melanosome

noun
me·​la·​no·​some | \ mə-ˈla-nə-ˌsōm How to pronounce melanosome (audio) , ˈme-lə-nə- \
plural melanosomes

Definition of melanosome

: one of the membrane-bound spherical to elliptical granules within a melanocyte (as in skin, eyes, or hair follicles) that functions in the synthesis, storage, and transport of melanin and that transfer melanin from melanocytes to keratinocytes in skin and hair shafts The melanin emerges from the cells in tiny cucumberlike particles called melanosomes that rise through a branching network of tubelike connections, eventually to board the keratinocytes rising from the basal-cell layer to the outer keratin layer.— James C. G. Conniff also : a similar melanin-producing granule in a melanophore In contrast to mammalian melanosomes, the melanosomes in fish and amphibian melanophores, which are equivalent to the melanocytes in mammals, are rapidly transported bidirectionally in response to extracellular stimuli and are not transferred to neighboring cells. — M. Fukada

Examples of melanosome in a Sentence

Recent Examples on the Web Niacinamide, a form of vitamin B3, inhibits melanosome transfer (with melanin) to skin cells. Dori Price, Good Housekeeping, 23 Mar. 2021 The color produced by melanosomes is determined by their shape—round ones indicate a color anywhere from yellow to brown, while elongated ones are grayscale. Rachel Fritts, Ars Technica, 15 Jan. 2020 Tiny cellular structures called melanosomes vary in color depending on their shape: Black ones are sausage-like; reds are round. Popular Science, 11 Apr. 2020 The researchers found that hummingbirds’ melanosomes are far more intricate than those of other birds. Kate Baggaley, Popular Science, 10 Jan. 2020 The team also looked for the tiny melanosomes that could give an indication of the feathers’ former colors. Rachel Fritts, Ars Technica, 15 Jan. 2020 Keratin doesn’t fossilize well, but melanosomes often do. Meilan Solly, Smithsonian, 28 June 2019 Babarović wondered: Was there a distinctive melanosome shape associated with non-iridescent blues? Michael Greshko, National Geographic, 25 June 2019 In animals, colors are determined by the shape of the melanosomes, as well as pigment. Kristin Hugo, Newsweek, 15 Jan. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'melanosome.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of melanosome

1961, in the meaning defined above

History and Etymology for melanosome

melano- + -some entry 3

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Time Traveler for melanosome

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The first known use of melanosome was in 1961

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Dictionary Entries Near melanosome

melanose

melanosome

melanospermous

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Cite this Entry

“Melanosome.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/melanosome. Accessed 5 Dec. 2021.

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More Definitions for melanosome

melanosome

noun
me·​la·​no·​some | \ mə-ˈlan-ə-ˌsōm, ˈmel-ə-nō- How to pronounce melanosome (audio) \

Medical Definition of melanosome

: one of the membrane-bound spherical to elliptical granules within a melanocyte (as in skin, eyes, or hair follicles) that functions in the synthesis, storage, and transport of melanin and that transfer melanin from melanocytes to keratinocytes in skin and hair shafts The size and shape of eumelanin particles in the body depend on the size and shape of the melanosomes, the organelles in melanocytes that synthesize melanin.— Corinna Wu, Science News also : a similar melanin-producing granule in a melanophore

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