Chromatin Originated in Ancient Microbes One to Two Billion Years Ago
Published:10 Jun.2022 Source:Center for Genomic Regulation
Histones are present in both eukaryotes, living organisms that have specialised cellular machinery such as nuclei and microtubules, and archaea, another branch of the tree of life consisting of single-celled microbes that are prokaryotic, meaning they lack a nucleus. In eukaryotic cells, histones are modified by enzymes, continuously shapeshifting the genomic landscape to regulate gene expression and other genomic processes. Despite this fundamental role, the exact origin of chromatin has been shrouded in mystery.
Researchers at the Centre for Genomic Regulation (CRG) now reveal that nature's storage solution first evolved in ancient microbes living on Earth between one and two billion years ago. The study is published today in the journal Nature Ecology and Evolution. To go back in time, the researchers used information written in the genomes of modern organisms, organizing life forms according to the evolution of genes and proteins linked to chromatin. They studied thirty different species obtained from water samples in Canada and France. The microbes were identified thanks to modern gene-sequencing technologies that allow the identification of species by filtering DNA. They were subsequently grown in the lab for proteomic and genome sequencing.