Black Eyed Whites

Pure white and pure black animals have always been more popular than the more mundane colors in between, but a lot of people find the common lab mouse, white with pink eyes, to be kind of spooky. Something about those little beady pink eyes, and perhaps a collective guilt over the large numbers of these creatures who’ve been used in laboratories to make our lives easier, makes them less than desireable pets. Perhaps this is why white mice with black eyes have been fondly sought after in ways that albino mice haven’t. It could also have a lot to do with the fact that the albino gene which creates the white lab mice is easily used, and to get albino mice is an easy enough task, while breeding a mouse that is white with black eyes is a lot more difficult. Whatever the case might be, these beautiful white animals with shining black eyes have captured my heart as much as they have captured the hearts of other mouse fanciers.

Double Banding

To begin with, in my very first mouse litters I got a black eyed white baby. I barely knew anything about mouse genetics at that time, but in an effort to understand how I got a black eyed white mouse from a brown banded mouse and a silver banded mouse, I began to study up on genetics. Now my understanding is much deeper and it is for that reason that I’m sharing my knowledge with you, the reader.

The two mice who had babies were Sara, whom I learned was an agouti banded mouse with a head spot, and Onion, who was a “mock” silver agouti banded mouse. One website referred to a mouse with only one c^ch (chinchilla) gene and with a c (albino) gene as mock silver agouti. The term works for me, and this is what Onion was. When bred together, the first litter of four babies had one baby who was agouti, one agouti banded, a silver agouti broken marked, and a black-eyed white baby (I’ll refer to it as BEW from this point on). In the picture below this baby was the one in the upper left hand corner. He was taken to a pet store to be sold as a pet. In Sara’s second litter, she had two more BEW babies. One was Bess, in the picture below, and the other BEW baby in the picture was the other one. The boy also went to the pet store, but I kept Bess.

Upon researching banded mice, where the technical name for the gene which causes the banding is Kit^W-sh, I learned that when a mouse is homozygous for this gene (has two banding genes instead of just one), the mouse will usually be BEW. Occasionally the mouse will have some small pigment around the ears, eyes, or tail. In the case of my three double banded mice, the first one had a small round spot of gray on one ear, and a similar spot on his tail shaft. Bess has a smudge on one ear, and her brother had a patch of gray over one eye which is apparent in the photograph. With selective breeding of double banded mice to one another, choosing those with the least amount of “smudging” a very beautiful black-eyed white mouse could be developed.

Extreme Dilution Gene

The extreme dilution gene c^e when combined with A^y yellow genes can cause BEW mice. When bred together these mice have coffee, cream and BEW offspring. In my case the two parent mice were a sooty brindle named Pepper, and a banded brindle named Olivia. When bred together two of the offspring were not only satin, they were mysteriously BEW. As they get older, their coloring is darkening, so at this time I’m calling them Black-Eyed Platiunum mice. They are like white gold. When they are adult, I plan to update this article with pictures of them next to a true BEW satin mouse, to demonstrate the difference. While I am not certain that it is the extreme dilution gene which is responsible, it seems to be the only possibility. If this is the case then when bred to other mice with the extreme dilution gene, as I may have, then they should result in some further BEW offspring.

Marked Mice

Another way to achieve BEW babies, is to selectively breed marked mice together, breeding the mice with the fewest markings until finally you have a mouse where the only markings are the pigment in the eyes. This method can work but is not always the quickest way to get a genetically stable line of BEW mice. Several of the marking genes, combined together, can often increase your chances of getting a BEW mouse, for example the W gene, responsible for variegated mice, can be combined into homozygous piebald spotted mice. The idea is that if one spotting gene wipes out the spots left behind by the first spotting gene, you are left with a BEW mouse. Care must be taken when trying this approach as there are a number of risks involved with the white spotting genes. Homozygous variegated W mice are anemic and usually die in the first weeks of life. The spotting piebald gene has also been known to cause megacolon in mice and this is a fatal defect which results in a painful death. One of my mystery BEW mice I am placing into this category, though truthfully I am not sure if this is a case of marking genes, or other genetic problems, as Itsy, the mouse in question, is still young, but her coat is unusual, and her size tiny. She is the offspring of Ingrid, an albino mouse, and Charlie, a marked mouse, who is himself an offspring of Sara and Onion, though the fact that some of his offspring were not banded reveals that he was not double banded as was suspected earlier in his life.

Chinchilla

The chinchilla gene c^ch dilutes the yellow pigment of a mouse’s coat and makes it white. When it is mixed with an agouti mouse, the result is a silver agouti mouse. When a fawn mouse gets the chinchilla gene also, the result is a BEW mouse. In my case the parent mice were Foxy, who was the Berkshire marked fawn offspring of a broken marked fawn mother and unknown father, and Onion. This meant that the two black-eyed white mice born in her first litter of ten babies was a chinchillated fawn baby with one albino gene “c” and one chinchilla gene. Several sources say that only a double doseof the chinchilla gene would work it’s magic, but since the Chinchilla gene is dominant over the albino, it makes sense that only one chinchilla gene is necessary to wash out the yellow in an otherwise fawn coat.

Other Methods

Sometimes a mouse is BEW without any explanation. Normally a BEW mouse will not have BEW offspring unless the mice being bred are carefully selected for specific genetic traits. Ivory, the one BEW mouse I purchased, who was a satin mouse, was bred to Sage, a long-haired satin broken-marked pink-eyed fawn. Her five offspring included an agouti banded, red banded, gold broken-marked, agouti broken-marked, and one inexplicable black eyed white baby who looked just like his mama and who was named Caspar. It could be that he inherited a dilution gene from the father and a chinchilla gene from the mother, but until he begins to have offspring, he’ll just be the mystery mouse in all of Mousedom.

Mousedom BEW Mice

Mousedom is currently breeding Caspar to his dam, Ivory, as well as to the above mentioned female mice, Roxy, and Bess. When they are of age, Caspar will be bred to Sugar and Spice as well, and if Itsy is ever up to being bred, and is fertile, she, too will be introduced to Caspar to try to obtain more of these beautiful mice.

Conclusion

To obtain a black-eyed white mouse through selective breeding is a very hit-and-miss procedure. There are some methods of working to get Black-Eyed whites that will produce animals which are close, but it is not an easy procedure. The best way to procure a BEW mouse is to find one in a petstore and purchase it. BEW mice are beautiful additions to the mouse fancy, and charming creatures. Mousedom is devoted to the propagation of these beautiful creatures through the methods mentioned above. As more BEW mice are produced, the methods of producing them will be chronicled here, and their picture, along with the known parent mice will be added to this document.

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