New Gray Gene in the Campbells

Linda Price

For over a year now, I have been doing test matings with a new gene in the Campbells. The gene leaves the black color pigment in the coat but removes all yellow pigment. Thus, the hamster has a silver gray appearance much the same as the color of a normal coated chinchilla. There is no brown coloration which is so typical of the Campbells normal.

Here are the results of some recent pairings.

  1. When the gray hamster was bred to a normal, all babies were normals. When two of those normal babies were paired together, approximately 25% of the babies were gray demonstrating that this is a recessive gene.
  2. When two grays were bred together, the babies were all gray. Thus, it does breed true and is not lethal.
  3. When a gray was bred to a black, all babies were normals. When those babies were paired together, I got normals, grays, and blacks as well as a couple of argentes. I did not know that argente was in the line. Some of the black babies from this pairing were a bit diluted. I did not do the tests to confirm that these were the combined black/gray color although that may have been the case. Our Black Campbells vary anyway, so only test matings would prove which they were.
  4. Two test matings were done to albinos from different lines. In both cases, when I bred a gray to an albino, I got all normal brown babies. This confirms that the gray gene is not on the c locus and is not the same as the "chinchilla" gene known in many other species.

I also have the gray color combined with opal, argente, and blue fawn (ddpp). All of these combined colors are quite attractive and what you would expect given the nature of the gene. All are distinct from the single gene color again confirming that this is a new gene and not a variation on the normal color. Some of these combined colors are nice pastel agouti colors. I have pictures of these colors on my website at

I have seen variation in the gray color. Right now I am doing some matings to look into this variation.

So far, there is no official name or symbol for this color. A number of names have been suggested including mock chinchilla, silver gray, and dark gray.

For over two years now I have been working to document another gene in the Campbells. I will give more details on that gene in the next issue.

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