ABSTRACT
N.M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences
INTRODUCTION
Shielding pigments of animal eyes are melanins for vertebrates and ommochromes for invertebrates. Melanins (eumelanins) represent a product of tyrosine or dioxyphenylalanine oxidative polymerizationon a protein matrix. In human eyes and eyes of vertebrates melanin is present as intracellular organelles - melanosomes, which are localized in the iris, retinal pigment epithelium (RPE) and choroids. Ommochromes represent the products of tryptophane oxidation and, similar to melanins, are encapsulated in small granules, localized in pigment and photoreceptor cells of the complex eye of the invertebrates.
