In: Biology
CRISPR is a unique technology that enables to edit parts of the genome by removing, adding or altering sections of the DNA sequence.
The CRISPR-Cas9 system consists of two key molecules which introduce a change in mutation of DNA.
Cas9 (CRISPR associated protein 9) is a protein that plays a vital role in the immunological defense of certain bacteria against DNA viruses and plasmids and which finds major application in genetic engineering applications. Its main function is to cut DNA and therefore it can alter a cell's genome. CRISPR activity is essential for the immune response, as the presence of a set of CRISPR-associated (cas) genes, that is adjacent to the CRISPR, which code for proteins. Since the genome is modified in the process of spacer acquisition, offspring inherit the protection.
CRISPR-Cas mediated defense process can be divided broadly into three stages. The first stage, adaptation, whcih leads to insertion of new spacers within the CRISPR locus. In the second stage, expression, the cas genes is ready which lead to transcribing the CRISPR into a long precursor CRISPR RNA (pre-crRNA). The pre-crRNA is processed towards the mature crRNA by Cas proteins and accessory factors. In the third and last stage, interference,by the combined action of crRNA and Cas proteins ensures target site of nucleic acid that is recognized and destroyed.