RESEARCH FIELD

Xenobiology

Xenobiology engineers living systems — or life-like molecular systems — that use chemistries orthogonal to the canonical DNA/RNA/protein alphabet, asking whether life could be instantiated in molecules with different backbones, base pairs, or amino-acid repertoires. Researchers have already demonstrated that synthetic genetic polymers (XNAs) like HNA and LNA can store information, evolve in directed-evolution campaigns, and encode functional aptamers, establishing that heredity and evolvability are not exclusive to natural nucleic acids. The expanded-alphabet work of the Romesberg and Benner groups pushed the genetic code beyond four bases to six, encoding new amino acids and enabling the synthesis of proteins with unprecedented side-chain chemistry. Biosafety motivates much of the field: orthogonal genetic systems that cannot exchange information with wild-type organisms represent a principled route to biocontainment of synthetic biology applications. Practitioners are a tight-knit community of chemical biologists and synthetic biologists working at the frontier where chemistry and the theory of life intersect.