Sooty

Is the At on the agouti locus or the extension locus? Could horses have At on the agouti locus and/or Ed (dominant black/melanism, called Es in rabbits) on the extension locus, with both having a similar phenotype but one being dominant to normal agouti and one being recessive?

It's on agouti.

PK, my Sooty is also Dun, so it gets a bit more confused :hammer
And she has Flaxen and possible Pangare..........
But, if it is any help, she started life as a "normal" Flaxen Red, a nasty ginger Red, to boot.
She only developed into this gorgeous, deep, rich, mahogany colour in later life, her mane and tail were only a bit Flaxen as a youngster, and as she aged they got lighter and lighter....now I have to go and see if I have any decent pictures, and then I have to find $25.00 to have her tested for Agouti!!

Hmmmm, I'm now not sure if my question still "exists" or not...if sooty 'mimics' dun, that's an argument [b][i]for[/i][/b] a separate sooty gene theory, and against the idea that sooty is the result of a "misfiring instruction"...

The question I was going to ask the other day (and yes, I wrote it down so I wouldn't forget where I was heading! LOL) is "could sooty be a "misfire" in either the agouti 'instruction' of red on body and/or a "misfire" in the extension 'instruction' of black on outline/points...

What's brought me thinking this way is our Bubba...he's out a very clear bay (well, as clear as a full leopard app bay mare can be), who has very cherry-red spots, including those areas where sooty would show up. And Teddy is, well, strange. LOL He's very much a "black" in phenotype, genotype EEAa (for the record, Bubba's dam is EeAA). So, from memory, the guy who 'found' At believed A is dominant to At, so why would Bubba be 'brown'? Also, Bubba's sooty changes, this year he has much more "dark" on his neck, chest and back than he did last year, which was also less "drippy" looking than the year before. Wonky 'colour me' instructions makes more sense in this scenario than a separate gene/mutation. And yes, Bubba is still exhibiting as much Lp as he did when he was born...pretty much just that one pink patch on his :o :oops: :angel

Diane

What color is the sire?

[quote]He's ... genotype EEAa (for the record, Bubba's dam is EeAA). [/quote]

Both parents are bay in genotype, but sire looks black and dam looks normal leopard bay.

http://www.wapspotted.com/" onclick="window.open(this.href);return false; Teddy's roaned out now to http://www.wapspotted.com/html/wap_pict…" onclick="window.open(this.href);return false;

Diane

How do we know he's not black?

Know who's not black? Teddy is EEAa so a bay and Bubba is out of a EeAA and by an EEAa so he is gauranteed a E-A-. Having seen Bubba in person, he is definitely bay-based.

I'm completely lost.

[quote="accphotography"]How do we know he's not black?[/quote]

Uhm, because as I've said twice already, Teddy's genetic makeup is EEAa...last I knew that makes a horse bay. and there's no doubt that Bubba is bay, given his red coat and black points...

Diane

[quote="accphotography"]I'm completely lost.[/quote]

Bubba is my horse. His sire is Teddy (aka Wap Spotted). Teddy has a genotype of EEAa. Teddy has a phenotype of "black. Bubba's dam is Pepper. She has a genotype of EeAA. She looks cherry-red on the torso, black on the legs (where there's no white). Bubba, based on his parents, can only be a bay...he cannot be black, he cannot be chestnut. He, however, exhibits sooty. Or "brown", if you prefer, since he currently looks very much like that I linked to in my earlier post.

Diane

I'm just stunned that WAP Spotted is Aa. He looks black. So why would the idea of Bubba being brown be a surprise?

It surprises me because it refutes the idea that "A" is dominant to "At"...a clear bay should not be able to produce a brown. And I've not heard that black bays test to At, so where would Bubba get "At"?

Diane

[quote="NZ Appaloosas"]It surprises me because it refutes the idea that "A" is dominant to "At"...a clear bay should not be able to produce a brown. And I've not heard that black bays test to At, so where would Bubba get "At"?

Diane[/quote]
A clear bay SHOULD be able to produce brown. A horse who is AAt will LOOK bay but can produce brown depending on what the other horse passes. A horse who IR AAt will test AA on everyone but PetDNAs brown test.

[quote="NZ Appaloosas"]It surprises me because it refutes the idea that "A" is dominant to "At"...a clear bay should not be able to produce a brown. And I've not heard that black bays test to At, so where would Bubba get "At"?

Diane[/quote]

As RMT said, a red bay can produce a brown as long as that red bay is 'AA' (it would really be 'A At'). Black bays DO test to At... black bay = brown/At.