Electron microscopy of 11-day-old Notophthalmus viridescens retinal pigmented epithelium reveals particulate premelanosomes which are identical to the melanosomes found in the oocyte. These organelles, when found in the pigmented epithelium, are called premelanosomes because they undergo further maturation to form relatively homogeneous, spherical melanosomes. At this stage, oocyte melanosomes ...

Melanosomes of retinal pigment epithelium (RPE) have many vision supporting functions. Melanosome research would benefit from a method to isolate pure and characterized melanosomes. Sucrose gradient centrifugation is the most commonly used method for isolation of RPE melanosomes, but the isolated products are insufficiently characterized and their quality is unclear. Here we introduce a new gen...

Melanocytes present in skin and other organs synthesize and store melanin pigment within membrane-delimited organelles called melanosomes. Exposure of human skin to ultraviolet radiation (UV) stimulates melanin production in melanosomes, followed by transfer of melanosomes from melanocytes to neighboring keratinocytes. Melanosomal function is critical for protecting skin against UV radiation, b...

Fossil melanin granules (melanosomes) are an important resource for inferring the evolutionary history of colour and its functions in animals. The taphonomy of melanin and melanosomes, however, is incompletely understood. In particular, the chemical processes responsible for melanosome preservation have not been investigated. As a result, the origins of sulfur-bearing compounds in fossil melano...

Ultrasonic measurement of the two different forms of melanosomes was carried out at 20 to 300 MHz on B16 and Harding-Passey mouse melanomas which produce ellipsoidal-lamellar and spherical-granular melanosomes, respectively. We found that the structure of the two forms is basically amorphous and copolymeric in the molecular dimension of a segment composed of 5 to 6 zigzag units. A marked differ...

An ultrasonic measurement of melanosomes was carried out in frequencies from 0.333 MHz to 300 MHz on B16 and Harding-Passey (HP) mouse melanomas, which produce two different forms of melanosomes, i.e., ellipsoidal-lamellar melanosomes in B16 and splherical-graniular melanosomes in HP. We found that the structure of the two melanosomes is basically amorphous and co-polymeric in the molecular dim...

Cell types that generate unique lysosome-related organelles (LROs), such as melanosomes in melanocytes, populate nascent LROs with cargoes that are diverted from endosomes. Cargo sorting toward melanosomes correlates with binding via cytoplasmically exposed sorting signals to either heterotetrameric adaptor AP-1 or AP-3. Some cargoes bind both adaptors, but the relative contribution of each ada...

Segmental vitiligo is a unilateral subtype of characterized by cutaneous depigmentation due to melanocyte loss from the epidermis and hair follicle reservoirs. In many cases, this skin shares several clinical features dysfunctions with herpes zoster (HZ). Thus, we searched sign viral infection presence VZV in samples 40 SV, 3 HZ 10 generalized vitiligo. We observed that nuclear fusion epidermal...

This study elucidates the nature of melanogenesis in B16 and Harding-Passey (HP) mouse melanomas producing melanin and melanosomes of different color and fine structure, i.e., brown-black eumelanosome-like B16 granules and reddish brown pheomelanosome-like HP granules, and compares them with "typical" 3,4-dihydroxyphenylalanine (DOPA) and sepia eumelanins and sepia eumelanosomes. The melanin co...