Colour gentics....

Spyda

Spyda

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Just had my bay filly tested for colour genes.

She's bright bay in phenotype and is homozygous for the Agouti gene (Aa) and carries the Red gene recessively. Apparently she's most likely to produce a bay or black, or less likely a chestnut from a non-chestnut stallion if it also carrying the Red gene recessively.

Anyway..... could anyone advice the offspring-colour ratios if I were to put her to a Cremelo, or Perlino stallion?

I have a beady eye on Milky Way ATM
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Not sure about what Perlino boy/s yet.

Many thanks.
 
Oooh where did you have this done, and how much did it cost?

I'm interested in having my filly tested, even looking at her daily I can't work out if shes dark brown, or bay....
 
I'll dig out the info and ket you know. My filly's DNA is on record with them already (from a previous test) so all I have to do now is phone them and ask then to run which ever extra tests I want. Each test costs £16.
 
Spyda you should take a trip up and meet Milky Way he is such a sweet chap.
He's gaining a huge fan club as everyone who visits him just falls in love with him.
He is the original princess pony
 
I've seen him
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I was at Centyfield when he very first arrived with them. My mare was already covered so too late for a Milky baby and Ireland was too far the following year.... Finally... maybe next year
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No chance of a smokey foal, then? Geneticist said there was equal chance of her throwing a bay or black foal, and a very small chance of a chestnut (to a non-chestnut stallion, that is).

I was assuming that since the black is equal to the bay, if the black gene was passed we'd get a smokey? Am I wrong? Sorry... despite doing degree level genetics - it was never my favorite sujects and I'm STILL confused!!!
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I think the confusion is that you said she was homozygous for agouti (I think that would be AA ... ?) but wrote Aa, which would be heterozygous.
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If she's heterozygous, then there is a 50% chance of her passing on her dominant agouti, and 50% chance of the recessive going through. So ... if she passes on her black gene and not her agouti gene, then I think there is an opportunity for smokey black ... ? If she passes on her black gene and the agouti gene, you will wind up with buckskin, and if she passes on her red gene (with or without agouti) you will have a palomino.

Then you have to factor in the stallion's agouti series, which you wouldn't know from phenotype as it's not expressed in a red base. He COULD be AA (someone else might know this info, I haven't bothered to look), in which case you would have no opportunity for smokey black. Hope this makes sense ... and I'm sure that one of the resident colour gurus will appear later and state this all much more simply!
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I think the confusion is that you said she was homozygous for agouti (I think that would be AA ... ?) but wrote Aa, which would be heterozygous

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Duh (again!) Yes, typo - sorry. She's def Aa and I meant to put heterozygous. Having one of those days today
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What I am unsure of is the recessive Red. I mean, if she's Aa (so half likely to pass bay or black to her foal) where does the Red come into it??? How is that written? Aa ee?
Is it "recessive-recessive"? If you know what I mean?

And how does that figure into the equation of calculating potential offspring colour?

Honestly, it's SO confusing. I understood it to the Aa level, but when I was told she also has a 'hidden' Red in there too - that just flumoxed me. Could she be carrying anything else apart from the Red???? Recessive brown for example?
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It means she is Ee ... Her dominant black base gene is expressed (E) but she carries the red/chestnut gene (e) hidden. EE and Ee will look the same phenotypically. The agouti (AA or Aa) just restricts the expression of her black base to the points--legs, mane, tail, etc. A cremello is a double-dilute chestnut (red base, or ee). So any offspring from your mare and Milky Way will be either heterozygous black base (Ee, or black/bay depending on the agouti influence) or homozygous red base (ee, or chestnut), and then diluted from then by the cream gene from the sire. You won't know the agouti series on an ee (chestnut, cremello, etc) horse just by looking at its phenotype, as there is no black to restrict, so you'd have to look at parentage, offspring, or genetic testing.

I don't know much (well, anything, really!) about the brown gene, think KarynK is the one for that one, I just have the basic colours and some modifiers down. Beyond that is far too complicated for me.
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Isn't it great fun, though, to figure out what colours are most likely from a breeding? Sometimes it's such a surprise when you see what actually results ...
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Aaah, okay. Many thanks for your patience!
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Most appreciated
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This is a great link:

Colour predictor

Expect this link has been posted on here before, but I've just discovered it, and it's great.
 
