Saso, A. | bioRxiv Science

bioRxiv2025

High-Coverage Jomon Genomes Provide Insights into Population Structure and Genetic Traits of Ancient Japanese Hunter-Gatherers

We analyzed eight high-coverage Jomon genomes spanning 9,000-2,800 years ago across the Japanese archipelago. Population genomic analyses revealed substantial genetic homogeneity across time and space reflecting post-glacial isolation, yet temporal stratification emerged: Initial Jomon (Iyai) individuals formed the earliest branch with weaker affinities to present-day Japanese. Using genomes from Todoroki and Chidorikubo sites, we estimated Jomon ancestry in mainland Japanese at [~]20%, substantially higher than previous estimates ([~]13%). Polygenic score analyses, based on the direct analysis of Jomon genomes, provided the genetic evidence for their phenotypic predispositions, including elevated BMI and metabolic trait scores, reduced immune-related scores, and larger cardiac dimensions, patterns consistent with hunter-gatherer adaptations. These ancestral genetic influences, including elevated risks for obesity and dyslipidemia, persist in present-day Japanese. Our findings demonstrate that Jomon populations maintained genetic continuity despite ecological diversity, while their greater-than-expected contribution to present-day Japanese reshapes population history models and reveals how ancient adaptations continue influencing contemporary disease susceptibility.

genomics↗

bioRxiv2018

Ancient DNA analysis of food remains in human dental calculus from the Edo period, Japan

Objectives: Although there are many methods for reconstructing diets of the past, detailed taxon identification is still challenging, and most plants hardly remain at a site. In this study, we applied DNA metabarcoding to dental calculus of Edo people for the taxonomic identification of food species.\n\nMaterials and Methods: DNA was extracted from 13 human dental calculi from the Unko-in site (18th-19th century) of the Edo period, Japan. Polymerase chain reaction (PCR) and sequencing were performed using a primer set specific to the genus Oryza, because rice (Oryza sativa) was a staple food and this was the only member of this genus present in Japan at that time. DNA metabarcoding targeting plants, animals (meat and fish), and fungi was also carried out to investigate dietary diversity.\n\nResults: We detected amplified products of the genus Oryza from more than half of the samples using PCR and Sanger sequencing. DNA metabarcoding enabled us to identify taxa of plants and fungi, although taxa of animals were not detected, except human.\n\nDiscussion: Most of the plant taxonomic groups are present in Japan and include species consumed as food at that time, as confirmed by historical literature. The other groups featured in the lifestyle of Edo people, such as for medicinal purposes and tobacco. The results indicate that plant DNA analysis from calculus provides information about food diversity and lifestyle habits from the past and can complement other analytical methods such as starch analysis and stable isotope analysis.

molecular biology↗