title: Involvement of FTZ-F1 in the regulation of pupation in Leptinotarsa decemlineata (Say).
abstract: During the final instar larvae of holometabolous insects, a pulse of 20-hydroxyecdysone (20E) and a drop in juvenile hormone (JH) trigger larval-pupal metamorphosis. In this study, two LdFTZ-F1 cDNAs (LdFTZ-F1-1 and LdFTZ-F1-2) were cloned in Leptinotarsa decemlineata. Both LdFTZ-F1-1 and LdFTZ-F1-2 were highly expressed just before or right after each molt, similar to the expression pattern of an ecdysteroidogenesis gene LdSHD. Ingestion of an ecdysteroid agonist halofenozide (Hal) enhanced LdFTZ-F1-1 and LdFTZ-F1-2 expression in the final larval instar. Conversely, a decrease in 20E by feeding a double-stranded RNA (dsRNA) against LdSHD repressed the expression. Moreover, Hal rescued the expression levels in LdSHD-silenced larvae. Thus, 20E peaks seem to induce the transcription of LdFTZ-F1s. Furthermore, ingesting dsLdFTZ-F1 from a common fragment of LdFTZ-F1-1 and LdFTZ-F1-2 successfully knocked down both LdFTZ-F1s, and impaired pupation. Finally, knocking down LdFTZ-F1s significantly repressed the transcription of three ecdysteroidogenesis genes, lowered 20E titer, and reduced the expression of two 20E receptor genes. Silencing LdFTZ-F1s also induced the expression of a JH biosynthesis gene, increased JH titer, but decreased the mRNA level of a JH early-inducible gene. Thus, LdFTZ-F1s are involved in the regulation of pupation by modulating 20E and JH titers and mediating their signaling pathways.
authors.affiliation: Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: 853422201@qq.com.
authors.forename: Xin-Ping
authors.initials: XP
authors.lastname: Liu
authors.affiliation: Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: 176061610@qq.com.
authors.forename: Kai-Yun
authors.initials: KY
authors.lastname: Fu
authors.affiliation: Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: 287148308@qq.com.
authors.forename: Feng-Gong
authors.initials: FG
authors.lastname: Lü
authors.affiliation: Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: mqw102082@163.com.
authors.forename: Qing-Wei
authors.initials: QW
authors.lastname: Meng
authors.affiliation: Department of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China. Electronic address: gwc1966@163.com.
authors.forename: Wen-Chao
authors.initials: WC
authors.lastname: Guo
authors.affiliation: Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: ligq@njau.edu.cn.
authors.forename: Guo-Qing
authors.initials: GQ
authors.lastname: Li
mesh_terms: D000818:Animals; D001517:Coleoptera / Q000502:physiology*; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D004441:Ecdysterone / Q000378:metabolism*; D019476:Insect Proteins / Q000502:physiology*; D008675:Metamorphosis, Biological; D034622:RNA Interference; D014157:Transcription Factors / Q000502:physiology*
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D019476:Insect Proteins; D014157:Transcription Factors; C499712:nuclear hormone receptor FTZ-F1, Drosophila; D004441:Ecdysterone
keywords: 20-Hydroxyecdysone; FTZ-F1; Juvenile hormone; Leptinotarsa decemlineata; Pupation