Large-scale investigation of species-specific orphan genes in the human gut microbiome elucidates their evolutionary origins.

ABSTRACT: Species-specific genes, also known as orphans, are ubiquitous across life's domains. In prokaryotes, species-specific orphan genes (SSOGs) are mostly thought to originate in external elements such as viruses followed by horizontal gene transfer, whereas the scenario of native origination, through rapid divergence or de novo, is mostly dismissed. However, quantitative evidence supporting either scenario is lacking. Here, we systematically analyzed genomes from 4644 human gut microbiome species and identified more than 600,000 unique SSOGs, representing an average of 2.6% of a given species' pangenome. These sequences are mostly rare within each species yet show signs of purifying selection. Overall, SSOGs use optimal codons less frequently, and their proteins are more disordered than those

SUBMITTER: Vakirlis N 

PROVIDER: S-EPMC11293555 | biostudies-literature | 2024 Jul

REPOSITORIES: biostudies-literature