Unequal division in Saccharomyces cerevisiae and its implications for the control of cell division.
Unequal division in Saccharomyces cerevisiae and its implications for the control of cell division.
复制标题
DOI：
10.1083/jcb.75.2.422
复制
发表时间：
1977-11
期刊：
影响因子：
--
通讯作者：
Unger MW
中科院分区：
文献类型：
--
作者：
Hartwell LH;Unger MW
芽殖酵母，酿酒酵母，在生长速率限制浓度的蛋白质合成抑制剂，放线菌酮的存在下，以不同的速度呈指数增长。测定了亲本细胞和芽的体积，以及用于未出芽和出芽期的细胞周期的间隔。我们发现S.酿酒酵母细胞分裂不均匀。子细胞（由前一个周期的芽分裂产生的细胞）比产生它的母细胞更小，随后的细胞周期更长。在出芽期，大部分体积增加发生在芽中，而母细胞的体积增加很少，而在未出芽期，子细胞和母细胞的体积都显著增加。细胞周期的出芽间隔的长度作为群体倍增时间的函数变化不大;亲本细胞的未出芽间隔变化适中;子细胞的未出芽间隔变化很大（在后一种情况下，群体倍增时间增加100分钟导致子细胞的未出芽间隔增加124分钟）。所有未出芽期的增加都发生在G1期的间隔中，该间隔在S细胞周期阻滞点之前。酿酒酵母α-交配因子这些结果在定性上与增长和分工协调模型（约翰斯顿，G. C.的方法，J. R. Pringle和L. H.哈特韦尔1977. Exp. Cell. Res. 105：79-98。）该模型指出，生长而不是DNA分裂周期的事件是细胞增殖的速率限制，并且达到临界细胞大小是DNA分裂周期中“开始”事件的必要先决条件，该事件需要cdc 28基因产物，被交配因子抑制并导致纺锤体极体的复制。
The budding yeast, Saccharomyces cerevisiae, was grown exponentially at different rates in the presence of growth rate-limiting concentrations of a protein synthesis inhibitor, cycloheximide. The volumes of the parent cell and the bud were determined as were the intervals of the cell cycle devoted to the unbudded and budded periods. We found that S. cerevisiae cells divide unequally. The daughter cell (the cell produced at division by the bud of the previous cycle) is smaller and has a longer subsequent cell cycle than the parent cell which produced it. During the budded period most of the volume increase occurs in the bud and very little in the parent cell, while during the unbudded period both the daughter and the parent cell increase significantly in volume. The length of the budded interval of the cell cycle varies little as a function of population doubling time; the unbudded interval of the parent cell varies moderately; and the unbudded interval for the daughter cell varies greatly (in the latter case an increase of 100 min in population doubling time results in an increase of 124 min in the daughter cell's unbudded interval). All of the increase in the unbudded period occurs in that interval of G1 that precedes the point of cell cycle arrest by the S. cerevisiae alpha-mating factor. These results are qualitatively consistent with and support the model for the coordination of growth and division (Johnston, G. C., J. R. Pringle, and L. H. Hartwell. 1977. Exp. Cell. Res. 105:79-98.) This model states that growth and not the events of the DNA division cycle are rate limiting for cellular proliferation and that the attainment of a critical cell size is a necessary prerequisite for the "start" event in the DNA-division cycle, the event that requires the cdc 28 gene product, is inhibited by mating factor and results in duplication of the spindle pole body.