Astronauts aboard the International Space Station have performed the first successful use of CRISPR-Cas9 genome editing in space.
As we continue to explore life beyond Earth, astronauts may be at greater risk of harmful DNA damage due to exposure to ionising radiation. Such DNA damage can lead to cancer and other detrimental health effects. This raises the question about the safety of long-duration space flights.
Double-strand breaks are a particularly harmful type of DNA lesion. There are two major cellular pathways to repair these breaks. The first is homologous recombination (HR), which uses a template for repair so that the DNA sequence remains unaltered. The second is non-homologous end joining (NEHJ), during which insertions or deletion can be added at the break site.
Previous studies have shown that space conditions can impact the choice of DNA repair pathway used by the cell. This potentially heightens the risks of increased radiation exposure. Nonetheless, our understanding of this problem has been limited by both technical and safety concerns, which have impeded our ability to study the DNA repair process in space.
CRISPR-based mutagenesis strategy in space
In this study, published in PLOS ONE, researchers harnessed the CRISPR-Cas9 system to study DNA repair in space. The system has several benefits for space research, including the fact that it does not utilise radiation or other reagents and can generate DSBs at precise locations that can be tracked. Their technique involves the use of CRISPR/Cas9 technology to create precise damage to DNA strands in yeast cells so that DNA repair mechanism can be observed.
The team successfully demonstrated the viability of their novel method in yeast cells aboard the International Space Station (ISS). This is both the first successful genetic transformation as well as the first use of CRISPR/Cas9 genome editing in space. These events represent a significant expansion of the molecular tools available aboard the ISS. It also paves the way for a plethora of future investigations. The team hope that CRISPR on the ISS will be used to not only understand biological responses to microgravity but may also help with future space exploration and colonisation, i.e., transforming for production of critical medicines.
Image credit: By hfrankWI – canva