In this way, it mimicked further invading viral attack. This mechanism of adaptive bacterial immunity was like a pair of molecular scissors that cut viral DNA and stored the ‘DNA memory’ of a past viral infection in their unique CRISPR-DNA sequences (a sort of bacterial vaccination card). Invading viral attackĭoudna and Sternberg collaborated with work from many laboratories in this fascinating story and the pace of research increased. How amazing that bacteria have a system designed to recognise, cut and destroy viral DNA, but also to store a memory of the attack for specific immunity. Finally they discovered that bacterial CRISPR- RNA molecules could guide the Cas9 protein to a specific viral DNA site and unzip and destroy the attacking viral DNA (or RNA) according to the sequence in the CRISPR-RNA, thus conferring immunity to the bacteria.

Furthermore, they found that CRISPR- associated genes ( cas genes) coded for a protein (Cas9) that could cut viral DNA or RNA. It was then found that these unique DNA sequences were a perfect match with sequences in the DNA of known bacterial viruses. The CRISPRs were present in a number of other prokaryote species, so represented an important basic function. These repeats were all identical, but in the spaces between the repeats were other unique DNA sequences. Working with Professor Jill Banyard, they found that bacteria contained sequences in their genes which had clusters of regularly interspaced short palindromic repeats of the DNA letters (called CRISPRs).

Initially the authors found a new form of adaptive immunity against viruses (bacteriophages) that can attack and kill bacteria. The book is an absorbing, urgent, and riveting read. But in addition to use in somatic cells, these tools can also be used to modify human germ cells (eggs or sperm) which will alter the genetic composition of the next generation, thus changing the physical health, or mental and psychological characteristics of our descendants. The authors developed biotechnology tools that could cut specific DNA sequences in human cells and then insert, delete, or edit genes to restore their functional activity for therapeutic purposes.

It traces the authors’ fascinating search to uncover the mechanisms of gene function and immune protection, and how to alter our genetic code – for good or for … other purposes. It has the awesome power to change our biological future. This gives us, for the first time, the power to cure disease and alleviate suffering, but also to ‘redesign’ any species, including humans, for our own ends. In the past decade Professor Jennifer Doudna and Dr Sam Sternberg, at the Universities of California and Columbia respectively, have discovered a cellular function that enables us to re-write our genetic code.

Doudna a crack in creation