# Pearl



## Roland

Hi,

I do not understand the discussion in the following thread:
viewtopic.php?f=21&t=5230
and hope that someone could enlighten me. For me the most reliable source of information about mouse genetics is Jax. They have a definition of Pearl (gene code pe) as a simple autosomal recessive mutation on chromosome 13. Therefore nobody can "recreate" it by breeding, there is only yes or no: If the mouse is pe/pe it is pearl, if it is Pe/* it is not. If Jax is true, nobody can create a Pearl by simple breeding of Pe/Pe mice, not from Chinchilla or Silveragouti or what ever. Nope.
All you can get is something looking similar to a Pearl more or less. If pe is lost, it is lost until the mutation happens by chance again. Could be tomorrow or not in hundred years. 
Here is the link to the Jax article:
http://www.informatics.jax.org/wksilver ... e5-7.shtml

Best regards, Roland
Chilloutarea Mousery - Tricolor , Splashed , Merle , Recessive Red
The place where science meets fun!


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## SarahC

I can't enlighten you,I know nothing.You should subscribe to the NMC news and join the debate.The mouse pictured is a self from silver grey breeding.


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## SarahC

I have a question for you Roland.How can you tell the real pearl from something that appears similar.Is it possible?


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## Roland

SarahC said:


> I can't enlighten you,I know nothing.You should subscribe to the NMC news and join the debate.The mouse pictured is a self from silver grey breeding.


Hi Sarah, I am already a member and read the news. I love it, btw.
Did you read the Jax article?
Regards, Roland.


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## moustress

I bet the problem is the language of genotype that mouse fanciers use; not all factors are defined separately as loci or modifiers. We like to keep things simple when it's really not.


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## SarahC

yes I did read it.I suppose I want some one to show me an actual definite genetic pearl and say this mouse is a pearl and this mouse is not.I'll have to hope the skin Eric has answers my question.I have some of his mice ,blacks bred out of his pearl buck and silver greys but can the pearl be in there or would it have shown up by now?Then there is the pearl from Finland but I don't know it's origins.Is it a mouse that just looks like a pearl.How can you tell?It isn't black ticked but is it just a good pearl that would have distinct ticking and the rest not?The bit about the yellow tinging was interesting and the white mask.


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## WNTMousery

Please email Karen Robbins. She is president of the AFRMA and has imported UK Pearl. She is very knowledgeable about it. Her email is afrma (at) afrma.org


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## Seawatch Stud

I am not convinced that the mice shown as Pearls in the U.K were ever true Pearls. I think the vast majority of pearls shown in England were derived from Silver Greys. I have found an account of the same mouse winning best in show two weeks running in the 1930s once as a Pearl, the next week as a Silver Grey!. If this kind of confusion existed then what hope have we of sorting it out now?. I think if it looks like a Pearl, and can win at shows as a Pearl, well then for me at least its a Pearl!. We show Phenotypes not Genotypes. I dont care where it came from, or what it is genetically, I only care if it looks like the animal the standard describes.


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## SarahC

WNTMousery said:


> Please email Karen Robbins. She is president of the AFRMA and has imported UK Pearl. She is very knowledgeable about it. Her email is afrma (at) afrma.org


I have looked at the pictures of her mice and Erics mice but still it comes back to how do you know what the mouse in front of you is genetically.I think probably the answer is you don't and that Phil is right ,people make the assumption on what the mouse is visually.I am looking forward to reading the second part of Erics article and an article on Phils theory next month.I have some spare boxes,Im going to throw everything in,Erics mice,the mouse from Finland and the light bug eyed silver greys and some black ones that have white undercoats and see what comes out over the next year.


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## WNTMousery

SarahC said:


> WNTMousery said:
> 
> 
> 
> Please email Karen Robbins. She is president of the AFRMA and has imported UK Pearl. She is very knowledgeable about it. Her email is afrma (at) afrma.org
> 
> 
> 
> I have looked at the pictures of her mice and Erics mice but still it comes back to how do you know what the mouse in front of you is genetically.I think probably the answer is you don't and that Phil is right ,people make the assumption on what the mouse is visually.I am looking forward to reading the second part of Erics article and an article on Phils theory next month.I have some spare boxes,Im going to throw everything in,Erics mice,the mouse from Finland and the light bug eyed silver greys and some black ones that have white undercoats and see what comes out over the next year.
Click to expand...

