Homozygousity

[animalhouse143]

from what i remember in biology class.... the only way u can assure a black calf is if both parents hold the dominant black gene. If one of them has a recessive gene its a 75% chance of being black, and 25% chance of being the other color. Unfortunetly it gets more complicated when 2 colors can merge, but if i remember correctly that only happens with certian recessive genes

 

[VanC]

Believe this is related. Unfortunatley it's a hobby for me and I don't know nothin.

How do two black animals produce a chocolate brown calf ? Is this the result of a diluter gene?

Thanks,
CW

RainMan- I won't pretend to know the answer to your question. You might try finding an animal geneticist at some university and ask them via e-mail. Most university types are more than happy to talk about their areas of interest.

As for the original question asked by El-Putzo, the answer is still no. I sent an e-mail earlier today to Doug Parrett, who is an animal science professor involved in cattle genetics at the U. of Illinois. I asked him if a homozygous black animal could still carry the dilution gene. His answer was simply "No- that is the definition of homozygous." Doesn't mean he couldn't be wrong, but I doubt it.

 

[randiliana]

I asked him if a homozygous black animal could still carry the dilution gene. His answer was simply "No- that is the definition of homozygous." Doesn't mean he couldn't be wrong, but I doubt it.

Actually, I think that an animal could be homozygous for black, and be grey in color, because, the dilution gene "acts on" the base color. From the way I read it, the animal could have 2 black genes and also carry the dilution gene, which would make him grey or white.

So in effect the animal could carry 2 black genes, which makes him homozygous for black AND it could carry 1 or 2 dilution genes which would make him grey in color rather than black.

Clear as mud :shock: :shock:

 

[txag]

Can an animal be homozygous for color (black) and still carry the diluter gene?

yes. an animal can have two copies of the gene for black (homozygous) and also carry the diluter gene (totally separate gene from the black/red color genes). phenotypically, this animal will not be black but will be some varying degree of grey to white.

 

[Carnivore]

What is really wierd is when you start with a black cow, and she turns gray over the years. This is happening to one of my cows as we speak.

 

[randiliana]

What is really wierd is when you start with a black cow, and she turns gray over the years. This is happening to one of my cows as we speak.

How old is she? Is she going grey all over?

 

[Carnivore]

She is only 4 years old, a Black Angus/Shorthorn cross. Her undercoat appears to be white, and that is showing through more and more. I frankly don't care, the meat is still red...

 

[heritagefarmer]

This calf is out of a grey cow that is less than 1/8th charolais and more than 7/8th black angus and sired by a black angus bull....Many generations of black bulls anyway and he still refuses to be black....

Is this little lad ever going to grow into that eartag?

 

[S.R.R.]

Can an animal be homozygous for color (black) and still carry the diluter gene?

NO

In a homozygous black, red or any other color animal there is NO diluter gene. Only animals that are heterozygous for a color carry a diluter gene.

When an organism is referred to as being homozygous for a specific gene, it means that it carries two identical copies of that gene for a given trait on the two corresponding chromosomes (e.g., the genotype is AA or aa). Such a cell or such an organism is called a homozygote.

When an organism is referred to as a heterozygote or as being heterozygous for a specific gene, it means that the organism carries a different version of that gene on each of the two corresponding chromosomes.

 

[txag]

Can an animal be homozygous for color (black) and still carry the diluter gene?

NO

In a homozygous black, red or any other color animal there is NO diluter gene. Only animals that are heterozygous for a color carry a diluter gene.

When an organism is referred to as being homozygous for a specific gene, it means that it carries two identical copies of that gene for a given trait on the two corresponding chromosomes (e.g., the genotype is AA or aa). Such a cell or such an organism is called a homozygote.

When an organism is referred to as a heterozygote or as being heterozygous for a specific gene, it means that the organism carries a different version of that gene on each of the two corresponding chromosomes.

the diluter gene is a separate gene (gene pair) than the color gene. an animal can be homozygous black BB and also be either heterozygous or homozygous for the diluter gene DD or Dd. A genotype of BBDd (homozygous black, heterozygous diluter) or BBDD (homozygous black, homozygous diluter) would give a phenotype of a varying shade of grey to white. so yes, an animal can be homozygous black and carry the diluter gene.

 

[S.R.R.]

