Zebrafish chromatophores mediate background adaptation on exposure to dark (top) and light environments (bottom).

Chromatophores are pigment-containing and light-reflecting cells found in amphibians, fish, reptiles, crustaceans, and cephalopods. They are largely responsible for generating skin and eye colour in cold-blooded animals and are generated in the neural crest during embryonic development. Mature chromatophores are grouped into subclasses based on their colour (more properly "hue") under white light: xanthophores (yellow), erythrophores (red), iridophores (reflective / iridescent), leucophores (white), melanophores (black/brown) and cyanophores (blue). The term can also refer to coloured, membrane associated vesicles found in some forms of photosynthetic bacteria. Image File history File links Zfishchroma. ... Image File history File links Zfishchroma. ... Binomial name Danio rerio (Hamilton-Buchanan, 1822) The Zebra Danio or Zebrafish (Brachydanio rerio or Danio rerio) is a tropical fish, commonly kept in aquaria and used for scientific research, belonging to the minnow family (Cyprinidae). ... Illustrating the concept, i. ... The monarch butterflys distinctive pigmentation reminds potential predators that it is poisonous. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hook from Micrographia which is the origin of the word cell. POOP Cells in culture, stained for keratin (red) and DNA (green). ... Subclasses and Orders    Order Temnospondyli - extinct Subclass Lepospondyli - extinct Subclass Lissamphibia    Order Anura    Order Caudata    Order Gymnophiona Amphibians (class Amphibia; from Greek αμφις both and βιος life) are a taxon of animals that include all living tetrapods (four-legged vertebrates) that do not have amniotic eggs, are ectothermic (term for the animals... A giant grouper at the Georgia Aquarium Fish are aquatic vertebrates that are typically cold-blooded; covered with scales, and equipped with two sets of paired fins and several unpaired fins. ... Subclasses Anapsida Diapsida Synonyms Reptilia Laurenti, 1768 Reptiles are tetrapods and amniotes, animals whose embryos are surrounded by an amniotic membrane, and members of the class Sauropsida. ... Classes & Subclasses Branchiopoda Phyllopoda Sarsostraca Remipedia Cephalocarida Maxillopoda Thecostraca Tantulocarida Branchiura Pentastomida Mystacocarida Copepoda Ostracoda Myodocopa Podocopa Malacostraca Phyllocarida Hoplocarida Eumalacostraca The nauplius larva of a dendrobranchiate Porcellio scaber, the common rough woodlouse, a terrestrial crustacean Pollicipes polymerus, the gooseneck barnacle Glyphea pseudastacus, a fossil glypheoid The crustaceans (Crustacea) are... Orders Subclass Nautiloidea †Plectronocerida †Ellesmerocerida †Actinocerida †Pseudorthocerida †Endocerida †Tarphycerida †Oncocerida †Discosorida Nautilida †Orthocerida †Ascocerida †Bactritida Subclass †Ammonoidea †Goniatitida †Ceratitida †Ammonitida Subclass Coleoidea †Belemnoidea †Aulacocerida †Belemnitida †Hematitida †Phragmoteuthida Neocoleoidea (most living cephalopods) ?†Boletzkyida Sepiida Sepiolida Spirulida Teuthida Octopoda Vampyromorphida The cephalopods (Greek plural (kephalópoda); head-foot) are the mollusk class... Eye color is a polygenic trait and is determined primarily by the amount and type of pigments present in the eyes iris. ... This article needs to be cleaned up to conform to a higher standard of quality. ... The neural crest, a component of the ectoderm, is one of several ridgelike clusters of cells found on either side of the neural tube in vertebrate embryos. ... Embryogenesis is the process by which the embryo is formed and develops. ... An image with the hues cyclically shifted The hues in the image of this Painted Bunting are cyclically rotated with time. ... The term reflection (also spelt reflexion) can refer to several different concepts: In mathematics, reflection is the transformation of a space. ... The iridescence of the Blue Morpho butterfly wings. ... Phototrophs or photoautotrophs are photosynthetic algae, fungi, bacteria and cyanobacteria which build up carbon dioxide and water into organic cell materials using energy from sunlight. ...

