title: Development of a heat shock inducible and inheritable RNAi system in silkworm.
abstract: A heat shock inducible and inheritable RNA interference (RNAi) system was developed in the silkworm (Bombyx mori). RNAi transgenic silkworms were generated by injecting silkworm eggs with a piggyBac transposon plasmid carrying RNAi sequence against target gene driven by the Drosophila heat shock protein 70 (HSP70) promoter and the helper plasmid expressing piggyBac transposase. The transgenic EGFP gene and the endogenous eclosion hormone (EH) gene were chosen respectively as the target genes. In the RNAi transgenic silkworms, heat shock at 42 degrees C significantly and specifically reduced the expression of EGFP or EH gene in silkworms according to the corresponding RNAi targeting sequence but not in silkworms with the irrelevant RNAi sequence demonstrating the efficiency and specificity of the RNAi effect. Heat shock in the pupal stage hampered pupal-adult eclosion and reduced egg fertility in EH RNAi transgenic silkworms but not in the wild type or EGFP RNAi transgenic silkworms. The establishment of this heat inducible and inheritable conditional RNA interference system in silkworms provided an approach for the first time to dissect the functions of target genes in silkworms at different stages.
authors.affiliation: Institute of Plant Physiology and Ecology, SIBS, CAS, Shanghai 200032, China.
authors.forename: Hongjiu
authors.initials: H
authors.lastname: Dai
authors.forename: Rongjing
authors.initials: R
authors.lastname: Jiang
authors.forename: Jue
authors.initials: J
authors.lastname: Wang
authors.forename: Guojiang
authors.initials: G
authors.lastname: Xu
authors.forename: Meixun
authors.initials: M
authors.lastname: Cao
authors.forename: Zhugang
authors.initials: Z
authors.lastname: Wang
authors.forename: Jian
authors.initials: J
authors.lastname: Fei
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified / Q000235:genetics / Q000502:physiology; D012831:Bombyx / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D018869:Heat-Shock Response / Q000502:physiology*; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference / Q000502:physiology*; D019895:Transposases / Q000235:genetics / Q000378:metabolism
chemical_list: D018840:HSP70 Heat-Shock Proteins; D019476:Insect Proteins; D019895:Transposases