title: Use of Sindbis virus-mediated RNA interference to demonstrate a conserved role of Broad-Complex in insect metamorphosis.
abstract: The transcription factor Broad-Complex (BR-C) is required for differentiation of adult structures as well as for the programmed death of obsolete larval organs during metamorphosis of the fruit fly Drosophila melanogaster. Whether BR-C has a similar role in other holometabolous insects could not be proven without a loss-of-function genetic test, performed in a non-drosophilid species. Here we use a recombinant Sindbis virus as a tool to silence BR-C expression in the silkmoth Bombyx mori. The virus expressing a BR-C antisense RNA fragment reduced endogenous BR-C mRNA levels in infected tissues (adult wing and leg primordia) via RNA interference (RNAi). The RNAi knock-down of BR-C resulted in the failure of animals to complete the larval-pupal transition or in later morphogenetic defects, including differentiation of adult compound eyes, legs, and wings from their larval progenitors. BR-C RNAi also perturbed the programmed cell death of larval silk glands. These developmental defects correspond to loss-of-function phenotypes of BR-C Drosophila mutants in both the morphogenetic and degenerative aspects, suggesting that the critical role of BR-C in metamorphosis is evolutionarily conserved. We also demonstrate that the Sindbis virus is a useful vehicle for silencing of developmental genes in new insect models.
authors.affiliation: Department of Molecular Biology, University of South Bohemia and Institute of Entomology, the Czech Academy of Sciences, Ceske Budejovice, 37005 Czech Republic.
authors.forename: Mirka
authors.initials: M
authors.lastname: Uhlirova
authors.forename: Brian D
authors.initials: BD
authors.lastname: Foy
authors.forename: Barry J
authors.initials: BJ
authors.lastname: Beaty
authors.forename: Ken E
authors.initials: KE
authors.lastname: Olson
authors.forename: Lynn M
authors.initials: LM
authors.lastname: Riddiford
authors.forename: Marek
authors.initials: M
authors.lastname: Jindra
mesh_terms: D000818:Animals; D001483:Base Sequence; D012831:Bombyx / Q000254:growth & development*; D002522:Chlorocebus aethiops; D006224:Cricetinae; D009033:Culicidae; D017931:DNA Primers; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000254:growth & development*; D005123:Eye / Q000254:growth & development; D007814:Larva; D008675:Metamorphosis, Biological; D008969:Molecular Sequence Data; D011679:Pupa; D034741:RNA, Small Interfering / Q000494:pharmacology / Q000502:physiology*; D012367:RNA, Viral / Q000502:physiology; D012845:Sindbis Virus / Q000235:genetics*; D014157:Transcription Factors / Q000378:metabolism*; D014709:Vero Cells
chemical_list: C102117:Br protein, Drosophila; D017931:DNA Primers; D029721:Drosophila Proteins; D034741:RNA, Small Interfering; D012367:RNA, Viral; D014157:Transcription Factors