Transposable element 'timestamps' reveal strawberry's complex polyploid origins

Researchers have developed a technique for dating and ordering the genome-merging events that gave rise to complex polyploid plant species, using the insertion patterns of transposable elements as molecular timestamps. Applied to the cultivated strawberry (*Fragaria × ananassa*), the approach revealed that the modern genome was assembled through a series of ancient hybridisation and whole-genome duplication events rather than a single ancestral merger — shedding new light on how one of the world's most commercially important berry crops came to carry its characteristic eight-copy (octoploid) genome.

Transposable elements — repetitive DNA sequences sometimes called 'jumping genes' — insert themselves at different points in evolutionary time and can be grouped into families with characteristic activity windows. By analysing when different element families were active relative to genome-duplication signatures, the team reconstructed a timeline that conventional phylogenomic methods struggle to resolve in highly repetitive polyploid genomes.

The work, reported by ScienceDaily from the underlying research group, adds a new tool to comparative plant genomics and has potential applications across other major polyploid crops including wheat, oilseed rape, and cotton. No institution or journal was named in the available feed text; readers should consult the primary publication for author and institutional detail.