7) Give an overview of microarray technology. How did the author use it for a hypothesis?
a. Microarray is a technique used for measuring the rate of transcription (level of gene expression) occurring in a cell; and, results of microarray technology can usually tell whether a cell has been up- or downregulated. The first step in this method is to create a microarray, a grid with thousands of different single stranded DNA polynucleotides. Then, the mRNA from the cell we are testing is obtained, as well as a control. The mRNA is converted into cDNA and the fluorescent labels are added. The single-stranded cDNA is then allowed to hybridize with the DNA from the microarray. If there is binding, there is expression of that gene that is bound. The colors will determine whether the gene is upregulated or downregulated.
b. The author used microarray because he hypothesized that the two species (domestic dogs and gray wolves), despite their similar DNA sequences, may differ in the pattern of gene expression. As a result, they measured the mRNA expression levels of genes in dogs, wolves, and coyotes in three regions of the brain: the frontal lobe, the amygdala, and the hypothalamus.