Cell membrane 出 CAS Double stranded viral DNA CAS 用中 Creation of a novel spacer Inactivation of viral DNA CRISPR Array CASI川l >一■IID心I心心O Transcription Targeting of viral DNA I0☐WD◇I心☐心II心 P 爱 CAS II CAS III I CAS crRNA complex Processed crRNAs CAS II