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Review
. 2020 Dec;235(12):8972-8982.
doi: 10.1002/jcp.29824. Epub 2020 Jun 2.

Molecular and biochemical mechanisms of human iris color: A comprehensive review

Saeed Dorgaleleh  1 , Karim Naghipoor  1 , Ahmad Barahouie  1 , Farzad Dastaviz  1 , Morteza Oladnabi  2   3   4
Affiliations
Review

Molecular and biochemical mechanisms of human iris color: A comprehensive review

Saeed Dorgaleleh et al. J Cell Physiol. 2020 Dec.

Abstract

Eye color is determined as a polymorphism and polygenic trait. Brown is the most common eye color in the world, accounting for about 79%, blue eye color for about 8-10%, hazel for 5%, and green for 2%. Rare-colored eyes include gray and red/violet. Different factors are involved in determining eye color. The two most important factors are the iris pigment and the way light is scattered from the iris. Gene expression determines the iris pigmentation and how much melanin is present in the eye, which is the number of melanin subunits that identify eye color. The genes involved in the pigmentation of single-nucleotide polymorphism (SNP) have a significant role; and even some genes are included only in the eye color through SNP. MicroRNAs also affect melanocyte synthesis, which is usually affected by the downregulation of essential genes involved in pigmentation. In this study, we assess the biochemical pathways of melanin synthesis, and the role of each gene in this pathway also has been examined in the signaling pathway that stimulates melanin synthesis.

Keywords: eumelanin; iris color; melanin pathway; pheomelanin; pigmentation gene.

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References

REFERENCES

    1. Ambrosio, A. L., Boyle, J. A., Aradi, A. E., Christian, K. A., & Di Pietro, S. M. (2016). TPC2 controls pigmentation by regulating melanosome pH and size. Proceedings of the National Academy of Sciences of the United States of America, 113(20), 5622-5627. https://doi.org/10.1073/pnas.1600108113
    1. Aoki, H., Yamada, Y., Hara, A., & Kunisada, T. (2009). Two distinct types of mouse melanocyte: Differential signaling requirement for the maintenance of non-cutaneous and dermal versus epidermal melanocytes. Development, 136(15), 2511-2521.
    1. Caliebe, A., Harder, M., Schuett, R., Krawczak, M., Nebel, A., & von Wurmb-Schwark, N. (2016). The more the merrier? How a few SNPs predict pigmentation phenotypes in the Northern German population. European Journal of Human Genetics, 24(5), 739-747. https://doi.org/10.1038/ejhg.2015.167
    1. Chao, Y. K., Schludi, V., Chen, C. C., Butz, E., Nguyen, O. N. P., Muller, M., … Grimm, C. (2017). TPC2 polymorphisms associated with a hair pigmentation phenotype in humans result in gain of channel function by independent mechanisms. Proceedings of the National Academy of Sciences of the United States of America, 114(41), E8595-e8602. https://doi.org/10.1073/pnas.1705739114
    1. d'Ischia, M., Wakamatsu, K., Cicoira, F., Di Mauro, E., Garcia-Borron, J. C., Commo, S., … Meredith, P. (2015). Melanins and melanogenesis: From pigment cells to human health and technological applications. Pigment Cell & Melanoma Research, 28(5), 520-544.

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