1
Kos cerny s leucismem Turdus merula Blackbird with leucism Iiri Safranek
Kos cerny s leucismem Turdus merula Blackbird with leucism Iiri Safranek
DATE: 2014/10/14::
2
Leucism and Albinism in American Robins
Leucism and Albinism in American Robins
DATE: 2013/11/18::
3
白変種ホオジロ♂囀り・鳴き声(leucism)(Meadow Bunting・Emberiza cioides)(song)
白変種ホオジロ♂囀り・鳴き声(leucism)(Meadow Bunting・Emberiza cioides)(song)
DATE: 2011/07/25::
4
Kos cerny s leucismem2 Turdus merula Blackbird with leucism Adolf Goebel
Kos cerny s leucismem2 Turdus merula Blackbird with leucism Adolf Goebel
DATE: 2014/03/02::
5
Vit duva. Albino / Leucism fågel.
Vit duva. Albino / Leucism fågel.
DATE: 2014/02/04::
6
White mallards by leucism
White mallards by leucism
DATE: 2013/08/18::
7
白いヒドリガモ  Wigeon (Leucism)
白いヒドリガモ  Wigeon (Leucism)
DATE: 2013/02/12::
8
White Tiger (Panthera tigris tigris) with leucism
White Tiger (Panthera tigris tigris) with leucism
DATE: 2013/05/29::
9
Kos cerny sber potravy Turdus merula Blackbird with leucism Adolf Goebel
Kos cerny sber potravy Turdus merula Blackbird with leucism Adolf Goebel
DATE: 2012/07/25::
10
Leucism in the Family . 1
Leucism in the Family . 1
DATE: 2014/08/16::
11
LEUCISM IN 2 BIRD SPECIES FILMED FEEDING TOGETHER
LEUCISM IN 2 BIRD SPECIES FILMED FEEDING TOGETHER
DATE: 2008/11/23::
12
Leucism in the Family . 2
Leucism in the Family . 2
DATE: 2014/08/16::
13
Introducing Luke The Leucistic Waterbuck Calf
Introducing Luke The Leucistic Waterbuck Calf
DATE: 2014/09/30::
14
白化鷹斑鷸 Wood Sandpiper(Leucism)
白化鷹斑鷸 Wood Sandpiper(Leucism)
DATE: 2014/01/26::
15
Amsel mit Leuzismus / blackbird with leucism
Amsel mit Leuzismus / blackbird with leucism
DATE: 2011/10/10::
16
Leucistic Greenfinch - Verdier d
Leucistic Greenfinch - Verdier d'Europe - Canto de Verderon
DATE: 2012/02/01::
17
How to Pronounce Leucism
How to Pronounce Leucism
DATE: 2013/01/23::
18
Leucistic Greenfinch - Pied Greenfinch - Verdier d
Leucistic Greenfinch - Pied Greenfinch - Verdier d'Europe - Canto de Verderon
DATE: 2012/07/17::
19
How to Pronounce Leucism
How to Pronounce Leucism
DATE: 2012/12/25::
20
Leucistic Red Kite (Milvus milvus)
Leucistic Red Kite (Milvus milvus)
DATE: 2014/07/31::
21
White Screech Owl - Leucistic or Albino. Update to
White Screech Owl - Leucistic or Albino. Update to 'White Owl - Leucistic Baby Screech Owl"
DATE: 2013/08/28::
22
Leucistic Snakehead: Close-Up View (2 Apr 2014)
Leucistic Snakehead: Close-Up View (2 Apr 2014)
DATE: 2014/04/02::
23
Leucistic House Sparrow
Leucistic House Sparrow
DATE: 2013/09/18::
24
White-headed (Leucistic) Golden Plover
White-headed (Leucistic) Golden Plover
DATE: 2012/10/30::
25
White Owl - Leucistic Baby Screech Owl
White Owl - Leucistic Baby Screech Owl
DATE: 2013/05/12::
26
We have a Leucistic Albino Hummingbird.
We have a Leucistic Albino Hummingbird.
DATE: 2009/08/09::
27
Leucistic alligator gar at the Tennessee Aquarium
Leucistic alligator gar at the Tennessee Aquarium
DATE: 2012/05/07::
28
Leucistic (White) Black-Capped Chickadee
Leucistic (White) Black-Capped Chickadee
DATE: 2011/01/13::
29
Falkor the Leucistic Axolotl Eating Blackworms
Falkor the Leucistic Axolotl Eating Blackworms
DATE: 2014/07/11::
30
Rare white headed(leucistic) cardinal in Palestine,Texas on Inwood Dr.
Rare white headed(leucistic) cardinal in Palestine,Texas on Inwood Dr.
DATE: 2011/07/22::
31
Laid-back (partially leucistic) Blackbird!
Laid-back (partially leucistic) Blackbird!
DATE: 2011/08/18::
32
White Leucistic Sparrow
White Leucistic Sparrow
DATE: 2012/08/12::
33
Trail of Highways ™; Leucistic Screech Owl, Boyd Hill Nature Preserve
Trail of Highways ™; Leucistic Screech Owl, Boyd Hill Nature Preserve
DATE: 2015/02/21::
34
Leucistic fur seal holds a territory.
Leucistic fur seal holds a territory.
DATE: 2009/06/10::
35
White Leucistic Hummingbird Ruby Throated
White Leucistic Hummingbird Ruby Throated
DATE: 2009/09/01::
36
Leucistic Common Redpoll
Leucistic Common Redpoll
DATE: 2009/03/06::
37
Leucistic Golden-crowned Sparrow, Sauvie Island, Oregon
Leucistic Golden-crowned Sparrow, Sauvie Island, Oregon
DATE: 2015/02/15::
38
Leucistic Blackbird, Rufford Country Park, Nottinghamshire
Leucistic Blackbird, Rufford Country Park, Nottinghamshire
DATE: 2008/02/04::
39
leucistic cardinal
leucistic cardinal
DATE: 2014/03/10::
40
Leucistic Common Redpoll
Leucistic Common Redpoll
DATE: 2009/03/07::
41
Leucistic House Finch
Leucistic House Finch
DATE: 2006/10/25::
42
Stunning looking male leucistic Blackbird
Stunning looking male leucistic Blackbird
DATE: 2012/01/29::
43
Leucistic Dark-eyed Junco
Leucistic Dark-eyed Junco
DATE: 2013/01/16::
44
Leucistic Blackbird (2)
Leucistic Blackbird (2)
DATE: 2015/02/10::
45
Leucistic White-throated Sparrow
Leucistic White-throated Sparrow
DATE: 2008/09/16::
46
Leucistic Neotropical Otter in Costa Rica
Leucistic Neotropical Otter in Costa Rica
DATE: 2013/03/26::
47
Leucistic Eurasian Collared Dove wandering around my yard
Leucistic Eurasian Collared Dove wandering around my yard
DATE: 2012/05/29::
48
Leucistic House Sparrow
Leucistic House Sparrow
DATE: 2009/01/27::
49
Leucistic Canada Geese HD
Leucistic Canada Geese HD
DATE: 2012/11/25::
50
Leucistic Bald Eagle in Klamath
Leucistic Bald Eagle in Klamath
DATE: 2015/02/27::
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RESULTS [51 .. 101]
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Leucistic white lions owe their colouring to a recessive allele. Note the eyes and lips remain the normal colour.
All-white dominant white horse with pink skin, brown eyes, and white hooves.
This white horse owes its colouring to a dominant allele (dominant white).
A leucistic rock pigeon. Both the eyes and legs are still of the normal colour.

