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White Cats Wallpaper Biography
White cats are domestic cats with a pure white coat. Some white cats suffer from congenital deafness caused by a degeneration of the inner ear.[1] This condition is associated with blue irises. In white cats with mixed-coloured eyes (odd-eyed cats), it has been found that deafness is more likely to affect the ear on the blue-eyed side.[1] White cats can have blue, gold, green, or copper coloured odd eyes.
In one 1997 study of white cats with varying degrees of hearing deficiency, 72% of the animals were found to be totally deaf. The entire organ of Corti was found to have degenerated within the first few weeks after birth; however, even during these weeks no brain stem responses could be evoked by auditory stimuli, suggesting that these animals had never experienced any auditory sensations. It was found that some months after the organ of Corti had degenerated, the spiral ganglion also began to degenerate.[2]
[edit]Genetics
The gene that causes a cat to have a white coat is a dominant masking gene. As a result, the cat will have an underlying coat colour and pattern. When the dominant white gene is present, however, that pattern will not be expressed. A cat that is homozygous (WW) or heterozygous (Ww) for this gene will have a white coat despite the underlying pattern/colour. A cat that lacks this dominant masking gene (ww) will exhibit a coat colour/pattern. It is, however, possible to have a cat with a naturally white coat without this gene, as an extreme form of white spotting, although this is rare - some small non-white patch usually remains (if only during kittenhood).
There are several sources for a white cat to have blue eyes. If the underlying coat pattern is one of a pointed cat (also referred to as a Siamese pattern), the blue eyes may come from the genetics of the pointed gene. A common misconception is that all white cats with blue eyes are deaf.[3]Contrary to popular belief, white cats with blue, orange or green eyes are not albino. Albino cats, such as the one in this photo, have pink (unpigmented) or bluish-pink eyes and, like most albino animals, their eyes are sensitive to light. The white colour in cats is due to a gene that masks any other colour genes (this is why white cats can have non-white or bi-colour kittens). Albinism is a different mutation that causes the absence of colour, not the covering up of colour. When owners talk about having green-eyed or orange-eyed albino cats, they mean green-eyed or orange-eyed "dominant white" cats. In this context, dominant means a gene that masks other genes, it does not mean the cat has a dominant personality.
Recessive white is an alternate name for the blue-eyed/pink-eyed albino gene which is part of the colourpoint series of genes. The white spotting gene can sometimes produced solid white cats and is also sometimes called recessive white.
It is also a fallacy that "all blue-eyed white cats are born deaf". All kittens are born blue-eyed and with their ears folded down. Whether they will stay blue-eyed and whether they will be deaf can only be ascertained after a few weeks. Not all blue-eyed white cats will be deaf (as this article explains).
DOMINANT WHITE
Dominant white (more properly "epistatic white" since it occurs on a different gene to the black-based or red-based colours) denoted by the gene symbol "W", is the colour associated with deafness in cats. Dominant white masks all other colours and cats may have blue, orange or odd eyes. Those with blue eyes have a high chance of deafness. Those with one blue eye have a high chance of deafness on the blue-eyed side. Those with orange eyes are far less likely to be deaf. Some dominant white kittens are born with smudges of coloured fur on top of the head where the colour is incompletely masked, this smudge of colour usually disappears by adulthood, but kittens with colour smudges are more likely to have normal hearing. These cats are not albinos; genetically they can be any colour, but the white is dominant to those other colours (albinism is an absence of other colours).
The white coat can be caused either by a gene for white coloration or by a gene for 'white patching' - sometimes the white patching is so extensive that the cat appears solid white. If the white cat exhibited a few colored hairs or a smudge of color on its body (usually on the head) as a kitten, then it should have normal hearing even if it has blue eyes because it has inherited a non-deafness causing gene for white coat! However, blue-eyed bicolour cats occur and the more white they have in the region of their eyes and ears, the more likely they are to be deaf. This is because one of those genes for white affects the development of both the eyes and ears - it causes lack of eye pigmentation (i.e. blue eyes) and deafness - and since the eyes and ears are close together, if that gene affects that area of the body, it is likely to affect both sense organs (hence odd eyed whites may be deaf on the blue-eyed side).
