Training your genome

Training your genome Founder and President of InsideOutBio, Alan Herbert, explores the evolving understanding of genome information storage, and the significance of repetitive sequences called flipons in genome training. These flipons can alter their shape without breaking DNA and are vital in cell biology, especially in responding to environmental stress. Our view of how genomes store information has rapidly changed. In the classical view, codons contain the important content. Each codon consists of three DNA bases uniquely mapped to an amino acid. The order of codons gives the position of amino acids in the protein product that determines its function. Mutations that change codons or their expression then cause disease. In this view, the repetitive sequences that comprise over 50% of the human genome are just a nuisance. They cause genomic instability by frequently breaking and disrupting DNA repair. However, some repeats are useful. For example, telomeric repeats help protect chromosome ends and prevent senescence, while those at centromeres play a role in cell division. Otherwise, most repeat sequences are confined by nucleosomal proteins to limit the harm that they can cause. Recently, a more nuanced understanding of how genomes work has emerged. With this new focus, repeats that dynamically change their conformation in a programmable manner play important roles in cell biology. This class of repeats is called flipons. They enable genomes to learn and optimize cell responses to environmental stressors.