Some species can rapidly change colour through mechanisms that translocate pigment and reorient reflective plates within chromatophores. This process, often used as a type of camouflage, is called physiological colour change. Cephalopods such as octopus have complex chromatophore organs controlled by muscles to achieve this, while vertebrates such as chameleons generate a similar effect by cell signaling. Such signals can be hormones or neurotransmitters and may be initiated by changes in mood, temperature, stress or visible changes in local environment. Countershaded Ibex are almost invisible in the Israeli desert. ... Suborders †Pohlsepia (incertae sedis) †Proteroctopus (incertae sedis) †Palaeoctopus (incertae sedis) Cirrina Incirrina Synonyms Octopoida Leach, 1817 The octopus (Greek , eight-legs) is a cephalopod of the order Octopoda that inhabits many diverse regions of the ocean, especially coral reefs. ... Genera Bradypodion Calumma Chamaeleo Furcifer Kinyongia Nadzikambia Brookesia Rieppeleon Rhampholeon Chameleons (family Chamaeleonidae) are squamates that belong to one of the best-known lizard families. ... Cell signaling is part of a complex system of communication that governs basic cellular activities and coordinates cell actions. ... Norepinephrine A hormone (from Greek όρμή - to set in motion) is a chemical messenger from one cell (or group of cells) to another. ... Chemical structure of D-Aspartic Acid, a common Amino Acid neurotransmitter. ...

Unlike cold-blooded animals, mammals and birds have only one class of chromatophore-like cell type: the melanocyte. The cold-blooded equivalent, melanophores, are studied by scientists to understand human disease and used as a tool in drug discovery. Subclasses Subclass Allotheria* Order Docodonta (extinct) Order Multituberculata (extinct) Order Palaeoryctoides (extinct) Order Triconodonta (extinct) Order Volaticotheria (extinct) Subclass Prototheria Order Monotremata Subclass Theria Infraclass Trituberculata (extinct) Infraclass Metatheria Infraclass Eutheria Mammals are a class of vertebrate animals characterized by the production of milk in females for the nourishment of... “Aves” redirects here. ... This article or section does not cite its references or sources. ... In medicine, biotechnology and pharmacology, drug discovery is the process by which drugs are discovered and/or designed. ...

Classification

Invertebrate pigment-bearing cells were first described as chromoforo in an Italian science journal in 1819.^[1] The term chromatophore was adopted later as the name for pigment bearing cells derived from the neural crest of cold-blooded vertebrates and cephalopods. The word itself comes from the Greek words khrōma (χρωμα) meaning "colour," and phoros (φορος) meaning "bearing". In contrast, the word chromatocyte (cyte or κυτε being Greek for "cell") was adopted for the cells responsible for colour found in birds and mammals. Only one such cell type, the melanocyte, has been identified in these animals. Invertebrate is a term that describes any animal without a spinal column. ... Classes and Clades See below Male and female Superb Fairy-wren Vertebrates are members of the subphylum Vertebrata (within the phylum Chordata), specifically, those chordates with backbones or spinal columns. ...

It wasn't until the 1960s that the structure and colouration of chromatophores were understood well enough to allow the development of a system of sub-classification based on their appearance. This classification system persists to this day even though more recent studies have revealed that certain biochemical aspects of the pigments may be more useful to a scientific understanding of how the cells function.^[2] Biochemistry is the study of the chemical processes and transformations in living organisms. ...

Colour-production falls into distinct classes: biochromes, schemochromes. The biochromes include true pigments, such as carotenoids and pteridines. These pigments selectively absorb parts of the visible light spectrum that makes up white light while permitting other wavelengths to reach the eye of the observer. Schemochromes, also known as "structural colours", produce colouration by reflecting some wavelengths (colours) of light and transmitting others, by causing light waves to interfere within the structure or by scattering light which falls upon them. The orange ring surrounding Grand Prismatic Spring is due to carotenoid molecules, produced by huge mats of algae and bacteria. ... Pteridine is a chemical compound composed of fused pyrimidine and pyrazine rings. ... The visible spectrum (or sometimes optical spectrum) is the portion of the electromagnetic spectrum that is visible to (can be detected by) the human eye. ... The wavelength is the distance between repeating units of a wave pattern. ...

While all chromatophores contain pigments or reflecting structures (except when there has been a genetic mutation resulting in a disorder like albinism), not all pigment containing cells are chromatophores. Haem, for example, is a biochrome responsible for the red appearance of blood. It is primarily found in red blood cells (erythrocytes), which are generated in bone marrow throughout the life of an organism, rather than being formed during embryological development. Therefore erythrocytes are not classified as chromatophores. It has been suggested that mutant be merged into this article or section. ... Albinism (from Latin albus; extended etymology), more technically hypomelanism or hypomelanosis, is a form of hypopigmentary congenital disorder, characterized by a lack of melanin pigment in the eyes, skin and hair (or more rarely the eyes alone). ... A hæm or heme is a metal-containing cofactor that consists of an iron atom contained in the center of a large heterocyclic organic ring called a porphyrin. ... Human red blood cells Red blood cells are the most common type of blood cell and the vertebrate bodys principal means of delivering oxygen from the lungs or gills to body tissues via the blood. ...

