Midichloria

Midichloria is a genus of Gram-negative, non-motile, non-sporeforming, bacteria, with bacillus shape of ~ 0.45 mm in diameter and ~1.2 mm in length. First described in 2004 with the temporary name IricES1[1], Midichloria are obligate mutualists of the hard tick Ixodes ricinus. They live in the cells of the ovary of the females of this tick species. These bacteria have been observed in the mitochondria of the host cells[2], a trait that has never been described in any other symbiont of animals. Midichloria bacteria seem to consume the mitochondria they parasite, possibly using them as a source of energy and/or molecules to multiply. The interaction of these symbionts with their host is currently unknown, though the 100% prevalence in the females of the host tick seems to suggest a mutualistic association[3].

Additional recommended knowledge

Weighing the right way

Guide to balance cleaning: 8 simple steps

Correct Test Weight Handling Guide: 12 Practical Tips

Species

Only one species is described in this genus: Midichloria mitochondrii

Naming

The name of this bacterial genus, Midichloria (mi.di.chlo’ria. N.L. fem. n.) is derived from the midi-chlorians, the bacteria of the fictional Star Wars universe. Midichlorians are symbionts that reside within the cells of living forms and ‘communicate with the Force’[4]. The higher the midichlorian count of a Jedi, the better his understanding of the Force can be. Star Wars creator George Lucas stated that the idea of the midichlorians is based on endosymbiotic theory. The word midichlorian is thought to be a blend of the words mitochondrion and chloroplast, the two organelles that according to the endosymbiotic theory are ancient prokaryotic symbionts of eukaryotic cells.

References

• Beninati, T., Lo, N., Sacchi, L., Genchi, C., Noda, H., and Bandi, C. (2004) A novel alpha-proteobacterium resides in the mitochondria of ovarian cells of the tick Ixodes ricinus. Appl. Environ. Microbiol. 70: 2596-2602.
• Sacchi, L., Bigliardi, E., Corona, S., Beninati, T., Lo, N., and Franceschi, A. (2004) A symbiont of the tick Ixodes ricinus invades and consumes mitochondria in a mode similar to that of the parasitic bacterium Bdellovibrio bacteriovorus. Tissue Cell 36: 43-53.
• Lo N, Beninati T, Sacchi L, Bandi C (2006b). An alpha-proteobacterium invades the mitochondria of the tick Ixodes ricinus. In Insect Symbiosis II, edited by K. Bourtzis and T. Miller, CRC Press Boca Raton.
• Sassera D, Beninati T, Bandi C, Bouman EA, Sacchi L, Fabbi M, Lo N. (2006) 'Candidatus Midichloria mitochondrii', an endosymbiont of the tick Ixodes ricinus with a unique intramitochondrial lifestyle. Int J Syst Evol Microbiol. Nov;56(Pt 11):2535-40.