1987/11/01 by Lynn W. Oliphant · 1 citation
Biochemistry, Genetics and Molecular Biology · #melanin and skin pigmentation #IRIS (biosensor) #Biology #Anatomy #Zoology #Artificial intelligence #Computer science
paper · doi:10.1111/j.1600-0749.1987.tb00414.x
openalex publication_date 1987/11/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/05/21
There are three genetically controlled iris types found in the pigeon, two of which contain stromal pigment cells, the third lacks pigment cells. The yellow (gravel) and white (pearl) iris types have pigment cells that contain birefringent pigment granules (crystals) and are ultrastructurally similar to iridophores of poikilothermic vertebrates. Both these iris types contain guanine as a major "pigment" and, in addition, the yellow iris contains at least two yellow fluorescing pigments that are tentatively identified as pteridines. The pigment cells of the yellow and white irises are structurally identical differing only in the presence or absence of these yellow pigments. The stromal pigment cells of the white iris correspond in structure and pigment chemistry to classical iridophores although they lack strong irridescence and are therefore perhaps best considered leucophores. The pigment cells of the yellow iris can be considered "reflecting xanthophores" having the combined properties of both classical xanthophores and iridophore/leucophores.