title: Wolbachia and DNA barcoding insects: patterns, potential, and problems.
abstract: Wolbachia is a genus of bacterial endosymbionts that impacts the breeding systems of their hosts. Wolbachia can confuse the patterns of mitochondrial variation, including DNA barcodes, because it influences the pathways through which mitochondria are inherited. We examined the extent to which these endosymbionts are detected in routine DNA barcoding, assessed their impact upon the insect sequence divergence and identification accuracy, and considered the variation present in Wolbachia COI. Using both standard PCR assays (Wolbachia surface coding protein--wsp), and bacterial COI fragments we found evidence of Wolbachia in insect total genomic extracts created for DNA barcoding library construction. When >2 million insect COI trace files were examined on the Barcode of Life Datasystem (BOLD) Wolbachia COI was present in 0.16% of the cases. It is possible to generate Wolbachia COI using standard insect primers; however, that amplicon was never confused with the COI of the host. Wolbachia alleles recovered were predominantly Supergroup A and were broadly distributed geographically and phylogenetically. We conclude that the presence of the Wolbachia DNA in total genomic extracts made from insects is unlikely to compromise the accuracy of the DNA barcode library; in fact, the ability to query this DNA library (the database and the extracts) for endosymbionts is one of the ancillary benefits of such a large scale endeavor--which we provide several examples. It is our conclusion that regular assays for Wolbachia presence and type can, and should, be adopted by large scale insect barcoding initiatives. While COI is one of the five multi-locus sequence typing (MLST) genes used for categorizing Wolbachia, there is limited overlap with the eukaryotic DNA barcode region.
authors.affiliation: Department of Integrative Biology and the Biodiversity, Institute of Ontario, University of Guelph, Guelph, Ontario, Canada. salex@uoguelph.ca
authors.forename: M Alex
authors.initials: MA
authors.lastname: Smith
authors.forename: Claudia
authors.initials: C
authors.lastname: Bertrand
authors.forename: Kate
authors.initials: K
authors.lastname: Crosby
authors.forename: Eldon S
authors.initials: ES
authors.lastname: Eveleigh
authors.forename: Jose
authors.initials: J
authors.lastname: Fernandez-Triana
authors.forename: Brian L
authors.initials: BL
authors.lastname: Fisher
authors.forename: Jason
authors.initials: J
authors.lastname: Gibbs
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Hajibabaei
authors.forename: Winnie
authors.initials: W
authors.lastname: Hallwachs
authors.forename: Katharine
authors.initials: K
authors.lastname: Hind
authors.forename: Jan
authors.initials: J
authors.lastname: Hrcek
authors.forename: Da-Wei
authors.initials: DW
authors.lastname: Huang
authors.forename: Milan
authors.initials: M
authors.lastname: Janda
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Janzen
authors.forename: Yanwei
authors.initials: Y
authors.lastname: Li
authors.forename: Scott E
authors.initials: SE
authors.lastname: Miller
authors.forename: Laurence
authors.initials: L
authors.lastname: Packer
authors.forename: Donald
authors.initials: D
authors.lastname: Quicke
authors.forename: Sujeevan
authors.initials: S
authors.lastname: Ratnasingham
authors.forename: Josephine
authors.initials: J
authors.lastname: Rodriguez
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Rougerie
authors.forename: Mark R
authors.initials: MR
authors.lastname: Shaw
authors.forename: Cory
authors.initials: C
authors.lastname: Sheffield
authors.forename: Julie K
authors.initials: JK
authors.lastname: Stahlhut
authors.forename: Dirk
authors.initials: D
authors.lastname: Steinke
authors.forename: James
authors.initials: J
authors.lastname: Whitfield
authors.forename: Monty
authors.initials: M
authors.lastname: Wood
authors.forename: Xin
authors.initials: X
authors.lastname: Zhou
mesh_terms: D000818:Animals; D058893:DNA Barcoding, Taxonomic / Q000379:methods*; D004272:DNA, Mitochondrial / Q000235:genetics; D007313:Insecta / Q000145:classification / Q000235:genetics* / Q000382:microbiology*; D010802:Phylogeny; D020577:Wolbachia / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial