Chapter 18, Problem 1CHI

Propose an experiment that can be done easily with a DNA microarray or RNA-seq that would have required years to do before these technologies were developed.

Summary Introduction

DNA microarrays and RNA-sequencing are the two techniques used to study the transcriptomes. Both these techniques are involved in assessing the expression of genes as a measure of individual transcripts (mRNA) of the gene. The process in which the sequencing of total mRNA is carried out directly is referred to as RNA sequencing. This technique replaced the microarrays and is used as a transcriptomic tool. This is because RNA sequencing provides the data without the limitations that are encountered in the microarray analysis.

Explanation of Solution

Both the microarray as well as the RNA-sequencing methodology is found to be highly parallel in nature. This is because, in these techniques, a large number of genes is examined at once. In the past, if a researcher was interested in studying the survival of heat stress, he or she would examine the genes one-by-one for its expression in the cells which are exposed to heat by the Northern blot or reverse transcriptase-PCR.

In addition to this, the researcher would have probably made a series of knock out mutants. This is carried out with the deletion of single and multiple genes. This effort is made to detect the function of the products of genes and their possible interactions. By contrast, the RNA-sequencing and microarray techniques analyze all the genes at the transcription level in one experiment itself. But of course, a sequenced genome is required for these methodologies.