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White, Black & Golden Tigers

United States Pckts Offline
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To my knowledge, there is only one adult White tiger seen in the wild and I believe it was Corbett who spotted and photographed it, Mohan was a cub and these white tigers in Nilgiris are still with their mother but they are much closer to being adult and seem to be able to hunt on their own, which would be common at their size. Like @parvez said, the only deformity you see in white tigers now is due to severe inbreeding, and even so, I still have doubts that "all white tigers are deformed" 
I have seen many healthy looking ones my self and India has a few that seem to be fairly healthy as well.
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United States paul cooper Offline
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(01-03-2018, 05:51 PM)parvez Wrote:
(01-03-2018, 03:04 PM)paul cooper Wrote:
(01-03-2018, 01:24 PM)Kparvez Wrote: White Tiger Genetics: The Basics

*This image is copyright of its original author
White coat with blue eyes: natural genetic inheritance.

The white coat/blue eyes trait of the White Tiger is caused by normal genetic inheritance from the parents, and follows a simple Mendelian recessive pattern.
  • It is not caused by inbreeding.
  • It is not caused by spontaneous mutation.
  • “Recessive” does not mean faulty 
  • The white gene does not cause defects, it affects only the pigmentation.
M
This is important, because it means that:
  • White Tigers are not “mutant freaks”, but are a natural color variant.
  • You do not have to breed white tiger with white tiger to produce a white cub, or to pass the white gene on to the next generation.
  • The white gene can be spread throughout a population of orange tigers. This is called out-crossing or out-breeding, and the more it is done, the healthier and more diverse the gene-pool.
  • It is not necessary to inbreed to produce white tigers. All that is necessary is to breed together 2 tigers each of which has at least one white gene. This can produce healthy white cubs without any inbreeding at all.
Identification of the Gene Responsible for the White Coat
The study “The Genetic Basis of White Tigers“, Luo et al, can be read here.
It was not until 2013 that the actual gene responsible was identified  – a change in a single amino acid (A477V) in one pigment-related gene, SLC45A2, that blocks the production of red/yellow pheomelanin while still allowing the black/brown melanin to be produced. This is the same gene that causes color variation in humans, horses, and chickens. The scientists concluded that it affected only pigmentation, and is a naturally occurring variant.
R Prasad, “White Bengal Tiger Enigma Solved“. The Hindu, May 24 2013
Quote:“They dismiss the notion that the white tiger trait is a genetic deformity. That matured white tiger adults have been sighted in the wild negates this notion. Despite its low frequency, they emphasise that the mutation is a naturally occurring one and should be considered as a “part of genetic diversity of tigers that is worth conserving.”

Before this, there were various theories that it was caused by albinism, or the chinchilla variant. The 2013 research proved these to be false.
Mendelian Recessive Inheritance
Physical traits are decided by genes. Genes come in pairs, one inherited from each parent. There can be different versions of the same gene, called alleles, causing different effects – these can be either dominant or recessive. Note that “recessive” does not mean inferior or defective, it merely indicates a trait that is masked (hidden) when paired with it’s dominant allele.
The tiger’s white coat/blue eyes allele is recessive – this can be written as a little “w” – with a capital “W” for the dominant orange coat. The possible gene pair combinations are WW, Ww, and ww.
In order for a tiger to be white, it must have ww, a full pair of the recessive gene, one w from each parent.  An orange tiger may have WW or Ww – as long as one of the pair of genes is W, ie dominant, the tiger will be orange colored.

*This image is copyright of its original author

Possible cubs from breeding white/orange tigers

This gives several possible combinations for breeding, including:
  • One ww (white) with WW (orange) – all the cubs will be Ww (orange, but carrying the white gene).
  • Ww (orange carrier) with ww (white) gives a 50% chance of white cubs (2 in 4)
  • Two Ww (orange carriers) gives a 25% chance of a white cub (1 in 4)
  • Two ww (white) together – all their cubs must be ww (white)
Mutation
The white gene is thought to have been caused by gene mutation at some time in the past – 100’s of years ago, or 1000’s or…. we don’t know when. This does not make the White Tiger a “mutant freak”. The genes do not spontaneously mutate every time a white tiger cub is conceived, it happens by normal genetic inheritance from the parents.
Mutation is normal and necessary for evolution and genetic diversity. Gene mutations can be good, bad, or indifferent. Harmful mutations tend not to survive, but the White Tiger did indeed survive and breed in the wild for 100’s of years so we really cannot call it a harmful trait.
Quote:“Mutations are changes in the genetic sequence, and they are a main cause of diversity among organisms …mutation is one of the fundamental forces of evolution”      [from Loewe, L. (2008) Genetic mutation.]

