# BEW



## Mymouse (Jul 2, 2010)

Is there any genetic code for BEW?
Do not see white anywhere on the list.

To find out what is behind one doe, is it good to breed from one doe and one buck from her litter (her son + daughter) and see what I get? Or better to breed son to mother?


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## moustress (Sep 25, 2009)

That's because there are a number of ways for a BEW to occur. the most common is a yellow mouse who is marked with white over 100% of it's body. Usually, BEW's have a dilution on the C locus, most often c^e (extreme dilution). There are probably other combos that do it as well. Check out this site: http://www.hiiret.fi/eng/breeding/varieties/index.html.

As for your second question, first you need to do Punnett grids of all the features you see in the mother and the babies. The codes for the proper color and fur types should all be available at the site I referred you to. The Punnett square will have the mother across the top and the mate down the side and then you just fill in the squares by picking one from the top and one from the side until you've crossed all the combos. If you don't know the genes, you just list the ones you see, and then figure out what the different combos are by loooking at the results of your grid.


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## Mymouse (Jul 2, 2010)

Thank you moustress. But is it then possible to have many letters in the gene code? 
(I am reading about genetics, google it, all nights now but it takes time to find it and I have not read about some things like the punnett grid before.)
So you put for ex. sa/sa for the mother who is satin BEW, no other letters?
And for the father who will most likely be BEW, I have blank?
Do I use c^e anywhere?


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## nuedaimice (May 26, 2010)

There were Variegated mice in the litter with your BEW, if I'm remembering correctly? Most likely your mouse is probably s/s W/w, which is a mouse that has the piebald spotting gene and Variegation on the same mouse, which causes so much white spotting that the mouse has no other color showing, making it BEW. (I knew of a breeder who used to breed BEWs this way).

That would be my guess as to what your BEW is. Moustress is also right, extreme dilution is another way to get it.


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## Mymouse (Jul 2, 2010)

The mice I have at my home now, I was not going to keep them all, but I think they are not from the same litter since the Variegated one was always a little bigger and they come from a cage with several mothers with litters together.

But I think the other 3 are siblings.

So they could be

*BEW buck longhair *- go/go or lgh/lgh (don´t know the diffirence)
*BEW doe* - one go or lgh because she isn´t longhaired but her brother has it
*BEW doe with tiny spot on the back *- one go or lgh (same as above) + ss (broken)?

and all of them my have e (recessive yellow) and/or ce (extreme dilution)?

But they still might have s/s W/w because they may have had a Variegated sibling.


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## nuedaimice (May 26, 2010)

Does recessive yellow exist in Iceland? I thought it was strictly a U.S. variety (besides the ones imported into Germany).

Since your one mouse has a tiny spot, I'm inclined to believe they are all s/s W/w. If they are from the same tank, it is possible either they or the mothers were all litter mates (or both). The breeder who used to have BEWs that were s/s W/w (which I purchased several from her) varied from all white to a tiny spot of color, usually near the rump area, but not always. Since Variegated is lethal when homozygous, all of the BEWs could only carry one copy of W. She also got Self, Variegated, and Broken (Piebald) mice in a litter when breeding them (depending on what she bred them to).


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## Mymouse (Jul 2, 2010)

I am not sure if recessive yellow exist in Iceland. The first mice here were PEW from labs I think, later colored mice were introduced but I do not know if BEW were imported or just made with mix between the lab mice and new imported mice.
So they must be s/s W/w. W and w being variegated but s being ....? (I only see ss on the list as broken, correct?)


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## nuedaimice (May 26, 2010)

Yes, Piebald but it creates Broken Marked and Even Marked mice.


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## moustress (Sep 25, 2009)

The full genotype for any mousie will have a full list of loci that would look something like this Aa Bb Cc Dd Ee Pp; those are the most common genes that are tracked, and then there would be other loci for coat type and other marking. In addition there different modifiers on many of these that alter the appearance of the mousie. The example I show would be a mousie that is heterozygous in all the major loci, meaning it has one dominant and one recessive in each spot.

You would only use c^e if that's how your mousie is diluted. The section in Finnmouse's Breeding pages explains a bunch of the different ways you can get a BEW or a REW.


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## Mymouse (Jul 2, 2010)

nuedaimice, ahh ok I understand 
moustress, Thank you, I have been reading about genetics and the Finnmouse´s breeding page, I thought I had gone through it well but I will take a better look.


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## WillowDragon (Jan 7, 2009)

If you have a 'white' mouse with black eyes, put it next to a Albino mouse. If the black eyed mouse looks a different shade at the side of it... chance are its actually a black eyed Cream (called 'Bone' in some countries) which is generally a/a c/c^e (a Black mouse with one albino gene, and one extreme dilute gene)

The only truely white black eyed white mice, are those that are coloured underneath, but totally covered in a white gene, either s/s (piebald) or W/w (lethal white, varigated) or both, as stated by neudaimice.


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## Mymouse (Jul 2, 2010)

Interesting WillowDragon
What can I do if I can´t get an albino mouse :? 
Would you say that PEW and albino look the same? I know there are at least 2 in my country that I think are PEW, but then I just have to try to find and see them.

So all truely BEW could have 'almost any colour' underneath because it is not visible?


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## WillowDragon (Jan 7, 2009)

A true PEW or 'Pink Eyed White' is Albino =o)

And yes, true Black Eyed Whites are any colour covered by a white gene.

W xx


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