Congratulations to both Professor Emmanuelle Charpentier and Professor Jennifer Doudna!
It has been a great start to the month, with the first week of October 2020 marking a new milestone for the scientific community. Professors Emmanuelle Charpentier and Jennifer Doudna have become winners of the Nobel Prize in Chemistry.1 Not only are they the sixth and seventh women in history to win the award, but it is the first time that two women have jointly won the Nobel Prize in Chemistry.
Brief History of the Nobel Prize in ChemistryThe concept of the Nobel Prize was established on 27 November 1895.2 Alfred Nobel, a Swedish chemist, engineer and industrialist, signed his last will and testament, which included the use of his fortune to award a series of prizes. A part of Nobel’s will was dedicated to ‘the person who shall have made the most important chemical discovery or improvement’. Thus, the Nobel Prize in Chemistry was born.3
On 10 December 1901, the first Nobel Prize in Chemistry was awarded at a ceremony in Sweden, to Jacobus Henricus van ‘t Hoff for ‘the extraordinary services he has rendered by the discovery of the laws of chemical dynamics and osmotic pressure in solutions’.1 Marie Curie, for her discovery of the elements radium and polonium and her pioneering research on radiation, was the first woman to be awarded the Nobel Prize in Chemistry (1911).4 She was also the first, and so far only, woman to win two Nobel awards, having won the prize in Physics with her husband in 1903. Overall, there have been seven (3.8%) women and 178 (96.2%) men who have won the Nobel Prize in Chemistry (186 laureates in total, with Frederick Sanger being awarded the prize twice).1
Cutting up the DNA – CRISPR/Cas9Charpentier and Doudna were awarded the prize for their contributions to the development of the Clusters of Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9 ‘genetic scissor’ DNA editing technique, a simple but powerful way to edit the genomes of living organisms.5 This unique approach, which they began collaborating on in 2011, is seen by many as a now crucial tool in fighting and curing many diseases.6
But how does it work? CRISPR was first reported in 1987 when an unusual genetic structure was observed by a group of Japanese scientists during a study involving Escherichia coli.7 This CRISPR region is composed of alternating repeating DNA sequences and non-repeating DNA sequences (spacers), and the scientists at the time were unsure of its role.7,8 Twenty years later, a study was able to provide evidence of CRISPR’s role in the prevention of viral infection in Streptococcus thermophilus, an essential lactic acid bacterium used to create dairy products.9.10
Following successful defence against viral infection, a small section of viral genetic material is kept and placed as a spacer within the CRISPR region.11 If the bacterium detects another infection from a similar virus, it produces two RNA molecule strands (CRISPR RNA [crRNA] and trans-activating crRNA [tracrRNA]) using the viral material stored – this contains a sequence which matches that of the invading virus.8,12 Both RNA strands form a complex with the Cas9 protein, an endonuclease that is able cleave the phosphodiester bond and cut DNA. Once the RNA strands are able to match and find their target within the viral genome, Cas9 cuts the target DNA, disabling the virus.
Research by Doudna and Charpentier published in 2012 showed that they were able to manipulate this mechanism to target genes of their own choice, which began the development of the RNA-programmable genome editing system known as CRISPR/Cas9.13 Since then, it has been developed further and is now being considered as a therapeutic option for a variety of diseases, including sickle cell anaemia and cancer.14,15
ConclusionThe widening and increasing acknowledgement of the contributions women make in science has taken a large step forward. As Charpentier put it, this milestone has showed how ‘science becomes more modern and develops more female leaders’.16 Furthermore, not only have Charpentier and Doudna contributed to driving the genome editing field forward, but they have also become inspirations and role models to the next generation of women who are considering a career within science.
By Will Shieu
