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They have a dominant gene that causes hyperpigmentation (Fibromelanosis), making the chicken entirely black; including feathers, beak, and internal organs. Melanism in feral rock doves are actually quite common,to some extent, especially if the area is abundant with the species. The amount of pigmentation is varied, from a slight darker ...
Hyperpigmentation results from an increase in melanin synthesis, which is mostly brought on by sun exposure, dermatological disorders, hormones, aging, genetic factors, skin injuries or inflammation, and acne. Sun exposure, which greatly increases the synthesis of melanin, is the most common cause of hyperpigmentation.
Hyperpigmentation can be diffuse or focal, affecting such areas as the face and the back of the hands. Melanin is produced by melanocytes at the lower layer of the epidermis . Melanin is a class of pigment responsible for producing color in the body in places such as the eyes, skin, and hair.
Illustration of a melanocyte Micrograph of melanocytes in the epidermis. Through a process called melanogenesis, melanocytes produce melanin, which is a pigment found in the skin, eyes, hair, nasal cavity, and inner ear.
Poikiloderma is a skin condition that consists of areas of hypopigmentation, hyperpigmentation, telangiectasias and atrophy. Poikiloderma of Civatte is most frequently seen on the chest or the neck, characterized by red colored pigment on the skin that is commonly associated with sun damage.
Melasma (also known as chloasma faciei, [1]: 854 or the mask of pregnancy [2] when present in pregnant women) is a tan or dark skin discoloration.Melasma is thought to be caused by sun exposure, genetic predisposition, hormone changes, and skin irritation. [3]
The POMC gene is located on chromosome 2p23.3. The POMC gene is expressed in both the anterior and intermediate lobes of the pituitary gland. This gene encodes a 285-amino acid polypeptide hormone precursor that undergoes extensive, tissue-specific, post-translational processing via cleavage by subtilisin-like enzymes known as prohormone convertases.
The melanocyte-stimulating hormones, known collectively as MSH, also known as melanotropins or intermedins, are a family of peptide hormones and neuropeptides consisting of α-melanocyte-stimulating hormone (α-MSH), β-melanocyte-stimulating hormone (β-MSH), and γ-melanocyte-stimulating hormone (γ-MSH) that are produced by cells in the pars intermedia of the anterior lobe of the pituitary ...