An intron-containing meiosis-induced recombination gene, rec15, of Schizosaccharomyces pombe.

Mutations in the rec15 gene of Schizosaccharomyces pombe reduce meiotic recombinant frequencies, in the three intervals tested, as much as 1000-fold but have no detectable mitotic phenotype. The rec15 gene was mapped to within 1 cM of mat1. The gene was cloned by genetic complementation and its nucleotide sequence determined. Deletion analysis and gene replacement confirmed that the clones contained the rec15 gene on DNA fragments as short as 1.3 kb. The nucleotide sequence of the 1.3 kb fragment predicted that rec15 had a 49 bp intron separating two exons encoding a 180-amino-acid polypeptide product. This predicted intron was confirmed by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. During thermally induced meiosis in a pat1-114 (Ts) mutant, the rec15 transcripts were induced to maximal levels at 2-3h but were present at much lower levels before and after this time. The transient induction of the transcripts and the phenotype of a rec15 null (deletion) mutation suggest that the rec15 gene product is required during the early stages of meiosis for meiotic recombination.