Scientists have synthesised a molecular system that, like DNA, can store and transmit information, and may help in the search for alien life. The team, including researchers from the University of Texas and Indiana University in the US, dubbed their creation “hachimoji” DNA. Hachimoji DNA meets all the structural requirements that allow our DNA to store, transmit and evolve information in living systems.
The finding, published in the journal Science, suggests there could be an alternative to DNA-based life that may be possible on other worlds. This new molecular system, which is not a new life form, suggests scientists looking for life beyond Earth may need to rethink what they are looking for. One way to imagine the kinds of foreign structures found on other worlds is to try to create something foreign on Earth.
The new molecule has eight informational ingredients instead of four. The synthetic DNA includes the four nucleotides present in Earth life — adenine, cytosine, guanine, and thymine — but also four others that mimic the structures of the informational ingredients in regular DNA. The result is a double-helix structure that can store and transfer information.