From UPSC perspective, the following things are important :
Prelims level : CRISPR-Cas9
Mains level : Paper 3- CRISPR-Cas9-Important tool in gene editing
The Nobel Prize in Chemistry for 2020 has been awarded for the discovery of CRISPR Cas9. The two scientists have pioneered the use of CRISPR – Cas9 (CRISPR-associated protein 9) system as a gene-editing tool.
Background of discovery of CRISPR
- In 1987a group of Japanese researchers observed an unusual homologous DNA sequence bearing direct repeats with spacing in a eubacterial gene.
- In subsequent years CRISPR was discovered and showed to be a bacterial adaptive immune system and to act on DNA targets.
- A notable discovery on the use of CRISPR as a gene-editing tool was by a Lithuanian biochemist, Virginijus Šikšnys, in 2012.
- Šikšnys showed that Cas9 could cut purified DNA in a test tube, the same discovery for which both Charpentier and Doudna were given the credit.
- Thus, the exclusion of Siksnys from this year’s Nobel is going to raise discussions.
Issue of gene-edited babies
- The world was alarmed by such a mission in 2018 when Chinese scientist edited genes in human embryos using the CRISPR-Cas9 system which resulted in the birth of twin girls.
- The incident became known as the case of the first gene-edited babies of the world.
- Following the incident, the World Health Organization formed a panel of gene-editing experts.
- The expert panel suggested a central registry of all human genome editing research in order to create an open and transparent database of ongoing work.
Guidelines and regulations in India
- In India, several rules, guidelines, and policies are notified under the Environment Protection Act, 1986 to regulate genetically modified organisms.
- The above Act and the National Ethical Guidelines for Biomedical and Health Research involving human participants, 2017, by the Indian Council of Medical Research (ICMR), and the Biomedical and Health Research Regulation Bill implies regulation of the gene-editing process.
- This is especially so in the usage of its language “modification, deletion or removal of parts of heritable material”.
- However, there is no explicit mention of the term gene editing.
Consider the question “What is CRISPR-Cas9? How it helps in the gene-editing? What are the concerns with use of it for gene-editing?”
It is time that India came up with a specific law to ban germline editing and put out guidelines for conducting gene-editing research giving rise to modified organisms.
Back2Basics: What is CRISPR?
- CRISPRs: “CRISPR” stands for “clusters of regularly interspaced short palindromic repeats.”
- It is a specialized region of DNA with two distinct characteristics: the presence of nucleotide repeats and spacers.
- Repeated sequences of nucleotides — the building blocks of DNA — are distributed throughout a CRISPR region.
- Spacers are bits of DNA that are interspersed among these repeated sequences.
- In the case of bacteria, the spacers are taken from viruses that previously attacked the organism.
- They serve as a bank of memories, which enables bacteria to recognize the viruses and fight off future attacks.