Edward J Maruska, “White Tiger: Phantom or Freak?” in “Tigers of the World”, Tilson & Seal, Ed. 1987 Noyes Publications
William Conway, Director of the New York Zoological Society, made a comment back in the ’80’s  referring to white tigers as  “Freaks….two-headed calves and white tigers”. But Edward Maruska of Cincinnati Zoo, pointed out the error in that type of sentiment:
Quote:Although the comment makes for interesting prose, his approach is not sound biology

Our knowledge of the White Tiger has come a long way since the 1980’s.
Source: https://whitetigertruths.wordpress.com/f...-genetics/

Haha lol. The idiot who thinks he is a researcher, still has not disproved the fact that all white tigers have deformities.
Now here is some truth: https://www.aza.org/assets/2332/aza_whit...n_2012.pdf

Not just white tigers are absolutely useless to tiger conservation, but can potentially kill all tigers.

White tigers now are seen in the wild in Nilgiris. I did not see any physical deformities in those tigers. Though wild they are thriving which indicates the absence of deformities. Otherwise they would be dead by now. But i agree to the fact that many white tigers are born out of inbreeding for commercial purposes and have deformities. Mohan the fore father of all white tigers in the world today was caught in the wild though as cub but if not caught surely would have survived in the wild. Your article is dated 2011. Mine is 2014. So, mine is the latest update. Get updated yourselves. Why you want to address me as Kparvez?

..those tigers were still orange. I highly doubt white tigers can survive. I think chinese culture portrays White tigers and were called mystical and rare. Doesnt matter is yours is 2014, it doesnt disprove anything lol.
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United States Pckts Offline
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( This post was last modified: 01-04-2018, 06:15 AM by Rishi )

(01-04-2018, 12:25 AM)paul cooper Wrote:
(01-03-2018, 05:51 PM)parvez Wrote:
(01-03-2018, 03:04 PM)paul cooper Wrote:
(01-03-2018, 01:24 PM)Kparvez Wrote: White Tiger Genetics: The Basics

*This image is copyright of its original author
White coat with blue eyes: natural genetic inheritance.

The white coat/blue eyes trait of the White Tiger is caused by normal genetic inheritance from the parents, and follows a simple Mendelian recessive pattern.
  • It is not caused by inbreeding.
  • It is not caused by spontaneous mutation.
  • “Recessive” does not mean faulty 
  • The white gene does not cause defects, it affects only the pigmentation.
M
This is important, because it means that:
  • White Tigers are not “mutant freaks”, but are a natural color variant.
  • You do not have to breed white tiger with white tiger to produce a white cub, or to pass the white gene on to the next generation.
  • The white gene can be spread throughout a population of orange tigers. This is called out-crossing or out-breeding, and the more it is done, the healthier and more diverse the gene-pool.
  • It is not necessary to inbreed to produce white tigers. All that is necessary is to breed together 2 tigers each of which has at least one white gene. This can produce healthy white cubs without any inbreeding at all.
Identification of the Gene Responsible for the White Coat
The study “The Genetic Basis of White Tigers“, Luo et al, can be read here.
It was not until 2013 that the actual gene responsible was identified  – a change in a single amino acid (A477V) in one pigment-related gene, SLC45A2, that blocks the production of red/yellow pheomelanin while still allowing the black/brown melanin to be produced. This is the same gene that causes color variation in humans, horses, and chickens. The scientists concluded that it affected only pigmentation, and is a naturally occurring variant.
R Prasad, “White Bengal Tiger Enigma Solved“. The Hindu, May 24 2013
Quote:“They dismiss the notion that the white tiger trait is a genetic deformity. That matured white tiger adults have been sighted in the wild negates this notion. Despite its low frequency, they emphasise that the mutation is a naturally occurring one and should be considered as a “part of genetic diversity of tigers that is worth conserving.”

