Thomas C M, Hull R, Bryant J A, Maule A J
Nucleic Acids Res. 1985 Jun 25;13(12):4557-76. doi: 10.1093/nar/13.12.4557.
Sub-cellular fractions, isolated from cauliflower mosaic virus (CaMV)-infected turnip protoplasts, are capable of synthesising CaMV DNA in vitro on an endogenous template and of reverse transcribing oligo dT-primed cowpea mosaic virus RNA. The activity was not detected in mock-inoculated protoplasts. In vitro-labelled DNA hybridized to single-stranded M13 clones complementary to the putative origins of (-) and (+) strand CaMV DNA synthesis and to restriction endonuclease fragments encompassing more than 90% of the CaMV genome. The synthesis of (-) and (+) strand DNA appeared asymmetric. The template(s) for in vitro CaMV DNA synthesis are in a partially nuclease-resistant form. Fractions capable of in vitro CaMV DNA synthesis contained CaMV RNA both heterogeneous and as discrete species; they also contained a range of different sizes of CaMV DNA. Several lines of evidence indicate that this range of in vitro-labelled CaMV DNA, extending from 0.6kb to 8.0kb in length, represents elongating (-) strand DNA. These are discussed in relation to their role as possible replicative intermediates.
从感染花椰菜花叶病毒（CaMV）的芜菁原生质体中分离得到的亚细胞组分，能够以自身模板在体外合成CaMV DNA，并能反转录以寡聚dT为引物的豇豆花叶病毒RNA。在模拟接种的原生质体中未检测到该活性。体外标记的DNA与与CaMV DNA（-）链和（+）链假定起始位点互补的单链M13克隆以及覆盖超过90% CaMV基因组的限制性内切酶片段杂交。（-）链和（+）链DNA的合成似乎不对称。体外CaMV DNA合成的模板呈部分耐核酸酶的形式。能够进行体外CaMV DNA合成的组分含有异质的CaMV RNA以及离散的CaMV RNA；它们还含有一系列不同大小的CaMV DNA。几条证据表明，这种长度从0.6kb到8.0kb的体外标记CaMV DNA代表正在延伸的（-）链DNA。文中讨论了它们作为可能的复制中间体的作用。
