Pedigree Query

Pictures of these rare Australian TBs
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Author:  belambi [ Sun Feb 12, 2012 1:46 pm ]
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We lost the hair that I had kept from Mata Biru when the house got washed away last year. But the colts hair will be done in the near future. (Mata Biru has been sold to WCF) and apparently has a solid foal by PIS this year .
The colt is slightly hearing impaired, but not nearly at the same level as the mare.

Author:  Jorge [ Tue Feb 14, 2012 7:46 am ]
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xfactor fan wrote:
There's a notation on one of the CAB roans that they are "true" roans. Anyone know if, or what kind of testing was done on these animals?

It sure looks like the CAB roan was a unique mutation starting with Catch a Bird. It would be unlikely that it is the exact same mutation as the regular roan.

Now I ask: did the so called "roan" mutation started with Catch A Bird,
who wasn't a phenotypical "roan" himself, or it was limited to his 4 "roan" offsprings (Odd Colours, Slip Catch, Red Noble, Goldhill Park)? Looks improbable that the mutation occurred on 4 independent occassions, so one tends to think that Catch A Bird was the sole culprit. If so, how to deal with a "roan" transmitter who wasn't carrying the phenotype. Connoisseurs affirm that a "roan" must have at least one "roan" parent. Well as the saying goes: "grab that pussy-cat by the tail".

Author:  accphotography [ Tue Feb 14, 2012 11:18 am ]
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I think CAB did show his roan, in his stripes. He was a chimera and I believe his chimera twin was the carrier of the roan (hence the white stripes). That chimera twin must have also been in charge of the testes.

Author:  xfactor fan [ Tue Feb 14, 2012 3:50 pm ]
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I sort of agree. However, don't think there was a "twin" involved. Rather that there was a mutation in one cell line (probably in KIT) which left him as a mosaic. Part of his cells carried the new mutation, part of his cells didn't.

As for who controlled the swimmers, given how few roans he produced, the mosaic tissue probably extended to the testes.

Other KIT mutations which pop up a lot are Dominant White, and Sabino. Just look at how many DW mutations have been found. And while they are all lumped under DW, they each have a slightly different "error" .

Roan, or the segment that is involved in the roan mutation seems to be very stable with only 3 known versions. 4 counting CAB.

Since CAB wasn't studied while he was alive, this makes a good "thought problem" with no chance of ever being solved.

Author:  belambi [ Tue Feb 14, 2012 4:11 pm ]
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Since CAB was a TB, There should be a blood sample on record, which could be reactivated using the buffy coat test. I think he was pre hair DNA (in Australia?)

Author:  accphotography [ Tue Feb 14, 2012 11:04 pm ]
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Mosaicism and chimerism are really very similar. We've seen enough other types like this to be pretty confident they're chimeric.

If he only produced 4 roans, how many non roans did he have? I have no idea how many foals he had all told.

Author:  xfactor fan [ Wed Feb 15, 2012 12:26 pm ]
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If roan were an established color in the TB, I'd agree with the idea that CAB was a chimera. (two embryo's fused into on) However since neither parent was roan, and roan doesn't exist in the gene pool of the TB, it looks like CAB was the original source of the new roan mutation. And this point to a mutation in some of his cells, which presented as the strange white streaks in CAB's coat.

Author:  accphotography [ Wed Feb 15, 2012 8:31 pm ]
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I agree, but a mutation is just as likely to happen in a chimera as it is in CAB on his own.

Author:  xfactor fan [ Wed Feb 15, 2012 11:47 pm ]
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There seem to be 31 listed in the PQ database. However there very well be more.

Just doing the rough math, if the mutation was on one of the KIT genes, there should have been something on the order of 15 foals with his odd coat.

If the mutation was a mosaic, and half of his testes carried the mutation the number of odd color foals should have been around 7. And this is close enough to the reported number of 4 to be within the margin of error for such a small sample.

Author:  summerhorse [ Thu Feb 16, 2012 10:04 pm ]
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I've seen enough of these stripey horses now I don't know that they have anything to do with whatever mutation CAB had that turned those foals roans. It might be a red herring as I don't know of any others (white striped or brindled) that produced roan. I asked Sponenberg about this and he said that CAB would not himself have or show the mutation but that it was just something he could pass on in his genetic code. In a limited way obviously. However remember he was also bred to standardbreds and australian stock horses and some of those were also roan (appearing). Too bad we'll never know those numbers as the woman stopped keeping records or registering them about the time she stopped feeding them! When taken altogether they might have showed a different % of roan foals. I wonder if his last owner saved any hair samples? Still his foals could be tested. There are enough of them alive and known to ask for samples. WCF has one for sale right now.

Author:  Jorge [ Fri Feb 17, 2012 11:01 am ]
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summerhorse wrote:
However remember he was also bred to standardbreds and australian stock horses and some of those were also roan (appearing).


Can you broaden your thoughts on this very interesting angle ---quite logical albeit not necessarily scientifically proven--- you are bringing up here.

I don't want to add words to your thoughts but it makes a lot of sense to me to ask to myself the following question: What if genuine roans from other breeds somehow had something to do with these "new" mutations.

Author:  xfactor fan [ Fri Feb 17, 2012 11:44 am ]
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While it is an interesting idea to speculate on other roans, it seems likely that Catch a Bird is where the mutation took place. Unless you of course want to speculate that there was fence jumper.

Mutations happen all the time. Genetic mistakes happen all the time. And the advent of modern DNA testing that can confirm who the parent are, pretty much rules out the idea of fence jumping.

The Dominant White mutation happened in KY Ky Colonel that gave rise to the Patchen White horses. Or Not Quite White dam of Airdrie Apache is where the that mutation happened.

We're lucky to be alive in an era where genetic testing is possible, otherwise fence jumping would be assumed, and the foals would have been quietly given away, if they didn't meet a worse fate.

If you have time, google Glitter Please the wonderful palomino dressage horse. He was bred to be a race horse, but once he shed out to palomino, he was offered by the farm manager to a dressage rider. Quietly removing him from race training.

Whatever problems the Australian vet who was breeding CAB had, she at least recognized that there was a new mutation, and was trying to preserve the trait.

Author:  summerhorse [ Fri Feb 17, 2012 5:24 pm ]
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I just meant there was a larger sample than we have records for Jorge. I don't think or know if any of the mares were roan, I don't THINK so because she was trying to produce "new roans" so to speak. The only ones I saw seemed to be mostly solid but there were several roan foals.

Author:  xfactor fan [ Fri Feb 17, 2012 8:21 pm ]
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Including the filly in the "That's not Slip Catch" thread.

Author:  belambi [ Thu Jun 07, 2012 9:14 pm ]
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Point number 6 on this newsletter from WCF is exciting! ... ch2012.htm

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