Female meiosis in wild-type Arabidopsis thaliana and in two meiotic mutants

Female meiosis in Arabidopsis has been analysed cytogenetically using an ad aptation of a technique previously applied to male meiosis. Meiotic progres sion was closely correlated with stages of floral development, including th e length and morphology of the gynoecium. Meiosis in embryo sac mother cell s (EMCs) occurs later in development than male meiosis, in gynoecia that ra nge in size between 0.3 and 0.8 mm. The earliest stages in EMCs coincide wi th the second division to tetrad stages in pollen mother cells. However, th e details of meiotic chromosome behaviour in EMCs correspond closely to the observations we have previously made in male meiosis. In addition, BrdU la belling coupled with an immunolocalisation detection system was used to mar k the S phase in cells preceding their entry into prophase I. These techniq ues allow female meiotic stages of Arabidopsis to be analysed in detail, fr om the S-phase through to the tetrad stage, and are shown to be equally app licable to the analysis of female meiosis in meiotic mutants.