# Where'd these 2 come from...?



## CatWoman (Jun 19, 2010)

Looks like the milkmouse stopped by for a visit.. :lol:

The Buck is a poor black tan. The Doe is BEW. She doesn't have a bit of color on her anywhere and to the eye, she looks as white as my PEWs when they're together. I'm not sure if that means she's a nice BEW or I have crappy PEWs.. it just seemed worth mentioning.. :lol:

















They produced a litter of 11 pups.

Obviously the 5 black tans make sense to me, because of the buck. And the blue (?) tans also make sense to me, because the buck's sister is that color and he has also produced that color in his other litters. (His first litter was 4 blue tans and 4 black tans, and his second litter was 5 blue tans and 4 black tans.)

















But these 2...? Are they brindle tans? Is there even such a thing? Their backs look like the brindles I've had in unrelated litters, but they have that dividing color line between the brindle and the solid belly.










And if it's brindle, would it have come from the buck or is there brindle hidden in that doe? I thought brindle was a kind of obnoxious dominant gene that took over when it was present? Granted I'm not terribly experienced, but every litter I've bred from my unmarked brindle boy has come out all brindles, marked and unmarked, even when the does were something completely different. Just recently, I bred the unmarked brindle buck to a chocolate doe and I got some rather odd coloration in babies, but they're still definitely marked brindle.

But anyway, here's the whole fam damily.. can anyone give me a crash course in the genetics of those brindle looking babies?


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## Jack Garcia (Oct 9, 2009)

Aww! They're definitely American brindles (Avy/*), and cute. They make me miss my brindles of yesteryear! Brindles can be tan (Avy/at). But sometimes, even a brindle who isn't tan (Avy/A, Avy/a, or Avy/ae) will still have a clear yellow belly although the line you're seeing wouldn't be there.

The brindle would had to have come from the doe, which means she is Avy/a D/d P/* that you know of (Brindle carrying black and blue). She also probably has something going on on the C-locus, to "wash out" the brindle and make her look white.* A brindle mouse who is also ce/c (called stone, ivory, or bone depending on where you live) can make a brindle mouse white.

*Another possibility is that she is actually marked and is one giant white spot, but this doesn't seem likely if none of her relatives are spotted.


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## Matt Haslam (Mar 13, 2010)

gorgeous litter. Wish we had brindle in the UK


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## Jack Garcia (Oct 9, 2009)

I've wondered why the folks who've done imports into the Netherlands, Germany, and Poland have never wanted American brindle. It has a lot of show potential.

I also wonder how the variety ended up in America and Australia, but skipped Europe. lol


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## Matt Haslam (Mar 13, 2010)

Jack Garcia said:


> I've wondered why the folks who've done imports into the Netherlands, Germany, and Poland have never wanted American brindle. It has a lot of show potential.
> 
> I also wonder how the variety ended up in America and Australia, but skipped Europe. lol


bizarre isn't it


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## JustMouse (Jul 23, 2010)

Yeah... I've always wondered that too. Brindles would be great for showing because they breed pretty much true.. and tend to be HUGE! Regardless, your mystery babies are beautiful.


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## Jack Garcia (Oct 9, 2009)

They do breed true in one sense--that they can be homozygous (Avy/Avy) and a homozygous brindle bred to a homozygous brindle will produce only homozygous brindles. But in another sense, they don't, really, because the Avy allele is probably the most epigenetic of any we deal with.

That is to say, the environment plays a big part in how they look in addition to genes. No matter what the father looks like in terms of color intensity and stripes, the mother and even maternal grandmother's diet during pregnancy determine stripes moreso than the father's appearance. This is what makes breeding brindle difficult, and why I gave up (that, along with the fact that the majority of my stock was petstore-derived and I didn't have the years necessary to make all the improvements I wanted).

This is important to note because the genotype of any given mouse who is Avy/Avy can resembled agouti or recessive yellow or anything inbetween. I've heard of them being black, even.

All these pet mice were bred by me years ago and were Avy/Avy or Avy/A:









(non-striped or "clear")









(over-striped, almost fully agouti)









(clumped together areas of color, stripes too muddy)









(stripes too muddy all over, base color is nowhere near red enough)









(this is as close to standard as I ever got before I gave up and switched to other varieties)


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## CatWoman (Jun 19, 2010)

That's so cool.. I actually understood that! I must've learned something along the way and not realized it! :lol: :lol:

(I'm not stupid or anything, it's just that scientific type endeavors have never been my strong point. My professional background and all of my degrees are social science/psychology related.)

So if the BEW is Avy/a D/d P/* then I need to add sa/sa because she's also satin, right? Her coat doesn't show well in the picture.

As far as the c-locus, I think you're right. I have an older litter from the black tan buck and I bred him with his (blue tan) sister. Although it was absolutely unintentional (after all, these are "just feeders," but I might as well learn what I'm doing along the way), I accidentally improved the coloring with that breeding. The black tan buck has some of the tan colored hairs randomly interspersed in the black section of his coat. Some of that shows in the picture, but a lot of it is hidden by the shininess. The blue tan doe has it too, but to a lesser degree.

