[DIYbio] Hachimoji -- Expanding the genetic alphabet from four to eight

A new form of synthetic DNA expands the information density of the genetic code, that likely preserves its capability for supporting life, according to a new study. By expanding the genetic alphabet from four letters to eight, researchers demonstrate the ability to double the information density in DNA. According to the report, the new DNA and RNA-like systems described expand the scope of genetic biopolymers, which may be useful for future synthetic biological applications. What's more, the expanded genetic code system could work with larger, more complex molecular structures. Central to biology is the ability to store, replicate and evolve genetic information. In current genetics, this is facilitated by DNA composed of combinations of 4 base pairs. While previous research has demonstrated the success of synthetic DNA by expanding the genetic code from four to six pairs - Shuichi Hoshika and colleagues test the limitations of molecular information storage by expanding it to eight. Hoshika et al. present hachimoji DNA, an eight (hachi-) letter (-moji) genetic system. They tested the alien GACTZPSB hachimoji DNA and discovered that it not only reproduced the molecular recognition behavior of standard 4-letter DNA, confirming its ability to perform as an informational system, it also met the Schrodinger requirements for a Darwinian system of molecular evolution - a hallmark for supporting life. Furthermore, using an engineered T7 RNA polymerase, the authors were able to demonstrate Hachimoji DNA's ability to be transcribed into RNA.