Symbiotic microoiganisms in aphids (Homoptera, Insecta): A secret of one thriving insect group

摘要: Most, if not all, aphids harbor intracellular bacterial symbionts, called Buchnera, in their bacteriocytes, huge cells differentiated for this purpose. The association between Buchnera and is so intimate, mutualistic obligate that neither of them can any longer reproduce independently. are vertically transmitted through generations the host insects. Evidence suggests were acquired by a common ancestor 160–280 million years ago, have been diversified, since then, parallel with aphid hosts. Molecular phylogenetic analyses indicate belong to g subdivision Proteobacteria. Although close relatives Escherichia coli, they contain more than 100 genomic copies per cell, genome size only one seventh E. coli. complete sequence revealed gene repertoire quite different from those parasitic bacteria such as Mycoplasma, Rickettsia Chlamydia, though ge...