title: Inactivation of Wolbachia reveals its biological roles in whitefly host.
abstract: BACKGROUND
  The whitefly Bemisia tabaci is cryptic species complex composed of numerous species. Individual species from the complex harbor a diversity of bacterial endosymbionts including Wolbachia. However, while Wolbachia is known to have a number of different roles, its role in B. tabaci is unclear. Here, the antibiotic rifampicin is used to selectively eliminate Wolbachia from B. tabaci so as to enable its roles in whitefly development and reproduction to be explored. The indirect effects of Wolbachia elimination on the biology of Encarsia bimaculata, a dominant parasitoid of B. tabaci in South China, were also investigated.
  
  
  RESULTS
  qRT-PCR and FISH were used to show that after 48 h exposure to 1.0 mg/ml rifampicin, Wolbachia was completely inactivated from B. tabaci Mediterranean (MED) without any significant impact on either the primary symbiont, Portiera aleyrodidarum or any of the other secondary endosymbionts present. For B. tabaci MED, Wolbachia was shown to be associated with decreased juvenile development time, increased likelihood that nymphs completed development, increased adult life span and increased percentage of female progeny. Inactivation was associated with a significant decrease in the body size of the 4(th) instar which leads us to speculate as to whether Wolbachia may have a nutrient supplementation role. The reduction in nymph body size has consequences for its parasitoid, E. bimaculata. The elimination of Wolbachia lead to a marked increase in the proportion of parasitoid eggs that completed their development, but the reduced size of the whitefly host was also associated with a significant reduction in the size of the emerging parasitoid adult and this was in turn associated with a marked reduction in adult parasitoid longevity.
  
  
  CONCLUSIONS
  Wolbachia increases the fitness of the whitefly host and provides some protection against parasitization. These observations add to our understanding of the roles played by bacterial endosymbionts.
authors.affiliation: Department of Entomology, South China Agricultural University, Guangzhou, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Xue
authors.forename: Shao-Jian
authors.initials: SJ
authors.lastname: Li
authors.forename: Muhammad Z
authors.initials: MZ
authors.lastname: Ahmed
authors.forename: Paul J
authors.initials: PJ
authors.lastname: De Barro
authors.forename: Shun-Xiang
authors.initials: SX
authors.lastname: Ren
authors.forename: Bao-Li
authors.initials: BL
authors.lastname: Qiu
mesh_terms: D000818:Animals; D000904:Antibiotics, Antitubercular / Q000494:pharmacology; D049628:Body Size / Q000187:drug effects; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D005798:Genes, Bacterial / Q000235:genetics; D006430:Hemiptera / Q000235:genetics / Q000382:microbiology* / Q000469:parasitology; D054884:Host-Pathogen Interactions / Q000187:drug effects; D017404:In Situ Hybridization, Fluorescence; D008136:Longevity / Q000187:drug effects; D008297:Male; D009758:Nymph / Q000235:genetics / Q000382:microbiology / Q000469:parasitology; D010270:Parasite Egg Count; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012293:Rifampin / Q000494:pharmacology; D012744:Sex Ratio; D013559:Symbiosis / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D014863:Wasps / Q000502:physiology; D020577:Wolbachia / Q000187:drug effects / Q000235:genetics / Q000502:physiology*
chemical_list: D000904:Antibiotics, Antitubercular; D012336:RNA, Ribosomal, 16S; D012293:Rifampin