D'abord, nous avons lu l'ADN, puis nous l'avons édité, et maintenant nous apprenons à l'écrire.

Dr Hugh Goold, a synthetic biologist with the NSW Department of Primary Industries and Regional Development (DPIRD), stands in a Sydney café, watching as Sogna Ocello slices through a wheel of firm goat’s cheese. The act is both ritualistic and scientific, a demonstration of how microscopic fungi transform simple ingredients into complex culinary wonders. Goold, who has dedicated much of his career to understanding and manipulating life at the molecular level, is here not just as a guest but as part of a groundbreaking scientific endeavor. His presence at Formaggi Ocello, a renowned cheese shop in Surry Hills, underscores the intersection of food science and genetic engineering. The fungi responsible for creating the cheeses, Penicillium roqueforti, for instance, are members of the eukaryotic kingdom, a group that includes humans, animals, plants, and countless other complex organisms. This connection between microbes and higher life forms is central to Goold’s work. Goold’s research focuses on synthetic biology, a field that seeks to design and construct new biological functions and systems. At the heart of this effort is the creation of a fully synthetic yeast genome. The project involves collaborators from at least ten international institutions, working together over two decades to build each of the yeast's 16 chromosomes. Goold recently confirmed that his team completed the final chromosome in a Sydney laboratory, marking a major milestone. This achievement is part of a broader initiative led by Professor Jef Boeke at New York University, where the assembled chromosomes will be combined to create the first organism with entirely human-designed genetics. Such an organism would represent a leap forward in synthetic biology, offering unprecedented control over genetic material. The journey toward this breakthrough began with the ability to read DNA, a foundational step in modern genetics. Scientists initially focused on sequencing the genetic code, akin to deciphering ancient texts. As understanding deepened, researchers moved beyond reading to editing DNA, altering specific genes to achieve desired outcomes. Today, the field is advancing further, transitioning from modification to creation. The goal is to write new genetic sequences from scratch, enabling the design of organisms tailored for specific purposes. These include producing pharmaceuticals, sustainable materials, and even novel food sources. Ian Paulsen, another key figure in the project, embodies the restless energy often associated with pioneering scientific work. Known for his hyperactivity, Paulsen frequently moves during video calls, sometimes causing motion sickness among participants. His office is filled with objects that reflect his fascination with tinkering, rainbow slinkies, silicone fidget toys, and a small Zen garden. Paulsen and Professor Sakkie Pretorius at Macquarie University initiated the project 13 years ago, driven by a vision that seemed almost impossible at the time. There were few resources available, and existing literature on constructing chromosomes was sparse. Despite these challenges, the project gained momentum, attracting support from NSW’s first chief scientist, Mary O’Kane, and the state government. The implications of this work extend far beyond the laboratory. Synthetic biology holds the potential to revolutionize industries ranging from healthcare to agriculture. Already, scientists have used gene-editing techniques to develop biological factories capable of producing cancer treatments, spider silk, and even hallucinogenic compounds. The creation of fully synthetic yeast could push these capabilities even further, opening doors to innovations previously thought unattainable. As the final chromosome joins the others in New York, the world watches with anticipation. The resulting organism will not only be a product of human ingenuity but also a symbol of the evolving relationship between nature and technology.