A WD REPEAT PROTEIN, REC14, ESSENTIAL FOR MEIOTIC RECOMBINATION IN SCHIZOSACCHAROMYCES-POMBE

Mutations in the Schizosaccharomyces pombe rec14 gene reduce meiotic r ecombination by as much as a factor of 1000 in the three intervals tes ted on chromosomes I and III. A DNA clone complementing the rec14 muta tion was shown by genetic and physical analysis to contain the rec14 g ene, which was functional in plasmid-borne inserts as small as 1.4 kb. The rec14 gene contains two exons separated by a 53-bp intron, which was confirmed by analysis of rec14 transcripts. The spliced transcript encodes a protein product of 302 amino acids, which contains six SVD repeat motifs found in the G-beta transducin family of proteins and ot her proteins, including the Saccharomyces cerevisiae Ski8 (Rec103) pro tein. Although the rec14 transcripts were present in mitotically divid ing cells, rec14 mutations had no detectable effect on mitotic recombi nation. The pattern of expression of rec14 differs from that of previo usly analyzed S. pombe rec genes. Based upon mutant phenotypes and ami no acid sequence similarities, we propose that S. pombe Rec14 is a fun ctional homologue of S. cerevisiae Rec103.