Fig. 4

Contribution of interneuromastic cells (INCs) to neuromast regeneration. a–d Complete elimination of all neuromasts and INCs between L3 and L8 was done 3 days post fertilization in tg(et20:GFP) larvae by electroablation (n = 20). Neuromasts were electroablated whereas INCs were ablated by mechanical displacement of the microelectrode through the skin. The white arrow in a shows the direction of the movement of the microelectrode. The asterisk in a shows the position of the L3 neuromast before electroablation. After injury, the behavior of INCs located proximal to the gap was examined at 11 hours post injury (hpi) (a), 30 hpi (b), 48 hpi (c), and 72 hpi (d). Starting at 30 hpi, INCs accumulated at the injury zone and organized to form a new neuromast. They also migrated, beginning at 48 hpi, extending caudally to create a new line of INCs. e–g An ectopic neuromast can appear de novo after electroablation. e The row of INCs between L2 and L3 was interrupted by electroablation at the position of the asterisk; the last remaining INCs are indicated by arrowheads. f At 21 hpi, INCs started to accumulate, reconnecting the line of cells. g At 72 hpi, a neuromast formed between L2 and L3 at a position where there was no preexisting neuromast (labeled ENm, ectopic new neuromast). At this stage, the secondary primordium (PrimII) was migrating close to L3 and had deposited secondary neuromast LII.3. Further details on replicates are provided in “Quantifications and statistical analysis” in the “Methods” section. Scale bar: 50 μm