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No chance of a smokey foal, then? Geneticist said there was equal chance of her throwing a bay or black foal, ...

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If it is the company I am thinking of they do not explain their results very well and what he said is misleading as you have to consider the stallions genes!!!!!!

If you want to understand it you need to break it down into the genes at work the first being the so called “E” series Black or Chestnut, Your mare is Black but carries Chestnut, So bred to a :

Chestnut you have a 50/50 chance of Black or Chestnut

Another black that carries chestnut you have a 75% chance of Black and 25% Chestnut (25% Homozygous black 50% Black carrying chestnut and 25% Chestnut)

A horse homozygous for black you will have a black foal. (50% homozygous black and 50% Black carrying chestnut)

Next is the Agouti gene which is thought to only have a visible effect on a black coated horse turning it to bay or brown. It appears that you have had her tested only for A (Bay) and not the new At (Brown) tests which can tell the two apart, this is a new test and only available in the US. So you cannot say for sure that your mare is a Bay until you have the At test.


So if your mare is homozygous for A (in this case Bay/Brown AA) then what you can predict is that she can never produce a black and will always produce a Bay/Brown.

If she has a foal that is black coated as above bred to another homozygous A you will get all homozygous A’s if bred to a Aa (one Agouti gene) You will get 50% homozygous 50% Bay/Brown carrying black. If bred to a black you get all Bay/Brown carrying black.

BUT what he is saying to you is that your mare is Heterozygous for A i.e. you have written it correctly Aa
In this case if bred to a homozygous A stallion you will not get a black, and chestnuts (I think a large number of them) can be homozygous without you knowing!

If bred to another Aa then 75% will have an A gene (25% will have two and 50% will be Aa but 25% will have noen which is a black horse aa. If you bred her to a black the there is a 50% chance of Aa and 50% aa.

(Caveat here there could very well be a dominant black gene on another locus that overrides A)

Then add in the cream dilution with is a sure thing with a cremello or perlino and you are looking at a golden Buckskin (Possibly from a Bay horse) or what I would call a “Dirty” buckskin, sort of a brown with yellow soft parts, which I think probably comes from a brown horse. Or if you get a chestnut the a Palomino of some shade . You will not get a black buckskin if she is AA but I think he means Aa so you could well do!

Phone them back and ask for the genetic terms in A's and E's to be sure!

There has not been much research into what coat shades and genes constitutes the shades of palomino or Buckskin, I know someone is studying chestnut shades so that may help soon.
 
Many thanks for that. Very helpful. I've not got the cert from them yet so will wait for that to arrive and see what it says. If it's like last time, it wont say much though.

Also, guess I really need that At test too.
 
You're welcome! It's terribly interesting stuff ... good luck with your mare this year! I do love this "stallion hunting season" and hearing about everyone's thought processes on selection, etc. The broodmare I take care of is grey, and we don't know if she is homozygous or heterozygous (both parents grey, dad was heterozygous, don't know mum's status). Don't really know what's underneath the grey--though I suspect a black base of some sort--and I'm really looking forward to meeting the mystery foalie (by a lovely chestnut stallion) which will arrive sometime in March-ish.
 
This is taken from one of Opie's posts, it may have already been put up can only have a postage stamp view of posts as meant to be back from lunch!!

Foxtrot, if you want find out if you could get a palomino foal, the simple answer is to pull a few hairs from her mane and send if off to www.avianbiotech.co.uk and test her to see if she carries the red gene. If she does then yes she could produce a palomino and if she doesn't then no she can't.
 
Here you go the link for At (Black and Tan) testing.

http://www.petdnaservicesaz.com/Equine.html

It’s $40 per test but I am sure if you wanted a group of tests or more horses done you can negotiate. Unfortunately not a good dollar rate ATM!!

It’s a hair follicle test but please note that you need to contact them BEFORE sending anything from outside the USA as you will need a USDA import permit which is free.

This is the person who managed to find the gene and is currently the only company that can tell the difference between A and At, so it is well worth doing this if you want to know what the A status really is.

All I ask is that if you use this that you let me know the results and let me have a picture!
 
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