title: Analysis of the transcriptional differences between indigenous and invasive whiteflies reveals possible mechanisms of whitefly invasion.
abstract: BACKGROUND
  The whitefly Bemisa tabaci is a species complex of more than 31 cryptic species which include some of the most destructive invasive pests of crops worldwide. Among them, Middle East-Asia Minor 1 (MEAM1) and Mediterranean have invaded many countries and displaced the native whitefly species. The successful invasion of the two species is largely due to their wide range of host plants, high resistance to insecticides and remarkable tolerance to environmental stresses. However, the molecular differences between invasive and indigenous whiteflies remain largely unknown.
  
  
  RESULTS
  Here the global transcriptional difference between the two invasive whitefly species (MEAM1, MED) and one indigenous whitefly species (Asia II 3) were analyzed using the Illumina sequencing. Our analysis indicated that 2,422 genes between MEAM1 and MED; 3,073 genes between MEAM1 and Asia II 3; and 3,644 genes between MED and Asia II 3 were differentially expressed. Gene Ontology enrichment analysis revealed that the differently expressed genes between the invasive and indigenous whiteflies were significantly enriched in the term of 'oxidoreductase activity'. Pathway enrichment analysis showed that carbohydrate, amino acid and glycerolipid metabolisms were more active in MEAM1 and MED than in Asia II 3, which may contribute to their differences in biological characteristics. Our analysis also illustrated that the majority of genes involved in 'drug metabolic pathway' were expressed at a higher level in MEAM1 and MED than in Asia II 3. Taken together, these results revealed that the genes related to basic metabolism and detoxification were expressed at an elevated level in the invasive whiteflies, which might be responsible for their higher resistance to insecticides and environmental stresses.
  
  
  CONCLUSIONS
  The extensive comparison of MEAM1, MED and Asia II 3 gene expression may serve as an invaluable resource for revealing the molecular mechanisms underlying their biological differences and the whitefly invasion.
authors.affiliation: Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China.
authors.forename: Yong-Liang
authors.initials: YL
authors.lastname: Wang
authors.forename: Yu-Jun
authors.initials: YJ
authors.lastname: Wang
authors.forename: Jun-Bo
authors.initials: JB
authors.lastname: Luan
authors.forename: Gen-Hong
authors.initials: GH
authors.lastname: Yan
authors.forename: Shu-Sheng
authors.initials: SS
authors.lastname: Liu
authors.forename: Xiao-Wei
authors.initials: XW
authors.lastname: Wang
mesh_terms: D000818:Animals; D006430:Hemiptera / Q000502:physiology*; D058865:Introduced Species; D011157:Population Dynamics; D013045:Species Specificity; D014158:Transcription, Genetic / Q000502:physiology*