Mimulus Finds Centromeres in the Driver's Seat

Sandler and Novitski first pointed out in 1957 that chromosomes could selfishly exploit meiotic asymmetries to maximize their own transmission, in a process termed 'meiotic drive'. However, since then, only post-meiotic processes of non-Mendelian inheritance have received serious scientific attention in studies of transmission distortion. A recent study by Fishman and Willis puts the focus squarely back on meiotic drive. They found completely biased transmission of a centromere-linked locus from an outcrossing Mimulus species over that from an inbred species, providing the first direct evidence that centromeres can act as general, powerful meiotic drivers. This study suggests that, although difficult to detect experimentally, female meiotic drive is a major evolutionary force in nature.