Molecular Mechanism Of Wing Dimorphism And Reproductive Plasticity In The Brown Planthopper,Nilaparvata Lugens

Phenotypic plasticity,a phenomenon that organisms with a genetype develop many different phenotypes,is a very important means for insects to adapt to heterogeneous environment and make them survival and reproduction.Polyphenism that a discontinuous plastic response produces two or more phenotypic morphs is the most extreme form of phenotypic plasticity.The brown planthopper(BPH)Nilaparvata lugens,exhibit obvious wing dimorphism which have the long-winged and short-winged dispersal morphs.The long-winged morphs bear fully developed forewings and hindwings which enable them migrate from deteriorating environments to new habitats;while the short-winged morphs have vestigial wings,and are thus flightless,but with higher fecundity.So the wing dimorphism of BPH mainly include the plastic development of wings,indirct flight muscle(IFM)and reproduction.In this study,we investigated the molecular mechanism of wing dimorphism in BPH by using RNAseq,RNAi,yeast one hybrid and so on.The mainly results are as follows:1.Obtaining two wing patterning genes which participated in the switching of winged morphs.To better understand the molecular mechanism underlying the alternative wing morphs development,we conducted the comparative transcriptional analysis of BPH during wing morphs switching by RNAseq.We found that genes related to amino acids and lipid metabolism were significantly down-regulated in the long winged nymphs.But expression of pyruvate dehydrogenase El which was involved in the energy generation was significantly up-regulated in the long winged nymphs.Furthmore,we find out two candidate genes related to wing development,Nlvestigial(Nlvg)and Nlspalt(Nlsal),were differentially expressed during wing morphs switching.These results provide valuable transcriptional information for us to uncover the mechanism of insulin signaling pathway in developmental plasticity of BPH.2.Nlvestigial regulate the developmental plasticity of wings and IFM.Here,the results showed Nlvestigial expression was regulated by NlFoxO.NlFoxO repressed the Nlvestigial transcription by interacting with FOXO-binding sites(GTAAACA)in intron of Nlvestigial.Then the reduced Nlvestigial inhibited wings and IFM development.On the contrary,inactive NIFoxO leads to the up-regulation of Nlvestigial and makes the BPH molt into long winged morphs.Moreover,Sfvestigial also was highly expressed in the long winged Sogatella furcifera and regulted by insulin signaling pathway.Suppression of Sfvestigial expression using RNA interference inhibited wings and IFM development,implying that Sfvestigial also regulated the developmental plasticity of wings and IFM in S.furcifera.3.Clarifying the acetylated regulation of reproductive plasticity of BPH.Silencing of NlHdacl substantially increased acetylation level of histones H3 and H4 in male adult,indicating NlHDAC1 is the main histone deacetylase in the males.Combined the compared transcriptomic analysis and qRT-PCR,we found NlHDAC1 regulate the production of courtship signal in male BPH might through regulating Nlflightin expression.These findings improve our understanding of reproductive strategies controlled by HDACs in insects and provide a potential target for pest control.