title: Programmed DNA deletion as an RNA-guided system of genome defense.
abstract: Genomewide DNA rearrangements occur in many eukaryotes during development, but their functions and mechanisms are poorly understood. Previous studies have implicated a sequence-recognition mechanism based on RNA-mediated interactions between nuclei in ciliated protozoa. In this study, we found that the process recognized and deleted a foreign gene integrated in a Tetrahymena chromosome, suggesting an unusual mechanism of genome surveillance. We further found that injection of double-stranded RNA into the cell at specific developmental stages triggers efficient deletion of the targeted genomic regions. Together the results indicate an RNA-based mechanism that directs genomewide DNA rearrangements and serves to disable invading genetic agents.
authors.affiliation: Division of Basic Sciences, Fred Hutchinson Cancer ResearchCenter, 1100 Fairview Avenue North, Post Office Box 19024, Seattle, WA 98109, USA. mcyao@fhcrc.org
authors.forename: Meng-Chao
authors.initials: MC
authors.lastname: Yao
authors.forename: Patrick
authors.initials: P
authors.lastname: Fuller
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Xi
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D016054:DNA, Protozoan / Q000235:genetics / Q000378:metabolism*; D017125:Genes, Protozoan; D018503:Genome, Protozoan; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D012330:RNA, Double-Stranded / Q000235:genetics / Q000378:metabolism*; D016053:RNA, Protozoan / Q000235:genetics / Q000378:metabolism*; D012045:Regulatory Sequences, Nucleic Acid; D012091:Repetitive Sequences, Nucleic Acid; D017384:Sequence Deletion; D016808:Tetrahymena thermophila / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D014158:Transcription, Genetic; D019076:Transgenes
chemical_list: D016054:DNA, Protozoan; D015800:Protozoan Proteins; D012330:RNA, Double-Stranded; D016053:RNA, Protozoan