The pups from their litter (4 blue tans, 4 black tans) don't show nearly as many of those stray hairs and most of them are at the color line, making it a bit "fuzzy" looking. Looking at the litter in isolation, the coloring in the blue tans doesn't draw the eye as much, but the black tans are strikingly black. They look like little bits of coal.

When they're in with the second litter, all snuggled up in the nest, it's not only obvious that the older litter has a much more solid, saturated black, it's equally obvious that the blacks from the younger litter are totally washed out and diluted. At first, I thought it was just the disparity between the older pups' coats as they were becoming more dense while the younger pups' coats that were still fairly thin. But as time goes on, it's clearly a dilution in the colors.










There are two "blue" babies that caught my eye. When their coats started to come in, they looked just like the other two blue pups, but as they started growing, their coats started lightening and looking more silvery compared to the blues. That, in itself, isn't particularly interesting, because a lousy example of blue would be no big surprise among feeder mice. But, now it looks like those two are getting brindle markings with the silvery and blue stripes. I thought I caught sight of it earlier, but they're also satin, so I thought it was the light playing tricks. Today, it -definitely- looks more like striping.

Here's pics from this evening. The striping is subtle and VERY hard to get in a picture.. serious hair puller there. This was the best I could do -


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## Jack Garcia (Oct 9, 2009)

CatWoman said:


> (I'm not stupid or anything, it's just that scientific type endeavors have never been my strong point. My professional background and all of my degrees are social science/psychology related.)


Mine too! In another time and place I might have gone into Biology.



> So if the BEW is Avy/a D/d P/* then I need to add sa/sa because she's also satin, right? Her coat doesn't show well in the picture.


Yep, sa/sa is satin.


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## CatWoman (Jun 19, 2010)

I have to admit, the relative certainty of science does have an attraction when you spend too much time immersed in the unpredictability of human emotion and behavior.

Ok, so I've been over on Finnmouse.. brace yourselves.. :lol:

For my black tan, the most I know about the lineage is that both of the parents were also black tans and the litter I took was comprised of was 2 black tans (one had died before I got there), 1 blue tan, and 3 that look like poor agouti tans compared to the pics on Finnmouse.

So, with that little bit known, is my black tan buck at/* because I don't know anything other than the tan that's showing? Or would it be at/a because both of his parents were black tans and he's not showing the agouti that his brothers show?

Then, he gets a B/* for being black.. and the P/* for his dark eyes. He would have to be carrying blue to make blue babies, so he gets a D/d too..? So all that makes him an at/* B/* P* D/d based on the things I know?

Am I getting any of this right? :lol:


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## Jack Garcia (Oct 9, 2009)

If both parents were black tan, then this buck is either at/a or at/at.

Agouti tans must be A/at, by the way (in which case the at allele is incompletely dominant).



> So all that makes him an at/* B/* P* D/d based on the things I know?


Yep! You can also add in "C/*") since he's not obviously C-diluted (though he may carry something on that locus).

Has he ever produced a self (non-tan) baby? If not, I'd bet he's homozygous tan (at/at).


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## CatWoman (Jun 19, 2010)

With the exception of the brindles, all of his offspring have been black tans and blue tans. With the brindles, the darker ones are definitely tans, but I'm not sure about the lighter ones. Between that silvery color, the satin coat, and the ghost stripes, they make my eyes cross if I look at them too long







I'll have to wait for their coats to come in a bit more solid to tell if there's any delineation between the brindle and the belly on those.


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## CatWoman (Jun 19, 2010)

These babies are fascinating me. :lol:

I took the two shades of brindled babies outside into the natural light today and got some updated pics. Even in the natural light, it's hard to see the brindling on the lighter colored babies. It's still not the easiest to see in life, but it's definitely there now and not just the light playing tricks on me.










Am I right that the lighter brindle baby is also Avy/at but with the previously suspected ce/* from the mother washing it out partially, rather than washing it out completely to make the baby a BEW like the Mom? Comparing the dark brindles to the lighter ones, the colors appear proportionally lighter, with the brown lightened to peach and the dark gray turned to an almost off-white tone of gray.

And, am I also correct that the 2 lighter babies would actually be considered brindle foxes, rather than a brindle tans, since their bellies are diluted to a more pure white? Even though my tans don't have the proper depth of color on their bellies, there's still a huge noticeable difference in the belly color between the tans in the rest of the litter and those 2 lighter colored brindles.


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## nuedaimice (May 26, 2010)

I think you have both blue brindle -blue stripes- and fawn brindle -black stripes- in that litter.

The reason your ''unmarked'' male is giving you only brindles is because he is Avy/Avy. Typically, homozygous American Brindles are a solid yellow color.


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