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Brown TA. Genomes. 2nd edition. Oxford: Wiley-Liss; 2002.
In order for the cell to utilize the biological information contained within its genome, groups of genes, each gene representing a single unit of information, have to be expressed in a coordinated manner. This coordinated gene expression determines the make-up of the transcriptome, which in turn specifies the nature of the proteome and defines the activities that the cell is able to carry out.
In Part 3 of Genomes we examine the events that result in the transfer of biological information from genome to proteome. Our knowledge of these events was initially gained through studies of individual genes, often as ‘naked’ DNA in test-tube experiments. These experiments provided an interpretation of gene expression that in recent years has been embellished by more sophisticated studies that have taken greater account of the fact that, in reality, it is the genome that is expressed, not individual genes, and that this expression occurs in living cells rather than in a test tube.
We begin our investigation of genome expression in Chapter 8, by examining the substantial and important impact that the nuclear environment has on the utilization of the biological information contained in the genomes of eukaryotes, the accessibility of that information being dependent on the way in which the DNA is packaged into chromatin and being responsive to processes that can silence or inactivate part or all of a chromosome.
Chapter 9 describes the events involved in initiation of transcription, and emphasizes the critical role the DNA-binding proteins play during the early stages of genome expression. The synthesis of transcripts and their subsequent processing into functional RNAs is dealt with in Chapter 10, and Chapter 11 covers the equivalent events that lead to synthesis of the proteome.
As you read Chapters 8–11 you will discover that control over the composition of the transcriptome and of the proteome can be exerted at various stages during the overall chain of events that make up genome expression. These regulatory threads will be drawn together in Chapter 12, where we examine how genome activity changes in response to extracellular signals during differentiation and development.
Chapter 8. Accessing the Genome
Chapter 9. Assembly of the Transcription Initiation Complex
Chapter 10. Synthesis and Processing of RNA