Melanophores are specialized cells derived from the neural crest that contain membrane bound vesicles called melanosomes. Melanosomes are filled with melanin, a dark, nonfluorescent pigment that plays a principal role in physiological color adaptation of animals. Melanophores regulate melanosome trafficking on cytoskeletal filaments to generate a range of striking chromatic patterns. The mechan...

A prominent element of the early larval pigment pattern in the salamander Ambystoma tigrinum tigrinum (family Ambystomatidae) is a horizontal stripe over the lateral surface of the myotomes where otherwise abundant, neural crest-derived melanophores are not found. This study examines the formation of this "melanophore-free region". When the trunk lateral lines were ablated (by removing cranial ...

The results thus obtained, had shown a clear picture that fishes depending on the level of pollutants surrounding them in aquous medium have got darker melanophores turn, skin pigmentation comparison to control group fishes.

Many factors, both internal and external, influence the chromatic changes of coldblooded vertebrates, and of these, three external variables are recognized as significant—light, heat and moisture. The frog can change its colour, from brown or black through intermediate tints to pale lemon, by changing the contraction and expansion of three types of chromatophores—the epidermal and dermal melano...

Multipotent neural crest stem cells have been identified in late gestation amniote embryos. Yet, significant questions remain about the mechanisms by which these cells are generated, maintained, and recruited during postembryonic development. The zebrafish, Danio rerio, offers an opportunity to identify genes essential for these processes, by screening for mutants with defects in traits likely ...

Colour patterns of adult fish are produced by several types of pigment cells that distribute in the dermis during juvenile development. The zebrafish, Danio rerio, displays a striking pattern of dark stripes of melanophores interspersed by light stripes of xanthophores. Mutants lacking either cell type do not form proper stripes, indicating that interactions between these two chromatophore type...

We used melanophores, cells specialized for regulated organelle transport, to study signaling pathways involved in the regulation of transport. We transfected immortalized Xenopus melanophores with plasmids encoding epitope-tagged inhibitors of protein phosphatases and protein kinases or control plasmids encoding inactive analogues of these inhibitors. Expression of a recombinant inhibitor of p...

Melanin concentrating hormone (MCH: 5 x 10(-12)-5 x 10(-8) M) induced a concentration related, rapid and reversible pigment aggregation in innervated melanophores of Labeo rohita. In inducing melanosome aggregation MCH was found to be 10(4) times more potent than norepinephrine. Experiments employing phentolamine and propranolol suggest that MCH acts through its own specific receptors on the me...

Full expansion and complete contraction are, then, the results of such stimuli as light, extremes of heat and cold, pituitrin, and adrenalin. Moderate contraction (B) might well be called a state of relaxation when the dermal melanophores are under no stimulation-room temperature and darkness being taken as the absence of all stimuli. My results on Necturus confirm those of Dawson in that the m...