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 Post subject: Re: color genetics II
 Post Posted: Mon Apr 23, 2012 2:38 pm 
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LOL Betty OK :- :- :- :-ss :-ss :-ss

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 Post subject: Re: color genetics II
 Post Posted: Mon Apr 23, 2012 3:19 pm 
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Jones insists that he have his attorney present when we swab, so it's taking longer than I expected!

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 Post subject: Re: color genetics II
 Post Posted: Mon Apr 23, 2012 4:23 pm 
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sometimes having an attorney present with audio and video equipment present is the only way tomake sure the swabs are applied correctly.......

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 Post subject: Re: color genetics II
 Post Posted: Mon Apr 23, 2012 6:40 pm 
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Looks like we have a lot of trollers waiting to see results also. A lot of hits on this topic all of the sudden.

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 Post subject: Re: color genetics II
 Post Posted: Mon Apr 23, 2012 7:01 pm 
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ya think?????? I think the results will be interesting at the very least.........probably a big blast as far as my genetics education is concerned.....

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 Post subject: Re: color genetics II
 Post Posted: Tue Apr 24, 2012 2:00 pm 
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OK, here ya go!

The info is written in part by me and I used 2 websites for info. One is Sheila Schmutz' site. http://homepage.usask.ca/~schmutz/dogcolors.html Dr. Schmutz is seen as one of the leaders in color genetics in the world. The other website is http://bowlingsite.mcf.com/Genetics/Genetics.html and I used it to help me thru understanding what I was talking about. JP Yousha is the wonderful person who is doing so much for me in mapping the color genetics of the Lacy breed. Here is her website http://www.chromadane.com/ Check out her website- what she is doing with her Great Danes is amazing!! JP edited my info, so it is written much better than I could and we kept it simple so that anyone who wants to, can understand it! I will answer any questions that I can. If I cant answer a question, I will send it on to JP for her to answer.

Chromosomes are essentially long strings of DNA molecules and are arranged in pairs. Offspring get one chromosome from the father and one from the mother. Each chromosome contains many individual genes.

Each gene has alternate forms resulting from mutation. Each of these alternate forms is called an allele. Just as each offspring gets one chromosome from the mother and one from the father, each get puppy gets one allele from its sire and one from its dam.

The place on the chromosome where a gene resides is called the locus; loci is the plural. Genes are made into proteins, proteins make up our bodies and all their individual traits. Coat color results from the interaction of several different genes.

Alleles that match are known as homozygous and shown as BB or bb. Non-matching alleles are called heterozygous and shown as Bb; this is the carrier state. Dominance is shown as a capital letter (B) and recessive is shown as lower case (b). As scientist discover genes, they give them symbolic names such as the TYPR1 gene for the B locus.

There is one more concept in genetics we must cover, the idea of one gene being epistatic to another. Just as one allele can dominate another at any given gene locus, one locus can dominate another locus. Another way to think of this is as one gene having a suppressive effect on another. There are two important epistatic relationships affecting coat color in Lacys: that of the K locus dominating the A locus, and that of the E locus dominating both A & K in a special way. This is discussed below.

Melanin is the pigment that is responsible for hair color in dogs. Eumelanin is what causes a dog to be black, gray (blue) or brown. Phaeomelanin is responsible for red, yellow and tan. Dogs that are E/E usually have some black or brown in the coat because of the production of eumelanin. Dogs that are e/e are red, tan or yellow because of the production of phaeomelanin.


I had my blue dog Abe tested for MC1R, the E locus, which is checking for eumelanin vs. phaeomelanin pigment. He came back as E/E, which means that he cannot produce clear red offspring (which must have two copies of the recesssive e allele). All blue dogs like Abe are EE or Ee: Ee carrier dogs can produce clear red puppies, EE dogs cannot. Now Abe has offspring that is known to us as red. I will cover that later.

I had Abe also tested for the K locus. All blue Lacys have at least one K allele. KK dogs cannot produce our tris. Kk dogs can. All tris are recessive <kk> at this locus. The K stands for the final letter in Dominant Black and this unique canine gene is also called CBD103. The dominant here produces a self or solid coat in black, gray or brown. The recessive allows for the agouti genes to express. Agouti is explained below.

Abe was tested for brown (TYPR1) which is shown as B. We tested him for brown because of the brownish shade to his coat. He does not carry brown. We did not test Abe for the D locus which is dilute because we know that he is dilute: all blue Lacys are recessive dd dogs.

Now, the agouti gene: it's complicated as has more than a simple pair of alleles. There are 4 agouti alleles. In order of dominance they are: A^y (yellow), a&w (wild-type), a*t (tan-point) & a^b (recessive black). A^y is a second way to produce a red dog, called agouti red (also referred to in some breed as fawn or sable). Agouti reds, unlike recessive (clear) reds, can have a trace of dark pigment on the ears and spine. The a^t allele produces the bicolor pattern (blue over red) that we call tri. Neither the wild-type nor the recessive black occur as far as we know in the Lacy. This is where things get crazy! Abe's test results show ay/at which means that he has both the agouti red and the tri gene. Since Abe cannot produce a clear red pup, his red offspring are agouti reds!

