REGULATION OF INITIATION OF DNA SYNTHESIS IN CHINESE HAMSTER CELLS
REGULATION OF INITIATION OF DNA SYNTHESIS IN CHINESE HAMSTER CELLS
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中国仓鼠细胞DNA合成起始的调控
DOI：
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发表时间：
1970
影响因子：
7.8
通讯作者：
Robert A. Tobey
中科院分区：
文献类型：
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作者：
K. D. Ley;Robert A. Tobey
悬浮培养的中国仓鼠细胞(CHO系)在F-10培养液中生长到高浓度后停止分裂并停滞在G1期，加入适量的异亮氨酸和谷氨酰胺可诱导其重新启动DNA合成并同步分裂。这两种氨基酸都是启动细胞周期遍历恢复所必需的。F-10培养液中包含的其他氨基酸的缺乏并没有导致G1期细胞的积累，这表明了限制异亮氨酸和谷氨酰胺的数量所产生的特定作用。在充足的谷氨酰胺存在下，所有细胞启动DNA合成大约需要2×10~(-6)M异亮氨酸。在类似的条件下，所有G1期停滞的细胞都需要大约4×10~(-6)M异亮氨酸才能通过细胞分裂。相反，1×10-4M谷氨酰胺是最大限度地启动G1细胞DNA合成所必需的，同时还有足够的异亮氨酸。本文描述了一种快速生产G1期滞留细胞的技术，在该技术中，来自指数增长群体的细胞放置在同时缺乏异亮氨酸和谷氨酰胺或仅缺乏异亮氨酸的F-10培养液中，30小时后在G1期积累。
Suspension cultures of Chinese hamster cells (line CHO), which had stopped dividing and were arrested in G1 following growth to high cell concentrations in F-10 medium, could be induced to reinitiate DNA synthesis and to divide in synchrony upon addition of the appropriate amounts of isoleucine and glutamine. Both amino acids were required to initiate resumption of cell-cycle traverse. Deficiencies in other amino acids contained in F-10 medium did not result in accumulation of cells in G1, indicating a specific action produced by limiting quantities of isoleucine and glutamine. In the presence of sufficient glutamine, approximately 2 x 10-6 M isoleucine was required for all cells to initiate DNA synthesis in a population initially containing 1.5 x 105 cells/ml. Under similar conditions, about 4 x 10-6 M isoleucine was required for all G1-arrested cells to progress through cell division. In contrast, 1 x 10-4 M glutamine was necessary for maximum initiation of DNA synthesis in G1 cells, along with sufficient isoleucine. A technique for rapid production of G1-arrested cells is described in which cells from an exponentially growing population placed in F-10 medium deficient in both isoleucine and glutamine or isoleucine alone accumulated in G1 after 30 hr.