title: Identification of ten mevalonate enzyme-encoding genes and their expression in response to juvenile hormone levels in Leptinotarsa decemlineata (Say).
abstract: The mevalonate pathway is responsible for the biosynthesis of many essential molecules important in insect development, reproduction, chemical communication and defense. Based on Leptinotarsa decemlineata transcriptome and genome data, we identified ten genes that encoded acetoacetyl-CoA thiolase (LdAACT1 and LdAACT2), hydroxymethylglutaryl (HMA)-CoA synthase (LdHMGS), HMG-CoA reductase (LdHMGR1 and LdHMGR2), mevalonate kinase (LdMevK), phospho-mevalonate kinase (LdPMK), mevalonate diphosphate decarboxylase (LdMDD), isopentenyl-diphosphate isomerase (LdIDI) and farnesyl pyrophosphate synthetase (LdFPPS). Nine of these genes (except for LdAACT1) were mainly expressed in the larval brain-corpora cardiaca-corpora allata complex, and adult ovary and testis. The 9 genes were transcribed at high levels right after each ecdysis, and at low levels in the mid instar. Therefore, the 9 genes were indicated to be involved in JH biosynthesis. Moreover, knockdown of a JH biosynthesis gene LdJHAMT to lower JH titer significantly downregulated the transcription of the 9 genes. Ingestion of JH to activate JH signaling also significantly suppressed the expression of the 9 genes. It appears that the accumulation of JH precursors in LdJHAMT RNAi larvae and a high JH titer in JH-fed specimens may cause negative feedbacks to repress the expression of the 9 mevalonate enzyme-encoding genes (excluding LdAACT1) to balance the enzyme quantity in L. decemlineata.
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: 781093280@qq.com.
authors.forename: Qian
authors.initials: Q
authors.lastname: Li
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: 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: 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: D000595:Amino Acid Sequence; D000818:Animals; D001517:Coleoptera / Q000235:genetics* / Q000378:metabolism; D004798:Enzymes / Q000737:chemistry / Q000235:genetics*; D007605:Juvenile Hormones / Q000378:metabolism*; D008798:Mevalonic Acid / Q000378:metabolism*; D008969:Molecular Sequence Data; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid
chemical_list: D004798:Enzymes; D007605:Juvenile Hormones; D008798:Mevalonic Acid
keywords: Gene expression; Juvenile hormone; Leptinotarsa decemlineata; Mevalonate pathway; RNA interference