Fig. (2).
Epigenetic effects of the agouti gene on mouse coat color. The agouti viable yellow alleles (AIAP and Ahvy) are formed by inserting an intracisternal A particle (IAP) into the agouti locus. When IAP is methylated, the gene is expressed only in the skin, similar to expression of the wild type allele. Hypomethylation of the IAP gene will generate a ubiquitous expression leading to a yellow coat color, obesity and tumors.