Color Question

[frostback]

What does Black "extension" mean?

 

[base pair]

Genetics of cattle coat color

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

 

[JSchroeder]

I'm referring to the extension gene which is actually what you are speaking of when talking about black being dominant to red.  The extension gene is one of the most basic aspects of color genetics in both cattle and horses.

Now that I’m at a computer I can type.

Blue roan to a Red
50% black calf
50% red roan

Since you imply that the blue roan is not homozygous black by the fact that there can be red offspring, your example is this…

Blue Roan – Ee (heterozygous black) & Rr (roan)

X

Red – ee (red) & rr (solid colored)

When those two are bred…

25% Blue Roan (Ee & Rr)
25% Red Roan (ee & Rr)
25% Black (Ee & rr)
25% Red (ee & rr)

Spotting is another completely separate gene.

edit:extension is the MC1R gene mentioned in the page base pair referenced.

 

[frostback]

NO NO NO I did not say you could get red offspring from that mating I said RED ROAN.( not yelling just defining)
    B  W
r  Br  rW


r  Br  rW

B =Black
W= roaning
r= red
BR= Hetro black
rW= red roan
Hope this comes through right.

 

[JSchroeder]

You are still incorrectly putting both the extension and roaning genes in the same punnett square.

You need one square for black/red and one for solid/roan/white.  The roaning gene impacts how the extension gene is expressed.

 

[JSchroeder]

And to correct my correction...

Blue Roan – Ee (heterozygous black) & Rr (roan)

X

Red Roan – ee (red) & Rr (roan)

When those two are bred…

25% White (RR double roan covers everything)
25% Blue Roan (Ee & Rr)
25% Red Roan (ee & Rr)
12.5% Black (Ee & rr)
12.5% Red (ee & rr)

 

[frostback]

I give up.

 

[JSchroeder]

No need for that kind of stuff, just tell me where I'm wrong.  You didn't know what extension refers to, you are in no place to make such a condescending remark.

 

[frostback]

One more try
The word "extention" means nothing when talking about simple coat colour. That is why I did not know what it means. So forget it please.
Forget about ee and Rr and such. Lets just use B for black, its a capital because it is dominant. We will use W for the roaning because it is co-dominant. Use a little r for red as it is recessive.
Therefor a blue roan is BW. Only,, it does not have 4 caractures. no EeRr only BW.
A red animal is rr.
So when put into the punnett square

      B    W

r    Br  Wr

r    Br  Wr

 

[JSchroeder]

I don’t mean to be rude but where exactly did you learn about genetics?

The word "extention" means nothing when talking about simple coat colour. That is why I did not know what it means. So forget it please.

Actually, yes, it means a lot and the fact that you don’t know what it is and want to claim it “means nothing” says a lot about the level of study you’ve done on the subject.  It’s the gene that controls black and red.  If you do any basic level research into the genetics of coat color in animals it will be one of the very first things you are exposed to.

And yes, you do need to understand it before you can discuss the subject with anything resembling accuracy.

Forget about ee and Rr and such. Lets just use B for black, its a capital because it is dominant.  We will use W for the roaning because it is co-dominant. Use a little r for red as it is recessive.

In your example, you are putting the “W” gene into a punnett square it does not belong in, the punnett square for extension.

Therefor a blue roan is BW. Only,, it does not have 4 caractures. no EeRr only BW

Yes, it does.  There is the Ee for the black and the Rr for the roan.

B     W

r    Br   Wr

r    Br   Wr

That is not a valid punnett square.  There is no “W” in the black/red relationship.  You need two punnett squares or a 4x4 matrix to do what you are trying to do.

You seem to be stuck on including roaning with the extension gene.  They are two different genes and function differently.  You first need to work out the extension and then apply the roaning to the results of that.  You don’t do them at the same time.

 

[frostback]

Ok ok I dont give up,,, I forfit.

 

[Okotoks]

I don’t mean to be rude but where exactly did you learn about genetics?

The word "extention" means nothing when talking about simple coat colour. That is why I did not know what it means. So forget it please.

