title: A new rickettsia from a herbivorous insect, the pea aphid Acyrthosiphon pisum (Harris).
abstract: An undescribed, maternally heritable, rod-shaped bacterium (or "tertiary symbiont") was detected by microscopy in hemolymph of about half (59/122) of pea aphid [Acyrthosiphon pisum (Harris)] clones collected from widely separated locations in California. On the basis of molecular phylogenetic analysis of 16S rDNA sequences, the bacterium was clearly placed among other Rickettsia in the alpha-subgroup of Proteobacteria, close to Rickettsia bellii-a rickettsia found in ticks. A PCR assay was developed to detect this bacterium in pea aphid clones with specific 16S rDNA PCR primers. Results of PCR-based assays completely correlated with detection by microscopy. This is the first confirmed detection of a Rickettsia in a herbivorous insect.
authors.affiliation: Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720-3112, USA.
authors.forename: D Q
authors.initials: DQ
authors.lastname: Chen
authors.forename: B C
authors.initials: BC
authors.lastname: Campbell
authors.forename: A H
authors.initials: AH
authors.lastname: Purcell
mesh_terms: D000818:Animals; D001042:Aphids / Q000382:microbiology*; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012281:Rickettsia / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal