Fig. 7: Central hypothesis: evolution of the neural crest is linked to homology of RPE and melanocytes.

a Suggested scenario of the neural crest origin based on EMT of the CNS progenitors of pigmented ocelli for their placement in subcutaneous tissues and subsequent evolutionary transformation into photosensory pigmented melanocytes. b Scheme of evolutionary diversification of melanocytes and RPE cell types from the common origin of pigmented photoreceptors residing inside of the ancient chordate CNS. Created with BioRender.com. Licensed content used with permission.