Himalayan ch

The ch allele is responsible for Himalayan Netherland Dwarfs.  Ch is also referred to as restricted albino, meaning the colour is restricted to the points, leaving the body void of pigment - or white.  The points include the nose, ears, feet and legs, and tail.  They eyes are not included in any of these points, and are therefore void of pigment and pink like in the 'full' albino.  In the Himalayan, there is no yellow pigment covering the fur shafts of the coloured points and only two units of black pigment available to provide the point colour.

The agouti-patterned Himalayan will show mixed 'roan' colour on the points due to its nature to band the fur shafts.  However, since the fur is so short on those portions comprising the points, definite bands of colour can scarcely be detected.  The normally white portions of the agouti will be evidenced by white intruding into the coloured extremities of the Himalayan.  The underside of the tail and insides of the legs will be white.  Light nostril edging will appear in the Himalayan's mask, and the inner ears will show a lighter colour.  The breed standard's description of the Himalayan variety, requiring that the upper as well as lower side of the tail to be well-coloured precludes exhibiting agouti-patterned Himalayans.  Agouti-patterned Himalayans are A and ch in genotype. The tan-patterned Himalayan (genetically at and ch) will show the desired solid colour on the points, but will also show intrusion of white on the underside of the tail and inner legs, white nostril edging in the mask, and white inside of the ears.  Consequently, tan-patterned Himalayans are unrecognised varieties. 

It is the self-patterned Himalayan that is himalayan

Himalayan (correct genotype)    Himalayan (c^hc)

Here again, even though the Himalayan's points are coloured with only two units of black pigment, the colour appears as dense as in the full colour Blacks, Blues, Browns and Lilacs.  The compression of the  pigment granules in the short fur shafts covering the nose, ears, feet,

Please note that while breeding medium-shaded Marten Sables requires a heterozygous genotype, (cchlch or cchlc), breeding properly coloured, well marked Himalayans requires a homozygous genotype (aa chch).  Some recognised Netherland Dwarf varieties cannot breed true to colour due to the heterozygous genotype necessary to produce their colour in the first place.  The Marten Sable and Siamese Sable are two examples of varieties requiring a heterozygous genotype and these varieties can be expected to produce a percentage of offspring of other varieties they carry a recessive gene for (such as Himalayan or Ruby-Eyed White).  There are a few varieties which will invariably breed true to colour, such as the Ruby-Eyed White and Blue-Eyed White while most varieties can be successfully bred in heterozygous or homozygous genotypes.  

Full Colour C    Dark Chinchilla cchd    Light Chinchilla cchl    Albino c

back to colour distribution in  the fur shaft

the basic patterns

the basic colours

extension of colour in the fur shaft

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