color genetics - Page 4

Uber land
I was going to talk about solid colors from B/R dog and I was glad that I was on your side since I do not want any negativity between us.
But you just will not give up and will disregard any scientific facts and even lie by saying that there are no diseases associated with diluted colors. That is not the truth!!! And you know it!  I am tired of talking about it again and again thus anybody interested what I have to say about blues and other diluted  degenerative genes  go to this thread:
http://www.pedigreedatabase.com/german_shepherd_dog/forum/65190.html 
None so Blind as Those Who Will Not See.
Prager Hans
http://www.alpinek9.com

Hi Jennifer, yes the Isabella is gorgeous. Was holding him in my arms yesterday at the breeders home. What a sweetie! The breeder lives about 5 miles from me. I will PM you since I don't think she wants to be dragged into the "fire" on this board. LOL

~Darlene~

oh yeah, I am lieing. 

there is absolutly no truth to people saying the blue and liver color IN THE GSD BREED causes any health problems.  Individual dogs, no matter what color they were born, have problems.  the color they were born was not a factor.  yes, there are some breeds where the dilute colors cause problems, but it hasn't be proven in this breed.  these colors are just as healthy as any other color that is NATURALLY in this breed.  these colors have been around since the begining.

whites, blues and livers were blamed for all the problems in the breed BEFORE genetic health testing was available and showed it wasn't the dogs color which was the problem, but other genes.  same as in the past people thought demons and bad blood caused health problems, not germs, viruses and bacteria.  epilepsy used to be blamed on demonic  possession

this is taken from the website Prager keeps posting as proof of the degenerative genetic timebombs that blues and livers are. I might not be reading this correctly, but so far, all I see them mention is the CDA and follicle disease. no other problems, the CDA can be tested for, and easily bred away from. and the website states the follicle disease is extremely rare.
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DILUTES

The main problem associated with dogs with the dilute gene (dd) is known as Colour Dilution Alopecia. It is also known to occur in mice, and causes hair loss and skin problems. A dog with this disorder will typically appear "mangy" and have partial hair loss. It is usually reported from blue dogs, particularly Dobermanns, but presumably it affects isabella dogs too (diluted livers).


This blue German Pinscher appears to have mild alopecia. Its coat is dull rather than having a healthy shine, and it seems thin and patchy.

CDA is recessive. That means that both parents must be carriers in order to pass it on, and only homozygous puppies will have it (they need two copies of the gene which causes it). It's a bit like Down's syndrome in humans - children with it are born to two parents who carry the gene. Most people carry it without knowing it, which is why the syndrome appears to occur randomly, but if one child is born with it, it is possible (but not certain) that any other children the couple has will also have it.
Any colour can carry CDA or be homozygous for it, but only blues and isabellas will have symptoms. There are now tests available for the CDA gene, which will hopefully help breeders to avoid breeding carriers.

The same problem can also occur (albeit rarely) on black or liver dogs, and is known as Black Hair Follicular Dysplasia. It affects black/liver hairs only, leaving all other hairs as normal. Because this condition is so rare, it often goes undiagnosed. I used to know a Jack Russell Terrier mix who was white except for a black patch on his back, which was hairless. His condition puzzled a whole string of vets and skin specialists, who suggested various types of mange and allergies, and he was never properly diagnosed as having Black Hair Follicular Dysplasia. Unfortunately for dogs with genetic hair loss conditions, there is no cure.

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If the breeding was done to deliberately produce dilute colors, how did they know to use this stud? Or was the breeder breeding for black/red dogs and just happened to get dilutes? The dilute gene is probably more common in the showlines than the solid black gene. :D

In this case... do we know whether the female could possibly be a dominant black carrier?

Uber land, just because someone mentions one problem does not mean that there are no others. As they say :"Absence of evidence is not evidence of absence." I have posted other examples in other posts on different threads. Also if you want to introduce CDA into bloodline because you want to breed off colors then I call that alone inexcusable, and malicious act as far as breeding goes.
 
Prager Hans
http://www.alpinek9.com

Here this is what I have written on different thread dealing with color influencig a temperament. :

Wolf had been domesticated in a short time ( some think it was 3 or so generations) because man changed his behavior and start throwing leftovers out. More tame wolves started to come closer and closer to the dwelling of these humans and became more and more tame. With tameness then came physical changes which we never see in wolves. Floppy ears , domed skulls, curled tails, different color patterns. So here we can see a change from temperament to color , size and structure and so on.
This was not a result of selective breeding for these traits but unintended consequence of breeding for single trait for non timid wolves . We can say that because some of these changes were not important or not desirable. Like heat cycle of the wolf in December 1x per year in contrast with multiple cycles of dog in different part of the year. The characteristic of one gene changing multiple characteristics is called pleiotropy and more importantly so called antagonistic pleiotropy where the effects may be contradictory. Some are beneficial and some are detrimental to such animal.
You were asking why not use people example . Well here is one. Some people are phenolketonuriaks.This is a change in a single gene which influences enzymes and diminishes important ability of one enzyme to change into another enzyme. This single gene change then also produces mental problems like mental retardation and diminished pigmentation of hair and skin and so on. That is one of many possible example which lead to a reasons why it is believed that diminishing of pigmentation is an early sign of degeneration. Thus breeding for blues, liver which is breeding for diminished or blocked pigmentation may or will bring eventually other unintended consequences.
Remember if you breed one trait long enough then you will invariable change other traits. It does not matter if you start with color and change temperament, or structure, or physiology, immunity or vice versa.
Modern day example of the same effect described above involving wolves was done by many, but most famous is Belyaev's experiment to breed silver foxes for tameness for period of 60 or so years. The animals after about 40 years changed other behavior like wagging tail, licking hands, jumping on care takers and it also changed physical structure like curly tails domed head and coming into heat 2 x per year. This is a famous experiment and it is a hardly a secret.
Belyaev's experiment lasted almost 60 years and involved thousands of foxes. Thus you can not expect that breeding for for examples colors like liver or blue will have instant pleiotropic changes. These changes are usually very gradual and are often missed by the breeder. Kind of a boiling frog effect. Frog thrown into boiling water will jump out but if we put a frog into cold water and increase heat gradually frog will boil to death.
So if you are trying produce something new in the breed always be aware that there are unintended consequences which are usually negative.
Prager Hans
http://www.alpinek9.com


 

Thus considering Belyaev's foxes where the changes took decades and in light of knowing that these changes are usually or often  antagonistic pleiotropy are you willing to meddle and fumble over to you unfamiliar fields of and naive perception of genetics with the risk of introducing genetic problems into  the breed?!
Changes which may show decades after you have done them?
Prager Hans
http://www.alpinek9.com