A veiled chameleon, Chamaeleo calyptratus. Structural green and blue colours are generated by overlaying chromatophore types to reflect filtered light.

Download high resolution version (1288x1220, 426 KB)Photograph of a female Chameleo Calyptratus. ... Download high resolution version (1288x1220, 426 KB)Photograph of a female Chameleo Calyptratus. ... Binomial name Chamaeleo calyptratus Duméril & Bibron, 1851 The Veiled Chameleon (Chamaeleo calyptratus), is a large species of chameleon found in the mountain regions of Yemen and Saudi Arabia. ...

Xanthophores and erythrophores

Chromatophores that contain large amounts of yellow pteridine pigments are named xanthophores and those with an excess of red/orange carotenoids termed erythrophores.^[2] It was discovered that pteridine and carotenoid containing vesicles are sometimes found within the same cell, and that the overall colour depends on the ratio of red and yellow pigments.^[3] Therefore the distinction between these chromatophore types is essentially arbitrary. The capacity to generate pteridines from guanosine triphosphate is a feature common to most chromatophores, but xanthophores appear to have supplemental biochemical pathways that result in an excess accumulation of yellow pigment. In contrast, carotenoids are metabolised from the diet and transported to erythrophores. This was first demonstrated by rearing normally green frogs on a diet of carotene-restricted crickets. The absence of carotene in the frog's diet meant the red/orange carotenoid colour 'filter' was not present in erythrophores. This resulted in the frog appearing blue in colour, instead of green.^[4] A yellow Tulip. ... Red is any of a number of similar colors evoked by light consisting predominantly of the longest wavelengths of light discernible by the human eye, in the wavelength range of roughly 625–750 nm. ... The orange, a fruit from which the modern name of the orange colour comes. ... This article or section is in need of attention from an expert on the subject. ... Guanosine triphosphate (GTP) is also known as guanosine-5-triphosphate. ... A few of the metabolic pathways in a cell. ... Carotene is responsible for the orange colour of the carrots and many other fruits and vegetables. ... Subfamilies See Taxonomy section Crickets, family Gryllidae (also known as true crickets), are insects somewhat related to grasshoppers and more closely related to katydids or bush crickets (order Orthoptera). ...

Iridophores and leucophores

Iridophores, sometimes also called guanophores, are pigment cells that reflect light using plates of crystalline schemochromes made from guanine.^[5] When illuminated they generate iridescent colours because of the diffraction of light within the stacked plates. Orientation of the schemochrome determines the nature of the colour observed.^[6] By using biochromes as coloured filters, iridophores create an optical effect known as Tyndall or Rayleigh scattering, producing bright blue or green colours.^[7] A related type of chromatophore, the leucophore, is found in some fish species. Like iridophores, they utilize crystalline purines to reflect light, providing the bright white colour seen in some fish. As with xanthophores and erythrophores, the distinction between iridophores and leucophores in fish is not always obvious, but generally iridophores are considered to generate iridescent or metallic colours while leucophores produce reflective white hues.^[7] Guanine is one of the five main nucleobases found in the nucleic acids DNA and RNA; the others being adenine, cytosine, thymine, and uracil. ... Shot of sunbeams breaking through nebula bank The term Tyndall effect is usually applied to the effect of light scattering on particles in colloid systems, such as suspensions or emulsions. ... Rayleigh scattering causing the blue hue of the sky and the reddening at sunset Rayleigh scattering (named after Lord Rayleigh) is the scattering of light, or other electromagnetic radiation, by particles much smaller than the wavelength of the light. ... YOU SUCK!!!!! ... Mossy, green fountain in Wattens, Austria. ... Purine is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring. ... A white rose. ... For alternative meanings see metal (disambiguation). ...

