerves, 10-HCT did not reduce the number of Schwann cells, excluding the possibility that 10-HCT is simply toxic to Schwann cells. However, after laser nerve transection, the number of Schwann cells was significantly reduced, suggesting that 10-HCT specifically ablated denervated Schwann cells.