title: Involvement of a putative allatostatin in regulation of juvenile hormone titer and the larval development in Leptinotarsa decemlineata (Say).
abstract: Juvenile hormone III (JH III) plays primary roles in regulation of metamorphosis, reproduction and diapause in Leptinotarsa decemlineata, a notorious defoliator of potato. The neurosecretory cell-borne substance(s) negatively affects the final two steps in JH biosynthesis, catalyzed respectively by an epoxidase CYP15A1 and a juvenile hormone acid methyltransferase (JHAMT). In a few insect species other than L. decemlineata, the inhibitory substance is allatostatin (AS) neuropeptide. In this study, two putative AS genes encoding LdAS-C and LdAS-B precursors were cloned. Both LdAS-C and LdAS-B were expressed in the egg, larvae, pupae and adults, and highly expressed in the brain and the gut. Dietary introduction of double-stranded RNAs (dsRNAs) targeting LdAS-C and LdAS-B successfully knocked down respective target genes. Ingestion during 3 and 6 consecutive days of dsLdAS-C significantly increased the LdJHAMT mRNA levels by 3.8 and 9.9 fold respectively. In contrast, ingestion of dsLdAS-B only slightly increased the LdJHAMT expression level by 1.1 and 1.7 fold. Moreover, after one, two and three days' ingestion of dsLdAS-C, the relative JH levels in the hemolymph of treated larvae were 2.5, 4.2 and 1.9 fold higher than those in control beetles. Furthermore, ingestion of dsLdAS-C and dsLdAS-B significantly affected larval growth and delayed larval development. Thus, we provide a line of experimental evidence in L. decemlineata to support the concept that AS-C acts as an allatostatin and inhibit JH biosynthesis.
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: 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.
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: 176061610@qq.com.
authors.forename: Kai-Yun
authors.initials: KY
authors.lastname: Fu
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; D003001:Cloning, Molecular; D001517:Coleoptera / Q000254:growth & development*; D020224:Expressed Sequence Tags; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D006458:Hemolymph / Q000378:metabolism*; D007605:Juvenile Hormones / Q000378:metabolism*; D007814:Larva / Q000254:growth & development; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000502:physiology*; D010802:Phylogeny; D012330:RNA, Double-Stranded / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D007605:Juvenile Hormones; D009479:Neuropeptides; D012330:RNA, Double-Stranded; D012333:RNA, Messenger; C076523:allatostatin
keywords: Allatostatin gene; Development; Growth; Juvenile hormone titer; Leptinotarsa decemlineata; RNA interference