The molecular controls over meiosis are poorly understood compared with those over mitosis. Here, we show that S. pombe men, which is essential for the initiation of premeiotic DNA synthesis, encodes an RNA-binding protein. A temperature-sensitive mei mutant performs premeiotic DNA synthesis but does not undergo meiotic divisions, suggesting that MeiP is required also for meiosis I. A novel, polyadenylated RNA species (meiRNA), which suppresses this temperature-sensitive defect if overexpressed, specifically binds to Mei both in vivo and in vitro. Cells without melRNA perform premeiotic DNAsynthesls but cannot undergo meiosis I. Mutations that apparently block the RNA binding ability of Mel2 inhibit premeiotic DNAsynthe&. Me12 is thus likely to couple with another RNA species to promote premeiotlc DNA synthesis.