Figures (2)  Tables (1)
    • Figure 1. 

      Illustration of HGTs from other organisms to insects described in the main text. Blue and red represents the donors and recipients, respectively. The tree is designed only for illustration purposes merely explaining the donors and recipient insects that have undergone HGTs and is unable to accurately reflect a true phylogeny, which is modified from previous studies[1,4].

    • Figure 2. 

      An overview of HGTs in insects and mainly available examples associated with their functions. Part I: 'Donors' represent several groups providing the candidate horizontally transferred genes. 'Recipients' represent the nine insect groups that have received the horizontally transferred genes from donors. Part II: The molecular process of horizontal gene transfer. Part III: The most obvious examples of insect HGT events that have acquired novel functions.

    • DonorRecipientGene nameFunctional categoryReference
      Ascomycetes: undefined speciesApriona japonica, Callosobruchus maculatus, Chrysomela tremula, Dendroctonus ponderosae, Diabrotica virgifera, Gastrophysa viridula, Leptinotarsa decemlineata, Phaedon cochleariae, Pissodes strobe, Sitophilus oryzaeColeopteraPectin-degrading polygalacturonase (PG)Carbohydrate metabolism[72]
      Bacteria and fungi: undefined speciesDiabrotica virgiferaGlycosyl hydrolase (GH45,
      GH48, and GH28)
      [65]
      γ-proteobacteria: Cellvibrio, TeredinibacterPhaedon cochleariaeGlycosyl hydrolase (GH11)[62]
      Bacilli: BacillusHypothenemus hampeiMannanase (HhMAN1)[13]
      Bacilli: Citrobacter, Enterobacter, KlebsiellaAgrilus planipennisβ-fructofuranosidase[64]
      Bacilli: Cedecea, Shigella, YersiniaSphenophorus levis[63]
      α-proteobacteria: WolbachiaCallosobruchus chinensiswspUndefined[25]
      57 genes[36]
      Monochamus alternatus31 genes[37]
      Zygomycetes: Blakeslea, Mucor, PhycomycesAsteromyia carbonifera, Chaitophorus populeti, Mayetiola destructorDipteraPhytoene
      synthase and desaturase
      Formation of body color[71]
      Cyanobacteria: Calothrix, TolypothrixAedes aegypti, Culex quinquefasciatusRibosome inactivating geneAntimicrobic defense[68,69]
      Bacteriophage: APSE-2Drosophila ananassae, D. biarmipes, D. bipectinata, D. primaeva, Myzus cerasi, M. persicae, Scaptomyza flava, S. nr. nigrita, S. pallidaCytolethal distending toxin B (cdtB)Defense against enemies[82]
      α-proteobacteria: WolbachiaAedes aegypti, A. mascarensis, Culex pipiens quinquefasciatusAAEL004181, AAEL004188Undefined[40]
      Drosophila ananassaenuwt[27]
      Glossina morsitans morsitans16S rRNA, wsp, fbpA[26,41]
      Culex pipiens quinquefasciatus, Drosophila ananassae, D. sechellia, D. simulansUndefined[8,15]
      α-proteobacteria: Wolbachia; γ-proteobacteria: BuchneraAcyrthosiphon pisumHemipteraldcA, rlpA, AmiD, bLys, DnaE, AtpH, RlpA4Amino acid metabolism, transport, and defense response[44, 45,
      4850]
      Saccharomycetes: Xanthophyllomyces; Zygomycetes: PhycomycesCarotenoid desaturase and synthaseFormation of body color[32]
      Zygomycetes: Blakeslea, Mucor, PhycomycesPhytoene
      synthase and desaturase
      [71]
      Plant: undefined speciesBemisia tabaciGlucoside malonyltrasferase (BtPMaT)Phenolic glycoside detoxification[11]
      Ribosome inactivating geneAntimicrobic defense[75]
      β-proteobacteria: Candidatus; γ-proteobacteria: CarsonellaDiaphorina citriribCRiboflavin biosynthesis[51]
