Widrow R J, Hansen R S, Kawame H, Gartler S M, Laird C D
Molecular and Cellular Biology Program of the University of Washington and Fred Hutchinson Cancer Research Center, Seattle, WA 98104, USA.
Proc Natl Acad Sci U S A. 1998 Sep 15;95(19):11246-50. doi: 10.1073/pnas.95.19.11246.
G2 was defined originally as the temporal gap between the termination of DNA replication and the beginning of mitosis. In human cells, the G2 period was estimated to be 3-4 h. However, the absence of replicative DNA synthesis during this period designated G2 has never been shown conclusively. In this report, we show that, at some autosomal and X linked loci, programmed DNA replication continues within 90 min of mitosis. Furthermore, the major accumulation of cyclin B1, a cell-cycle marker that is usually ascribed to G2, overlaps extensively with very late DNA replication. We conclude that the G2 period is much shorter than previously thought and may, in some cells, be nonexistent.
G2最初被定义为DNA复制终止与有丝分裂开始之间的时间间隔。在人类细胞中,G2期估计为3 - 4小时。然而,在此期间(即所谓的G2期)不存在复制性DNA合成这一点从未得到确凿证明。在本报告中,我们表明,在一些常染色体和X连锁基因座上,程序化DNA复制在有丝分裂的90分钟内仍在继续。此外,细胞周期蛋白B1(一种通常被认为属于G2期的细胞周期标志物)的主要积累与非常晚期的DNA复制广泛重叠。我们得出结论,G2期比以前认为的要短得多,并且在某些细胞中可能不存在。