Information about Leucism
Leucism is a condition characterized by reduced pigmentation in animals. Unlike albinism, it is caused by a reduction in all types of skin pigment, not just melanin.
Leucism is a general term for the phenotype resulting from defects in pigment cell differentiation and/or migration from the neural crest to skin, hair or feathers during development. This results in either the entire surface (if all pigment cells fail to develop) or patches of body surface (if only a subset are defective) having a lack of cells capable of making pigment.
Since all pigment cell-types differentiate from the same multipotent precursor cell-type, leucism can cause the reduction in all types of pigment. This is in contrast to albinism, for which leucism is often mistaken. Albinism results in the reduction of melanin production only, though the melanocyte (or melanophore) is still present. Thus in species that have other pigment cell-types, for example xanthophores, albinos are not entirely white, but instead display a pale yellow colour.
More common than a complete absence of pigment cells is localized or incomplete hypopigmentation, resulting in irregular patches of white on an animal that otherwise has normal colouring and patterning. This partial leucism is known as a "pied" or "piebald" effect; and the ratio of white to normal-coloured skin can vary considerably not only between generations, but between different offspring from the same parents, and even between members of the same litter. This is notable in horses, the urban crow[1] and the ball python[2] but is also found in many other species. In contrast, albinism always affects the entire animal.
A further difference between albinism and leucism is in eye colour. Due to the lack of melanin production in both the retinal pigmented epithelium (RPE) and iris, albinos typically have red eyes due to the underlying blood vessels showing through. In contrast, leucistic animals have normally coloured eyes. This is because the melanocytes of the RPE are not derived from the neural crest, instead an outpouching of the neural tube generates the optic cup which, in turn, forms the retina. As these cells are from an independent developmental origin, they are typically unaffected by the genetic cause of leucism.
Genes that, when mutated, can cause leucism include, c-kit [3], mitf [4] and ''ednrb [5]
Morphogenesis (from the Greek morphê shape and genesis creation) is one of three fundamental aspects of developmental biology along with the control of cell growth and cellular differentiation.
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The retina is a thin layer of neural cells that lines the back of the eyeball of vertebrates and some cephalopods. It is comparable to the film in a camera.
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The retina is a thin layer of neural cells that lines the back of the eyeball of vertebrates and some cephalopods. It is comparable to the film in a camera.
..... Click the link for more information.
..... Click the link for more information.
Leucism is a general term for the phenotype resulting from defects in pigment cell differentiation and/or migration from the neural crest to skin, hair or feathers during development. This results in either the entire surface (if all pigment cells fail to develop) or patches of body surface (if only a subset are defective) having a lack of cells capable of making pigment.
Since all pigment cell-types differentiate from the same multipotent precursor cell-type, leucism can cause the reduction in all types of pigment. This is in contrast to albinism, for which leucism is often mistaken. Albinism results in the reduction of melanin production only, though the melanocyte (or melanophore) is still present. Thus in species that have other pigment cell-types, for example xanthophores, albinos are not entirely white, but instead display a pale yellow colour.
More common than a complete absence of pigment cells is localized or incomplete hypopigmentation, resulting in irregular patches of white on an animal that otherwise has normal colouring and patterning. This partial leucism is known as a "pied" or "piebald" effect; and the ratio of white to normal-coloured skin can vary considerably not only between generations, but between different offspring from the same parents, and even between members of the same litter. This is notable in horses, the urban crow[1] and the ball python[2] but is also found in many other species. In contrast, albinism always affects the entire animal.
A further difference between albinism and leucism is in eye colour. Due to the lack of melanin production in both the retinal pigmented epithelium (RPE) and iris, albinos typically have red eyes due to the underlying blood vessels showing through. In contrast, leucistic animals have normally coloured eyes. This is because the melanocytes of the RPE are not derived from the neural crest, instead an outpouching of the neural tube generates the optic cup which, in turn, forms the retina. As these cells are from an independent developmental origin, they are typically unaffected by the genetic cause of leucism.
