Intracellular Bacterial Symbionts of Aphids Possess Many Genomic Copies Per Bacterium

J Mol Evol. 1999 Jun;48(6):717-22. doi: 10.1007/pl00006516.


Although Buchnera, the endosymbiotic bacteria of aphids, are close relatives of Escherichia coli, their genome size is only a seventh that of E. coli. In this study, we estimated the genomic copy number of Buchnera by dot-blot hybridization and fluorimetry using a video-intensified microscope photon-counting system and obtained convincing evidence that each cell of these bacteria contains an average of 120 genomic copies. Thus, the Buchnera symbiont, with many copies of a small-sized genome, is reminiscent of cell organelles such as mitochondria and chloroplasts.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Aphids / microbiology*
  • Bacteria / genetics*
  • Bacterial Proteins / genetics
  • Chaperonins
  • DNA, Bacterial*
  • DNA, Fungal / genetics
  • DNA, Ribosomal / genetics
  • Escherichia coli / genetics
  • Escherichia coli Proteins
  • Gene Dosage
  • Genome, Bacterial*
  • Heat-Shock Proteins / genetics
  • Saccharomyces cerevisiae / genetics
  • Symbiosis


  • Bacterial Proteins
  • DNA, Bacterial
  • DNA, Fungal
  • DNA, Ribosomal
  • Escherichia coli Proteins
  • GroE protein, E coli
  • Heat-Shock Proteins
  • Chaperonins