Agouti
Although wild house mice are agouti, the fancy's golden agouti is much richer and redder. In the late 1870s Walter Maxey took the basic agouti and bred it with chocolates and reds, selecting from the offspring until he achieved the more familiar deep rich colour.
The agouti's coat consists of three colours, namely yellow (the fancier's red), black and chocolate. The hairs are black at the base with a bar of chocolate in the centre and some hairs (but not all of them) are tipped with yellow. The guard hairs tend to be longer, and dark or black, which produces the ticked effect. The amount of yellow in the coat determines the extent of the 'golden' effect.
Agouti is a dominant gene on the A locus. If combined with homozygous pink eyed dilution it produce argentes, with chocolate dilution it produces cinnamons and combined with the chinchillation gene (c^ch) creates silver agouti. It is also the basis for the chinchilla and argente creme varieties.
Outcrosses for the agouti include reds, cinnamons and black tans. Reds are used if the agouti lacks 'gold', which produces richly coloured agoutis but introduces faults of the red (poor type, small ears and thin tail). Crossing agoutis with cinnamons will produce poorly coloured mice in the first generation, but mating these youngsters back to agoutis should produce more brightly coloured mice.
The agouti's coat consists of three colours, namely yellow (the fancier's red), black and chocolate. The hairs are black at the base with a bar of chocolate in the centre and some hairs (but not all of them) are tipped with yellow. The guard hairs tend to be longer, and dark or black, which produces the ticked effect. The amount of yellow in the coat determines the extent of the 'golden' effect.
Agouti is a dominant gene on the A locus. If combined with homozygous pink eyed dilution it produce argentes, with chocolate dilution it produces cinnamons and combined with the chinchillation gene (c^ch) creates silver agouti. It is also the basis for the chinchilla and argente creme varieties.
Outcrosses for the agouti include reds, cinnamons and black tans. Reds are used if the agouti lacks 'gold', which produces richly coloured agoutis but introduces faults of the red (poor type, small ears and thin tail). Crossing agoutis with cinnamons will produce poorly coloured mice in the first generation, but mating these youngsters back to agoutis should produce more brightly coloured mice.
If the agouti does not have enough ticking, it can be outcrossed to a black tan. It is generally accepted that only does should be retained from these litters and mated back to an agouti buck. Any tans that show up in the litters should not be used. Any mice exhibiting a dark spine or lack of ticking on the flank should be avoided as this fault will be bred into your stock. It may take three or four generations of backcrossing to get back to the correct colour so the breeder must be patient and continue to select well for breeding. One fault that this cross can introduce is a tan vent, so any mice with a lot of tan should not be used. The benefit of a black tan cross is that it can improve size, type and other minor points as well as ticking, as long as good quality tans are used.
A dark spot on the head should also be avoided as this will be 'marked down' during judging. Common faults include tans vents and white toes/toenails. Belly colour should match the top as closely as possible, though as observed by Cooke, "the belly colour differs from the top colour and ... this is recognised in the laid down standard".
A dark spot on the head should also be avoided as this will be 'marked down' during judging. Common faults include tans vents and white toes/toenails. Belly colour should match the top as closely as possible, though as observed by Cooke, "the belly colour differs from the top colour and ... this is recognised in the laid down standard".