Now there is one of the biggest challenges currently facing the fields of genomics and genetics, which Scientists from Australia and the United States bring into our concept of the three-dimensional structure of the genome.
DNA, roughly 3 metres is tightly folded into the nucleus of every cell in our body. This folding facilitates some genes to be ‘expressed’, or activated, while excluding others.
Genes consist of ‘exons’ and ‘introns’ the former being the sequences that code for protein and are expressed, and the latter being stretches of noncoding DNA in-between. As the genes are copied, or ‘transcribed’, from DNA into RNA, the intron sequences are cut or ‘spliced’ out and the remaining exons are strung together to form a sequence that encodes a protein. Depending on which exons are strung together, the same gene can generate different proteins.
Referring vast amounts of data from the ENCODE project*, Dr Tim Mercer and colleagues have examined the folding of the genome, finding that even within a gene, selected exons are easily exposed.
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