GENETIC CONTROL OF CELL DIVISION CYCLE IN YEAST .4. GENES CONTROLLING BUD EMERGENCE AND CYTOKINESIS
GENETIC CONTROL OF CELL DIVISION CYCLE IN YEAST .4. GENES CONTROLLING BUD EMERGENCE AND CYTOKINESIS
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DOI：
10.1016/0014-4827(71)90223-0
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发表时间：
1971-01-01
影响因子：
3.7
通讯作者：
HARTWELL, LH
中科院分区：
文献类型：
--
作者：
HARTWELL, LH
一个酵母基因（cdc1）的温度敏感突变导致芽出现缺陷。在从允许温度到限制温度的转变之后，缺陷细胞incdc 1的异步培养物作为未出芽细胞（或具有非常小的芽的细胞）均匀地收集。同步培养的研究表明，cdc1的不耐热产物在芽出现时（细胞周期的0.2个部分）完成其芽出现的功能（执行点）。当在限制温度下此功能未完成时。细胞完成DNA复制但不进行核分裂。4个基因（cdc3、10、11和12）的温度敏感性突变导致胞质分裂缺陷。在限制性温度下，这些突变株产生多个伸长的芽，这些芽不与亲本细胞分离。一种酵母胞质分裂的测定方法被开发出来，突变体被证明没有完成这一过程。突变体在限制性温度下进行多轮DNA复制和核分裂，从而成为多核体。这些基因产物的执行点在同步实验中被确定为大约在。0.08（CDC11）、0.27（CDC3）和0.58（CDC10）的细胞周期片段。胞质分裂发生在细胞周期的0.9个分数。我从这些观察中得出结论，芽的出现是不是一个必要的先决条件完成DNA复制，但显然是必要的核分裂。胞质分裂和细胞分离不是芽出现、DNA复制或核分裂的必要先决条件。
Temperature-sensitive mutations in one gene (cdc1) ofSaccharomyces cerevisiaeconfer a defect in bud emergence. Asynchronous cultures of cells defective incdc1 collect uniformly as unbudded cells (or cells with very tiny buds) following a shift from the permissive to the restrictive temperature. Studies with synchronous cultures demonstrate that the thermolabile product ofcdc1 completes its function (the execution point) for bud emergence at the time of bud emergence (0.2 fractions of a cell cycle). When this function is not completed at the restrictive temperature. cells complete DNA replication but do not undergo nuclear division.Temperature-sensitive mutations in four genes (cdc3, 10, 11, and 12) result in a defect in cytokinesis. At the restrictive temperature these mutant strains develop multiple elongated buds that do not separate from the parent cell. An assay for cytokinesis in yeast was developed and the mutants were shown not to have completed this process. The mutants undergo several rounds of DNA replication and nuclear division at the restrictive temperature and hence become multinucleate. The execution points for these gene products were determined in synchrony experiments to be at approx. 0.08 (cdc11), 0.27 (cdc3) and 0.58 (cdc10) fractions of a cell cycle. Cytokinesis takes place at 0.9 fractions of a cell cycle.I conclude from these observations that bud emergence is not a necessary prerequisite for the completion of DNA replication but is apparently necessary for nuclear division. Cytokinesis and cell separation are not necessary prerequisites for bud emergence, DNA replication, or nuclear division.