This article is from the WSSF 2010 AFRMA Rat & Mouse Tales news-magazine.

By Karen Robbins

Jack Garcia, Jack’s Mousery, KY, e-mail
Q I have another question, this time about a mouse I have bred here at JM. I am wondering if I have Argenté Crème, or something close to it, here. These babies are just about three weeks old. Here is the litter’s background:

Sire: the father is a very pale dove (a/a C/c p/p) ultimately from European lines, who is from mice who are linked on the C-and P-locus (dove x dove often produces PEWs). (WNT Don)

Dam: the mother is a homozygous Agouti ultimately from European lines (A/A C/? P/p). She may or may not carry Chinchilla—it is in her background, for sure. (WNT Myrna)

Now the babies. There are five from this litter. One is a regular Agouti. Another is a darker Agouti. One is Argenté. One appears to be a PEW, although that isn’t possible if the mother doesn’t carry PEW. And one . . . is a bit darker than the one who appears PEW, but dark enough to notice the difference.

I am pretty good with genetics, but I am scratching my head over this litter. I am a little bit unsure of what is going on, mostly because I have never seen an Argenté Crème or a P.E. Cream, or whatever this baby is. The only colors I have seen online of any mouse similar to this are the Argenté Crème pictures on Finnmouse.

My only guess as to genotype for this mouse is A/a c^ch/c p/p. She would have had to have inherited the c^ch from mom and the c from dad, and also inherited a copy of p from each of them, right?

But if that’s the case, then how did one baby end up a regular PEW? Both the mom and the dad can’t carry “c” because then the mother would be c^ch/c, and she is Agouti.

A First off, let me say when I saw the photos, my first thought was it is a Himi, but you don’t say there is any Siamese/Himi in the background. As far as Argente Creme, this is one color that I have never worked with and have not known anyone in AFRMA to breed and show this color so I don’t have any first-hand experience with it. Regular Argente is one color that I have worked with and do know it can be too dark, and I’m sure with selection you could make it lighter. I have had some Champagnes recently that are extremely pale and perhaps if this was put with the Agouti, it could look almost like an Argente Creme though may not be the right “yellow cream” color. Most of the Chocolate Argentes (P.E. Cinnamons) just look like a pale Argente. Since you can select Champagnes to be so pale to look PEW, then you should be able to have extremely light Argentes. You don’t mention Chocolate being anywhere in there though.

To be a proper Argente Creme they need to have a bluish undercolor with a white belly from the tan gene that the Chinchilla dilutes. Also, the top color needs to be yellow enough so you see the white belly. You don’t say if it has the undercolor and neither parent is Tan or Fox.

To be a P.E. Cream you need the dominant Fawn plus Chinchilla plus pink-eye (Chinchillated Fawn: A^ya c^chc^ch pp), or dominant Fawn plus Blue plus pink-eye (A^ya dd pp), or be a Chinchillated Dove (aa bb c^chc^ch dd pp). In Tony Cooke’s book Exhibition and Pet Mice for P.E. Cream he has dominant Fawn plus Chocolate plus Blue plus pink-eye (A^y- bb dd pp), or dominant Fawn plus Chocolate plus Chinchilla plus pink-eye (A^y- bb c^chc^ch pp). Neither parent is dominant Fawn and there is no Blue or Chocolate in the parents.

From what Dave Bumford says in our Mouse Genetics book, for Argente Creme without the white belly it used to be made from P.E. Blue Agouti (AA dd pp) or can be a P.E. Silver Agouti (AA c^chc^ch pp) but you have the linkage problem of the c^ch and p on the same chromosome. We had an article in the 2008 newsletter on Linkage referring exactly to this question of making Argente Creme, and I have put it online.

One way to make an Argente Creme would be Silver Agouti (AA c^chc^ch) to Lilac Fox (Dove in England—a P.E. Black aa pp) that in the F2 should be your Argente Creme. In Tony Cooke’s book he has one possibility as being white-bellied Agouti (A^w) with P.E. Chinchilla (A^wA^w c^chc^ch pp). We don’t have the white-bellied gene here in AFRMA so have never seen one in person, only photos on the genetics sites.

