Mus81 nuclease and Sgs1 helicase are essential for meiotic recombination in a protist lacking a synaptonemal complex

摘要: Mus81 resolvase and Sgs1 helicase have well-established roles in mitotic DNA repair. Moreover, is part of a minor crossover (CO) pathway the meiosis budding yeast, plants vertebrates. The major depends on meiosis-specific synaptonemal complex (SC) formation, ZMM proteins MutLγ for CO-directed resolution joint molecule (JM)-recombination intermediates. has also been implicated this pathway, although it may mainly promote non-CO outcome meiotic We show Tetrahymena, that homologous chromosomes fail to separate JMs accumulate absence or Sgs1, whereas deletion MutLγ-component Mlh1 does not affect divisions. Thus, our results are consistent with being an essential, if predominant, CO Tetrahymena. exert functions similar those other eukaryotes. However, we propose additional role supporting formation by promoting over intersister interactions. Tetrahymena shares predominance fission yeast. these two organisms, which independently lost SC during evolution, basal set repair sufficient executing recombination.