From microarray analysis, how do we know what genes are being expressed in a specific tissue?

When the S. cerevisiae genome was sequenced and surveyed for possible genes, only about 40% of those genes had been previously identified in forward genetic screens. This left about 60% of predicted genes with no known function, leading some to dub the genes fun (function unknown) genes. As an approach to understanding the function of a certain fun gene, you wish to create a loss-of-function allele. How will you accomplish this?

Which of the following terms describes the study of physical interactions between DNA, RNA, and Protein?

Which of the following methods is used to study protein interactions in live cells?

Which of the following methods is used to study protein-DNA interactions?

In the discussion we focused on the analysis of genomes, transcriptomes, and proteomes and considered important applications and findings from these endeavors. At the same time, we found many opportunities to consider the methods and reasoning by which much of this information was acquired. From the explanations given in the chapter, what answers would you propose to the following fundamental questions?

How have microarrays demonstrated that, although all cells of an organism have the same genome, some genes are expressed in almost all cells, whereas other genes show cell- and tissue-specific expression?

Discuss the similarities and differences between forward and reverse genetic approaches, and when you would choose to utilize each of the approaches.

What is functional genomics? How does it differ from comparative genomics?

What are the advantages and disadvantages of using insertion alleles versus alleles generated by chemicals (as in TILLING) in reverse genetic studies?