Are you saying just throw them all in together?

Why not set up some test matings that cross the different possible pearls with each other to see exactly what comes of each combination before possibly ruining what is left of them?


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## SarahY

WNT, SarahC is less likely to _ruin_ them than anyone. She's a superb breeder, has won many top awards with her mice, has made her mark on many varieties - improving them to a winning standard from just a few rubbish examples, and has been doing this a lot longer than you. So perhaps a bit more respect is deserved.

Sarah.


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## Seawatch Stud

As one of the best stockpersons in the U.k with a proven track record as an exhibitor of some of the most difficult varieties of fancy mice I think Sarah should trust her own judgement and instincts here. I cant think of anyone less likely to "ruin whats left of them" than her.


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## WNTMousery

It wasn't intended as an insult.

Do you think throwing them all together in the same box is a good choice?


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## SarahY

Well it certainly came across as one. Think before you post.

Sarah.


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## Seawatch Stud

WNTMousery said:


> It wasn't intended as an insult.
> 
> Do you think throwing them all together in the same box is a good choice?


Yep.


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## WNTMousery

WNTMousery said:


> ...before possibly ruining what is left of them?


omg, I said "possibly ruining"

I didn't say, "She's a horrible breeder who has no idea what she's doing and is going to ruin all the pearls!"

I'm so sorry you didn't like the way I worded the sentence. It wasn't written in an insulting way or to insinuate Sarah doesn't know what she's doing. :? It was to provoke thought about the POSSIBILITY of ruining what is left by "throw everything in" some spare boxes (her words, not mine!!).

No need to be so sensitive. It is the internet and tone cannot be expressed very well at all so you just have to assume it is a friendly tone unless blatantly obvious that it is not (which isn't the case here).


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## SarahC

oh I only went to answer the phone and now look.Well wnt I have had them for about 7 years and managed to keep them when all others were lost.They've been ticking along quite nicely but I have decided that this year is to be their year and I'm going to breed a lot.The only difference is the Finnish mouse who has until now been kept in a separate line.The young he has produced are looking good and I can't see any reason to keep going along a separate route.I have enough of a foundation stock to allow for the odd mistake.Thanks for the vote of confidence Phil and Sarah and thanks for the pictures Phil,they make me optimistic.I'm just interested in all view points.


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## Stina

Are you interested in determining what is happening genetically with your pearls? If so, wouldn't you get a better idea of what is going on genetically if you test cross some specific animals instead of having breeding groups? I just don't see how mixing everything together will allow determination of what is going on genetically.


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## SarahC

I was interested in knowing if they are the real deal,yes.They are all related,line bred apart from the one from Europe.I can tell you what they produce when bred together,silver greys,blacks and pearls or are they pearls?that was what I was getting at.I must add that it's a project to enjoy not life and death,I really am interested in every ones input.If nothing good turns up I won't be sobbing into my pillow but I do like a challenge.


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## Stina

Perhaps try breeding some different appearing does from the related line to a buck from the european line and keep track of what the different does produce? That should allow you to determine if you have "overlapping" or all the same gene....or completely different genes...in the 2 lines?


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## Roland

I have to think about genetics and ways to differentiate pe/pe from mice who look like Pearl. For me it is no problem at all, if a mouse looks like something else and wins. I have some very nice "champagnes" from UK, which give Agoutis, when bred to a black mouse. If you have a very very close look, you see a pale shade of ticking. But I am happy to have them. Nevertheless I think it is always helpfull and interesting to know what the genotype really is.
Give me food to think about the question how we could tell what is what: What do you think is a Silver grey genetically?
When you read the Jax article about the genetically true Pearl, you understand that not a single "true" pearl exists. 
Example: Ay/* pe/pe is a dominant red pearl, and d/d pe/pe is a blue Pearl. The influence of pe/pe on other colours could be a way to tell who is who by test crossings.

The question first: What do you think is a Silver grey genetically?

Regards, Roland


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## Wight Isle Stud

Hi Roland, I will say your Knowledge of Genetics is of course, very much more advanced than mine,However, you say you have champagnes which on close examination show ticking, and produce agouti when mated to black. Might I respectfully submitt that your champagnes are in fact cinnamons with a double dose of Pink eyed dilution ?


