Back to photostream

Der leuzistische Spatz wird langsam wagemutiger und kommt jetzt auch mal aus der Deckung hervor - The leucistic sparrow is slowly becoming more daring and is now coming out of hiding as well

Leuzismus (von altgr. λευκός leukós „weiß“) ist eine Defekt-Mutation bei Tieren, die dazu führt, dass das Fell weiß und die darunterliegende Haut rosa sind, da die Haut keine Melanozyten (farbstoffbildende Zellen) enthält. Im Gegensatz dazu sind beim Albinismus die Zellen zwar vorhanden, aber unfähig, den Farbstoff Melanin zu bilden. Die meisten Formen der Scheckung sind auf abgeschwächte Formen des Leuzismus zurückzuführen.

 

de.wikipedia.org/wiki/Leuzismus

 

Leucism is a wide variety of conditions which result in the partial loss of pigmentation in an animal—which causes white, pale, or patchy coloration of the skin, hair, feathers, scales or cuticles, but not the eyes. It is occasionally spelled leukism.

'Leucism' is often used to describe the phenotype that results 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 that can make 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.

 

en.wikipedia.org/wiki/Leucism

1,209 views
19 faves
6 comments
Uploaded on February 9, 2021
Taken on February 1, 2021