Can an animal be homozygous for color (black) and still carry the diluter gene?

NO

In a homozygous black, red or any other color animal there is NO diluter gene. Only animals that are heterozygous for a color carry a diluter gene.

When an organism is referred to as being homozygous for a specific gene, it means that it carries two identical copies of that gene for a given trait on the two corresponding chromosomes (e.g., the genotype is AA or aa). Such a cell or such an organism is called a homozygote.

When an organism is referred to as a heterozygote or as being heterozygous for a specific gene, it means that the organism carries a different version of that gene on each of the two corresponding chromosomes.

the diluter gene is a separate gene (gene pair) than the color gene. an animal can be homozygous black BB and also be either heterozygous or homozygous for the diluter gene DD or Dd. A genotype of BBDd (homozygous black, heterozygous diluter) or BBDD (homozygous black, homozygous diluter) would give a phenotype of a varying shade of grey to white. so yes, an animal can be homozygous black and carry the diluter gene.

Your wrong on this one plain and simple.

 

[txag]

Your wrong on this one plain and simple.

http://www.simmental.com.au/tech_newsit ... itance.pdf

(page 2 at the bottom)

 

[S.R.R.]

Your wrong on this one plain and simple.

http://www.simmental.com.au/tech_newsit ... itance.pdf

(page 2 at the bottom)

O.K. you are calling the gene by its right name a diluter gene. I will give you that, my bad. The next line on that page makes my point. A homozygous black bull can only pass on a black gene not any other color. A heterozygous black bull can past on a gene of another color.

 

[txag]

O.K. you are calling the gene by its right name a diluter gene. I will give you that, my bad. The next line on that page makes my point. A homozygous black bull can only pass on a black gene not any other color. A heterozygous black bull can past on a gene of another color.

there are color genes and then there are diluter genes that can mask or "dilute" (not replace) the color gene. the color is still there but is being "diluted" by the diluter gene.

you're right......a homozygous black bull can only pass on the black color but he can also carry & pass on the diluter gene. ;-)

 

[S.R.R.]

O.K. you are calling the gene by its right name a diluter gene. I will give you that, my bad. The next line on that page makes my point. A homozygous black bull can only pass on a black gene not any other color. A heterozygous black bull can past on a gene of another color.

there are color genes and then there are diluter genes that can mask or "dilute" (not replace) the color gene. the color is still there but is being "diluted" by the diluter gene.

you're right......a homozygous black bull can only pass on the black color but he can also carry & pass on the diluter gene. ;-)

So a homozygous black Angus bred to the same can have a gray calf if their diluter genes meet?

 

[txag]

So a homozygous black Angus bred to the same can have a gray calf if their diluter genes meet?

angus don't carry the diluter gene. if they did, they'd be grey. the diluter gene is dominant & only takes one copy to "dilute" the color gene.

 

[S.R.R.]

So a homozygous black Angus bred to the same can have a gray calf if their diluter genes meet?

angus don't carry the diluter gene. if they did, they'd be grey. the diluter gene is dominant & only takes one copy to "dilute" the color gene.

Now your not making any sense! Your paper that you posted says at the bottom of page 1 "every animal carries two of the diluter gene."

So the right responce to El_Putzo is yes but only in some breeds.

 

[txag]

Now your not making any sense! Your paper that you posted says at the bottom of page 1 "every animal carries two of the diluter gene."

So the right responce to El_Putzo is yes but only in some breeds.

typically when an animal doesn't show a gene, in layman's terms, it's said they don't carry it. for example, the angus also doesn't show the gene for spotting (like simmentals) or white-face (like herefords), so we just say they don't carry those genes. so, when i say they don't carry the diluter, i'm saying they're recessive for the diluter (dd) which means their color is not diluted. angus would be BBdd (assuming they're also homozygous black) & when the two are crossed, you'll still get BBdd.....black, non-diluter (phenotype=black).

you're making this more complicated than it is.....and we're probably confusing people even more. pm me if you have more questions.

 

[S.R.R.]

and we're probably confusing people even more.

You got that right! Let me go get a couple advil and I will pm you if the pain goes away. :? :? :lol:

 

[txag]

Let me go get a couple advil and I will pm you if the pain goes away. :? :? :lol:

you might want to bring a couple extra for me. :lol: