Global control of meiotic recombination genes by Schizosaccharomyces pombe rec16 (rep1).

Abstract

The Schizosaccharomyces pombe rec16-125 mutation reduces meiotic recombination, delays premeiotic DNA synthesis, and reduces the accumulation of some but not other rec gene transcripts. To elucidate the function of the Rec16 global meiotic regulator, we cloned and sequenced rec16. The data revealed that rec16 is identical to rep1, which was previously shown to encode a protein with a zinc-finger motif required for pre-meiotic DNA synthesis. Transcripts of rec16 (rep1) were strongly induced and subsequently degraded during meiosis. In a rec16 (rep1) deletion mutant, meiotic induction of the seven rec genes tested, which appear to be directly involved in meiotic recombination, was significantly reduced or essentially abolished. Deletion of 80% of the gene essentially abolished meiotic recombination, whereas strains deleted for approximately one-quarter of the gene, from either end, retained partial activity. The rec16-125 mutation strongly reduced recombination in the intervals tested on chromosomes I and III, a phenotype characteristic of mutations in rec genes, such as rec7, whose expression requires Rec16 (Rep1). These results show that Rec16 (Rep1) does not have the regional specificity of Rec10. We infer that Rec16 (Rep1) is a transcriptional activator that is required for meiotic replication and recombination because it plays a role in the transcriptional induction of the rec and other meiosis-specific genes.