Department of Cell Biology, Roche Institute of Molecular Biology, Roche Research Center, 07110, Nutley, NJ, USA.
Plant Mol Biol. 1985 Jan;4(1):3-12. doi: 10.1007/BF02498710.
The relationship between nuclear and plastid DNA synthesis in cultured tobacco cells was measured by following(3)H-thymidine incorporation into total cellular DNA in the absence or presence of specific inhibitors. Plastid DNA synthesis was determined by hybridization of total radiolabeled cellular DNA to cloned chloroplast DNA.Cycloheximide, an inhibitor of nuclear encoded cytoplasmic protein synthesis, caused a rapid and severe inhibition of nuclear DNA synthesis and a delayed inhibition of plastid DNA synthesis. By contrast, chloramphenicol which only inhibits plastid and mitochondrial protein production, shows little inhibition of either nuclear or plastid DNA synthesis even after 24 h of exposure to the cells.The inhibition of nuclear DNA synthesis by aphidicolin, which specifically blocks the nuclear DNA polymeraseα, has no significant effect on plastid DNA formation. Conversely, the restraint of plastid DNA synthesis exerted by low levels of ethidium bromide has no effect on nuclear DNA synthesis.These results show that the synthesis of plastid and nuclear DNA are not coupled to one another. However, both genomes require the formation of cytoplasmic proteins for their replication, though our data suggest that different proteins regulate the biosynthesis of nuclear and plastid DNA.
我们通过检测（3）H-胸腺嘧啶核苷掺入培养烟草细胞的总细胞 DNA 来测量核和质体 DNA 合成之间的关系。质体 DNA 合成通过将总放射性标记的细胞 DNA 与克隆的叶绿体 DNA 杂交来确定。细胞色素抑制剂，一种抑制核编码细胞质蛋白合成的抑制剂，迅速且严重地抑制核 DNA 合成，并延迟抑制质体 DNA 合成。相比之下，仅抑制质体和线粒体蛋白产生的氯霉素，即使在暴露于细胞 24 小时后，对核或质体 DNA 合成的抑制作用也很小。放线菌酮特异性阻断核 DNA 聚合酶α，其对核 DNA 合成的抑制作用对质体 DNA 的形成没有显著影响。相反，低浓度溴化乙锭对质体 DNA 合成的抑制作用对核 DNA 合成没有影响。这些结果表明，质体和核 DNA 的合成彼此不相关。然而，两个基因组的复制都需要细胞质蛋白的形成，尽管我们的数据表明，不同的蛋白质调节核和质体 DNA 的生物合成。