Before this, there were various theories that it was caused by albinism, or the chinchilla variant. The 2013 research proved these to be false.
Mendelian Recessive Inheritance
Physical traits are decided by genes. Genes come in pairs, one inherited from each parent. There can be different versions of the same gene, called alleles, causing different effects – these can be either dominant or recessive. Note that “recessive” does not mean inferior or defective, it merely indicates a trait that is masked (hidden) when paired with it’s dominant allele.
The tiger’s white coat/blue eyes allele is recessive – this can be written as a little “w” – with a capital “W” for the dominant orange coat. The possible gene pair combinations are WW, Ww, and ww.
In order for a tiger to be white, it must have ww, a full pair of the recessive gene, one w from each parent.  An orange tiger may have WW or Ww – as long as one of the pair of genes is W, ie dominant, the tiger will be orange colored.

*This image is copyright of its original author

Possible cubs from breeding white/orange tigers

This gives several possible combinations for breeding, including:
  • One ww (white) with WW (orange) – all the cubs will be Ww (orange, but carrying the white gene).
  • Ww (orange carrier) with ww (white) gives a 50% chance of white cubs (2 in 4)
  • Two Ww (orange carriers) gives a 25% chance of a white cub (1 in 4)
  • Two ww (white) together – all their cubs must be ww (white)
Mutation
The white gene is thought to have been caused by gene mutation at some time in the past – 100’s of years ago, or 1000’s or…. we don’t know when. This does not make the White Tiger a “mutant freak”. The genes do not spontaneously mutate every time a white tiger cub is conceived, it happens by normal genetic inheritance from the parents.
Mutation is normal and necessary for evolution and genetic diversity. Gene mutations can be good, bad, or indifferent. Harmful mutations tend not to survive, but the White Tiger did indeed survive and breed in the wild for 100’s of years so we really cannot call it a harmful trait.
Quote:“Mutations are changes in the genetic sequence, and they are a main cause of diversity among organisms …mutation is one of the fundamental forces of evolution”      [from Loewe, L. (2008) Genetic mutation.]

Edward J Maruska, “White Tiger: Phantom or Freak?” in “Tigers of the World”, Tilson & Seal, Ed. 1987 Noyes Publications
William Conway, Director of the New York Zoological Society, made a comment back in the ’80’s  referring to white tigers as  “Freaks….two-headed calves and white tigers”. But Edward Maruska of Cincinnati Zoo, pointed out the error in that type of sentiment:
Quote:Although the comment makes for interesting prose, his approach is not sound biology

Our knowledge of the White Tiger has come a long way since the 1980’s.
Source: https://whitetigertruths.wordpress.com/f...-genetics/

Haha lol. The idiot who thinks he is a researcher, still has not disproved the fact that all white tigers have deformities.
Now here is some truth: https://www.aza.org/assets/2332/aza_whit...n_2012.pdf

Not just white tigers are absolutely useless to tiger conservation, but can potentially kill all tigers.

White tigers now are seen in the wild in Nilgiris. I did not see any physical deformities in those tigers. Though wild they are thriving which indicates the absence of deformities. Otherwise they would be dead by now. But i agree to the fact that many white tigers are born out of inbreeding for commercial purposes and have deformities. Mohan the fore father of all white tigers in the world today was caught in the wild though as cub but if not caught surely would have survived in the wild. Your article is dated 2011. Mine is 2014. So, mine is the latest update. Get updated yourselves. Why you want to address me as Kparvez?

..those tigers were still orange. I highly doubt white tigers can survive. I think chinese culture portrays White tigers and were called mystical and rare. Doesnt matter is yours is 2014, it doesnt disprove anything lol.
Those tigers aren't orange, they are white.

*This image is copyright of its original author


http://www.thehindu.com/sci-tech/energy-...005567.ece

*This image is copyright of its original author

http://www.thehindu.com/news/national/ta...217223.ece
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Rishi Offline
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( This post was last modified: 01-04-2018, 03:35 PM by Rishi )

@Pckts @parvez @paul cooper wild white tigers in several occasions have been hunted in India. Even the Indian Museum the has a stuffed taxidermy specimen. Here read these:
All about white tigers.
Complete genetic history of all captive white tigers.

The tiger in whom the mutation took place might not have been white. The gene had surfaced from time to time later on. 

*This image is copyright of its original author


c.1930s Van Ingen – White Tiger Skin

*This image is copyright of its original author

In the Forest Research Institute, Dehradun 

*This image is copyright of its original author


*This image is copyright of its original author

And last but definitely not the least... A painting from Akbarnama, biography of Mughal Emperor Akbar the great (reigned. 1556-1605).

