Shrinking genomics


Two bacteria are featured this month, and both are at the lower end of the genome size scale. The first, Mycoplasma gallisepticum, belongs to a group of bacteria that have been studied both as important human and animal pathogens and in the pursuit of understanding the essential functions of a self-replicating minimal cell. The second, Nanoarchaeum equitans, is an obligate symbiont that only grows in co-culture with another archaeon. N. equitans seems to be the coelacanth of the microbial world — it has been assigned to a new phylum and represents a primitive form of prokaroytic life.

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Figure 1: Prokaryotic genomes published in 2003.


  1. 1

    Papazisi, L. et al. The complete genome sequence of the avian pathogen Mycoplasma gallisepticum strain Rlow . Microbiology 149, 2307–2316 (2003).

  2. 2

    Waters, E. et al. The genome of Nanoarchaeum equitans: insights into early archaeal evolution and derived parasitism. Proc. Natl Acad. Sci. 100, 12984–12988 (2003).

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Mycoplasma gallisepticum

Nanoarchaeum equitans


Genomes OnLine Database

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