Andreeva L F, Andreeva T F, Merkulova N A, Borkhsenius S N
Tsitologiia. 1979 Mar;21(3):318-26.
The size of replication units (or replicons) measured in Tetrahymena pyriformis GL macronuclear DNA reaches 20--30 microns, according to the two independent methods: DNA fiber autoradiography, and alkaline isokinetic sucrose gradient centrifugation. The synthesis of new DNA fragments--replicons and their subsequent assembly are separated by time intervals (30 min). The rate of DNA synthesis for one fork averaged 0.6--0.7 microns/min. These data were obtained for cells of cultures being both in the expotential phase of growth, and those synchronized by starvation-refeeding. The generation time of T. pyriformis cells, calculated by the increase of the part of labeled nuclei, is almost 2 hours; the synthesis lasts 1 hour. Total amount of replication units in polyploid (polygenomic) Tetrahymena macronucleus is about 3000. Their initiation during S-period is presumably asynchronous.
DNA纤维放射自显影术和碱性等速蔗糖梯度离心法，梨形四膜虫GL大核DNA中复制单位（或复制子）的大小达到20-30微米。新DNA片段（复制子）的合成及其后续组装被时间间隔（30分钟）隔开。一个复制叉的DNA合成速率平均为0.6-0.7微米/分钟。这些数据是针对处于生长指数期的培养细胞以及通过饥饿-再投喂同步化的细胞获得的。通过标记细胞核部分的增加计算得出，梨形四膜虫细胞的世代时间约为2小时；合成持续1小时。多倍体（多基因组）梨形四膜虫大核中复制单位的总数约为3000个。它们在S期的起始大概是异步的。
