Common Origin of Pigment Cells

TLDR

Vertebrate pigment cells—melanophores, xanthophores, and iridophores—harbor distinct pigmentary organelles (melanosomes, pterinosomes, reflecting platelets) that contain melanins, pteridines, and purines. The study proposes that all pigment cells arise from a stem cell bearing a primordial endoplasmic reticulum–derived organelle. The primordial organelle is capable of differentiating into any of the known pigmentary organelles. Mosaic pigment cells and organelles containing multiple pigment types have been observed.

Abstract

The fundamentally diverse vertebrate pigment cells, melanophores, xanthophores, and iridophores, contain pigmentary organelles known, respectively, as melanosomes, pterinosomes, and reflecting platelets. Their pigments are melanins, pteridines, and purines. Mosaic pigment cells containing more than one type of organelle have been observed and mosaic organelles containing more than one type of pigment have been discovered. It is proposed that the various pigment cells are derived from a stem cell that contains a primordial organelle of endoplasmic reticular origin. This primordial organelle can differentiate into any of the known pigmentary organelles.