# twin mice



## mouselover (Mar 25, 2010)

Can mice have twins if so how often and is it usually or on a rare occasion


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## moustress (Sep 25, 2009)

I'm not sure, but I think it must be what happens when a mouse has 18 to 24 babies in one litter. How many wombs does a mouse have? Do they all develop in one big uterus?

See, I've added two more questions to the list....aren't I useful?


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## windyhill (Jan 19, 2010)

Ive seen mice that look the same, but not sure whetherf or not they are twins.
Good question


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## Onyx (May 2, 2010)

I'm sure it is possible, however how you would tell two are twins I wouldn't know, unless you watched the birth. Even snakes can have twins (two babies, one egg) so I don't see why not =) x


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## WillowDragon (Jan 7, 2009)

http://www.flyfishingdevon.co.uk/salmon/year2/hysterectomyovariectomy/intact2.gif

Shape and location of uterus in mice.

And I'm assuming that you mean Identical twins? Probably! lol

W xx


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## Jack Garcia (Oct 9, 2009)

Mice can and do have twins, but generally there is no way to know because even identical twins will have different appearance and most fanciers cannot afford to do DNA tests on mice.


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## Rhasputin (Feb 21, 2010)

Even _identical_ twins will have different appearances?
How does that work/make sense? :lol:


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## WillowDragon (Jan 7, 2009)

Enviromental influences can change the appearences of even genetically identical mice.


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## Rhasputin (Feb 21, 2010)

Oh, this is true.


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## Jack Garcia (Oct 9, 2009)

Rhasputin said:


> Even _identical_ twins will have different appearances?
> How does that work/make sense? :lol:


Here's how. In the case of identical twins, "identical" refers not to appearance, but to the twins' zygosity (i.e. arising from the same--identical--zygote). Identical twins of any mammal species have slightly or greatly different appearances, while sharing the same DNA. This is possible due to the effects of the environment (prenatal or postnatal). For example, with prenatal environmental differences: in two hypothetical identical twin broken marked mice, one could be black with only a few splotches of white and one could be a near BEW, yet both would be identical twins, from a biological standpoint, even though they looked very different. Or, as an example of postantal environmental differences, two genetically identical Siamese mice kept in different temperature environments, would appear very different after only a couple weeks or so (the one in the warmer environment would have weaker points and probably molt more often). As Katie said, environment affects appearance as much as (or in some cases more than) genes.


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## Rhasputin (Feb 21, 2010)

Makes much more sense now.


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## Jack Garcia (Oct 9, 2009)

Heh...you can blame your fellow humans for the confusion. They (well, we, I guess, lol) use "identical twin" incorrectly all the time.


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## Rhasputin (Feb 21, 2010)

I never knew! Well . . . I guess I also never looked into it / needed to look into it before.


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