eumelanin/melasma

Stressful situations during development can shape the phenotype for life by provoking a trade-off between development and survival. Stress hormones, mainly glucocorticoids, play an important orchestrating role in this trade-off. Hence, how stress sensitive an animal is critically determines the

The occurrence of black fur, or melanism, in many mammalian species is known to be linked to DNA sequence variation in the agouti signaling protein (Asip) gene, which is a major determinant of eumelanin and pheomelanin pigments in coat color. We investigated 38 agouti (i.e., banded wildtype) and

Melasma, a hypermelanosis of the face, is a common skin problem of middle-aged women of all racial groups, especially with dark complexion. Its precise etio-pathogenesis is evasive, genetic influences, exposure to sunlight, pregnancy, oral contraceptives, estrogen-progesterone therapies, thyroid

BACKGROUND The morphology and contents of melanosomes are important features for differentiating melanocyte-derived melanotic lesions such as melanosis and malignant melanoma. METHODS In this study, we attempted to elucidate the structure of melanin and sulphur content in oral melanosis and

Melanosis of the urinary bladder is a very rare condition characterized by an abnormal black or brownish-black pigmentation of the organ. The pigmentary disorder can involve both the urothelial cell layers and/or the submucosa. The biologic potential of the melanosis of urinary bladder remains

The melanocortin system is implicated in the expression of many phenotypic traits. Activation of the melanocortin MC(1) receptor by melanocortin hormones induces the production of brown/black eumelanic pigments, while activation of the four other melanocortin receptors affects other physiological

An interesting example of extradermal deposition of melanin in vertebrates, notably in mammals, is splenic melanosis. In particular, if the phenomenon of splenic melanosis is correlated with hair or skin pigmentation, it must reflect the amount and perhaps the quality of pigment produced in hair

BACKGROUND Intra-specific variation in melanocyte pigmentation, common in the animal kingdom, has caught the eye of naturalists and biologists for centuries. In vertebrates, dark, eumelanin pigmentation is often genetically determined and associated with various behavioral and physiological traits,

Throughout the animal kingdom, adaptive colouration serves critical functions ranging from inconspicuous camouflage to ostentatious sexual display, and can provide important information about the environment and biology of a particular organism. The most ubiquitous and abundant pigment, melanin,

The black squirrel is a melanic variant of the gray squirrel (Sciurus carolinensis). We found 3 coat color variants in the gray squirrel: the wild-type gray, a jet-black, and a brown-black phenotype. These 3 morphs are due to varying distributions of eumelanin and phaeomelanin pigment in hairs. The