CRISPR: the hero of genome editing

Are designer genes nearly here? Joanna Chustecki examines the new toolkit in our hands

Genome editing, the science behind the manipulation of the very code of life, has seen remarkable advances in recent years. The toolkits allowing the changing of gene have varied, but leading the charge is our very hero: CRISPR/Cas9.

CRISPR/Cas9 is cheaper, more efficient and less time consuming that its predecessors, it allows precise editing of the string of letters that make us who we are. This has applications covering a broad range of issues, such as good security, drug development and future fuels. But with such an explosion of knowledge in this field of research, how can we keep up?

What is CRISPR/Cas9 genome editing?

This toolkit originates in bacteria, as a protective defence system against invading viruses. The system acts by cutting by the viral genome before it wreaks havoc to the bacterium. CRISPR refers to the short DNA sequences in the bacterium, stored from previous exposure to one or more bacterial; viruses. A virus inserts its genetic material into the bacteria, and these sequences are used to guide the Cas9 nuclease, a DNA cutter, to the viral material. The Cas9 nuclease cuts the invading viral DNA at the specific points where the sequences match. This renders the viral DNA useless, and the bacteria safe.

How can we use this technique?

Scientists have hijacked and applied this process to a huge range of different organisms, including mice and monkeys, to edit genes with precision. By creating their own short sequences, scientists can guide Cas9 to any point in the genome of the organise they wish to edit, creating a break in the DNA, allowing us ot either remove genes, or edit them precisely. The action of this small Cas9 protein has profound effects for potentially curing genetic disease, creating new sustainable fuels, producing new materials and boundless applications in basic genetic research.

What does the future hold for our hero?

The power of our CRISPR/Cas9 hero is outstanding, but as with all heros, with great power comes great responsibility. The editing of germ lines has the potential to carry any mutations made into future generations, and research on stem cells is still a hotly disputed topic, research being undertaken at the Francis Crick Institute in London, for the use of CRISPR technology for editing human embryos, has only just been approved, a landmark decision for science in the UK and the world. CRISPR/Cas9 editing was widely debated last December at the International Summit on Human Gene Editing in Washington DC. Members warned of a slippery slope towards germ line editing, and potentially dangerous experiments occurring without the right regulations. However, it was argued that shitting the door on embryo research would be damaging to advancement of this field, and hold back research that could be potentially life changing for millions of people.

For now, CRISPR/Cas9 continues to be applied to new areas every day, and the pace at which this field is evolving shows testament to CRISPR/Cas9 genome editing being a true hero of modern science.

From Issue 11