All around the world ' in the oceans, the soil, your body ' an invisible battle is raging. Earth's vast population of roughly 1030 bacteria faces an unending onslaught from an even larger army of viruses, known as bacteriophages. The bacteria have a variety of defences at their disposal: they chop up viral components, deny the invaders key ingredients for replication and even shut down their own biological systems to halt infections, sacrificing themselves to protect nearby kin. The viruses, in turn, evolve counter-defence mechanisms, resulting in an ever-escalating arms race. Although microbiologists are just beginning to understand the extent of this eternal contest, microbial immune mechanisms have already inspired technologies that have revolutionized biology. The discovery of restriction enzymes, bacterial proteins that slice DNA at specific sites, sparked the field of molecular biology in the 1970s, enabling everything from the development of genetically modified organisms to DNA forensics. CRISPR'Cas, a bacterial defence system that recognizes and slashes specific sequences in viral genomes, gave scientists the power to delete or edit genes with remarkable precision. Developed in the early 2010s, CRISPR-based gene editing has attracted billion-dollar investments and earned its key discoverers the 2020 Nobel Prize in Chemistry....
Within the human digestive tract are trillions of bacteria from thousands of different species. These bacteria form communities that help digest food, fend off harmful microbes, and play many other roles in maintaining human health. These bacteria can be vulnerable to infection from viruses called bacteriophages. One of bacterial cells' most well-known defenses against these viruses is the CRISPR system, which evolved in bacteria to help them recognize and chop up viral DNA. A study from MIT biological engineers has yielded new insight into how bacteria in the gut microbiome adapt their CRISPR defenses as they encounter new threats. The researchers found that while bacteria grown in the lab can incorporate new viral recognition sequences as quickly as once a day, bacteria living in human gut add new sequences at a much slower rate ' on average, one every three years. The findings suggest that the environment within the digestive tract offers many fewer opportunities for bacteria and bacteriophages to interact than in the lab, so bacteria don't need to update their CRISPR defenses very often. It also raises the question of whether bacteria have more important defense systems than CRISPR....
A fresh wave of gene-editing therapies is surging to the fore ' even as the field wrestles with the challenge of getting the first generation of expensive and complex CRISPR treatments to the people who need them....
In 2025, we will see AI and machine learning begin to amplify the impact of Crispr genome editing in medicine, agriculture, climate change, and the basic research that underpins these fields. It's worth saying upfront that the field of AI is awash with big promises like this. With any major new technological advance there is always a hype cycle, and we are in one now. In many cases, the benefits of AI lie some years in the future, but in genomics and life science research we are seeing real impacts right now. In my field, Crispr gene editing and genomics more broadly, we often deal with enormous datasets'or, in many cases, we can't deal with them properly because we simply don't have the tools or the time. Supercomputers can take weeks to months to analyze subsets of data for a given question, so we have to be highly selective about which questions we choose to ask. AI and machine learning are already removing these limitations, and we are using AI tools to quickly search and make discoveries in our large genomic datasets....
