Researchers in the UK may have just redefined the meaning of life. An international group based at the MRC Laboratory of Molecular Biology in Cambridge has developed synthetic genetic material they have named XNA.
All life contains genetic information in the form of DNA (deoxyribonucleic acid) or RNA (ribonucleic acid). DNA and RNA consist of a molecular backbone structure and a variety of ‘bases’ that code genetic data: adenine, cytosine, guanine, thymine and uracil. In the case of XNA, these naturally occurring genetic bases have been replaced by different, ‘alien’ bases (the ‘X’ in XNA stands for ‘xeno’, referring to the alien or foreign nature of the bases).
This synthetic genetic material opens some interesting doors in a variety of fields, including the study of evolution, the potential for genetically designed therapeutics, and exobiology, which is the search for life beyond Earth.
Scientists have successfully created six types of XNA molecules that mimic DNA and RNA structurally and, most interestingly, behaviourally. Genetic information stored in DNA can be accurately translated onto these XNA molecules through the use of a specially designed enzyme. Another enzyme is capable of translating information back from XNA to DNA. In a sense, XNA is like a different genetic language, and these enzymes can act as interpreters.
The benefits of this new genetic ‘language’ are numerous. XNA molecules are designed to be difficult to degrade, which gives them broader applications in genetic medications and therapeutics than natural DNA and RNA. XNA molecules will be less likely to be deconstructed by the body, prolonging their activity and usefulness. The more robust XNA also expands research parameters. Scientists working with XNA will be able to run experiments in a wider range of temperatures and acidities, widening the scope of genetic research.
Researchers have also discovered that XNA is capable of replication and random mutation, or in other words, evolution (just like DNA and RNA). This offers intriguing insights into heredity and evolution, suggesting that there is nothing innately ‘special’ about DNA and RNA, and that any molecule structured in a similar way can adapt to changing surroundings.
DNA and RNA have long been considered indicators or defining factors of ‘living organisms’. The creation of XNA will no doubt reignite discussion about what it truly means to be ‘alive’.