Resumen: Our understanding of polyploid genome evolution is constrained because we cannot know the exact founders of a particular polyploid. To differentiate between founder effects and post polyploidization evolution, we use a pan-genomic approach to study the allotetraploid Brachypodium hybridum and its diploid progenitors. Comparative analysis suggests that most B. hybridum whole gene presence/absence variation is part of the standing variation in its diploid progenitors. Analysis of nuclear single nucleotide variants, plastomes and k-mers associated with retrotransposons reveals two independent origins for B. hybridum, ~1.4 and ~0.14 million years ago. Examination of gene expression in the younger B. hybridum lineage reveals no bias in overall subgenome expression. Our results are consistent with a gradual accumulation of genomic changes after polyploidization and a lack of subgenome expression dominance. Significantly, if we did not use a pan-genomic approach, we would grossly overestimate the number of genomic changes attributable to post polyploidization evolution. Idioma: Inglés DOI: 10.1038/s41467-020-17302-5 Año: 2020 Publicado en: Nature Communications 11, 1 (2020), 3670 [16 pp] ISSN: 2041-1723 Factor impacto JCR: 14.919 (2020) Categ. JCR: MULTIDISCIPLINARY SCIENCES rank: 4 / 73 = 0.055 (2020) - Q1 - T1 Factor impacto SCIMAGO: 5.559 - Biochemistry, Genetics and Molecular Biology (miscellaneous) (Q1) - Physics and Astronomy (miscellaneous) (Q1) - Chemistry (miscellaneous) (Q1)