title: Comparative analysis of genome sequences from four strains of the Buchnera aphidicola Mp endosymbion of the green peach aphid, Myzus persicae.
abstract: BACKGROUND
  Myzus persicae, the green peach aphid, is a polyphagous herbivore that feeds from hundreds of species of mostly dicot crop plants. Like other phloem-feeding aphids, M. persicae rely on the endosymbiotic bacterium, Buchnera aphidicola (Buchnera Mp), for biosynthesis of essential amino acids and other nutrients that are not sufficiently abundant in their phloem sap diet. Tobacco-specialized M. persicae are typically red and somewhat distinct from other lineages of this species. To determine whether the endosymbiotic bacteria of M. persicae could play a role in tobacco adaptation, we sequenced the Buchnera Mp genomes from two tobacco-adapted and two non-tobacco M. persicae lineages.
  
  
  RESULTS
  With a genome size of 643.5 kb and 579 predicted genes, Buchnera Mp is the largest Buchnera genome sequenced to date. No differences in gene content were found between the four sequenced Buchnera Mp strains. Compared to Buchnera APS from the well-studied pea aphid, Acyrthosiphon pisum, Buchnera Mp has 21 additional genes. These include genes encoding five enzymes required for biosynthesis of the modified nucleoside queosine, the heme pathway enzyme uroporphyrinogen III synthase, and asparaginase. Asparaginase, which is also encoded by the genome of the aphid host, may allow Buchnera Mp to synthesize essential amino acids from asparagine, a relatively abundant phloem amino acid.
  
  
  CONCLUSIONS
  Together our results indicate that the obligate intracellular symbiont Buchnera aphidicola does not contribute to the adaptation of Myzus persicae to feeding on tobacco.
authors.forename: Zhijie
authors.initials: Z
authors.lastname: Jiang
authors.forename: Derek H
authors.initials: DH
authors.lastname: Jones
authors.forename: Sawsan
authors.initials: S
authors.lastname: Khuri
authors.forename: Nicholas F
authors.initials: NF
authors.lastname: Tsinoremas
authors.forename: Tania
authors.initials: T
authors.lastname: Wyss
authors.forename: Georg
authors.initials: G
authors.lastname: Jander
authors.affiliation: Department of Biology, University of Miami, Coral Gables 33146, FL, USA. acwilson@bio.miami.edu.
authors.forename: Alex C C
authors.initials: AC
authors.lastname: Wilson
mesh_terms: D000220:Adaptation, Biological; D000818:Animals; D001042:Aphids / Q000382:microbiology*; D020635:Buchnera / Q000145:classification / Q000235:genetics*; D002874:Chromosome Mapping; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D016680:Genome, Bacterial; D018895:Microsatellite Repeats; D010957:Plasmids / Q000235:genetics; D017422:Sequence Analysis, DNA; D013559:Symbiosis; D014026:Nicotiana
chemical_list: D004269:DNA, Bacterial