We reportDNA- andRNA-like systems built from eight nucleotide "letters" (hence the name "hachimoji") that form four orthogonal pairs. These synthetic systems meet the structural requirements needed to support Darwinian evolution, including a polyelectrolyte backbone, predictable thermodynamic stability, and stereoregular building blocks that fit a Schrödinger aperiodic crystal. Measured thermodynamic parameters predict the stability ofhachimojiduplexes, allowinghachimojiDNAto increase the information density of natural terranDNA. Three crystal structures show that the synthetic building blocks do not perturb the aperiodic crystal seen in theDNAdouble helix.HachimojiDNAwas then transcribed to givehachimojiRNAin the form of a functioning fluorescenthachimojiaptamer. These results expand the scope of molecular structures that might support life, including life throughout the cosmos.

doi: 10.1126/science.aat0971

Science 新文章，科学家人工合成8碱基DNA，可像4碱基一样正常支持生命体活动！