Fig. S3

Precision of Kaede photoconversion within the anterior somites of zebrafish. Primary green Kaede (Kaede^green) fluorescence and photoconverted red Kaede (Kaede^red) fluorescence. All images are whole-mount lateral views of a single embryo taken immediately after photoconversion, with anterior towards the left and dorsal towards the top. (A) Stereomicroscopic view of S1+2 photoconversion at 18 ss. (B) Superficial section through a ventral region photoconversion of S1+2 at 18 ss to avoid neural crest cells in the migratory zone (arrowheads). (C) Higher magnification view of unconverted neural crest cells. (D,E) Mesenchymal Kaede^red cells in ventral somite regions (D, arrowheads) share similar morphology to Kaedegreen somite cells (E, arrowheads). These cells are shown at higher magnification in M,N. (F) Middle section through a ventral region photoconversion of S1+2 at 18 ss. (G,H) Kaede^red cells in ventral somite regions (G, arrowheads) are distinct from endoderm (G, asterisk) and share identical morphology to Kaede^green myofibres that protrude anteriorly from the ventral somite (H, arrowhead). These cells are shown at higher magnification in K,L. (I,J) Medial section through a ventral region photoconversion of S1+2 at 18 ss reveals neural tube (NT) photoconversion (arrowheads). (K,L) High magnification of Kaede^red or Kaede^green myofibres that protrude from the ventral somite (dotted lines). (M,N) Mesenchymal Kaedegreen or Kaedered ventral somite cells have similar rounded morphology distinct from fibres that includes large intracellular zones of low Kaede fluorescence (asterisks). (O) These ‘rounded’ somite cells are distinct from endoderm cells, which are tightly connected and have a distinctive ‘flattened’ morphology (dotted lines).