Kim C S, Preer J R, Polisky B
Department of Biology, Indiana University, Bloomington 47405.
Dev Genet. 1992;13(2):97-102. doi: 10.1002/dvg.1020130202.
We show that bacteriophage lambda DNA fragments microinjected into the macronucleus of the ciliated protozoan Paramecium can replicate as unit-length linear molecules. These linear DNA molecules are substrates for the addition of Paramecium telomeres by an endogenous telomerase. The linear DNA pieces can exist at copy numbers much higher than that of typical endogenous macronuclear chromosomes. We show that the copy number of injected DNA many fissions after microinjection reflects that of the original input copy number, suggesting that active control of copy number does not occur. Instead, the results suggest that injected DNA is replicated once per cell division.
我们发现，显微注射到纤毛原生动物草履虫大核中的噬菌体λ DNA片段能够作为单位长度的线性分子进行复制。这些线性DNA分子是内源性端粒酶添加草履虫端粒的底物。线性DNA片段的拷贝数可以比典型的内源性大核染色体的拷贝数高得多。我们发现，显微注射后许多次细胞分裂中注入DNA的拷贝数反映了原始输入拷贝数，这表明不存在对拷贝数的主动控制。相反，结果表明注入的DNA在每次细胞分裂时复制一次。
