The Schizosaccharomyces pombe rec16 Gene Product Regulates Multiple Meiotic Events

Abstract

Previously isolated meiotic recombination (rec) mutants of Schizosaccharomyces pombe define 16 complementation groups. The rec genes cloned and sequenced to date reveal little amino acid sequence identity to other reported proteins. We examined the rec mutants for alterations in meiotic events other than recombination to gain insight into the rec gene functions and to assess whether they affect recombination directly or indirectly. While mutations in the rec6–12, 14, 15 and 19 genes appeared to affect only meiotic recombination, a mutation in rec16 delayed meiotic DNA synthesis and, in some instances, reduced its amount; mitotic DNA synthesis was not detectably altered, indicating that the rec16 effect is limited to meiosis. In the rec16 mutant some meiotically induced transcripts (e.g., rec7 and 15) were significantly reduced in abundance, whereas others (e.g., rec10 and exo1) were induced and degraded with normal timing and extent during meiosis, indicating that the rec16 mutation leaves the basic meiotic program intact. These results indicate that the rec genes other than rec16 have their primary effect on meiotic recombination. In contrast, the rec16 gene product is essential for normal meiotic replication, recombination, and induction of some transcripts. These meiotic events may be coupled via a dependence of recombination and transcription on replication or via a cascade of gene expression.

Dynamic configurations of meiotic DNA-break hotspot determinant proteins

“…Furthermore, in these studies, cells were from azygotic cultures at higher temperatures (30°C or 34°C), and they were mostly chemically fixed or used for nuclear spreads. Spore formation, spore viability and meiotic recombination are sensitive to temperature (Li and Smith, 1997;Brown et al, 2020). Studies of LinE morphology under the conditions most physiologically relevantlive cells from zygotic (homothallic) cultures at the optimal temperature (∼25°C)are limited (Fowler et al, 2013).…”

DNA replication and damage checkpoints and meiotic cell cycle controls in the fission and budding yeasts

“…Rep1 is required specifically for premeiotic DNA replication, since rep1∆ cells arrest before premeiotic DNA replication but show no significant phenotype during mitotic cycles [136][137][138]. Rep1 is a zinc-finger protein with limited homology to Rep2 [134,136], and acts as an activator of the Res2-Cdc10 or Res1-Cdc10 complexes, since overexpression of rep1 + rescues growth defects of res1∆, res2∆, rep2∆ and weakly rescues cdc10 ts cells [136].…”

“…However, the meiotic defect of rep1∆ cells is not rescued by overexpression of either res1 + or res2 + , suggesting that the Res1\Res2-Cdc10 complex is not the sole target of Rep1 [133]. Further support for this notion comes from the observation that the induction of recombination genes requires the Rep1 protein [137,138].…”