Self-incompatibility (SI) is generally controlled by the S-locus, and comprises allelic pollen and pistil S-determinants. Poulter et al. review and discuss our current understanding of the cytoskeletal alterations induced in incompatible pollen during SI and their relationship with programmed cell death in Papaver rhoeas, focussing on data relating to the formation of F-actin punctate foci. Analysis [...]