Plant sex regions can “jump” in strawberry (PLOS Biol.)

Sex chromosome restructure has happened frequently during the evolution of eukaryotes, often resulting in highly differentiated sex chromosomes. However, little is known about this process in plants. The wild North American octoploid strawberries (Fragaria) have separate sexes with homomorphic, female heterogametic (ZW) inheritance. However, “sex” maps to three different chromosomes in different taxa. Tennessen and colleagues use genomic and phylogenetic analyses to understand female-specific regions of DNA which are associated with sex. The genomic location of these regions has changed over time. Each time the genomic locations changed, the size of the hemizygous female-specific sequence on the W sex chromosome increased. This indicates that plant sex regions can “jump”, potentially aiding in gathering new genes into linkage with sex. (Summary by Julia Miller) PLOS Biol. 10.1371/journal.pbio.2006062