Trends in research on the primary endosymbiont of aphids,Buchnera aphidicola

Endosymbiosis of bacteria within animals is a major research topic in biology.Studies on endosymbiosis are important not only for understanding the growth and reproduction of animal hosts,but also for investigating of the origin and evolution of life.Aphids harbor obligatory endosymbiotic bacteria,Buchnera aphidicola,which are nutritionally and developmentally indispensable to them.Due to this obligate relationship,the aphid-Buchnera model is ideal for investigating many significant theoretical issues in symbiosis.This paper reviews research on the basic biological characteristics of Buchnera,evolutionary relationship between aphids and Buchnera,the roles of Buchnera in symbiotic association as well as functional genomics of Buchnera.We then highlight some scientific questions worthy of concern in the future.