Research creates DNA-like molecule to aid search for alien life

In a research breakthrough funded by NASA, scientists have synthesized a molecular system that, like DNA, can store and transmit information. This unprecedented feat suggests there could be an alternative to DNA-based life, as we know it on Earth – a genetic system for 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. The research appears in Thursday's edition of Science Magazine.

DNA is a complex molecule that stores and transmits genetic information, is passed from parent to offspring in all living organisms on Earth, and its components include four key ingredients called nucleotides – all standard for life as we know it. But, what about life on other worlds?

"Life detection is an increasingly important goal of NASA's planetary science missions, and this new work will help us to develop effective instruments and experiments that will expand the scope of what we look for," said Lori Glaze, acting director of NASA's Planetary Science Division.

One way to imagine the kinds of foreign structures found on other worlds is to try to create something foreign on Earth. A team of researchers, led by Steven Benner at the Foundation for Applied Molecular Evolution in Alachua, Florida, successfully achieved the fabrication of a new informational molecular system that is like DNA, except in one key area: 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.