What Is CRISPR? The Gene Editing System

CRISPR innovation is a simple yet potent tool for editing genomes. It permits scientists to alter DNA sequences easily and modify gene function. Its many possible applications consist of remedying hereditary defects, treating and avoiding the spread of diseases and improving crops. Nevertheless, its promise also raises ethical concerns.

In popular usage, “CRISPR” (pronounced “crisper”) is shorthand for “CRISPR-Cas9.” CRISPRs are specialized stretches of DNA. The protein Cas9 (or “CRISPR-associated”) is an enzyme that acts like a pair of molecular scissors, efficient in cutting strands of DNA.

CRISPR innovation was adapted from the natural defense mechanisms of germs and archaea (the domain of single-celled microorganisms). These organisms utilize CRISPR-derived RNA and various Cas proteins, consisting of Cas9, to foil attacks by infections and other foreign bodies. They do so primarily by chopping up and destroying the DNA of a foreign invader. When these parts are moved into other, more complex, organisms, it enables the adjustment of genes, or “editing.”.

Up until 2017, no one knew what this procedure looked like. In a paper released Nov. 10, 2017, in the journal Nature Communications, a team of scientists led by Mikihiro Shibata of Kanazawa University and Hiroshi Nishimasu of the University of Tokyo revealed what it looks like when a CRISPR is in action for the initial time. [A Breathtaking New GIF Shows CRISPR Chewing Up DNA] CRISPR-Cas9: The essential players.

CRISPR-Cas9: The main players

CRISPRs: “CRISPR” stands for “clusters of regularly interspaced short palindromic repeats.” It is a specific region of DNA with two unique characteristics: the existence of nucleotide repeats and spacers. Repeated sequences of nucleotides — the building blocks of DNA — are dispersed throughout a CRISPR area. Spacers are bits of DNA that are interspersed among these duplicated series.

When it comes to bacteria, the spacers are taken from viruses that previously assaulted the organism. They function as a bank of memories, which allows germs to recognize the viruses and battle future attacks.

This was first demonstrated experimentally by Rodolphe Barrangou and a team of scientists at Danisco, a food components business. In a 2007 paper released in the journal Science, the scientists utilized Streptococcus thermophilus germs, which are frequently discovered in yogurt and other dairy cultures, as their design. They observed that after an infection attack, brand-new spacers were incorporated into the CRISPR area. Furthermore, the DNA series of these spacers corresponded parts of the virus genome. They also controlled the spacers by taking them out or putting in brand-new viral DNA sequences. In this way, they were able to alter the germs’ resistance to an attack by a particular virus. Hence, the scientists verified that CRISPRs contribute to controlling bacterial immunity.

Read more at: What Is CRISPR? How Does It Work? Is It Gene Editing?