title: Choroidal melanocytes - a model for studying the aging process in nonreplicative differentiated cells.
abstract: Choroidal melanocytes differentiate and cease to divide early in postnatal life. They have characteristic organelles, the melanosomes, which are formed from tyrosine in a reaction catalyzed by tyrosinase. As animals become old, enzyme activity declines and the melanosomes show changes that are quantitatively and qualitatively correlated to the animal's increasing age.
mesh_terms: D000375:Aging; D000818:Animals; D002829:Choroid / Q000166:cytology* / Q000648:ultrastructure; D000882:Haplorhini; D008062:Lipofuscin / Q000032:analysis; D008253:Macaca mulatta; D008544:Melanocytes / Q000648:ultrastructure*; D008856:Microscopy, Fluorescence; D010857:Pigment Epithelium of Eye / Q000648:ultrastructure
chemical_list: D008062:Lipofuscin