Multiple origins, one evolutionary trajectory: gradual evolution characterizes distinct lineages of allotetraploid Brachypodium.

ABSTRACT: The "genomic shock" hypothesis posits that unusual challenges to genome integrity such as whole genome duplication may induce chaotic genome restructuring. Decades of research on polyploid genomes have revealed that this is often, but not always the case. While some polyploids show major chromosomal rearrangements and derepression of transposable elements in the immediate aftermath of whole genome duplication, others do not. Nonetheless, all polyploids show gradual diploidization over evolutionary time. To evaluate these hypotheses, we produced a chromosome-scale reference genome for the natural allotetraploid grass Brachypodium hybridum, accession "Bhyb26." We compared 2 independently derived accessions of B. hybridum and their deeply diverged diploid progenitor species Brachypodium stace

SUBMITTER: Scarlett VT 

PROVIDER: S-EPMC9910409 | biostudies-literature | 2023 Feb

REPOSITORIES: biostudies-literature