Melanophores

See also: Melanocyte

Melanophores contain eumelanin, a type of melanin, that appears black or dark brown because of its light absorbing qualities. It is packaged in vesicles called melanosomes and distributed throughout the cell. Eumelanin is generated from tyrosine in a series of catalysed chemical reactions. It is a complex chemical containing units of dihydroxyindole and dihydroxyindole-2-carboxylic acid with some pyrrole rings.^[8] The key enzyme in melanin synthesis is tyrosinase. When this protein is defective, no melanin can be generated resulting in certain types of albinism. In some amphibian species there are other pigments packaged alongside eumelanin. For example, a novel deep red coloured pigment was identified in the melanophores of phyllomedusine frogs.^[9] This was subsequently identified as pterorhodin, a pteridine dimer that accumulates around eumelanin. While it is likely that other lesser studied species have complex melanophore pigments, it is nevertheless true that the majority of melanophores studied to date do contain eumelanin exclusively. This article or section does not cite its references or sources. ... Melanin is a polymer of either or both of two monomer molecules: indolequinone, and dihydroxyindole carboxylic acid. ... Broadly, melanin is any of the polyacetylene, polyaniline, and polypyrrole blacks and browns or their mixed copolymers. ... Black cat, thought by some to cause bad luck (see superstition) Black is the shade of objects that do not reflect light in any part of the visible spectrum. ... Brown, when used as a general term, is a color which is a dark orange, red or rose, of very low intensity. ... Tyrosine (from the Greek tyros, meaning cheese, as it was first discovered in 1846 by German chemist Justus von Liebig in cheese[1][2]), 4-hydroxyphenylalanine, or 2-amino-3(4-hydroxyphenyl)-propanoic acid, is one of the 20 amino acids that are used by cells to synthesize proteins. ... Indole is an aromatic heterocyclic organic compound. ... Structure of a carboxylic acid The 3D structure of the carboxyl group A space-filling model of the carboxyl group Carboxylic acids are organic acids characterized by the presence of a carboxyl group, which has the formula -C(=O)OH, usually written -COOH or -CO2H. [1] Carboxylic acids are Bronsted... Pyrrole, or pyrrol, is a heterocyclic aromatic organic compound, a five-membered ring with the formula C4H5N. Pyrroles are components of larger aromatic rings, including the porphyrins of heme, the chlorins and bacteriochlorins of chlorophyll, and the corrin ring of vitamin B12. ... Tyrosinase (monophenol monooxygenase) (EC 1. ... Distribution of frogs (in black) Suborders Archaeobatrachia Mesobatrachia Neobatrachia - List of Anuran families The frogness babe is an amphibian in the order Anura (meaning tail-less from Greek an-, without + oura, tail), formerly referred to as Salientia (Latin saltare, to jump). ... Sucrose, or common table sugar, is composed of glucose and fructose. ...

Humans have only one class of pigment cell, the mammalian equivalent of melanophores, to generate skin, hair and eye colour. For this reason, and because the large number and contrasting colour of the cells usually make them very easy to visualise, melanophores are by far the most widely studied chromatophore. However, there are differences between the biology of melanophores and melanocytes. In addition to eumelanin, melanocytes can generate a yellow/red pigment called phaeomelanin. This article or section does not cite its references or sources. ... Melanin is a polymer of either or both of two monomer molecules: indolequinone, and dihydroxyindole carboxylic acid. ...

Dendrobates pumilio, a poison dart frog. Some brightly coloured species have unusual chromatophores of unknown pigment composition.

Image File history File linksMetadata Download high resolution version (1000x709, 300 KB) Summary Dendrobates pumilio (dart poison frog) from Costa Rica, Central America Licensing File links The following pages link to this file: Frog Poison dart frog User:Pstevendactylus Talk:Frog/Archive2 Metadata This file contains additional information, probably added... Image File history File linksMetadata Download high resolution version (1000x709, 300 KB) Summary Dendrobates pumilio (dart poison frog) from Costa Rica, Central America Licensing File links The following pages link to this file: Frog Poison dart frog User:Pstevendactylus Talk:Frog/Archive2 Metadata This file contains additional information, probably added... Distribution of Dendrobatidae (in black) Genera Proposed Subfamily Colostethinae proposed genus Ameerega Colostethus Epipedobates proposed genus Silverstoneia Proposed Subfamily Hyloxalinae Proposed genus Hyloxalus Proposed Subfamily Dendrobatinae Proposed genus Adelphobates Dendrobates Minyobates Proposed genus Oophaga Phyllobates Proposed genus Ranitomeya Proposed obsolete (invalid) Dendrobatidae genera: Cryptophyllobates Nephelobates The poison dart frog, poison...

Cyanophores

In 1995 it was demonstrated that the vibrant blue colours in some types of mandarin fish are not generated by schemochromes. Instead, a cyan biochrome of unknown chemical nature is responsible.^[7] This pigment, found within vesicles in at least two species of callionymid fish, is highly unusual in the animal kingdom, as all other blue colourings thus far investigated are schemochromatic. Therefore a novel chromatophore type, the cyanophore, was proposed. Although they appear unusual in their taxonomic restriction, there may be cyanophores (as well as further unusual chromatophore types) in other fish and amphibians. For example, bright coloured chromatophores with undefined pigments have been observed in both poison dart frogs and glass frogs.^[10] Binomial name Siniperca chuatsi Basilewsky, 1855 Mandarin fish, or Chinese Perch, Siniperca chuatsi, is a freshwater carnivorous fish which lives in China. ... Cyan (from Greek κυανοs, meaning blue) may be used as the name of any of a number of a range of colors in the blue/green part of the spectrum. ... “Animalia” redirects here. ... Distribution of Dendrobatidae (in black) Genera Proposed Subfamily Colostethinae proposed genus Ameerega Colostethus Epipedobates proposed genus Silverstoneia Proposed Subfamily Hyloxalinae Proposed genus Hyloxalus Proposed Subfamily Dendrobatinae Proposed genus Adelphobates Dendrobates Minyobates Proposed genus Oophaga Phyllobates Proposed genus Ranitomeya Proposed obsolete (invalid) Dendrobatidae genera: Cryptophyllobates Nephelobates The poison dart frog, poison... Genera Centrolene Cochranella Hyalinobatrachium The Centrolenidae, is a family of order Anura consisting of members commonly known as glass frogs. ...

