# Extreme Black debate (Split from 'Red eyed cinnamon?')



## Rhasputin (Feb 21, 2010)

Sarah are you saying extreme black doesn't exist in the fancy, or doesn't exist at all?


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## SarahY (Nov 6, 2008)

I'm saying it doesn't exist in the fancy. Apparently they have it in labs (and I believe the lab people), but I think the confusion has arisen from the a/a blacks that are insanely _black_, like a UK show quality black, and people think this is what 'extreme' means. Everyone goes on about our mice being 'extreme blacks' but they're not; our blacks are a/a and it is proven by the tan hairs they have in their ears as babies. On the other thread where it was being discussed, the laboratory photograph of an extreme and a normal black showed very little difference in the strength of black, all of the difference was in the non-black hairs; faded yellow on the extreme black and tan on the normal black.

Edited to add: this is the full discussion:
http://www.fancymicebreeders.com/phpBB3/viewtopic.php?f=26&t=8209


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## Rhasputin (Feb 21, 2010)

You don't think it's in any country outside of labs?


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## SarahY (Nov 6, 2008)

Nah, I haven't seen any evidence or any reason to believe in a magic 'extreme' gene. I am of the mind that when one hears hooves, one thinks a horse is coming - not a zebra. Since ALL of the show quality blacks in Europe and the USA came from us in England, and we don't have extreme black, it stands to reason that no-one does.


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## Stina (Sep 24, 2010)

I believe a^e exists in the fancy at least in the US....I have seen quite a few blacks with no tan hairs whatsoever, even as babies and the lack of tan seems to act as a simple recessive. They are not necessarily darker black, but do not have any tan pigment. However it wouldn't affect an agouti (A/a^e) mouse's color.

If it exists in labs what makes you think its so difficult for it to have gotten into the hobby ever? I only just this year got hairless mice from a lab....its not that difficult to get mice from a lab and it would only have taken one person to have gotten a^e at some point to have had it spread throughout the hobby.


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## m137b (Sep 22, 2010)

I do think extreme non-agouti exists in the fancy, But I think people give it more credit that it is due, and try to pawn it off as better than normal non-agouti when it isn't.

It's not magic, it doesn't make a black perfect. It just gives them a different set of faults to work on.


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## SarahY (Nov 6, 2008)

Of course it's entirely possible; most of our varieties have come from labs! I've just seen no evidence of it in the fancy, that's all I'm saying. Why say we have something when no-one actually knows for sure? Show agoutis are a TOTALLY different colour to pet agoutis, but no-one says "aah, yes. That's because of the 'mahogany' agouti gene, 'Am'. That would be rubbish, it's because of careful selective breeding over decades. So why say it about blacks when the deep inky black is also a result of careful selective breeding over decades? My main problem with the whole thing is that people are under the misconception that any 'proper' black is an 'extreme' black when it's not. People think the extreme black gene magically produces a show quality black, but that just isn't the case.

The ones that have no tan hairs still may not necessarily be extreme black unless those hairs are white. The extreme black gene won't show red pigment but the actual fault of non-black hairs in the coat would still be there unless carefully selected against. Even if those hairs were white, that could well be due to the chinchilla or silvering genes, not extreme black. So white hairs won't tell us the truth either without well thought out experimental outcrosses.

If someone says "yes, I got extreme blacks from labs and spread them round the fancy" then fine, the mouse fancy has extreme blacks. Until then, we must assume that all blacks, regardless of their strength of colour, are a/a blacks.


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## Stina (Sep 24, 2010)

> The extreme black gene won't show red pigment but the actual fault of non-black hairs in the coat would still be there unless carefully selected against. Even if those hairs were white, that could well be due to the chinchilla gene, not extreme black. So white hairs won't tell us the truth either without an experimental outcross to chinchilla.


I have the chinchilla gene have/have had what I believe to be a^e and the mice I believe/have believed to be a^e have definitley not been chinchillated....it wouldn't require c^ch to prove either, ANY c-dilute would work. If you crossed a c-diluted mouse to a mouse believed to be a^e/a^e and didn't get all c-dilutes it would be definitive that it wasn't chinchillated or c-diluted....and I have gotten that result. The hairs without yellow pigment also become translucent, so if they are intermingled with black hairs the black will become more dominant visually and give the impression of fewer light hairs.


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## SarahY (Nov 6, 2008)

> t wouldn't require c^ch to prove either, ANY c-dilute would work


Yes, I had already edited that bit of my post


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## Stina (Sep 24, 2010)

Oh I didn't reread your post....I started doing mine in the other thread and then it didn't show the post thing and copied and refreshed and saw you moved the topic...so I just came over to this thread and posted it...lol


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## SarahY (Nov 6, 2008)

Yeah, sorry about that Stina!  I thought it was better to move this discussion rather than overtake moustress' thread :lol:


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## moustress (Sep 25, 2009)

I had extreme blacks from the Robbinses in California. They are unbelievably, utterly, entirely black, black black. No hint of pink at all on the ears, around the eyes, toes, vent...they didn't breed, unfortunately, except for the accidental litter from the mating with the champagne tan doe in transit. And since I was breeding champagnes, and then found I had argente, and some of those from the accidental litter contributed to the argente that I have now, I still think it's there, contributing to the overly dark argentes that keep showing up, darker and darker with each year. Now, I don't know where it came from, and I was warned to conserve the strain by not diluting it. So it is possible that it's another example of a characteristic that is developed by inbreeding darker individuals with each successive generation. And, as I've been breeding argentes for ten years or more, it makes sense to me that the extreme darkness factor is causing the excess darkness.

There is good correlation between what I propose in human beings, as skin color does dilute or darken as folks of different complexions mate. As an additive factor, conservation would be essential to maintaining extreme blackness.


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## Laigaie (Mar 7, 2011)

In that case, you'd be talking about a collection of modifiers, rather than a simple on/off gene. It seems to me that mice hardly ever have simple on/off genes, so much as they have genes that make something possible.


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## moustress (Sep 25, 2009)

Yes, I agree entirely, Laigaie. The alphabet of mousie coat and eye 'genes' describe more the location certain characteristics are found, and not the actual genes themselves, which are more complex. And genes do not not operate in a vacuum, but are affected by many things that we normally do not take into account. That is the reason why one can see such a wide variation in any given color, and also makes clear the insistence of show breeders that you need show stock to get show stock from.


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