Genes that, when mutated, can cause leucism include, c-kit [3], mitf [4] and ''ednrb [5]
Term origin and pronunciation
The terms leucistic and leucism are derived from medical terminology. The prefix leuc- is the Latin variant of leuk- from the Greek leukos meaning "white" (see Steadman’s, Dorland’s or Taber’s medical dictionaries). The correct pronunciation of leucistic is (loo-kiss-tic) and leucism is (loo-kism) since the prefix in Greek and Latin are pronounced with the hard C or K sound. Since the prefix leuc- is a variant of leuk-, in medical circles the terms may also be spelled with a k (leukistic and leukism).Gallery
) Leucistic Texas Rat Snake (Elaphe obsoleta) | ) Leucistic Common Grackle (Quiscalus quiscula) | ) | ) Leucistic Chipping sparrow (Spizella passerina) |
See also
pigment is a material that changes the color of light it reflects as the result of selective color absorption. This physical process differs from fluorescence, phosphorescence, and other forms of luminescence, in which the material itself emits light.
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Albinism
Classification & external resources
Albinistic boy
ICD-10 E 70.3
ICD-9 270.2
OMIM 203100 103470 , 203200 , 203280 ,
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Classification & external resources
Albinistic boy
ICD-10 E 70.3
ICD-9 270.2
OMIM 203100 103470 , 203200 , 203280 ,
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Broadly, melanin is any of the polyacetylene, polyaniline, and polypyrrole "blacks" and "browns" or their mixed copolymers. The most common form of biological melanin is a polymer of either or both of two monomer molecules: indolequinone, and dihydroxyindole carboxylic acid.
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phenotype describes the total physical appearance of an organism, as opposed to its genotype. This genotype-phenotype distinction was proposed by Wilhelm Johannsen in 1911 to make clear the difference between an organism's heredity and what that heredity produces.
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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
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The neural crest, a transient component of the ectoderm, is located in between the neural tube and the epidermis (or the free margins of the neural folds) of an embryo during neural tube formation.
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For the band, see .
Morphogenesis (from the Greek morphê shape and genesis creation) is one of three fundamental aspects of developmental biology along with the control of cell growth and cellular differentiation.
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pigment or biochrome is any material resulting in color of plant or animal cells, which is the result of selective color absorption. Many biological structures, such as skin, eyes, fur and hair contain pigments (such as melanin) in specialized cells called chromatophores.
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Multipotent progenitor cells can give rise to several other cell types, but those types are limited in number. An example of a multipotent stem cell is a hematopoietic cell — a blood stem cell that can develop into several types of blood cells, but cannot develop into brain
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Broadly, melanin is any of the polyacetylene, polyaniline, and polypyrrole "blacks" and "browns" or their mixed copolymers. The most common form of biological melanin is a polymer of either or both of two monomer molecules: indolequinone, and dihydroxyindole carboxylic acid.
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Melanocytes are cells located in the bottom layer (the stratum basale) of the skin's epidermis and in the middle layer of the eye (the uvea).
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Melanogenesis
Through a process called melanogenesis..... Click the link for more information.
MeSH D017496 Hypopigmentation is the loss of skin color. It is caused by melanocyte depletion — a decrease in the amino acid tyrosine, which is used by melanocytes to make melanin.
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piebald is an animal, especially a horse, that has a spotting pattern of large white and black patches. The colour of the horse's skin underneath its coat may vary between black (under the black patches of hair) and pink (under the white patches).
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H.O.R.S.E. is a form of poker commonly played at the high stakes tables of casinos. It consists of rounds of play cycling among:
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- Texas Hold 'em,
- Omaha eight or better,
- Razz,
- Seven card Stud, and
- Seven card stud E
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Corvus
Linnaeus, 1758
Species
See text.
