Coding and regulatory sequence

The regions of DNA that encode and regulate the synthesis of proteins are called genes; at the latest estimate the human genome contains only 20 000-25 000 genes and only

Figure 2.4 The human genome can be classified into different types of DNA based on its structure and function. Modified with permission from Jasinska, A., and Krzyzosiak, W.J. (2004) Repetitive sequences that shape the human transcriptome. FEBS Letters 567, 136-141).

Figure 2.4 The human genome can be classified into different types of DNA based on its structure and function. Modified with permission from Jasinska, A., and Krzyzosiak, W.J. (2004) Repetitive sequences that shape the human transcriptome. FEBS Letters 567, 136-141).

around 1.5 % of the genome is directly involved in encoding for proteins [2-4]. Gene structure, sequence and activity are a focus of medical genetics due to the interest in genetic defects and the expression of genes within cells. Approximately 23.5 % of the genome is classified as genic sequence, but does not encode proteins. The non-coding genic sequence contains several elements that are involved with the regulation of genes, including promoters, enhancers, repressors and polyadenylation signals; the majority of gene related DNA, around 23 %, is made up of introns, pseudogenes and gene fragments.

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