Guest Blogger Smidgeons of Science discusses natural repetition in living systems
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The element of repetition in art and design serves to bring a sense of consistency and to highlight an event that occurs over and over in a predictable pattern. Did you know that there are repeats that are found in genomes, and that each one of these repeats have defined roles? In the next couple of blogs, I will be profiling four different types of repeats found in living systems: CRISPR’s, Telomeres, Transposable elements, and Proteasome initiation regions. In this mini-series, I want to not only inform you about them but also provide a small window into their roles and relevance in Cell Biology.
So, what are CRISPR’s, and why are they interesting? First, the acronym CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats. In every living organism is a genome, which is essentially a list of rules made out of a molecule called DNA that determines how the organism runs. In prokaryotes (single celled organisms), there is a spot in their genome where there are these sequential repeats called CRISPR’s, and surprisingly enough, in between each repeat is a short segment of DNA from viruses that have tried to attack the cell in the past. In this way, these repeats confer immunity because there is a family of proteins that recognizes both the repeats and that short segment of foreign DNA, and can target invading viruses quickly.
This fundamental finding has now been crafted into an ingenious and powerful genome editing tool because it was discovered that scientists could ‘upload’ custom guides onto the protein, and this guide would take the protein to a specific location anywhere on a genome (viral or not) to target whatever DNA one wanted to eliminate. This has a large therapeutic potential: can you imagine being able to excise a piece of a disease causing gene out of a genome? This tool allows you to do so.
Stay posted for next week’s mini-profile on another type of repeat and its role in biology.