—Life cycle highlighting main processes happening upon meiosis and plasmogamy/karyogamy: (a) duplication of DNA during interphase (synthesis phase); (b) meiosis-specific bouquet formation, promoted by BQT1 and BQT2 in Schizosaccharomyces pombe (; ); (c) the assembly of synaptonemal complex (; ) involves many meiosis-specific structural proteins, some of them high conserved, PHC2 and HOP1 (; ) and ZMM complex protein ZIP4/SPO22 (); (d) sister chromatids are kept close together by cohesin complexes, composed by SMC1, SMC3, RAD21 or its meiotic paralog REC8 (; ; ; ), which keep together sister chromatids until anaphase II when they are finally cleaved by separases (); double-strand breaks are introduced onto DNA by SPO11 and TopoVIB-like proteins working as dimers or tetramers (; ; ); before the activation of the homologous recombination machinery SPO11 is removed and DNA strands are processed (resection) by MRN complex (MRE11, RAD50 and NBS1) resulting in the single 3′ strand used for invasion of the homologous chromosome, where it is extended by a DNA polymerase forming a D-loop (; ; ); (e) homologous recombination mediated by RAD51A and its meiotic paralog DMC1, HOP2 and MND1 (; ); (f) chiasmata contain double-Holliday junctions, which can be resolved in order to promote cross-overs by two main pathways: the main interference bearing pathway I, which involves MER3, MSH4-5, MLH1-3, EXO1, and SGS1 (; ; ; ) and pathway II, which involves MUS81 and MMS4 (; ); the correct assortment of chromosomes depends on the occurrence of cross-overs (); both pathways work at the same time, but pathway I is responsible for most cross-overs in Saccharomyces and Arabidopsis; however, some organisms relay completely on pathway II for cross-over resolution (Schizosaccharomyces pombe and Tetrahymena thermophila) (; ; ); (g) the mismatches formed are corrected by the nuclear mismatch repair system composed basically by MSH2-6 and MLH1-PMS1 (in yeast) (); (h) canonical meiosis results in four haploid cells; (i) Gametes of a single mating type express the transmembrane HAP2, that facilitates cell membrane fusion (; ); (j) GEX1 is a nuclear membrane protein involved in karyogamy ()