Imagine venturing into the cosmos and encountering life unlike anything we've ever imagined. This is the exciting frontier astrobiologists are exploring, and it all starts with understanding the building blocks of life.
As we journey beyond Earth, we're bound to stumble upon the unexpected. Life on other planets could be wildly different, perhaps using chemical pathways entirely foreign to us. Or, it might surprisingly resemble life here on Earth. The question is, how do we prepare to search for the unknown?
The genetic code of life on Earth, with a few exceptions, is based on a four-letter genomic code. It's like an alphabet, with each letter representing a nucleotide. While it's possible that early Earth life used a different set of letters, the current code has been around for quite a while. But what if life on other planets uses a completely different genetic alphabet?
As we delve into the world of genomics for commercial and health purposes, we're discovering innovative ways to modify the standard genomic model and alter the outcome of a genetic sequence. This research, using Artificially Expanded Genetic Information Systems (AEGIS), shows that pairing non-standard nucleotides is at least feasible. But here's where it gets controversial... Whether these new sequences will actually function is another question, but it gives us valuable insights into how genetic sequences work, and by extension, how they might function elsewhere in the universe.
Scientists synthesized and tested about 300 phage genomes in dishes containing E. coli, and 16 of them were functional.
The experiment itself wasn't dangerous, and designing “life” is a far heavier lift than the simple phage — a bacteria-infecting virus — that they created. Scientists used “Evo,” a generative AI model trained on the genomes of living things. Similar to how other AI large language models are trained on a massive corpus of text, the most advanced version of Evo ingested about 9 trillion letters of DNA from an atlas spanning all domains of life.
Many crucial biological functions arise from complex interactions encoded by entire genomes, not just single genes.
Genome language models have become a promising strategy for designing biological systems, but their ability to generate functional sequences at the scale of whole genomes has remained untested.
This study reports the first generative design of viable bacteriophage genomes. They used cutting-edge genome language models, Evo 1 and Evo 2, to generate whole-genome sequences with realistic genetic architectures and desirable host tropism, using the lytic phage ΦX174 as their design template.
Experimental testing of AI-generated genomes yielded 16 viable phages with significant evolutionary novelty. Cryo-electron microscopy revealed that one of the generated phages utilizes an evolutionarily distant DNA packaging protein within its capsid.
Multiple phages showed higher fitness than ΦX174 in growth competitions and in their lysis kinetics. A cocktail of the generated phages quickly overcomes ΦX174-resistance in three E. coli strains, demonstrating the potential of this approach for designing phage therapies against rapidly evolving bacterial pathogens.
This work provides a blueprint for designing diverse synthetic bacteriophages and, more broadly, lays a foundation for the generative design of useful living systems at the genome scale.
So, what do you think? Does this research open exciting doors for understanding life beyond Earth, or are there ethical considerations we should be discussing? Let me know your thoughts!
