Scientists have created a strain of brewer’s yeast (Saccharomyces cerevisiae) whose genome is more than half synthetic. Seven-and-a-half chromosomes were synthesized or stitched together in the laboratory. To make sure the genome was stable, biologists removed repetitive regions of DNA and sequestered all genes for transfer RNAs — essential for protein synthesis — in a single ‘neochromosome’. It’s a milestone for the Sc2.0 consortium, whose aim is to create yeast with a fully synthetic genome. https://doi.org/10.1016/j.xgen.2023.100438 DOI:https://doi.org/10.1016/j.cell.2023.10.015 DOI:https://doi.org/10.1016/j.cell.2023.09.025