Identification of differential regulator of mitosis and meiosis

研究了cdc2、cdc13和cdc25基因在粟酒裂殖酵母减数分裂中的作用。使用温度敏感突变体和三种不同条件诱导减数分裂，发现与以前的报道相反，所有这些基因都是减数分裂I和减数分裂II所需的。cdc25和cdc13基因的表达与减数分裂前的DNA合成同步，在第一次核分裂前达到高峰。cdc22的表达也被诱导，但在减数分裂前DNA合成前达到峰值。如果DNA合成受到抑制，则cdc25和cdc13的诱导受到阻碍，但cdc22的诱导没有受到抑制。减数分裂所必需的mei4基因是诱导cdc13和cdc25所必需的。依赖于DNA的合成，对p34激酶的激活起重要作用的基因的诱导<cdc2>在有丝分裂中尚未观察到，似乎是减数分裂所特有的。这可能是减数分裂检查点控制的一种机制。

Involvement of the cdc2, cdc13 and cdc25 genes in meiosis in Schizosaccharomyces pombe was investigated. Using temperature- sensitive mutants and three different conditions to induce meiosis, it was found that, in contrast to the previous reports, all of these genes are required for both meiosis I and meiosis II. The cdc2 gene, which is known to be essential for the initiation of both M-phase and S-phase in mitosis, is also required for premeiotic DNA synthesis.Expression of the cdc25 and cdc13 genes was induced in concomitant with premeiotic DNA synthesis, reaching a sharp peak before the first nuclear division. Expression of cdc22 was also induced but with a peak before premeiotic DNA synthesis. The induction of cdc25 and cdc13 was hampered if DNA synthesis was inhibited, but that of cdc22 was not. The mei4 gene that is essential for meiosis is required for the induction of cdc13 and cdc25. Dependency on DNA synthesis of the induction of genes that are important for activation of p34^<cdc2> kinase has not been observed in mitosis and appears to be unique to meiosis. This may constitute a mechanism of checkpoint control in meiosis.