In your research you are analyzing the changes in liver gene expression in a mouse model of non-alcoholic fatty liver disease. You previously performed microarray analysis on livers of mice given a high-fat diet verses mice on regular diet and found a number of genes that were abnormally expressed in the high-fat diet mice. You perform quantitative RT-PCR on some of these genes and receive the following Ct values:
high-fat diet: Gapdh-10, Cyp8b1-27, Cyp17a1-25, Asns-21, Past1-23.
Regular diet: Gapdh-11, Cyp8b1-25, Cyp17a1-21, Asns-26, Past1-30.
Question a: For each of the genes, complete calculations using the delta-delta Ct method to determine the relative fold change in gene expression for the mice with the high-fat diet. (hint use Gapdh as the reference gene and SHOW YOUW WORK).
Question b: Which of the four genes are up-regulated and which of the four genes are down-regulated in mice with high-fat diets?
Question c: You want to determine exactly where in the liver these genes are normally expressed. Pick one of the genes above and design an experiment to perform in livers of high-fat diet mice and regular diet mice (as a control) to determine the location of the gene expression in the liver. Describe the results you expect to see from this experiment in the two different mouse livers.
Question d: You hypothesize that the change in expression of the gene you picked in part C. Above is a result of differences in epigenetic marks. Briefly describe what changes in epigenetic marks at this gene's locus are expected to occur as a result of the high-fat diet. In your answer address both DNA methylation and histone modifications.