Answer the following questions about DNA microarrays and gene expression analysis
a. Why aren't all genes expressed all the time?
b. What is the advantage of using DNA arrays vs. one gene at a time analysis?
c. What is the significance of co-regulated genes?
d. What is the significance of a condition specific gene expression pattern?
e. How can gene expression analysis be applied to Medical research?
A) It would be energy inefficient to express all genes at the same time. Genes are turned on and off as they are needed for cellular function. An example of this is euchromatin or loosely packaged DNA and heterochromatin or tightly packaged DNA. Heterochromatin is bound by proteins called histomes and can not be readily transcribed. Histone modification by histone acteyltransferases (HATS) add an acetyl group to lysine and arginine residues on the histone. This allows the DNA to loosen so that it can be transcribed and then translated.
B) The advantage to using a DNA array vs one-gene-at a time analysis is that you are able to get more data out of your sample. DNA arrays allow you to examine changes in DNA expression patterns of many genes instead of examining the changes in 1 gene (1).
C) Co-regulation is ...
DNA arrays are a common tool for examining changes in gene expression. This response will examine why DNA arrays are more beneficial than single gene analysis. We will also briefly discuss the molecular genetics cell and to better understand applications for using DNA arrays to understand co-regulation of genes and implications for studying human disease.