Intracellular symbionts

P. Baumann, L. Baumann, C.-Y. Lai, and D. Rouhbakhsh, Genetics, physiology and evolutionary relationships of the genus Buchnera intracellular symbionts of aphids, Annii. Rev. Microbiol. 49 55 (1995). 

Masui, S., Sasaki, T. and Ishikawa, H. (1997) groE-homologous operon of Wolbachia, an intracellular symbiont of arthropod a new approach to their phylogeny. Zoological Science 14, 701-706. 

Baumann, P., Baumann, L., Lai, C.Y., Rouhbakhsh, D., Moran, N.A. and Clark, M.A. (1995) Genetics, physiology, and evolutionary relationships of the genus Buchnercv. intracellular symbionts of aphids. Annual Review of Microbiology 49, 55-94. 

Law R, Hutson V (1992) Intracellular symbionts and the evolution of uniparental cytoplasmic inheritance. Proc Roy Soc Lond B Biol Sci 248 69-77 Lill R, Mfihlenhoff U (2005) Iron-sulfur-protein biogenesis in eukaryotes. Trends Biochem Sci 30 133-141... 

Sulfur metabolism of insects. IV. Conversion of inorganic sulfate to organic sulfur compounds in cockroaches. Role of intracellular symbionts. Con-tribs. Boyce Thompson Inst., 20, 317 (1960). With S. M. Henry. 

Mitochondria were first observed by R. Altmann in 1890. He named them bioblasts, because he speculated that they and chloroplasts (the green chlorophyll-containing organelles of plants) might be intracellular symbionts that arose from bacteria and algae, respectively. This idea lay in disrepute until the recent discovery of mitochondrial nucleic acids. 

In fact, bacteria do not have mitochondria, but some types do have membranous intrusions into the cytoplasm called mesosomes. These are similar in function to the inner membrane of mitochondria (Chap. 14). The reason mitochondria are distinct from other membranous structures in higher cells is posssibly due to their evolutionary origin as intracellular symbionts and to the fact that the spatial separation of functions leads to more advantageous (in terms of natural selection) control of the various metabolic processes. 

Figure 7. Andrimid, a potent and specific antibiotic from an intracellular symbiont.

---