The true crows are large passerine birds that comprise the genus Corvus. Ranging in size from the relatively small pigeon-sized jackdaws (Eurasian and Daurian) to the Common Raven of the
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Linnaeus, 1758
Species
See text.
The true crows are large passerine birds that comprise the genus Corvus. Ranging in size from the relatively small pigeon-sized jackdaws (Eurasian and Daurian) to the Common Raven of the
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P. regius
Binomial name
Python regius
(Shaw, 1802)
Synonyms
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Binomial name
Python regius
(Shaw, 1802)
Synonyms
- Boa regia - Shaw, 1802
- [Enygrus] regi[us].
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Eye color is a polygenic trait and is determined primarily by the amount and type of pigments present in the eye's iris.[1][2] Humans and animals have many phenotypic variations in eye color.
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- For the moth genus, see Retina (moth).
The retina is a thin layer of neural cells that lines the back of the eyeball of vertebrates and some cephalopods. It is comparable to the film in a camera.
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In anatomy, the iris (plural irises or irides) is the most visible part of the eye of vertebrates, including humans. The following describes the iris of vertebrates, not the independently evolved iris found in some cephalopods.
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neural tube is the embryo's precursor to the central nervous system, which comprises the brain and spinal cord. The neural groove gradually deepens as the neural folds become elevated, and ultimately the folds meet and coalesce in the middle line and convert the groove into a
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Optic cup can refer to:
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- Optic cup (embryology)
- Optic cup (ophthalmology)
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- For the moth genus, see Retina (moth).
The retina is a thin layer of neural cells that lines the back of the eyeball of vertebrates and some cephalopods. It is comparable to the film in a camera.
..... Click the link for more information.
For a non-technical introduction to the topic, see .
A gene is a locatable region of genomic sequence, corresponding to a unit of inheritance, which is associated with regulatory regions, transcribed regions and/or other functional sequence regions...... Click the link for more information.
mutations are changes to the base pair sequence of the genetic material of an organism. Mutations can be caused by copying errors in the genetic material during cell division, by exposure to ultraviolet or ionizing radiation, chemical mutagens, or viruses, or can occur deliberately
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CD117 is a cytokine receptor expressed on the surface of hematopoietic stem cells as well as other cell types.
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Synonyms
c-Kit, KITCell Surface Marker
Cluster of differentiation (CD) molecules are markers on the cell surface, as recognized by specific sets of..... Click the link for more information.
Microphthalmia (or microphthalmos) means small eyes. In mammals the failure of expression of a transcription factor, MITF (microphthalmia-associated transcription factor), in the pigmented retina prevents this structure from fully differentiating.
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Medical terminology is a vocabulary for accurately describing the human body and associated components, conditions, processes and procedures in a science-based manner. This systematic approach to word building and term comprehension is based on the concept of: (1) Word roots, (2)
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A prefix is the initial portion of some object or term (typically in text or speech) with a distinct and he base semantics for a word.
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- Numerical prefix, used for magnitudes of SI units, like 'kilo' and 'milli' in 'kilometre' and 'milligram'. See also SI prefix.
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Latin}}}
Official status
Official language of: Vatican City
Used for official purposes, but not spoken in everyday speech
Regulated by: Opus Fundatum Latinitas
Roman Catholic Church
Language codes
ISO 639-1: la
ISO 639-2: lat
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Official status
Official language of: Vatican City
Used for official purposes, but not spoken in everyday speech
Regulated by: Opus Fundatum Latinitas
Roman Catholic Church
Language codes
ISO 639-1: la
ISO 639-2: lat
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Greek}}}
Writing system: Greek alphabet
Official status
Official language of: Greece
Cyprus
European Union
recognised as minority language in parts of:
European Union
Italy
Turkey
Regulated by:
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Writing system: Greek alphabet
Official status
Official language of: Greece
Cyprus
European Union
recognised as minority language in parts of:
European Union
Italy
Turkey
Regulated by:
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