Amplification of 4'-ThioDNA in the Presence of 4-Thio-dTTP and 4'-Thio-dCTP, and 4'-ThioDNA-Directed Transcription in Vitro and in Mammalian Cells

摘要

A number of modified oligonucleotides (ONs), prepared by a general chemical approach using the corresponding phosphoramidite units, have been synthesized in order to evaluate their functions. An alternative enzymatic method using the corresponding nucleo-side triphosphates could also be used. Since this approach affords long chain sequences from readily available natural DNA templates, if successful, it would be useful in a large number of biotechnologies.' Therefore, intense efforts are currently underway toward an efficient enzymatic synthesis of modified ONs.2 However, this approach may have limited use because of the low-substrate specificity of the modified nucleoside triphosphates to DNA/RNA polymerases.