Red

A red “should be rich, deep and sparkling with no sootiness”. It is difficult to describe the correct red colour, but I have heard it likened to a red setter (dog). As with fawns, the red is a result of the A^y gene, one of the few that are dominant to agouti.
The variety was available early on in the UK mouse fancy and no date is attributed to the standard. It was first described in science in 1905 by Cuenot, who recognised the fact that the gene is homozygous lethal. This means that babies inheriting two copies of the gene (one from each parent) die at a very early stage of development (in the case of the A^y gene, early on the sixth day of gestation) and are reabsorbed by the mother. This is not harmful for the doe and it is fine to breed two reds together. This will result in smaller than average litters due to approximately 25% of the litter being A^y/A^y and therefore reabsorbed.
The variety was available early on in the UK mouse fancy and no date is attributed to the standard. It was first described in science in 1905 by Cuenot, who recognised the fact that the gene is homozygous lethal. This means that babies inheriting two copies of the gene (one from each parent) die at a very early stage of development (in the case of the A^y gene, early on the sixth day of gestation) and are reabsorbed by the mother. This is not harmful for the doe and it is fine to breed two reds together. This will result in smaller than average litters due to approximately 25% of the litter being A^y/A^y and therefore reabsorbed.
Reds (and fawns) tend to suffer from obesity and poor type. For this reason they are often bred with agouti and cinnamon, to counteract small ears and eyes and improve type. However, reds bred with agoutis may produce sooty reds, where the colour is not clear but rather murky and a little dark. Chocolate-based mice such as the cinnamon and chocolate tan may be better a better choice for outcrossing to improve type and belly colour. In the nest, fanciers should look for the brightest orange coloured babies as these usually make up into the best adults for show purposes.