Pigment translocation

Many species have the ability to translocate the pigment inside chromatophores, resulting in an apparent change in colour. This process, known as physiological colour change, is most widely studied in melanophores, since melanin is the darkest and most visible pigment. In most species with a relatively thin dermis, the dermal melanophores tend to be flat and cover a large surface area. However, in animals with thick dermal layers, such as adult reptiles, dermal melanophores often form three-dimensional units with other chromatophores. These dermal chromatophore units (DCU) consist of an uppermost xanthophore or erythrophore layer, then an iridophore layer, and finally a basket-like melanophore layer with processes covering the iridophores.^[11] Physiology (in Greek physis = nature and logos = word) is the study of the mechanical, physical, and biochemical functions of living organisms. ... The dermis is a layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. ...

Both types of dermal melanophores are important in physiological colour change. Flat dermal melanophores will often overlay other chromatophores so when the pigment is dispersed throughout the cell the skin appears dark. When the pigment is aggregated towards the centre of the cell, the pigments in other chromatophores are exposed to light and the skin takes on their hue. Similarly, after melanin aggregation in DCUs, the skin appears green through xanthophore (yellow) filtering of scattered light from the iridophore layer. On the dispersion of melanin, the light is no longer scattered and the skin appears dark. As the other biochromatic chomatophores are also capable of pigment translocation, animals with multiple chromatophore types can generate a spectacular array of skin colours by making good use of the divisional effect.^[12],[13]

A single zebrafish melanophore imaged by time-lapse photography during pigment aggregation

The control and mechanics of rapid pigment translocation has been well studied in a number of different species, particularly amphibians and teleost fish.^[14],[7] It has been demonstrated that the process can be under hormonal, neuronal control or both. Neurochemicals that are known to translocate pigment include noradrenaline, through its receptor on the surface on melanophores.^[15] The primary hormones involved in regulating translocation appear to be the melanocortins, melatonin and melanin concentrating hormone (MCH), that are produced mainly in the pituitary, pineal gland and hypothalamus respectively. These hormones may also be generated in a paracrine fashion by cells in the skin. At the surface of the melanophore the hormones have been shown to activate specific G-protein coupled receptors that, in turn, transduce the signal into the cell. Melanocortins result in the dispersion of pigment, while melatonin and MCH results in aggregation.^[16] Image File history File links Melanophore. ... Image File history File links Melanophore. ... Binomial name Danio rerio (Hamilton-Buchanan, 1822) The Zebra Danio or Zebrafish (Brachydanio rerio or Danio rerio) is a tropical fish, commonly kept in aquaria and used for scientific research, belonging to the minnow family (Cyprinidae). ... The flower of a geranium opening over a period of about two hours. ... Superorders Osteoglossomorpha Elopomorpha Clupeomorpha Ostariophysi Protacanthopterygii Sternopterygii Cyclosquamata Scopelomorpha Lampridiomorpha Polymyxiomorpha Paracanthopterygii Polymyxiomorpha Acanthopterygii Teleostei is one of three infraclasses in class Actinopterygii, the ray-finned fishes. ... Norepinephrine A hormone (from Greek όρμή - to set in motion) is a chemical messenger from one cell (or group of cells) to another. ... Chemical structure of D-Aspartic Acid, a common Amino Acid neurotransmitter. ... Norepinephrine, known as noradrenaline outside the USA, is a catecholamine and a phenethylamine with chemical formula C8H11NO3. ... The adrenergic receptors (or adrenoceptors) are a class of G_protein coupled receptors that is the target of catecholamines. ... Melanocortins are a group of pituitary peptide hormones that include adrenocorticotropin (ACTH) and the alpha, beta and gamma melanocyte stimulating hormones (MSH). ... Melatonin, 5-methoxy-N-acetyltryptamine, is a hormone found in all living creatures from algae[1] to humans, at levels that vary in a diurnal cycle. ... Melanin-concentrating hormone (MCH) is a cyclic orexinogenic hypothalamic peptide involved in the regulation of feeding behavior and energy balance. ... Paracrine signalling is a form of signalling in which the target cell is close to the signal releasing cell, and the signal chemical is broken down too quickly to be carried to other parts of the body. ... In cell biology, G-protein-coupled receptors, also known as GPCR, seven transmembrane receptors, heptahelical receptors, or 7TM receptors, are a class of transmembrane receptors. ...