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## Roland

I'll be back. said:


> Hi Roland, I will say your Knowledge of Genetics is of course, very much more advanced than mine,However, you say you have champagnes which on close examination show ticking, and produce agouti when mated to black. Might I respectfully submitt that your champagnes are in fact cinnamons with a double dose of Pink eyed dilution ?


Exactly, you got it, but the british and price winning breeder told me they would be champagne 

This was meant as an example that I do not care if a mouse is exhibited as something with a different genotype and looks more or less as something different (here: looks like a/a b/b p/p Champagne), but it is nice, although in reality the genotype is A/* b/b p/p.


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## Roland

Hi,

perhaps nobody noticed this question, so I push the thread up again:

What do you think is a Silver grey genetically?

Regards, Roland


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## SarahY

As far as I'm aware a silver grey is a/a si/si - black with a gene to add silvering.

Sarah xxx


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## WNTMousery

SarahY said:


> As far as I'm aware a silver grey is a/a si/si - black with a gene to add silvering.
> 
> Sarah xxx


I've heard these called Silvered Black but never Silver Gray.


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## SarahY

> I've heard these called Silvered Black but never Silver Gray.


They are standardised with the NMC as silver grey. I suppose because the white hairs make them look grey instead of black.

Sarah xxx


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## Jack Garcia

Hi Roland, I always thought that pearls (show pearls) were blacks who were silvered and who were also heterozygous for chocolate, bred toward a pearl standard, thus:

a/a B/b si/si

a/a B/B si/si and a/a b/b si/si would neither be pearl. The first would be silvered black (or "silvered gray" in the UK) and the other would be silvered chocolate.

This would make pearls hard to breed (as they characteristically are), since you'd need to keep the B/b heterozygosity in any population and breeding two pearls to each other wouldn't produce all pearl babies but would rather produce varying statuses on the B-locus.

I can't remember who told me all that. It might actually have been Karen, now that I think about it. I just can't remember for sure.

In the same way that umbrous affects the dominance on the agouti-locus (see here: http://www.springerlink.com/content/x3l42618rp178607/), my hunch is that silver (si/si) affects the dominance of the B-locus on a pearl mouse.



SarahY said:


> Well it certainly came across as one. Think before you post.
> 
> Sarah.


Sarah, your posts are coming across as rude, too. Believe me, I know a little bit about this so no offense is intended in pointing this out. Hehe.


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## WoodWitch

Oh, what nonsense!

SarahY is a moderator and does her job exceptionally well!

The offending person has been spoken to before about her attitude but continues to repeat. Besides which, the dispute had dropped and nothing can be gained from dragging it up AGAIN and making personal comments!

And those that "know a little bit" about coming across as rude, should probably sit back and keep shtum unless disputes directly involve them.

Now for goodness sake, let it go!!


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## Jack Garcia

I'm primarily responding to Roland's question about the genotype of pearl, which nobody else has been able to do in depth. Both Sarahs are great moderators, there's no question.


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## Jack Garcia

BTW, I also recommend emailing Karen, to be sure. She is always very helpful and has more years' experience than many of us put together! 

Edited to add:

In doing a little web research I just discovered that Finnmouse actually agrees with me:

http://www.hiiret.fi/eng/breeding/varieties/pearl.html



> Mating Silver Grey to Silver Brown should produce Pearl, as this variety requires 'B' from Black and 'b' from Chocolate. Pearl mice are difficult to show as their tendency to molt affects their appearance.


They also point out that there's a difference between the gene called "pearl" and the show mouse called pearl, which makes sense regarding the confusion.

So there you have it.


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## moustress

It does my heart good to see substantive discussion about issues like this. It makes folks think more about what it is they are doing and educates everybody a bit. We 'clue up' by doing so, and it helps to take it with a little grace, even if we don't agree with what is said.

'Kudos', I say, even to the cranky and impatient. Learning is a lifelong process, not a contest to see who knows better.

ps no, i wouldn't know anything about cranky and impatient as i am always sunshine and roses


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## Roland

I think we all agree that it is good to check out things by brainstormings like this. I did not find the time (because nearly 2.400 tiny feet have higher priority) to think in depth about the way how we could come closer to the genetic/outcrossing possibilities of finding out who is who, but I think we should continue this teamwork and brainstorming. 
If it is right, that Agouti B/B si/si have hairs of different colour, there are white-tipped, all-white, and black and white hairs, than this might be a way to separate them from the "genetically true" pe/pe. The pe/pe mice have on the agouti black ( A/A;B/B) background on which pearl occurres the pigmentation of the entire hair diluted with the base of the hair being affected to a disproportionately greater extent than the tip.

