title: Genetic interactions between P elements involved in piRNA-mediated repression of hybrid dysgenesis in Drosophila melanogaster.
abstract: Previous studies have shown that telomeric P elements inserted at the left end of the X chromosome are anchors of the P cytotype, the maternally inherited state that regulates P-element activity in the germ line of Drosophila melanogaster. This regulation is mediated by small RNAs that associate with the Piwi family of proteins (piRNAs). We extend the analysis of cytotype regulation by studying new combinations of telomeric and nontelomeric P elements (TPs and non-TPs). TPs interact with each other to enhance cytotype regulation. This synergism involves a strictly maternal effect, called presetting, which is apparently mediated by piRNAs transmitted through the egg. Presetting by a maternal TP can elicit regulation by an inactive paternally inherited TP, possibly by stimulating its production of primary piRNAs. When one TP has come from a stock heterozygous for a mutation in the aubergine, piwi, or Suppressor of variegation 205 genes, the synergism between two TPs is impaired. TPs also interact with non-TPs to enhance cytotype regulation, even though the non-TPs lack regulatory ability on their own. Non-TPs are not susceptible to presetting by a TP, nor is a TP susceptible to presetting by a non-TP. The synergism between TPs and non-TPs is stronger when the TP was inherited maternally. This synergism may be due to the accumulation of secondary piRNAs created by ping-pong cycling between primary piRNAs from the TPs and mRNAs from the non-TPs. Maternal transmission of P-element piRNAs plays an important role in the maintenance of strong cytotype regulation over generations.
authors.affiliation: Department of Genetics, Cell Biology, and Development, University of Minnesota, St. Paul, Minnesota 55108-1095 simmo004@umn.edu.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Simmons
authors.affiliation: Department of Genetics, Cell Biology, and Development, University of Minnesota, St. Paul, Minnesota 55108-1095.
authors.forename: Marshall W
authors.initials: MW
authors.lastname: Meeks
authors.affiliation: Department of Genetics, Cell Biology, and Development, University of Minnesota, St. Paul, Minnesota 55108-1095.
authors.forename: Erik
authors.initials: E
authors.lastname: Jessen
authors.affiliation: Department of Genetics, Cell Biology, and Development, University of Minnesota, St. Paul, Minnesota 55108-1095.
authors.forename: Jordan R
authors.initials: JR
authors.lastname: Becker
authors.affiliation: Department of Genetics, Cell Biology, and Development, University of Minnesota, St. Paul, Minnesota 55108-1095.
authors.forename: Jared T
authors.initials: JT
authors.lastname: Buschette
authors.affiliation: Department of Genetics, Cell Biology, and Development, University of Minnesota, St. Paul, Minnesota 55108-1095.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Thorp
mesh_terms: D000818:Animals; D000090266:Chromobox Protein Homolog 5; D003433:Crosses, Genetic; D004251:DNA Transposable Elements / Q000235:genetics; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics*; D005260:Female; D006059:Gonadal Dysgenesis / Q000235:genetics*; D008297:Male; D009154:Mutation; D034741:RNA, Small Interfering / Q000235:genetics*; D016615:Telomere / Q000235:genetics*; D014960:X Chromosome
chemical_list: D004251:DNA Transposable Elements; D029721:Drosophila Proteins; D034741:RNA, Small Interfering; C000716867:Su(var)205 protein, Drosophila; D000090266:Chromobox Protein Homolog 5
keywords: cytotype regulation; ping-pong cycle; telomere; transposon