ab name: (non-agouti) Recessive Yellow
Fancier name: Recessive Yellow (RY)
Genotype: a/a e/e
Chromosome: recessive yellow is on chromosome 8
Originated: Spontaneous mutation. This mutation is a frameshift caused by a deletion of one nucleotide.
Show class: Gold, Fawn, Orange, or Red depending on shade of coat and eye color.
General description: These mice can come in any number of yellow shades ranging from flame red, light blond, and even dark sable-looking. Their appearance can be hard to tell apart from Lethal Yellow. However, recessive yellow mice are very different genetically. In youth, recessive yellow mice are usually sooty, having uneven color, often with dark ticking (often being more prevalent over the rump). This usually goes away with their adult coat.

Recessive Yellow mice can have any color eyes. Pink eyed recessive yellow mice tend to be more flame red while dark eyed recessive yellow mice tend to be more blond or "sable" in appearance.

Recessive Yellow is often referred to as "The safe Yellow" (as opposed to Lethal Yellow). Recessive Yellow is capable of giving you the same varieties (and more, actually) that Lethal yellow can, yet Recessive Yellow doesn't have any of the problems Lethal Yellow is notoriously susceptible to.

Recessive Yellow, when combind with spotting genes, causes reduced white spotting.

Lab name: Yellow
Fancier name: Lethal Yellow, Fawn, Red, Orange.
Genotype: AY/* Note that AY/AY is lethal.
Chromosome: 2
Originated: Old mutation originating from non-commercial fanciers.
Show class: Red, Fawn, Orange depending on shade.
General description: Much like Recessie yellow, Lethal yellow cna come in a wide range of colors, therefor they can be shown in a wide range of classes. Always refer to your local club for show standards.

Lethal Yellow, when combind with spotting genes, causes reduced white spotting.

Health: Lethal Yellow mice are more susceptible to an array of health abnormalities. They are models for Diabetes because of their abnormal insulin levels. They have a higher instance of food allergies than most other varieties. They are also prone to obesity, which leads to many other health problems. Weight gain generally starts after 10 weeks of age. Even with an adjusted diet and increased exercise it's hard, if not impossible in many cases, to control their weight. Weight gain causes low fertility, therefore breeders tend to breed females younger than they may breed other varieties (but still not before acceptable breeding age). These mice are also far more susceptible to tumors. Note that this does NOT mean that all Lethal Yellow mice will have these problems. These mice just need to be thoroughly screened for health problems. Careful breeding needs to be done. It is not recommended to obtain a Lethal Yellow mouse from anywhere other than a *good* breeder, even if you don't intend to breed.

Fancier name: BEW
Genotype: There are *many* ways to make a BEW.
1) ce/c with any dark eyed mouse.
2) A Yellow mouse (be it Recessive Yellow e/e, Lethal Yellow Ay, or under marked viable yellow Avy) combined with many different c-dilutes.
3) A combination of spotting genes used together (such as pied and variegated s/s W/*, among many others) will sometimes make a mouse with one big white spot consuming the entire body, causing BEW. Sometimes a single spotting gene will cause BEW, though rare.
Show class: BEW

Non en fait il y a aussi le variegated, "dominant white spotting" noté W-.
Il est également léthal quand homozygote.

Voilà pour quoi c'est dangereux de croiser deux bew ensembles, car ceux ci peuvent être obtenus comme dit si dessus à base de dilutions sur Ay (léthal homozygote) ou bien avec un mélange de variegated W- et de "recessive white spotting" ss.. Donc en croisant deux bew on prend le risque d'avoir des WW qui meurent prématuremment.

Il faut noter aussi le RumpWhite qu'il ne vaut mieux pas croiser ensemble, ni le brindle.


J'ajoute qu'il me semble que le Recessive Yellow aussi appelé "viable yellow" aa ee, n'est pas léthal. D'où son nom en opposition avec notre lethal yellow Ay-