title: How conserved are the bacterial communities associated with aphids? A detailed assessment of the Brevicoryne brassicae (Hemiptera: Aphididae) using 16S rDNA.
abstract: Aphids harbor a community of bacteria that include obligate and facultative endosymbionts belonging to the Enterobacteriaceae along with opportunistic, commensal, or pathogenic bacteria. This study represents the first detailed analysis of the identity and diversity of the bacterial  community associated with the cabbage aphid, Brevicoryne brassicae (L.). 16S rDNA sequence analysis revealed that the community of bacteria associated with B. brassicae was diverse, with at least four different bacterial community types detected among aphid lines, collected from  widely dispersed sites in Northern Britain. The bacterial sequence types isolated from B. brassicae showed little similarity to any bacterial endosymbionts characterized in insects; instead, they were closely related to free-living extracellular bacterial species that have been isolated  from the aphid gut or that are known to be present in the environment, suggesting that they are opportunistic bacteria transmitted between the aphid gut and the environment. To quantify variation in bacterial community between aphid lines, which was driven largely by differences in the proportions  of two dominant bacterial orders, the Pseudomonales and the Enterobacteriales, we developed a novel real-time (Taqman) qPCR assay. By improving our knowledge of aphid microbial ecology, and providing novel molecular tools to examine the presence and function of the microbial community, this  study forms the basis of further research to explore the influence of the extracellular bacterial community on aphid fitness, pest status, and susceptibility to control by natural enemies.
authors: Ecological Sciences Group, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA, Scotland, UK. emclark@rvc.ac.uk
authors: E L
authors: EL
authors: Clark
authors: T J
authors: TJ
authors: Daniell
authors: J
authors: J
authors: Wishart
authors: S F
authors: SF
authors: Hubbard
authors: A J
authors: AJ
authors: Karley
mesh_terms: D000818:Animals; D001042:Aphids / Q000382:microbiology*; D044822:Biodiversity; D004269:DNA, Bacterial / Q000737:chemistry; D004275:DNA, Ribosomal / Q000737:chemistry; D004755:Enterobacteriaceae / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D016013:Likelihood Functions; D010802:Phylogeny; D011549:Pseudomonas / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal