A small microbial genome: the end of a long symbiotic relationship?
Intracellular bacteria are characterized by genome reduction. The 422,434-base pair genome of Buchnera aphidicola BCc, primary endosymbiont of the aphid Cinara cedri, is approximately 200 kilobases smaller than the previously sequenced B. aphidicola genomes. B. aphidicola BCc has lost most metabolic functions, including the ability to synthesize the essential amino acid tryptophan and riboflavin. In addition, most retained genes are evolving rapidly. Possibly, B. aphidicola BCc is losing its symbiotic capacity and is being complemented (and might be replaced) by the highly abundant coexisting secondary symbiont.
Pérez-Brocal
Vicente
V
Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Apartado Postal 22085, 46071 València, Spain.
Gil
Rosario
R
Ramos
Silvia
S
Lamelas
Araceli
A
Postigo
Marina
M
Michelena
José Manuel
JM
Silva
Francisco J
FJ
Moya
Andrés
A
Latorre
Amparo
A
D000596:Amino Acids / Q000096:biosynthesis; D000818:Animals; D001042:Aphids / Q000382:microbiology* / Q000502:physiology; D020029:Base Pairing; D020635:Buchnera / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D002876:Chromosomes, Bacterial / Q000235:genetics; D019143:Evolution, Molecular; D005798:Genes, Bacterial; D016680:Genome, Bacterial; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D012705:Serratia / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D013559:Symbiosis; D014364:Tryptophan / Q000096:biosynthesis
D000596:Amino Acids; D014364:Tryptophan