title: Juvenile hormone-receptor complex acts on mcm4 and mcm7 to promote polyploidy and vitellogenesis in the migratory locust.
abstract: Juvenile hormone (JH), a sesquiterpenoid produced by the corpora allata, coordinates insect growth, metamorphosis, and reproduction. While JH action for the repression of larval metamorphosis has been well studied, the molecular basis of JH in promoting adult reproduction has not been fully elucidated. Methoprene-tolerant (Met), the JH receptor, has been recently shown to mediate JH action during metamorphosis as well as in vitellogenesis, but again, the precise mechanism underlying the latter has been lacking. We have now demonstrated using Met RNAi to phenocopy a JH-deprived condition in migratory locusts, that JH stimulates DNA replication and increases ploidy in preparation for vitellogenesis. Mcm4 and Mcm7, two genes in the DNA replication pathway were expressed in the presence of JH and Met. Depletion of Mcm4 or Mcm7 inhibited de novo DNA synthesis and polyploidization, and resulted in the substantial reduction of vitellogenin mRNA levels as well as severely impaired oocyte maturation and ovarian growth. By using luciferase reporter and electrophoretic mobility shift assays, we have shown that Met directly regulates the transcription of Mcm4 and Mcm7 by binding to upstream consensus sequences with E-box or E-box-like motifs. Our work suggests that the JH-receptor complex acts on Mcm4 and Mcm7 to regulate DNA replication and polyploidy for vitellogenesis and oocyte maturation.
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Guo
authors.affiliation: School of Life Sciences, University of Science and Technology of China, Hefei, China.
authors.forename: Zhongxia
authors.initials: Z
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Jiasheng
authors.initials: J
authors.lastname: Song
authors.affiliation: Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Shun
authors.initials: S
authors.lastname: Deng
authors.affiliation: Department of Biology, Queen's University, Kingston, Ontario, Canada.
authors.forename: Virginia K
authors.initials: VK
authors.lastname: Walker
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Shutang
authors.initials: S
authors.lastname: Zhou
mesh_terms: D000818:Animals; D006110:Grasshoppers / Q000235:genetics / Q000502:physiology; D006801:Humans; D007605:Juvenile Hormones / Q000235:genetics* / Q000378:metabolism; D007814:Larva / Q000235:genetics; D008726:Methoprene; D064148:Minichromosome Maintenance Complex Component 4 / Q000235:genetics* / Q000378:metabolism; D064168:Minichromosome Maintenance Complex Component 7 / Q000235:genetics* / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics; D009865:Oocytes / Q000254:growth & development / Q000378:metabolism; D009866:Oogenesis; D011123:Polyploidy; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics; D015398:Signal Transduction / Q000235:genetics; D014818:Vitellogenesis / Q000235:genetics*
chemical_list: D007605:Juvenile Hormones; D009687:Nuclear Proteins; D012333:RNA, Messenger; D008726:Methoprene; D064148:Minichromosome Maintenance Complex Component 4; D064168:Minichromosome Maintenance Complex Component 7