Transplantation of basal epidermal cells demonstrates contribution to the EVL at late stages.

A: Schematic of transplantation strategy to test if the EVL of post metamorphosis larvae derives from the basal layer. Deep cells from krtt1c19e:lyn-tdtomato; krt4:lyn-egfp double transgenic embryos were transplanted into wild-type embryos after segregation of the EVL lineage at 4.3 hpf. Labelling of different epidermal cells was checked at 2 timepoints. B–G: Confocal images of the epidermis of representative recipient embryo at 7 dpf (B–D) and 26 dpf (E–G), immunostained for ΔNp63 (white; B,D–E, G), tdTomato (red; B,D–E, G) and eGFP (green; C–D, F–G). Transplanted deep cells only generate clones of basal cells expressing lyn-tdTomato at 7 dpf (B–D), but do not contribute to the EVL. The superficial layer is eGFP positive at 26 dpf indicating it is descended from the basal cells (E–G). n = 5 transplants were followed.