Numerous melanocortin, MCH and melatonin receptors have been identified in fish^[17] and frogs,^[18] including a homologue of MC1R,^[19] a melanocortin receptor known to regulate skin and hair colour in humans.^[20] Inside the cell, cyclic adenosine monophosphate (cAMP) has been shown to be an important second messenger of pigment translocation. Through a mechanism not yet fully understood, cAMP influences other proteins such as protein kinase A to drive molecular motors carrying pigment containing vesicles along both microtubules and microfilaments.^{[21],[22],[23]} In biology, homology is any similarity between structures that is due to their shared ancestry. ... The Melanocortin-1 receptor (Mc1r) is one of the key proteins in hair colour production. ... Historical data for native populations collected by R. Biasutti prior to 1940. ... Human beings have many variations in hair color and texture. ... Structure of cAMP cAMP represented in three ways, the left with sticks-representation, the middle with structure formula, and the right with space filled representation. ... In biology, second messengers are low-weight diffusible molecules that are used in signal transduction to relay signals within a cell. ... In cell biology, cAMP-dependent protein kinase (cAPK), also known as protein kinase A (PKA)(EC 2. ... It has been suggested that this article or section be merged into Molecular motors. ... Microtubules are one of the components of the cytoskeleton. ... This article or section should be merged with actin Microfilaments or actin filaments are made up of two twisted monomeric actin subunits. ...

Background adaptation

See also: Camouflage

Most fish, reptiles and amphibians undergo a limited physiological colour change in response to a change in environment. This type of camouflage, known as background adaptation, most commonly appears as a slight darkening or lightening of skin tone to approximately mimic the hue of the immediate environment. It has been demonstrated that the background adaptation process is vision dependent (it appears the animal needs to be able to see the environment to adapt to it),^[24] and that melanin translocation in melanophores is the major factor in colour change.^[16] Some animals, such as chameleons and anoles, have a highly developed background adaptation response capable of generating a number of different colours very rapidly. They have adapted the capability to change colour in response to temperature, mood, stress levels and social cues, rather than to simply mimic their environment. Countershaded Ibex are almost invisible in the Israeli desert. ... A mimic is any species that has evolved to appear similar to another successful species in order to dupe predators into avoiding the mimic, or dupe prey into approaching the mimic. ... Genera Anolis Norops Phenacosaurus Polychrus Polychrotidae is a family of lizards commonly known as Anoles. ...

Transverse section of a developing vertebrate trunk showing the dorsolateral (red) and ventromedial (blue) routes of chromatoblast migration.

Image File history File links Download high resolution version (643x666, 260 KB) Summary I made this composite an release all rights Licensing File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links Download high resolution version (643x666, 260 KB) Summary I made this composite an release all rights Licensing File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... The term transverse means side-to-side, as opposed to longitudinal, which means front-to-back. In automotive engineering, the term transverse refers to an engine in which the crankshaft is oriented side-to-side relative to the wheels of the vehicle. ... A 3-D view of a beverage-can stove with a cross section in yellow. ... The human torso Torso is an anatomical term for the greater part of the human body without the head and limbs. ...

Development

During vertebrate embryonic development, chromatophores are one of a number of cell types generated in the neural crest, a paired strip of cells arising at the margins of the neural tube. These cells have the ability to migrate long distances, allowing chromatophores to populate many organs of the body, including the skin, eye, ear and brain. Leaving the neural crest in waves, chromatophores take either a dorsolateral route through the dermis, entering the ectoderm through small holes in the basal lamina, or a ventromedial route between the somites and the neural tube. The exception to this is the melanophores of the retinal pigmented epithelium of the eye. These are not derived from the neural crest, instead an outpouching of the neural tube generates the optic cup which, in turn, forms the retina. Embryogenesis is the process by which the embryo is formed and develops. ... The neural crest, a component of the ectoderm, is one of several ridgelike clusters of cells found on either side of the neural tube in vertebrate embryos. ... In the developing vertebrate nervous system, the neural tube is the precursor of the central nervous system, which comprises the brain and spinal cord. ... The ectoderm is outermost of the three germ layers of the developing embryo, the other two being the mesoderm and the endoderm. ... The basal lamina (often erroneously called basement membrane) is a layer on which epithelium sits. ... In the developing vertebrate embryo, somites are masses of mesoderm distributed along the two sides of the neural tube and that will eventually become dermis, skeletal muscle and vertebrae. ... The outer wall of the bulb of the optic vesicles becomes thickened and invaginated, and the bulb is thus converted into a cup, the optic cup (or ophthalmic cup), consisting of two strata of cells). ... Human eye cross-sectional view. ...

