α-L-Threofuranosyl-(3′2′)-oligonucleotides (‘TNA') are part of a systematic experimental inquiry into the base-pairing properties of potentially natural nucleic acid alternatives taken from RNA's close structural neighborhood. TNA is an efficient Watson-Crick base-pairing system and has the capability of informational cross-pairing with both RNA and DNA. This property, together with the system's constitutional
A TNA loop modified primer pair was designed to construct a stable terminal-closed linear gene, which can be used as an efficient gene expression system in eukaryotic cells.