CRISPR-Cas systems enable bacteria and other microbes to acquire immunity against viruses by capturing snippets of their DNA. Marraffini investigates the molecular mechanisms that make CRISPR immunity possible, as well as its evolutionary implications. His lab also explores genome editing and other potential applications for CRISPR-Cas systems.

Sequence-directed genetic interference pathways control gene expression and preserve genome integrity in all kingdoms of life. In many bacteria and most archaea, CRISPRs—clustered, regularly interspaced, short palindromic repeats—specify a recently discovered genetic interference pathway that protects cells from phages and conjugative plasmids. Within CRISPR sites, the repeats are separated by short spacer sequences that match phage or plasmid genomes and specify the targets of interference.

See website link opposite for further details on Prof Marraffini’s research.