      γ-proteobacteria: CarsonellaPachypsylla venustaargH, cm, rsmJ, ribC, ydcJAmino acid metabolism, transport, and defense response[52]
      α-proteobacteria: Wolbachia; γ-proteobacteria: Carsonella, Serratia, SodalisPlanococcus citri≥ 22 genesCarbohydrate metabolism[54]
      Plant: undefined speciesTrialeurodes vaporariorumRibosome inactivating geneAntimicrobic defense[75]
      Zygomycetes: Phycomyces, Rhizopus34 AphidsCarotenoid desaturase and synthaseFormation of body color[70]
      Chytridiomycetes: RozellaCopidosoma oridanum, Melittobia spp., Muscidifurax raptor, M. raptorellus, M. uniraptor, Nasonia longicornis, N. giraulti, N. Oneida, N. vitripennis, Spalangia cameroni, S. endius, Tachinaephagus zealandicus, Trichogramma pretiosum, Trichomalopsis sarcophagae, Urolepis rupesHymenopteraChitinase (GH19)Antifungal defense[73]
      α-proteobacteria: WolbachiaNasonia giraulti, N. longicornis, N. vitripennis, Melittobia digitataAnkyrin repeat-containing geneEmbryogenesis[8,38,39]
      Bracoviruses: Cotesia vestalis bracovirusCotesia vestalisHelitronUndefined[80]
      Bacilli: Bacillus;
      γ-proteobacteria: Cedecea, Rahnella, Yersinia
      Amyelois transitella, Bicyclus anynana, Bombyx mori, Danaus plexippus, Junoni coenia, Heliconius melpomene, Papilio glaucus, P. machaon, P. xuthus, Plodia interpunctella, Spodoptera frugiperdaLepidopteraβ-fructofuranosidaseCarbohydrate metabolism and alkaloid detoxification[56,61]
      Bacilli: Bacillus;
      γ-proteobacteria: Serratia;
      Baculovirus: Autographa californica nucleopolyhedrovirus
      Bombyx moriChitinase (GH19)Antifungal defense[55]
      Bacilli: Bacillus, Enterococcus, Lactococcus, Listeria, Streptococcus
      α-proteobacteria: Methylobacterium, Wolbachia;
      γ-proteobacteria: Edwardsiella, Photorhabdus, Providencia, Pseudomonas, Salmonella, Serratia;
      Ascomycetes: Talaromyces
      24 genesMetabolic detoxification[5860]
      Chlorophyceae: ChlamydomonasDioxygenaseUndefined[57]
      Bacilli: Bacillus, Enterococcus, Listeria, Streptococcus;
      α-proteobacteria: Methylobacterium, Rickettsia;
      γ-proteobacteria: Erwinia, Pseudomonas, Serratia, Yersinia;
      Ascomycetes: Talaromyces
      Danaus plexippus22 genesCarbohydrate metabolism and detoxification[59,60]
      Bacilli: Alicyclobacillus, Bacillus, Enterococcus, Lactobacillus, Listeria;
      α-proteobacteria: Methylobacterium;
      γ-proteobacteria: Pseudomonas, Serratia
      Ascomycetes: Talaromyces
      Heliconius melpomene20 genes[60]
      Ascovirus, baculovirus, poxvirus: undefined speciesHelicoverpa, Heliothis, SpodopteraParasitoid killing factor (PKF)Defense against parasitoids[79]
      Bacilli: EnterococcusPlutella xylostellaGlycosyl hydrolase (GH31)Metabolic detoxification[59]
      Bacilli: ListeriaAlcohol dehydrogenase (LOC105383139)Courtship behavior[10]
      Bracoviruses: Cotesia kariyai bracovirusSpodoptera littoralisGasminAntimicrobic defense[78]
      α-proteobacteria: WolbachiaChorthippus parallelusOrthopteraMinor capsid geneUndefined[28]
      γ-proteobacteria: Frateuria, PantoeaAretaon asperrimus, Extatosoma tiaratum, Medauroidea extradentata, Peruphasma schultei, Ramulus artemis, Sipyloidea sipylusPhasmatodeaGlycosyl hydrolase (pectinase)Carbohydrate metabolism[66,67]

      Table 1. 

      A list of horizontally transferred genes in insects.