Self-fertilisation (selfing) in plants is prevented mainly by the self-incompatibility recognition system, which consists of male and female specificity genes and modifier genes. Selfing does occur in Arabidopsis plants, but it is not known how it arose. Here it is reported that selfing in Arabidopsis results from a geographically widespread, 213-base-pair inversion within the male specificity gene. When this inversion is returned to its original orientation, selfing is prevented once more.
Evolution of self-compatibility in Arabidopsis by a mutation in the male specificity gene