10.1126Ndence.1136466 CRISPR Provides Acquired Resistance Against Viruses in Prokaryotes Rodolphe Barrangou,' Christophe Fremaux,2 Hake Deveau,3 Melissa Richards,' Patrick Boyava1,2 Sylvain Moineau,3 Dennis A. Romero,' Philippe Horvath's' Clustered regularly interspaced short palindromic repeats (CRISPR) are