Mice with low levels of agouti gene expression tend to have yellow fun and are o
ID: 83779 • Letter: M
Question
Mice with low levels of agouti gene expression tend to have yellow fun and are obese, while mice with higher levels of expression are brown and of normal weight. Studies show that expression of the agouti gene in mice can be controlled by epigenetics. What scenario describes epigenetic regulation of the agouti gene? Mice with one allele in the agouti gene produce more agouti protein compared to mice with a different allele. Mother mice fed methyl-rich diets during pregnancy give birth to offspring with decreased gene expression compared to those fed a methyl-poor diet. A mouse that acquires a spontaneous mutation in a transcription factor is able to more easily activate the agouti gene than mice without the mutation. A mother mouse exposed to radiation acquires a mutation in the agouti gene that makes a detective agouti protein in her offspring.Explanation / Answer
Answer is 2) mother mice fed methyl-rich diets during pregnancy Give birth to offspring with decreased agouti gene expression compared to those fed a methyl-poor diet because when a mouse's agouti gene is completely unmethylated, its coat is yellow and it is obese and prone diabetes and cancer. When the agouti gene is methylated (as it is in normal mice), the coat color is brown and the mouse has a low disease risk.