The Pneumocystis life cycle

Mem Inst Oswaldo Cruz. 2009 May;104(3):419-26. doi: 10.1590/s0074-02762009000300004.


First recognised as 'schizonts' of Trypanosoma cruzi, Pneumocystis organisms are now considered as part of an early-diverging lineage of Ascomycetes. As no robust long-term culture model is available, most data on the Pneumocystis cell cycle have stemmed from ultrastructural images of infected mammalian lungs. Although most fungi developing in animals do not complete a sexual cycle in vivo, Pneumocystis species constitute one of a few exceptions. Recently, the molecular identification of several key players in the fungal mating pathway has provided further evidence for the existence of conjugation and meiosis in Pneumocystisorganisms. Dynamic follow-up of stage-to-stage transition as well as studies of stage-specific proteins and/or genes would provide a better understanding of the still hypothetical Pneumocystislife cycle. Although difficult to achieve, stage purification seems a reasonable way forward in the absence of efficient culture systems. This mini-review provides a comprehensive overview of the historical milestones leading to the current knowledge available on the Pneumocystis life cycle.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Cell Cycle / genetics
  • Cell Cycle / physiology*
  • Genes, Mating Type, Fungal / genetics
  • Genes, Mating Type, Fungal / physiology*
  • Life Cycle Stages / physiology*
  • Microscopy, Electron, Transmission
  • Pneumocystis / genetics
  • Pneumocystis / growth & development*
  • Pneumocystis / ultrastructure