-> Sarah C, did you examine the different mice with a binocular already, or could you do it? Did someone look to Eric's "last Pearl fur" with a binocular or microscope?

Peace!
Roland
Chilloutarea Mousery - Tricolor , Splashed , Merle , Recessive Red


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## SarahC

No I haven't and Erics skin is not finished,apparently it takes some time.However to my eyes,the picture of the last pearl of Erics which is the bottom one on the back cover of this months news,looks different to all the others pictured.I have plenty that look like others that have been posted.What is unclear to me is,was that last buck just an exceptional example(albeit old in the photo)and in general they resembled the more grey ticked ones?Or were they white in general with a black tip.If this is the case then the others pictured are not the real thing.Exhibition pearls were finished on the show bench by the time I joined so I can only rely on other people for a description but it seems impossible to get an actual answer.I have a good few silver browns Jack but they haven't produced anything that stands out.Perhaps my expectations are unrealistic.I feel an obsession developing.


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## SarahC

I'm looking at the pictures of Erics mice now and the body looks whiter and the ticking more distinct than other mice I have seen pictured.I've spoken to Eric at length on this but still it is unclear.


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## SarahC

in my shed,


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## Roland

SarahC said:


> No I haven't and Erics skin is not finished,apparently it takes some time.However to my eyes,the picture of the last pearl of Erics which is the bottom one on the back cover of this months news,looks different to all the others pictured.


Hi Sarah, 
thank you for jumping in here again. Well, the human eye is not good enough to see the differences. Completely solid grey hairs look similar to our eyes as a mixture of black and white hairs. Our brain counts this as grey. Therefore I think it would be very interesting to have a closer look into the fur and see the colour of single hairs. Is there a mixture of different hairs, eg. black and white hairs? Perhaps you do not need a binocular or microscope, perhaps a good magnifier should work well.

Best regards, Roland


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## WNTMousery

Roland, Jack posted that genetic pearl (pe/pe) is NOT the same as what is exhibited as pearl in the fancy.


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## WillowDragon

I wasn't even aware there WAS a pearl 'gene' in mice... I knew there was in rats.

I was always told and have read the the colour pearl is part of the 'silvered' family' si/si


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## Roland

WNTMousery said:


> Roland, Jack posted that genetic pearl (pe/pe) is NOT the same as what is exhibited as pearl in the fancy.


I am not sure that this was fact at any time anywhere. pe/pe mice where around for a while, see Jax.
However, probably today there are at least three (or more) possibilities what a mouse, which is shown as "Pearl" phenoptype, could be genetically:

- si/si
- pe/pe (which is the true Pearl, see Jax)
- some c-dilution mixes: I have seen mice which are A/* B/* c/cch or A/* b/b c/cch for sure and had a similar look too.
Having a look to the furs with a magnifier (or better a binocular) could be helpful to figure out, who is who.

Another way to find out if the mice are si/si or some c-dilutuin, especially cch, would be to breed them to a Silver Agouti A/ cch/cch or to a Chinchilla A/at cch/cch: If the test mouse is based on c-dilutions, we will get diluted mice in the F1, if it is si/si, we will get Agouti or black mice in the F1. 
This could be a simple method to tell what the existing "Pearl", eg Sarah's, are.

Regards, Roland


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## WNTMousery

Roland said:


> WNTMousery said:
> 
> 
> 
> Roland, Jack posted that genetic pearl (pe/pe) is NOT the same as what is exhibited as pearl in the fancy.
> 
> 
> 
> Another way to find out if the mice are si/si or some c-dilutuin, especially cch, would be to breed them to a Silver Agouti A/ cch/cch or to a Chinchilla A/at cch/cch: If the test mouse is based on c-dilutions, we will get diluted mice in the F1, if it is si/si, we will get Agouti or black mice in the F1.
> This could be a simple method to tell what the existing "Pearl", eg Sarah's, are.
> 
> Regards, Roland
Click to expand...

I agree that very careful test matings are the best way to determine what exactly the mice are genetically.


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## Roland

WNTMousery said:


> I agree that very careful test matings are the best way to determine what exactly the mice are genetically.


Probably some people do not even want to know what they breed. Any pale something is ok, if it is pale enough to win, and if there is a judge at the show who does not know anything about genetics too.


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