PT  - JOURNAL ARTICLE
AU  - Zhiyan Xi
AU  - Lloyd Davis
AU  - Kieran Baxter
AU  - Ailish Tynan
AU  - Angeliki Goutou
AU  - Sebastian Greiss
TI  - Using a Quadruplet Codon to Expand the Genetic Code of an Animal
AID  - 10.1101/2021.07.17.452788
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.07.17.452788
4099  - http://biorxiv.org/content/early/2021/07/18/2021.07.17.452788.short
4100  - http://biorxiv.org/content/early/2021/07/18/2021.07.17.452788.full
AB  - Genetic code expansion in multicellular organisms is currently limited to the use of repurposed amber stop codons. Here we introduce a system for the use of quadruplet codons to direct incorporation of non-canonical amino acids in vivo in an animal, the nematode worm Caenorhabditis elegans. We develop hybrid pyrrolysyl tRNA variants to incorporate non-canonical amino acids in response to the quadruplet codon UAGA. We demonstrate the efficiency of the quadruplet decoding system by incorporating photocaged amino acids into two proteins widely used as genetic tools. We use photocaged lysine to express photocaged Cre recombinase for the optical control of gene expression and photocaged cysteine to express photo-activatable caspase for light inducible cell ablation. Our approach will facilitate the routine adoption of quadruplet decoding for genetic code expansion in eukaryotic cells and multicellular organisms.Competing Interest StatementThe authors have declared no competing interest.