Actually, yes, it means a lot and the fact that you don’t know what it is and want to claim it “means nothing” says a lot about the level of study you’ve done on the subject.  It’s the gene that controls black and red.  If you do any basic level research into the genetics of coat color in animals it will be one of the very first things you are exposed to.

And yes, you do need to understand it before you can discuss the subject with anything resembling accuracy.

Forget about ee and Rr and such. Lets just use B for black, its a capital because it is dominant.  We will use W for the roaning because it is co-dominant. Use a little r for red as it is recessive.

In your example, you are putting the “W” gene into a punnett square it does not belong in, the punnett square for extension.

Therefor a blue roan is BW. Only,, it does not have 4 caractures. no EeRr only BW

Yes, it does.  There is the Ee for the black and the Rr for the roan.

B     W

r    Br   Wr

r    Br   Wr

That is not a valid punnett square.  There is no “W” in the black/red relationship.  You need two punnett squares or a 4x4 matrix to do what you are trying to do.

You seem to be stuck on including roaning with the extension gene.  They are two different genes and function differently.  You first need to work out the extension and then apply the roaning to the results of that.  You don’t do them at the same time.

The one animal in this example only carries two red genes and Black is dominant over red. The white gene is codominant to both black and red.
Color expression in cattle is not the same as in horses or dogs. There are some similarities but the roan color in cattle is produced by the W White gene pairing with either the r red or the B Black. The punnet square for this is very simple. A animal with BW (black and white codominant) called blue roan does not carry a r (red recessive gene). Frostback is actuallly correct.
Beside Belgium Blues and Shorthorns anew breed with the same codominant color pattern is the Specckle Park. Their website explains the color pattern very well. They call roan speckle!
http://www.canadianspecklepark.ca/content/colour-pattern

 

[JSchroeder]

W. As you refer to it is roaming, not extension.

 

[frostback]

http://www.zampwiki.com/?t=Equine_coat_color_genetics

Did some research and cattle dont have this. Is this what you are talking about? Roaning is not a "condition" for my lack of a better term, it is a colour.

 

[Okotoks]

W. As you refer to it is roaming, not extension.

Having both horses and cattle I can assure you that they are not the same in regards color inheritance. You are using equine to describe bovine color inheritance. No wonder we are all confused! ???

 

[JSchroeder]

I'm not talking about horses but I have developed multi gene color models based on literature that are used by schools for both.

Did some research and cattle dont have this. Is this what you are talking about? Roaning is not a "condition" for my lack of a better term, it is a colour

No, it is not what I am talking about.  I am talking about roaning as in RR = white, Rr = roan, rr = no impact.  I use the verb because it impacts the extension gene and turns a black calf into a white, blue roan or black calf and a red calf into a white, red roan, or red calf.

 

[frostback]

If that link is not what you are referring to, could you show me some reading material as it pertains to cattle so I could learn. I have read the first link you put up and it has nothing about the extension gene.

 

[OH Breeder]

http://www.piedmontese.org/Coat%20Color%20Cattle.pdf

This article is very specific about extension roaning etc. Thought it was a good read. Also goes over the blue roan etc.

 

[frostback]

Thanks B thats was just what I was looking for.
It is a dominant recessive thing.

 

[JSchroeder]

I have read the first link you put up and it has nothing about the extension gene.

Actually, yes, it does.  In that resource it’s referred to as MC1R which is the extension gene.  Put simply, if you are talking about the black/red relationship, you are talking about the extension gene.  Not only does it exist in cattle and horses, it exists in humans as well.

That UF book excerpt OH breeder posted is probably the most thorough explanation on color available on the web.

To beat the dead horse a bit more, the single square model you are using works as long as you are talking about homozygous black or red cattle.  Of course, the reason it works in that scenario is the extension gene is irrelevant because it remains the same.  Using two squares in that case would still return the proper result but the extension punnett square would be a waste of time.

When you start mixing red and black genetics, you have to switch to a two square model or make your square a 4x4 instead of 2x2 because it is too complex to fit in one 2x2 square.