Nonagouti; agouti yellow (Ay) is a semidominant spontaneous mutation with homozygotes dying before implantation. Heterozygotes are characterized by obesity, yellow hair pigment, black eyes, elevated malic enzyme in the liver, and susceptibility to several kinds of tumors.Read More +
Mice homozygous for the yellow spontaneous mutation (Ay) die before implantation or shortly thereafter. The time of death and type of abnormality is, in part, determined by the genetic background on which the mutation is placed. Hair pigment in heterozygous mice is yellow, but eyes are black. Heterozygotes usually become obese and infertile after the first few months. Increased adipose tissue mass is due to fat-cell hypertrophy. It has been hypothesized that the obesity results from the observed reduction in hypothalamic norepinephrine and dopamine levels. Insulin resistance and hyperglycemia follow development of hyperinsulinemia in early adulthood, although the degree is less severe than on the KK/UpJ genetic background (Stock No. 002468). Heterozygotes are also more susceptible to several kinds of tumors than normal mice, and their spleen cells cause a significantly lower graft vs. host reaction. The level of malic enzyme in the liver is elevated.
|Allele Name||agouti yellow|
|Allele Synonym(s)||A(y); Ay|
|Gene Symbol and Name||a, nonagouti|
|Strain of Origin||old mutant of the mouse fancy|
|Molecular Note||The Ay mutation appears to be a DNA structural alteration that disrupts a gene, hnRNP associated with lethal yellow (Raly), 5' to the agouti locus and places the agouti locus under the control of the Raly promotor. A report of recombination between Ay and the a and ax alleles suggests that Ay was a pseudoallele of the a locus on the proximal side. However, cloning of the agouti locus and molecular analysis of a showed that the coding region of the three alleles is identical.|
Mice heterozygous for Aycan be identified phenotypically; see Strain Description. Ay/Ayhomozygotes die embryonically. The weanlings are sometimes small and can be aggressive.
When using the lethal yellow mouse strain in a publication, please cite the originating article(s) and include JAX stock #000021 in your Materials and Methods section.