Scientists alter the genetic code of a living being for the first time

The pathogenic fungus Candida albicans is one of several microorganisms with the unusual ability to produce various amino acids (the building blocks of proteins) from the same three-letter DNA code (called a codon). This ability breaks one of the rules of the genetic code, according to which each DNA codon codes for only one amino acid. In the latest issue of the journal Proceedings of the National Academies of Science –USA (PNAS), Manuel dos Santos and his team at the University of Aveiro recreated in the laboratory what the Candida albicans fungus achieves in nature: altering its genetic code so that the CUG codon produces the amino acid leucine instead of serine. This was the first time that the genetic code of a living being had been altered in the laboratory. Surprisingly, the genetically altered fungi show a remarkable ability to adapt to different environments, resist antifungal drugs, and induce immune and inflammatory responses in infected mice. This research, funded by FCT and a European 7th Framework Program project, helps to understand how manipulating the genetic code of fungi and other microorganisms can be used to combat drug resistance and applied in biotechnology and medicine.