title: Cytotype Regulation Facilitates Repression of Hybrid Dysgenesis by Naturally Occurring KP Elements in Drosophila melanogaster.
abstract: P elements inserted in the Telomere Associated Sequences (TAS) at the left end of the X chromosome are determiners of cytotype regulation of the entire P family of transposons. This regulation is mediated by Piwi-interacting (pi) RNAs derived from the telomeric P elements (TPs). Because these piRNAs are transmitted maternally, cytotype regulation is manifested as a maternal effect of the TPs. When a TP is combined with a transgenic P element inserted at another locus, this maternal effect is strengthened. However, when certain TPs are combined with transgenes that contain the small P element known as KP, stronger regulation arises from a zygotic effect of the KP element. This zygotic effect is observed with transgenic KP elements that are structurally intact, as well as with KP elements that are fused to an ancillary promoter from the hsp70 gene. Zygotic regulation by a KP element occurs only when a TP was present in the maternal germ line, and it is more pronounced when the TP was also present in the grand-maternal germ line. However, this regulation does not require zygotic expression of the TP These observations can be explained if maternally transmitted piRNAs from TPs enable a polypeptide encoded by KP elements to repress P element transposition in zygotes that contain a KP element. In nature, repression by the KP polypeptide may therefore be facilitated by cytotype-mediating piRNAs.
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: Craig D
authors.initials: CD
authors.lastname: Grimes
authors.affiliation: Department of Genetics, Cell Biology, and Development, University of Minnesota, St. Paul, Minnesota 55108-1095.
authors.forename: Cody S
authors.initials: CS
authors.lastname: Czora
mesh_terms: D000818:Animals; D003433:Crosses, Genetic; D004251:DNA Transposable Elements; D004331:Drosophila melanogaster / Q000235:genetics* / Q000378:metabolism; D005260:Female; D005838:Genotype; D005854:Germ Cells / Q000378:metabolism; D006059:Gonadal Dysgenesis / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D040582:Inheritance Patterns; D011401:Promoter Regions, Genetic; D034741:RNA, Small Interfering / Q000235:genetics* / Q000378:metabolism; D016615:Telomere / Q000737:chemistry / Q000378:metabolism; D019076:Transgenes; D019895:Transposases / Q000235:genetics / Q000378:metabolism
chemical_list: D004251:DNA Transposable Elements; D018840:HSP70 Heat-Shock Proteins; D034741:RNA, Small Interfering; D019895:Transposases
keywords: P element; hybrid dysgenesis; piRNA; ping-pong cycle; telomere