Leucism /ˈljsɪzəm/[1] is a condition in which there is partial loss of pigmentation in an animal resulting in white, pale, or patchy coloration of the skin, hair, feathers, scales or cuticle, but not the eyes.[2] Unlike albinism, it is caused by a reduction in multiple types of pigment, not just melanin.

Details[edit]

(video) A tiger with leucism at Tobu Zoo, in Saitama, Japan.

Leucism (occasionally spelled leukism) 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, cows, cats, dogs, the urban crow[3] and the ball python[4] but is also found in many other species.

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, most 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,[5] mitf[6] and EDNRB.[7]

Etymology[edit]

The terms leucistic and leucism are derived from medical terminology. The stem leuc- is the Latin variant of leuk- from the Greek leukos meaning "white" (see Stedman’s, Dorland’s or Taber’s medical dictionaries).

Gallery[edit]

See also[edit]

References[edit]

  1. ^ "leucistic". Oxford English Dictionary (3rd ed.). Oxford University Press. September 2005. 
  2. ^ "Leucism". YourDictionary. Retrieved January 28, 2015. 
  3. ^ White crows at Cornell University.
  4. ^ Piebald ball pythons at Constrictors.com (archived 9 October 2006, from the original, accessed 18–22 July 2006).
  5. ^ Coat colour, dominant white at Online Mendelian Inheritance in Animals.
  6. ^ An L1 element intronic insertion in the black-eyed white (Mitf[mi-bw]) gene: the loss of a single Mitf isoform responsible for the pigmentary defect and inner ear deafness at Human Mulecular Genetics.
  7. ^ Waardenburg syndrome at Atlas of Genetics and Cytogenetics in Oncology and Haematology (archived 26 December 2005, from the original, accessed 18–22 July 2006).
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