Cohesin and Recombination Proteins Influence the G1-to-S Transition in Azygotic Meiosis inSchizosaccharomyces pombe

Abstract

To determine whether recombination and/or sister-chromatid cohesion affect the timing of meiotic prophase events, the horsetail stage and S phase were analyzed in Schizosaccharomyces pombe strains carrying mutations in the cohesin genes rec8 or rec11, the linear element gene rec10, the pairing gene meu13, the double-strand-break formation genes rec6, rec7, rec12, rec14, rec15, and mde2, and the recombination gene dmc1. The double-mutant strains rec8 rec11 and rec8 rec12 were also assayed. Most of the single and both double mutants showed advancement of bulk DNA synthesis, start of nuclear movement (horsetail stage), and meiotic divisions by up to 2 hr. Only mde2 and dmc1 deletion strains showed wild-type timing. Contrasting behavior was observed for rec8 deletions (delayed by 1 hr) compared to a rec8 point mutation (advanced by 1 hr). An hypothesis for the role of cohesin and recombination proteins in the control of the G 1 -to-S transition is proposed. Finally, differences between azygotic meiosis and two other types of fission yeast meiosis (zygotic and pat1-114 meiosis) are discussed with respect to possible control steps in meiotic G 1 .

The C-terminus of S. pombe DDK subunit Dfp1 is required for meiosis-specific transcription and cohesin cleavage

“…We showed previously that Dfp1 chromatin association in response to MMS treatment is disrupted by loss of this domain (Dolan et al, 2010). Since meiotic cohesion and prDSB formation are both linked to progression of S phase (Doll et al, 2008; Kugou et al, 2009; Ogino and Masai, 2006), it is plausible that both Rec8 and Rec12 meet the replication fork, and possibly, a fork-linked DDK.…”

Characterization of Schizosaccharomyces pombe Copper Transporter Proteins in Meiotic and Sporulating Cells

“…pombe is a genetically amenable organism that is commonly used for identifying and characterizing cellular components that regulate molecular aspects of meiosis (21). This yeast is of special interest as growth conditions and temperaturesensitive mutants have been developed that allow synchronization of cells for their entry into the meiotic program (22,23). Under conditions of nitrogen starvation, haploid cells arrest in the G 1 phase of the cell cycle.…”

Mfc1 Is a Novel Forespore Membrane Copper Transporter in Meiotic and Sporulating Cells

“…S. pombe is a key model because growth conditions and temperature-sensitive mutants have been developed that allow the synchronization of cells for their entry into the meiotic program (10). The three frequently analyzed types of meiosis in S. pombe are called zygotic, azygotic, and pat1-induced meiosis (11). In response to nitrogen source starvation, haploid cells of opposite mating type fuse, and the resulting zygote usually undergoes meiosis immediately by a process called zygotic meiosis.…”