White Cats Wallpaper Biography
White cats are domestic cats with a pure white coat. Some white cats suffer from congenital deafness caused by a degeneration of the inner ear.[1] This condition is associated with blue irises. In white cats with mixed-coloured eyes (odd-eyed cats), it has been found that deafness is more likely to affect the ear on the blue-eyed side.[1] White cats can have blue, gold, green, or copper coloured odd eyes.
In one 1997 study of white cats with varying degrees of hearing deficiency, 72% of the animals were found to be totally deaf. The entire organ of Corti was found to have degenerated within the first few weeks after birth; however, even during these weeks no brain stem responses could be evoked by auditory stimuli, suggesting that these animals had never experienced any auditory sensations. It was found that some months after the organ of Corti had degenerated, the spiral ganglion also began to degenerate.[2]
[edit]Genetics
The gene that causes a cat to have a white coat is a dominant masking gene. As a result, the cat will have an underlying coat colour and pattern. When the dominant white gene is present, however, that pattern will not be expressed. A cat that is homozygous (WW) or heterozygous (Ww) for this gene will have a white coat despite the underlying pattern/colour. A cat that lacks this dominant masking gene (ww) will exhibit a coat colour/pattern. It is, however, possible to have a cat with a naturally white coat without this gene, as an extreme form of white spotting, although this is rare - some small non-white patch usually remains (if only during kittenhood).
There are several sources for a white cat to have blue eyes. If the underlying coat pattern is one of a pointed cat (also referred to as a Siamese pattern), the blue eyes may come from the genetics of the pointed gene. A common misconception is that all white cats with blue eyes are deaf.[3]Contrary to popular belief, white cats with blue, orange or green eyes are not albino. Albino cats, such as the one in this photo, have pink (unpigmented) or bluish-pink eyes and, like most albino animals, their eyes are sensitive to light. The white colour in cats is due to a gene that masks any other colour genes (this is why white cats can have non-white or bi-colour kittens). Albinism is a different mutation that causes the absence of colour, not the covering up of colour. When owners talk about having green-eyed or orange-eyed albino cats, they mean green-eyed or orange-eyed "dominant white" cats. In this context, dominant means a gene that masks other genes, it does not mean the cat has a dominant personality.
Recessive white is an alternate name for the blue-eyed/pink-eyed albino gene which is part of the colourpoint series of genes. The white spotting gene can sometimes produced solid white cats and is also sometimes called recessive white.
It is also a fallacy that "all blue-eyed white cats are born deaf". All kittens are born blue-eyed and with their ears folded down. Whether they will stay blue-eyed and whether they will be deaf can only be ascertained after a few weeks. Not all blue-eyed white cats will be deaf (as this article explains).
DOMINANT WHITE
Dominant white (more properly "epistatic white" since it occurs on a different gene to the black-based or red-based colours) denoted by the gene symbol "W", is the colour associated with deafness in cats. Dominant white masks all other colours and cats may have blue, orange or odd eyes. Those with blue eyes have a high chance of deafness. Those with one blue eye have a high chance of deafness on the blue-eyed side. Those with orange eyes are far less likely to be deaf. Some dominant white kittens are born with smudges of coloured fur on top of the head where the colour is incompletely masked, this smudge of colour usually disappears by adulthood, but kittens with colour smudges are more likely to have normal hearing. These cats are not albinos; genetically they can be any colour, but the white is dominant to those other colours (albinism is an absence of other colours).
The white coat can be caused either by a gene for white coloration or by a gene for 'white patching' - sometimes the white patching is so extensive that the cat appears solid white. If the white cat exhibited a few colored hairs or a smudge of color on its body (usually on the head) as a kitten, then it should have normal hearing even if it has blue eyes because it has inherited a non-deafness causing gene for white coat! However, blue-eyed bicolour cats occur and the more white they have in the region of their eyes and ears, the more likely they are to be deaf. This is because one of those genes for white affects the development of both the eyes and ears - it causes lack of eye pigmentation (i.e. blue eyes) and deafness - and since the eyes and ears are close together, if that gene affects that area of the body, it is likely to affect both sense organs (hence odd eyed whites may be deaf on the blue-eyed side).
White Cats Wallpaper
White Cats Wallpaper
White Cats Wallpaper
White Cats Wallpaper
White Cats Wallpaper
White Cats Wallpaper
White Cats Wallpaper
White Cats Wallpaper
White Cats Wallpaper
White Cats Wallpaper
White Cats Wallpaper
White Cats Wallpaper
White Cats Wallpaper
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