Data from: Dioecy and chromosomal sex determination are maintained through allopolyploid speciation in the plant genus Mercurialis

Polyploidization may precipitate dramatic changes to the genome, including
chromosome rearrangements, gene loss, and changes in gene expression. In
dioecious plants, the sex-determining mechanism may also be disrupted by
polyploidization, with the potential evolution of hermaphroditism.
However, while dioecy appears to have persisted through a ploidy
transition in some species, it is unknown whether the newly formed
polyploid maintained its sex-determining system uninterrupted, or whether
dioecy re-evolved after a period of hermaphroditism. Here, we develop a
bioinformatic pipeline using RNA-sequencing data from natural populations
to demonstrate that the allopolyploid plant Mercurialis canariensis
directly inherited its sex-determining region from one of its diploid
progenitor species, M. annua, and likely remained dioecious throughout the
transition. Interestingly, the sex-determining region of M. canariensis is
smaller than that of its diploid progenitor, suggesting that the non -
recombining region of M. annua expanded subsequent to the polyploid origin
of M. canariensis. Furthermore, we find some evidence for sexual
subfunctionalization of homeologous pairs, suggesting that polyploids may
use gene duplicates created by polyploidization to resolve sexual
antagonism.