When and how multipotent chromatophore precursor cells (called chromatoblasts) develop into their daughter subtypes is an area of ongoing research. It is known in zebrafish embryos, for example, that by 3 days after fertilization each of the cell classes found in the adult fish — melanophores, xanthophores and iridophores — are already present. Studies using mutant fish have demonstrated that transcription factors such as kit, sox10 and mitf are important in controlling chromatophore differentiation.^[25] If these proteins are defective, chromatophores may be regionally or entirely absent, resulting in a leucistic disorder. Multipotent stem cells can give rise to several other cell types, but those types are limited in number. ... Categories: Biology stubs ... In molecular biology, a transcription factor is a protein that binds DNA at a specific promoter or enhancer region or site, where it regulates transcription. ... Sox genes belong to a super-family of genes characterised by a homologous sequence called the HMG (high mobility group) box. ... Microphthalmia means small eyes. ... A form of albinism. ...

Practical applications

In addition to basic research into better understanding of chromatophores themselves, the cells are used for applied research purposes. For example, zebrafish larvae are used to study how chromatophores organise and communicate to accurately generate the regular horizontal striped pattern in seen in adult fish.^[26] This is seen as a useful model system for understanding patterning in the evolutionary developmental biology field. Chromatophore biology has also been used to model human condition or disease, including melanoma and albinism. Recently the gene responsible for the melanophore-specific golden zebrafish strain, Slc24a5, was shown to have a human equivalent that strongly correlates with skin colour.^[27] For the suburb of Melbourne, Australia, see Research, Victoria. ... Animal model refers to a non-human animal with a disease that is similar to a human condition. ... Evolutionary developmental biology (evolution of development or informally, evo-devo) is a field of biology that compares the developmental processes of different animals in an attempt to determine the ancestral relationship between organisms and how developmental processes evolved. ... Melanoma is a malignant tumor of melanocytes. ... SLC24A5 (solute carrier family 24, member 5) is a gene that is thought to be one of many genes that control skin pigmentation in humans, and therefore implicated in defining race. ...

Chromatophores are also used as a biomarker of blindness in cold-blooded species, as animals with certain visual defects fail to background adapt to light environments.^[24] Human homologues of receptors that mediate pigment translocation in melanophores are thought to involved in processes such as appetite suppression and tanning, making them attractive targets for drugs.^[19] Therefore pharmaceutical companies have developed a biological assay for rapidly identifying potential bioactive compounds using melanophores from the African clawed frog.^[28] Other scientists have developed techniques for using melanophores as biosensors,^[29] and for rapid disease detection (based on the discovery that pertussis toxin blocks pigment aggregation in fish melanophores).^[30] Potential military applications of chromatophore mediated colour changes have been proposed, mainly as a type of active camouflage.^[31] In medicine, a biomarker is an indicator of a particular disease state or a particular state of an organism. ... The appetite is the desire to eat food, felt as hunger. ... Despite the risks, many female teens said in a survey with Seventeen that they look better with a tan and feel healthier, more sophisticated Sun tanning describes a darkening of the skin (especially of fair-skinned individuals) in a natural physiological response stimulated by exposure to ultraviolet radiation from sunshine... Pharmacology (in Greek: pharmacon is drug, and logos is science) is the study of how chemical substances interfere with living systems. ... Bioassay is a shorthand commonly used term for biological assay and is a type of in vitro experiment. ... Binomial name Xenopus laevis Daudin, 1802 The African clawed frog (Xenopus laevis, also known as platanna) is a species of South African aquatic frog of the genus Xenopus. ... A biosensor is a device for the detection of an analyte that combines a biological component with a physicochemical detector component. ... According to Sigma product information Pertussis toxin is released from B. pertussis in an inactive form. ... Illustrating the concept, i. ...

