20 November 2017
ByAppeared in BioNews 927
The short video, made by a team of researchers led by Professor Osamu Nureki at the University of Tokyo, and published in Nature Communications, records the CRISPR-Cas9 enzyme physically cutting the strand of DNA with which it interacts.
Although this does not show anything new about the behaviour of CRISPR, it confirms what scientists had previously hypothesised about the mode of action of CRISPR/Cas9 from other observations, and is the first 'live-action' demonstration of this technology.
The video was originally presented in June at a CRISPR conference held in Big Sky, Montana. Speaking to The Atlantic, Dr Sam Sternberg – who works with CRISPR and attended the conference, but was not associated with the project – emphasised the reaction of the scientific audience to the novel video clip, saying 'I was sitting in the front, and I just heard this gasp from everyone behind me'.
Professor Nureki and colleagues made the video using a technique known as atomic-force microscopy. This involves drawing a minuscule needle over the surface of the molecules that the researchers are imaging, with a laser simultaneously detecting changes in the light being deflected from the needle. By using a high-speed version of this technology, which scans very quickly, the team were able to capture the dynamic process of CRISPR and DNA interaction in real-time.
Importantly, although the video shows CRISPR in action, it does not show genome editing in a living cell: the DNA sequence that was cut is not part of an organism's complete genome, but a short selected sequence, purified and attached to a solid surface. In addition, the researchers did not observe the DNA sequence being repaired – so it does not give a complete view of the genome editing process.
Nonetheless, many believe this type of representation makes molecular biology more accessible – and exciting – to a wider audience. 'The result is fairly easy to understand,' said Dr Hiroshi Nishimasu, a study co-author, also at the University of Tokyo. 'People say "Wow!" It's very simple.'
The latest developments in CRISPR and genome editing will be discussed at the session 'What Next for Genome Editing? Politics and the Public', at the Progress Educational Trust's upcoming public conference 'Crossing Frontiers: Moving the Boundaries of Human Reproduction'.
The conference is taking place in London on Friday 8 December 2017. Full details - including sessions, speakers and how to book your place - can be found here.