PEW’s can be cc (albino), c^ec^e pp (P.E. Beige/Coffee/Reverse Siamese—Stone in England), c^ec pp (P.E. Ivory—B.E. Cream in England), or c^hc pp (P.E. Himi—I had one PEW out of Siamese stock bred to a Siamese expecting to make an entire litter of Himis and got nice Siamese and Himi—Himis are off white as babies). You can also select your light pink-eyed colors to be so pale as to look PEW. Also, Red Point Siamese are not supposed to be able to express pigment and will look pink-eyed white. Many breeders have attempted (me included) to make Fawn/Red Point Siamese that would look like a flame point Siamese cat and have never been able to. You don’t mention having any of the Beige colors or Siamese in the background so we can rule out it being one of those P.E. White versions, so are left with cc.

If you plug in the codes for mom to be Cc, then the outcome based on dad being aa Cc pp and mom AA Cc Pp:

If you say dad is aa Cc pp and mom AA Cc^ch Pp, then you get:

Based on the results of the litter (Agouti, Argente, PEW, and unknown), my best conclusion is your mom carries c and not c^ch as you can’t get PEW (cc) if c^ch. So your pale Argente Creme looking mouse has to be a very pale Argente if it has an undercolor, though where it came from being that light, I’m not sure. The only way it can’t be cc is if your PEW changes color later when it matures, then it would have to be a very pale P.E. Silver Agouti that looked PEW as a baby.

One way to try and determine what the parents are is to use the codes of the litter produced and backtrack your results.

Your PEW is Agouti based if mom is AA. Breeding this PEW (cc) to something such as Siamese would make an entire litter of Himis—half regular and half Agouti Points which would be very pale; bred to Reverse Siamese would make an entire litter of Ivories—half Agouti (mealy looking), half regular.

According to Nichole Royer (our genetics expert), linked genes can carry down from one side only but works better if both parents are linked to make sure the kids will have linked genes.

Hopefully this answers your question. Karen Robbins

The 8-week-old Agouti Point Himi owned and bred by Jack Garcia.

UPDATE: So the two mice are now one day short of being eight weeks old. There’s been another development so I thought I’d update you. The male is getting points(!).

His ears and tail are also getting darker, but the main portion of his body seems to have gotten lighter. Whether it actually has, I can’t say. He’s molting pretty heavily right now so that might be something to do with it. The female might be molting too but since she’s solid white, I can’t tell.

I spoke with the original breeder of the Agouti parent (Jenny Erwin, WNT) and she said that the agouti’s Chinchilla parent had Himalayan in her background a few generations ago through an accidental outcross.

So that makes more sense to me, at least, as to why the points are so faint and have taken so long to come in—they’re on an agouti background and since they were introduced accidentally they are poor.

The only thing I can think of now is that the PEW sister is actually an agouti-based Himalayan, too, but one who shows no shading or points whatsoever. She couldn’t be a true PEW because then her brother couldn’t be a Himi, and he is.

Regardless, I’m not going to be breeding from them. Too much headache! This is why I like to keep my lines pure!

A So my first thought of your “creamish” mouse being Himi was correct! Based on the outcome possible from the parents, then he has to be an Agouti Point and the female is an Argente Point and her points/color does not show up because of her color base. I confirmed this with Nichole Royer when I talked to her. Which means that some of the normal colored kids carry the Himalayan gene and some don’t and only by breeding to each other or to the mom to determine which ones have it, can you salvage the non-carriers if you wanted to continue this line.

If you plug in the new codes for mom to be Cc^h, then the outcome based on dad being aa Cc pp and mom AA Cc^h Pp:

In rats, you can tell Agouti Points when they are babies with their lack of foot color along with the little bit different body color from the Seal Points. In Nichole’s article on “Burmese Rat Genetics” in the WSSF 2007 newsletter, she goes into what Agouti Point Himis look like and how they can be confused with a PEW when they are babies. Agouti Point Siamese as adults with a quick glance look like Seal Point on the nose but lack the color on their other extremities. Some breeders use these when breeding for the Burmese colors (Agouti Burmese, Russian Blue Agouti Burmese) but this is a color that isn’t one to be standardized.

One interesting question/thought I had come up with on the linkage topic and in talking it over with Nichole, is that Argente Creme is the only one that will come out a color once the p and c^ch are linked, We don’t have cⁱ, c^m, or c^p so we aren’t sure if those would make a color once linked with p, but we do know that c^e plus p and c^h plus p make “PEW/not albinos” as you find out when breeding to their color versions and don’t get the expected outcome (I’ve done breedings on both of these and found out that particular PEW was not cc—I have a line now of c^ec^e pp PEWs that are linked). You can get cc pp either not-linked or linked but wouldn’t know the difference as they both look like PEW and test breedings would need to be done to figure out if it was linked or not.

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