Required for fertility. Involved in chromatid cohesion establishment, in chromosome structure during male and female meiosis (e.g. the synapse formation between homologous chromosomes, the recombination, and the cohesion of both chromatid arm and centromere), and in axial element formation. Regulates the switch from mitosis to the reductional meiosis division of megaspores prior to the female gametogenesis (megasporogenesis). Localized in meiocyte nuclei just before meiosis, exclusively in meiotic G1 and S phase (at protein level). Meiocytes (at protein level). Plants contain 2 cells with prominent nuclei in the central region of the ovule where the embryo sac is normally located. Sometimes, an unreduced diploid female gamete, arising from apomeiosis, can be fertilized by a haploid male gamete, leading to a viable triploid embryo.