title: DNA sequencing reveals the midgut microbiota of diamondback moth, Plutella xylostella (L.) and a possible relationship with insecticide resistance.
abstract: BACKGROUND
  Insect midgut microbiota is important in host nutrition, development and immune response. Recent studies indicate possible links between insect gut microbiota and resistance to biological and chemical toxins. Studies of this phenomenon and symbionts in general have been hampered by difficulties in culture-based approach. In the present study, DNA sequencing was used to examine the midgut microbiota of diamondback moth (DBM), Plutella xylostella (L.), a destructive pest that attacks cruciferous crops worldwide. Its ability to develop resistance to many types of synthetic insecticide and even Bacillus thuringiensis toxins makes it an important species to study.
  
  
  RESULTS
  Bacteria of the DBM larval midgut in a susceptible and two insecticide (chlorpyrifos and fipronil) resistant lines were examined by Illumina sequencing sampled from an insect generation that was not exposed to insecticide. This revealed that more than 97% of the bacteria were from three orders: Enterobacteriales, Vibrionales and Lactobacillales. Both insecticide-resistant lines had more Lactobacillales and the much scarcer taxa Pseudomonadales and Xanthomonadales with fewer Enterobacteriales compared with the susceptible strain. Consistent with this, a second study observed an increase in the proportion of Lactobacillales in the midgut of DBM individuals from a generation treated with insecticides.
  
  
  CONCLUSIONS
  This is the first report of high-throughput DNA sequencing of the entire microbiota of DBM. It reveals differences related to inter- and intra-generational exposure to insecticides. Differences in the midgut microbiota among susceptible and insecticide-resistant lines are independent of insecticide exposure in the sampled generations. While this is consistent with the hypothesis that Lactobacillales or other scarcer taxa play a role in conferring DBM insecticide resistance, further studies are necessary to rule out other possibilities. Findings constitute the basis for future molecular work on the functions of insect midgut microbiota taxa and their possible role in conferring host resistance to toxins.
authors.affiliation: Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Xia
authors.forename: Dandan
authors.initials: D
authors.lastname: Zheng
authors.forename: Huanzi
authors.initials: H
authors.lastname: Zhong
authors.forename: Bingcai
authors.initials: B
authors.lastname: Qin
authors.forename: Geoff M
authors.initials: GM
authors.lastname: Gurr
authors.forename: Liette
authors.initials: L
authors.lastname: Vasseur
authors.forename: Hailan
authors.initials: H
authors.lastname: Lin
authors.forename: Jianlin
authors.initials: J
authors.lastname: Bai
authors.forename: Weiyi
authors.initials: W
authors.lastname: He
authors.forename: Minsheng
authors.initials: M
authors.lastname: You
mesh_terms: D000818:Animals; D044822:Biodiversity; D041981:Gastrointestinal Tract / Q000382:microbiology*; D007305:Insecticide Resistance / Q000235:genetics*; D007306:Insecticides / Q000494:pharmacology*; D007814:Larva / Q000382:microbiology; D054892:Metagenome; D064307:Microbiota; D009036:Moths / Q000187:drug effects* / Q000382:microbiology*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S
chemical_list: D007306:Insecticides; D012336:RNA, Ribosomal, 16S
references.citation: Genomics. 2012 Mar;99(3):169-77
references.pmid: 22240003
references.citation: Anaerobe. 2012 Jun;18(3):378-80
references.pmid: 22579986
references.citation: Appl Environ Microbiol. 2009 Dec;75(23):7537-41
references.pmid: 19801464
references.citation: BMC Biol. 2009 Mar 04;7:11
references.pmid: 19261175
references.citation: Appl Environ Microbiol. 2013 Mar;79(6):2088-91
references.pmid: 23291548
references.citation: J Appl Microbiol. 2007 Dec;103(6):2664-75
references.pmid: 17973916
references.citation: J Insect Physiol. 2008 Sep;54(9):1377-83
references.pmid: 18706909
references.citation: Annu Rev Entomol. 2016;61:277-96
references.pmid: 26667272
references.citation: ISME J. 2011 Apr;5(4):741-9
references.pmid: 20962877
references.citation: Chem Res Toxicol. 1998 Dec;11(12):1529-35
references.pmid: 9860498
references.citation: PLoS One. 2009 Oct 09;4(10):e7401
references.pmid: 19816594
references.citation: PLoS Genet. 2008 Nov;4(11):e1000255
references.pmid: 19023400
references.citation: Mol Ecol. 2012 Oct;21(20):5138-50
references.pmid: 22988916
references.citation: Appl Environ Microbiol. 1999 Dec;65(12):5372-7
references.pmid: 10583991
references.citation: Environ Microbiol. 2010 Oct;12(10):2730-7
references.pmid: 20482744
references.citation: FEMS Microbiol Rev. 2013 Jan;37(1):3-22
references.pmid: 22540421
references.citation: Science. 2004 Mar 26;303(5666):1989
references.pmid: 15044797
references.citation: Rev Environ Contam Toxicol. 1995;144:1-93
references.pmid: 8599033
references.citation: Insect Mol Biol. 2005 Jun;14(3):327-34
references.pmid: 15926902
references.citation: PLoS Biol. 2008 Nov 18;6(11):e280
references.pmid: 19018661
references.citation: Proc Natl Acad Sci U S A. 2005 Sep 6;102(36):12795-800
references.pmid: 16120675
references.citation: Appl Environ Microbiol. 2004 Jan;70(1):293-300
references.pmid: 14711655
references.citation: Parasit Vectors. 2012 Jun 07;5:113
references.pmid: 22676389
references.citation: Mol Biol Evol. 2011 Oct;28(10):2731-9
references.pmid: 21546353
references.citation: J Econ Entomol. 2012 Aug;105(4):1115-29
references.pmid: 22928287
references.citation: Insect Biochem Mol Biol. 2008 Feb;38(2):125-35
references.pmid: 18207074
references.citation: J Microbiol Methods. 2007 May;69(2):330-9
references.pmid: 17391789
references.citation: FEMS Microbiol Ecol. 2004 Feb 1;47(2):161-77
references.pmid: 19712332
references.citation: J Insect Sci. 2010;10:107
references.pmid: 20874394
references.citation: Methods. 2001 Dec;25(4):402-8
references.pmid: 11846609
references.citation: Can J Microbiol. 2006 Nov;52(11):1085-92
references.pmid: 17215900
references.citation: Proc Biol Sci. 2011 Mar 7;278(1706):760-6
references.pmid: 20843842
references.citation: Nat Genet. 2013 Feb;45(2):220-5
references.pmid: 23313953
references.citation: J Exp Biol. 2011 Feb 1;214(Pt 3):462-8
references.pmid: 21228205
references.citation: Proc Natl Acad Sci U S A. 2012 May 29;109(22):8618-22
references.pmid: 22529384
references.citation: PLoS One. 2010 Oct 26;5(10):e15406
references.pmid: 21048977
references.citation: Proc Natl Acad Sci U S A. 2010 Nov 16;107(46):20051-6
references.pmid: 21041648