title: Subtraction by addition: domesticated transposases in programmed DNA elimination.
abstract: The ciliate Paramecium tetraurelia must eliminate approximately 60,000 short sequences from its genome to generate uninterrupted coding sequences in its somatic macronucleus. In this issue of Genes & Development, Baudry and colleagues (pp. 2478-2483) identify the protein that excises these noncoding sequences: a domesticated piggyBac transposase that has been adapted to remove what are likely the remnants of transposon insertions. This new study reveals how addition of a transposase to small RNA-directed silencing machinery can guide major genome reorganization.
authors.affiliation: Biology Department, Washington University in St. Louis, St. Louis, Missouri 63130, USA.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Motl
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Chalker
mesh_terms: D000818:Animals; D016054:DNA, Protozoan / Q000378:metabolism*; D016678:Genome / Q000235:genetics*; D048648:Macronucleus / Q000201:enzymology*; D016805:Paramecium tetraurelia / Q000201:enzymology* / Q000235:genetics*; D034622:RNA Interference / Q000502:physiology; D019895:Transposases / Q000378:metabolism*
chemical_list: D016054:DNA, Protozoan; D019895:Transposases