- The 2020 Nobel Prizes for chemistry was exclusively shared by two women scientists Jennifer Doudna and Emmanuelle Charpentier for the development of a method for genome editing.
- The discovery of “one of gene technology’s sharpest tools: the CRISPR/Cas9 genetic scissors” will lead to the emergence of novel biological applications by making it easier to edit genes, and “may make the dream of curing inherited diseases come true”.
What is CRISPR/Cas9?
- Much like what Microsoft (MS) Word does for writing, the CRISPR/Cas9 system allows for adding, altering and deleting the genomic code in living beings.
- Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) are pieces of DNA that bacteria snip off from viruses that once attacked them, much like file names used to store various documents we write in MS Word.
- CRISPR is a dynamic, versatile tool that allows us to target nearly any genomic location and potentially repair broken genes. It can remove, add or alter specific DNA sequences in the genome of higher organisms.
- CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) are sections of DNA and are sections of genetic code containing short repetitions of base sequences followed by spacer DNA segments.
- CAS-9 (CRISPR-associated protein 9) is an enzyme. It uses a synthetic guide RNA to introduce a double strand break at a specific location within a strand of DNA. It is a system used by bacterial cells to recognize and destroy viral DNA as a form of adaptive immunity.
Working of CRISPR – Cas9
- CRISPR scans the genome looking for the right location and then uses the Cas9 protein as molecular scissors to snip through the DNA.
- Cas9 endonuclease – guide RNAs to direct it to a particular sequence to be edited. The genetic sequence of the RNA matches the target sequence of the DNA that has to be edited.
- When Cas9 cuts the target sequence, the cell repairs the damage by replacing the original sequence with an altered version.
- Unlike other gene-editing methods, it is cheap, quick, easy, safer and more accurate to use because it relies on RNA–DNA base pairing, rather than the engineering of proteins that bind particular DNA sequences.
- CRISPR could be used to modify disease-causing genes in embryos brought to term, removing the faulty script from the genetic code of that person’s future descendants as well.
- Genome editing (Gene editing) could potentially decrease, or even eliminate, the incidence of many serious genetic diseases, reducing human suffering worldwide.
- It might also be possible to install genes that offer lifelong protection against infection.
- The most controversial application of CRISPR/Cas9 was in 2018, when Chinese researcher He Jiankui announced that he had used it to create ‘gene-edited twins’ Lula and Nana via in-vitro fertilisation. He used the gene scissors on the children when they were embryos to edit a gene, CCR5, that in its modified form would ostensibly protect the babies from HIV. The HIV uses the CCR5 to infect cells and the modified gene would shut the door against such an entry. He was widely condemned and sentenced to three years in jail, and stripped of his position at Shenzhen University, where he worked.
- While he broke a number of medical rules, what is particularly controversial is that the specific mutations that would supposedly protect the children from HIV were not achieved. There were a host of other unintended mutations too. It is not known how these mutations are going to play out over the children’s lifetimes and whether they will spread to humanity more widely in due course. Thus, even though the CRISPR/Cas-9 system allows a democratic usage in labs across the world to tinker with genomes, it still has not reached the level of precision required to be sure that it does not cause unintentional side effects.
Nobel Prize for Chemistry
- The Nobel Prize in Chemistry is awarded annually by the Royal Swedish Academy of Sciences to scientists in the various fields of chemistry.
- It is one of the five Nobel Prizes established by the 1895 will of Alfred Nobel, who died in 1896. These prizes are awarded for outstanding contributions in chemistry, physics, literature, peace, and physiology or medicine.
- As dictated by Nobel’s will, the award is administered by the Nobel Foundation and awarded by the Royal Swedish Academy of Sciences.
- The first Nobel Prize in Chemistry was awarded in 1901 to Jacobus Henricus van ‘t Hoff, of the Netherlands.
- Each recipient receives a medal, a diploma and a monetary award prize that has varied throughout the years.
- In 1901, van ‘t Hoff received 150,782 SEK, which is equal to 7,731,004 SEK in December 2007. The award is presented in Stockholm at an annual ceremony on 10 December, the anniversary of Nobel’s death.
Nobel Prize and Women
- This year has seen a remarkable representation of women. Four women have been named Nobel Laureates in 2020 against five men so far. The Sveriges Riksbank (Sweden’s national bank) Prize for economics, or the ‘economics Nobel’, will be announced next week.
- The 2001-2019 interval has seen the maximum number of women Laureates — 24 — compared to just 11 from 1981 to 2000 and 7 from 1961 to 1980. There were only 12 women Laureates from 1901 to 1960.
- Only one woman, Marie Curie, has been honoured twice, with the 1903 Nobel Prize in Physics and the 1911 Nobel Prize in Chemistry.
- The Hindu
- Nobel Prize Committee Official Website