Kozu T, Yagura T, Seno T
Exp Cell Res. 1983 Nov;149(1):189-200. doi: 10.1016/0014-4827(83)90391-9.
An analysis was made of the size maturation process of nascent DNA intermediates in macronuclear DNA replication of Tetrahymena pyriformis. The first discrete size class of nascent intermediates larger than Okazaki fragments were replicon-sized DNA (about 2 X 10(7) D single-stranded (ss) DNA) and accumulated in cells treated with cycloheximide. On removal of cycloheximide, the replicon-sized intermediates were converted to middle-sized intermediates (about 10 X 10(7) D ssDNA) and then merged into chromosomal-sized DNA. As indicated by either aphidicolin inhibition or the technique of the photolysis of bromodeoxyuridine (BrdU)-substituted DNA with long-wave ultraviolet light, four to eight replicon-sized intermediates were joined together to form a middle-sized intermediate after rapid sealing by DNA synthesis of the late-replicating regions located between adjacent replicon-sized intermediates. The late-replicating regions may represent the short gaps or terminal regions where DNA synthesis was retarded by cycloheximide, since the size of late-replicating regions was suggested to be shorter than the replicon size by DNA fiber autoradiography. Therefore, it is probable that four to eight completed replicons are joined as a group such as a replicon cluster, as has been reported in DNA replication of other eukaryotic cells.
对梨形四膜虫大核DNA复制过程中新生DNA中间体的大小成熟过程进行了分析。新生中间体中比冈崎片段大的第一个离散大小类别是复制子大小的DNA（约2×10⁷D单链（ss）DNA），并在经环己酰亚胺处理的细胞中积累。去除环己酰亚胺后，复制子大小的中间体转变为中等大小的中间体（约10×10⁷D ssDNA），然后合并为染色体大小的DNA。如通过阿非迪霉素抑制或用长波紫外光对溴脱氧尿苷（BrdU）取代的DNA进行光解技术所表明的，在相邻复制子大小的中间体之间的晚期复制区域通过DNA合成快速封闭后，四到八个复制子大小的中间体连接在一起形成一个中等大小的中间体。晚期复制区域可能代表了短间隙或末端区域，在这些区域DNA合成因环己酰亚胺而受阻，因为通过DNA纤维放射自显影术表明晚期复制区域的大小比复制子大小短。因此，很可能四到八个完整的复制子作为一组连接在一起，例如一个复制子簇，正如在其他真核细胞的DNA复制中所报道的那样。