Image
waiting at the gate by scarebetty, on Flickr
Abe is the blue with the gray collar on. You can see some of the red tone to him and definitely see the blue stripe down his back and his darker tail.

I also tested my tri bitch Lucy, but only for one gene, the E (MCR1) Locus. Why? because we already know she is a dd recessive as she is a blue/red dog, we know she is a kk recessive dog because she is a tri, and for the same reason, we also know she is an a^t/a^t recessive. All we need to find out is if she is an Ee carrier or not. She is not: she is EE, so she also cannot produce clear red puppies.

Image
Lucy looking pretty in the bluebonnets by scarebetty, on Flickr
This is Lucy, my tri-color.

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 Post subject: Re: color genetics II
 Post Posted: Tue Apr 24, 2012 2:33 pm 
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Wow....I need a drink..........great info Betty.......Its gonna take a few readings for me to get this digested if at all..........

Has the question been asked where it can go from here or where will it go from here????

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 Post subject: Re: color genetics II
 Post Posted: Tue Apr 24, 2012 3:59 pm 
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Good stuff Betty very good I will need to read it more also. kevin I think it can give us breeders a road map as to what to do and what not to do . Of coarse all your breeding dogs in your kennels would need to be tested so you know what you are working with.

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 Post subject: Re: color genetics II
 Post Posted: Tue Apr 24, 2012 4:04 pm 
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good point John.........

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 Post subject: Re: color genetics II
 Post Posted: Wed Apr 25, 2012 9:19 am 
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Great information Betty, can"t wait till some of the other lacy's results come in. At least we have some proof of what colors can be produced from breeding OR MIXING the 3 colors that is accepted in the NLDA. I hope there was enough people that sumitted their [off colored dogs] that we can get information on them.
Grandmadawg


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 Post subject: Re: color genetics II
 Post Posted: Wed Apr 25, 2012 11:59 am 
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There is a lot of interest in this!! Some of the dogs that are off-colored have not been tested, but they will be. Some people are wanting their dogs tested just for their own info.

Anyone who wants their dogs tested can contact me. It's not expensive, unless you check for everything and even that is not bad. A single test is $45 and each test after that is $25.

I am looking for a 'clear red' and a 'true blue'. I am having Rob's dog, Colt, tested because he is pretty red, but since he comes from a blue dog that is not real blue and a tri- I no longer expect him to be a clear red. The clear reds may be a thing of the past, as might be a true blue. But, we shall see.

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 Post subject: Re: color genetics II
 Post Posted: Mon Apr 30, 2012 12:09 pm 
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Here is some info that I was able to find that may help us understand the white patterns. I will post the hard to understand part and then the more easy version that best fits our dogs.

http://abnormality.purpleflowers.net/genetics/white.htm

This section I think fits where our dogs would fall. Betty you may correct me if I am wrong. I still really trying to understand this.
There are pictures on the link that explained more in detail white patterns and marking.

RESIDUAL WHITE

Sometimes dogs with no white spotting (SS) can have a small amount of white on their extremities. This is caused by the pigment not reaching far enough while the foetus is developing, and is not counted as a white pattern, but just as residual white, because it has no genetic basis. It usually appears as just a small chest patch, white toes or a white tail tip.

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 Post subject: Re: color genetics II
 Post Posted: Mon Apr 30, 2012 12:46 pm 
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This is another that also talks about white with dogs that do not carry the white gene. But have white on chest in paws. they call it White Chest.



The site I took it from.

http://homepage.usask.ca/~schmutz/dogspots.html

White Chest Spot

Because melanocytes migrate down from the spinal column during embryogenesis (see the page about this), not all animals complete this process by birth or thereafter. In dogs, it is therefore not uncommon to see white toes on an otherwise black or red dog. This is probably more a random event than the result of a specific allele. Another common "white spot" on dogs occurs on the chest. This must again be a site where melanocytoe migration occurs very late in fetal development and a cold or other developmental delay prevents the completion of melanocyte migration. It may be that the rate of melanocyte migration is itself inherited.


In some dogs, such as the Gordon Setter at the left, a white chest spot occurs. Some standards mention this as a fault. This is likely simply incomplete pigment migration in the particular individual, and not an inherited trait. Such small amounts of white on the chest or on the toes, do not seem to be caused by mutations in MITF.

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 Post subject: Re: color genetics II
 Post Posted: Mon Apr 30, 2012 3:30 pm 
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Exactly! Which leaves me with only one conclusion... My little doggies that have almost no white on them are more perfect than the ones that do! LOL!!!! ;)

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 Post subject: Re: color genetics II
 Post Posted: Mon Apr 30, 2012 4:40 pm 
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Quote:


This is the website of Dr. Sheila Schmutz, that I referenced in my post.
Quote:
The info is written in part by me and I used 2 websites for info. One is Sheila Schmutz' site. http://homepage.usask.ca/~schmutz/dogcolors.html Dr. Schmutz is seen as one of the leaders in color genetics in the world.

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"You did then what you knew how to do, and when you knew better, you did
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Maya Angelou

"You have enemies? Good, that means you stood up for something in your life!"
Winston Churchill

http://www.flickr.com/photos/bjleek/


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