*This image is copyright of its original author


Mohan was one of many such cases. After his capture in 1915, at the age of 2, he became the sole source of the genetic trait in captivity & improper management of breeding have given rise to inbreeding related genetic depression in foreign zoos as they tried to take a shortcut.
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United States paul cooper Offline
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@Pckts 

Those tigers arent white lol, they just have really light orange coats. You can still differentiate the original white markings and the orange from each other
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United States paul cooper Offline
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(01-04-2018, 07:26 AM)Rishi Wrote: @Pckts @parvez @paul cooper wild white tigers in several occasions have been hunted in India. Even the Indian Museum the has a stuffed taxidermy specimen. Here read these:
All about white tigers.
Complete genetic history of all captive white tigers.

The tiger in whom the mutation took place might not have been white. The gene had surfaced from time to time later on. 

*This image is copyright of its original author


c.1930s Van Ingen – White Tiger Skin

*This image is copyright of its original author

In the Forest Research Institute, Dehradun 

*This image is copyright of its original author


*This image is copyright of its original author

And last but definitely not the least... A painting from Akbarnama, biography of Mughal Emperor Akbar the great (reigned. 1556-1605).

*This image is copyright of its original author


Mohan was one of many such cases. After his capture in 1915, at the age of 2, he became the sole source of the genetic trait in captivity & improper management of breeding have given rise to inbreeding related genetic depression in foreign zoos as they tried to take a shortcut.

"15 white tigers were killed in the region of BiHar alone"
https://books.google.com/books?id=WwuJEk...rs&f=false
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United States Pckts Offline
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(01-05-2018, 12:32 AM)paul cooper Wrote: @Pckts 

Those tigers arent white lol, they just have really light orange coats. You can still differentiate the original white markings and the orange from each other

They are white, I'm not sure where you're seeing orange in them.
I'm curious as to your point, do you think that white tigers don't exist in the wild or don't exist as adults?
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parvez Offline
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Relieving news,
Abstract

White tigers are greatly cherished by the public, making them valuable to zoos and breeders. Unfortunately, a number of health issues have occasionally surfaced within some of the white tiger population such as neurological and facial defects. There is interest amongst private tiger breeders to determine if these maladies are associated with the coat color or breeding practices, and to find ways to prevent these health issues. The genes involved in producing the white phenotype and the disease phenotype are currently unknown. Furthermore, the relationship between the genes associated with coat color and levels of inbreeding also remain unknown. Microsatellites are a tool frequently used by geneticists and ecologists alike. These segments of highly repeatable DNA mutate frequently and are variable in length. Thus microsatellites can be used to determine heterozygosity within a population by detecting the alleles present at the loci of interest. The amount of heterozygosity within a population can be indicative of the amount of inbreeding present and overall levels of genetic diversity. A panel of twelve microsatellites was used to analyze heterozygosity, thus inferring the levels of genetic diversity present. Among the tigers sampled, estimated heterozygosity was determined to be 0.761 in white tigers and 0.772 in orange tigers. The genes Melanocortin-1-Receptor (MC1R) and Agouti Signaling Protein (ASIP) have been found to affect coat color phenotypes in other species similar to that of the white tiger, making them ideal candidates for this project. These genes work antagonistically to each other in production of melanin. MC1R is responsible for the production of α-melanocyte stimulating hormone (α-MSH) while ASIP silences this activity. Thus, a loss-of-function associated with MC1R or a gain-of-function associated with ASIP could lead to reduced pigment production. This study continues the initial investigation by focusing on sequencing MC1R. Differences in the nucleotides and amino acids of the sequences were compared through alignment in Sequencher. At this time a causal mutation has not been found within exons 1 and 2 of ASIP or MC1R.
http://oaktrust.library.tamu.edu/handle/1969.1/148870
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Roflcopters Offline
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( This post was last modified: 03-16-2019, 10:39 AM by Rishi )


*This image is copyright of its original author


Kaziranga female caught in camera trap.12/24/2016.
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United States paul cooper Offline
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@Roflcopters 
Wild golden tiger? Is that..
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Roflcopters Offline
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( This post was last modified: 02-06-2018, 02:42 PM by Roflcopters )

Yes sir.

she was sighted last year again by the field director of Kanha National Park.


*This image is copyright of its original author


here is Sanjay Shukla's post from January/2017.

