Question

Consider the microarray in Figure 20.12. If a sample from normal tissue is labeled with a green fluorescent dye and a sample from cancerous tissue is labeled red, what color spots would represent genes you would be interested in if you were studying cancer? Explain.

Short answer

The researcher would be interested in both the green and red color spots. This is because both colors represent genes from the types of tissues whose level of expression is different.

In these tissues, the expression of some genes is regulated because of cancer development, while the other might play an important in causing cancer.

Step-by-step solution

DNA microarray

DNA (deoxyribonucleic acid) microarray is a collection of DNA fragments that represents the different genes attached to a glass slide. It is a molecular tool widely used to study and analyze the expression of mRNA of almost all genes of an organism.

Tissue-specific microarray

Tissue-specific microarray allows the comparison of gene expression in different tissues. In this process, mRNA from the tissue of interest is isolated, and cDNA is generated.

Both the color spots would be of interest to researchers

The red and green spots represent genes from cancerous and normal tissues, respectively. This exhibits the level of expression of genes in these tissues differ. The expression of some genes in these tissues alters due to the presence of cancer.

However, the other genes might be involved in cancer development. As a result, the researchers would be interested in both the color spots.