Sporothrix schenckii is a human pathogen that causes sporotrichosis, an important cutaneous mycosis with a worldwide distribution. It produces dark-brown conidia, which infect the host. We found that S. schenckii synthesizes melanin via the 1,8-dihydroxynaphthalene pentaketide pathway. Melanin biosynthesis in the wild type was inhibited by tricyclazole, and colonies of the fungus were reddish b...

Diversity in insect pigmentation, encompassing a wide range of colors and spatial patterns, is among the most noticeable features distinguishing species, individuals, and body regions within individuals. In holometabolous species, a significant portion of such diversity can be attributed to the melanin synthesis genes, but this has not been formally assessed in more basal insect lineages. Here ...

Evidence is presented that the resistance of Aspergillus nidulans hyphae to lysis by a beta-(1-->3) glucanase-chitinase mixture results from the presence of melanin in the fungal walls. The resistance of the walls to digestion was directly correlated with the melanin content of the mycelium. A melanin-less mutant of A. nidulans was highly susceptible to hydrolysis by the enzyme mixture. Preincu...

A primary role of melanin in skin is the prevention of UV-induced nuclear DNA damage to human skin cells, where it serves to screen out harmful UV radiation. Melanin is delivered to keratinocytes in the skin after being excreted as melanosomes from melanocytes. Defects in melanin production in humans can cause diseases, many of which currently lack effective treatments due to their genetic orig...

Melanins are enigmatic pigments produced by a wide variety of microorganisms including bacteria and fungi. Here, we have isolated and characterized extracellular melanin from mushroom fungus, Schizophyllum commune. The extracellular dark pigment produced by the broth culture of S. commune, after 21 days of incubation was recovered by hot acid-alkali treatment. The melanin nature of the pigment ...

Melanin is capable of transforming 99.9% of the absorbed sunlight energy into heat, reducing the risk of skin cancer. We here develop a melanin-mediated cancer immunotherapy strategy through a transdermal microneedle patch. B16F10 whole tumor lysate containing melanin is loaded into polymeric microneedles that allow sustained release of the lysate upon insertion into the skin. In combination wi...

The relationship between cell pigmentation and radiosensitivity was investigated in two selected human melanoma cell lines with different melanin content (mixed type: eumelanin and pheomelanin, and pheomelanotic phenotypes). The same study was also done after stimulation of melanogenesis (1) by addition of the melanin precursor l-tyrosine to each of the cell lines separately and (2) by irradiat...

The control mechanisms and information content of melanin-based color signals in birds have generated much recent interest and controversy among evolutionary biologists. Initial experimental studies on this topic manipulated coarse metrics of an individual's condition (i.e. food intake, disease state) and failed to detect significant condition-dependence of melanin ornament expression. However,...

the present study was designed to investigate the anti-melanogenic and cytotoxic activities of methanol extract of phlomis kurdica. the antioxidant and anti-tyrosinase activity of meoh extract from p. kurdica (mpk) were examined by dpph radical scavenging and mushroom tyrosinase activity assays (in vitro), respectively. furthermore, the effect of mpk on the melanin content, cellular tyrosinase ...