Royzman I, Orr-Weaver T L
Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
Genes Cells. 1998 Dec;3(12):767-76. doi: 10.1046/j.1365-2443.1998.00232.x.
A modified cell cycle, the endo cycle, produces the polyploid or polytene cells that are present in some tissues of most organisms. In the endo cycle, the S phase alternates with a gap phase, but mitosis does not occur. Genes needed to inhibit mitosis during the endo cycle and to promote the onset of S phase have been identified in Drosophila. Genomic intervals are differentially replicated during the endo cycle S phase such that some regions are under-replicated, while others can be amplified. Cyclin E and E2F are needed for this differential DNA replication during Drosophila oogenesis.
一种经过修饰的细胞周期，即内复制周期，产生了大多数生物体某些组织中存在的多倍体细胞或多线体细胞。在内复制周期中，S期与一个间隙期交替出现，但不发生有丝分裂。在果蝇中已经鉴定出在内复制周期中抑制有丝分裂并促进S期开始所需的基因。基因组区间在内复制周期S期进行差异复制，使得一些区域复制不足，而另一些区域则可以扩增。在果蝇卵子发生过程中，细胞周期蛋白E和E2F是这种差异DNA复制所必需的。