Royal Bengal Tiger (Panthera tigris)

I was lucky enough to see a tiger also in Kaziranga. I was in the Agoratoli (Eastern ) Range and the sun has gone down the horizon. I just wanted to see some of the Anti Poaching Camps.  The determined and committed frontline staff in these camps has fought hard with the poachers to make this a safe place for rhinoceros now. The forester driving the vehicle was narrating me many stories of ambush with the poachers. Suddenly we saw one tiger moving ahead of us on the road. The light was pretty bad and distance was much. This was the best image which I could get before the tiger suddnly disappeared in the bushes. This was clicked at 20,000 ISO and 500 mm (equivalent to 750 mm).


another photo of this girl


*This image is copyright of its original author
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Rishi Offline
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( This post was last modified: 02-20-2018, 05:25 PM by Rishi )

Latest images of Subhranshu & Krishna, the only captive melanistic tigers in the world, residents of Nandan Kanan zoo safari-zone in Bhubaneswar, Odisha; the 2nd largest zoo in India. 

*This image is copyright of its original author


*This image is copyright of its original author

Although we don't really know when & where the mutation took place, but presently only the Simlipal TR has about a half a dozen melanistic tigers (as per previous census, latest data isn't available yet).

As most of the facilities specimens had been sourced from Odisha's own forests, probably some carrier/s of the gene were among them.
Unbeknownst to everyone, one white tigress (Sneha) & her mate (Manish) were carriers & she surprised the authorities by giving birth to a litter of 4 with two melanistics in mid-2014.
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Rishi Offline
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( This post was last modified: 03-03-2018, 09:46 PM by Rishi )

About the issue that some believe the Nilgiri duo to not be pure white tigers but "Pale orange tigers"...

The word "white tiger" is misdirecting. The body colour varies from snow-white..

*This image is copyright of its original author

..to cream..

*This image is copyright of its original author

..to  what you can call dirty-white (like dirty blonde in people)..

*This image is copyright of its original author

..to pale (like them).

*This image is copyright of its original author

As NO SCIENTIFIC STUDY OF THEIR GENES could have been done, we don't know whether these are classic white tigers or a new different mutation. (They do live a bit far from where the last case was in 1950s. Rewa, MP!)

Thus experts might feel it safer to call them pale...
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GuateGojira Offline
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(01-11-2017, 10:22 PM)Pckts Wrote: Royal Bengal Tiger (Panthera tigris)

I was lucky enough to see a tiger also in Kaziranga. I was in the Agoratoli (Eastern ) Range and the sun has gone down the horizon. I just wanted to see some of the Anti Poaching Camps. The determined and committed frontline staff in these camps has fought hard with the poachers to make this a safe place for rhinoceros now. The forester driving the vehicle was narrating me many stories of ambush with the poachers. Suddenly we saw one tiger moving ahead of us on the road. The light was pretty bad and distance was much. This was the best image which I could get before the tiger suddnly disappeared in the bushes. This was clicked at 20,000 ISO and 500 mm (equivalent to 750 mm).


*This image is copyright of its original author

*This image is copyright of its original author

To my knowledge, this is the first "golden tabby" wild tiger photographed but I could be mistaken on that.

Wow, white and tabby tiger DO exist in the wild! That is perfect. I told you @Pckts Wink 

It is incredible that with such a low tiger population there are at elast two new records of white and tabby tigers in the wild. This is amazing but at the same time is necesary to get more protection for the tigers in this areas.
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United States Pckts Offline
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(09-15-2018, 10:35 PM)GuateGojira Wrote:
(01-11-2017, 10:22 PM)Pckts Wrote: Royal Bengal Tiger (Panthera tigris)

I was lucky enough to see a tiger also in Kaziranga. I was in the Agoratoli (Eastern ) Range and the sun has gone down the horizon. I just wanted to see some of the Anti Poaching Camps. The determined and committed frontline staff in these camps has fought hard with the poachers to make this a safe place for rhinoceros now. The forester driving the vehicle was narrating me many stories of ambush with the poachers. Suddenly we saw one tiger moving ahead of us on the road. The light was pretty bad and distance was much. This was the best image which I could get before the tiger suddnly disappeared in the bushes. This was clicked at 20,000 ISO and 500 mm (equivalent to 750 mm).


*This image is copyright of its original author

*This image is copyright of its original author

To my knowledge, this is the first "golden tabby" wild tiger photographed but I could be mistaken on that.

Wow, white and tabby tiger DO exist in the wild! That is perfect. I told you @Pckts Wink 

It is incredible that with such a low tiger population there are at elast two new records of white and tabby tigers in the wild. This is amazing but at the same time is necesary to get more protection for the tigers in this areas.

Haha you were right, it's a shame that neither of the two white brothers have been seen recently and the Tabby has also evaded photo capture since this shot as well.
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