Cephalopod chromatophores

An infant cuttlefish, using background adaptation to mimic the local environment

Coleoid cephalopods have complex multicellular 'organs' which they use to change colour rapidly. This is most notable in brightly coloured squid, cuttlefish and octopuses. Each chromatophore unit is composed of a single chromatophore cell and numerous muscle, nerve, glial and sheath cells.^[32] Inside the chromatophore cell, pigment granules are enclosed in an elastic sac, called the cytoelastic sacculus. To change colour the animal distorts the sacculus form or size by muscular contraction, changing its translucency, reflectivity or opacity. This differs from the mechanism used in fish, amphibians and reptiles, in that the shape of the sacculus is being changed rather than a translocation of pigment vesicles within the cell. However a similar effect is achieved. Download high resolution version (2016x1512, 1057 KB)An infant cuttlefish Picture from Disney World. ... Download high resolution version (2016x1512, 1057 KB)An infant cuttlefish Picture from Disney World. ... Orders and Families †Vasseuriina †Vasseuriidae †Belosepiellidae Sepiina †Belosaepiidae Sepiadariidae Sepiidae Cuttlefish are marine animals of the order Sepiida belonging to the Cephalopoda class (which also includes squid, octopuses and nautiluses). ... Orders Sepiida Sepiolida Spirulida Teuthida Octopoda Vampyromorphida Subclass Coleoidea is the grouping of cephalopods containing all the primarily soft-bodied creatures. ... Suborders Myopsina Oegopsina Squid are a large, diverse group of marine cephalopods. ... Orders and Families †Vasseuriina †Vasseuriidae †Belosepiellidae Sepiina †Belosaepiidae Sepiadariidae Sepiidae Cuttlefish are marine animals of the order Sepiida belonging to the Cephalopoda class (which also includes squid, octopuses and nautiluses). ... This article or section does not cite its references or sources. ... In optics, transparency is the property of being transparent, or allowing light to pass. ... A substance or object that is opaque is neither transparent nor translucent. ...

Octopuses operate chromatophores in complex, wavelike chromatic displays, resulting in a variety of rapidly changing colour schemes. The nerves that operate the chromatophores are thought to be positioned in the brain, in a similar order to the chromatophores they each control. This means the pattern of colour change matches the pattern of neuronal activation. This may explain why, as the neurons are activated one after another, the colour change occurs in waves.^[33] Like chameleons, cephalopods use physiological colour change for social interaction. They are also among the most skilled at background adaptation, having the ability to match both the colour and the texture of their local environment with remarkable accuracy. A. A schematic view of an idealized action potential illustrates its various phases as the action potential passes a point on a cell membrane. ... Texture in geology refers to the physical appearance or character of a rock, such as grain size, shape, and arrangement, at both the megascopic or microscopic surface feature level. ...

Bacteria

Chromatophores are also found in membranes of phototrophic bacteria. Used primarily for photosynthesis, they contain bacteriochlorophyll pigments and carotenoids.^[34] In purple bacteria, such as Rhodospirillum rubrum the light-harvesting proteins are intrinsic to the chromatophore membranes. However, in green sulphur bacteria they are arranged in specialised antenna complexes called chlorosomes.^[35] Phototrophs or photoautotrophs are photosynthetic algae, fungi, bacteria and cyanobacteria which build up carbon dioxide and water into organic cell materials using energy from sunlight. ... Bacteriochlorophylls are photosynthetic pigments that occur in various bacteria. ... Purple bacteria or purple photosynthetic bacteria are proteobacteria that are phototrophic, i. ... This article lacks an appropriate Taxobox You can help Wikipedia by adding one. ... Green sulfur bacteria - Wikipedia, the free encyclopedia /**/ @import /skins-1. ... The antenna complex is an array of chlorophyll molecules embedded in the thylakoid membrane that transfer energy to a pair of chlorophyll a molecules at the reaction center of a photosystem. ... A Chlorosome is a photosynthetic antenna complex found in green sulfur bacteria (GSB) and some green filamentous anoxygenic phototrophs (FAP) (Chloroflexaceae, Oscillochloridaceae). ...

Notes

Oxford University Press (OUP) is a highly-respected publishing house and a department of the University of Oxford in England. ... Portable Document Format (PDF) is a file format created by Adobe Systems in 1993 for desktop publishing use. ... Portable Document Format (PDF) is a file format created by Adobe Systems in 1993 for desktop publishing use. ... Doheny Library. ... Portable Document Format (PDF) is a file format created by Adobe Systems in 1993 for desktop publishing use. ... A kibibyte (a contraction of kilo binary byte) is a unit of information or computer storage, commonly abbreviated KiB (never kiB). 1 kibibyte = 210 bytes = 1,024 bytes The kibibyte is closely related to the kilobyte, which can be used either as a synonym for kibibyte or to refer to...

External links

• Nature's Palette - how animals produce colourPDF (1.20 MiB)
• Video footage of octopus background adaptation
• Video footage of squid chromatophore patterning
• Tree of Life Web Project: Cephalopod Chromatophores