In addition to its medical importance as para- sitic pathogen, Entamoeba has aroused people’s interest in its evolutionary status for a long time. Lacking mitochondrion and other intracellular organelles common to ty...In addition to its medical importance as para- sitic pathogen, Entamoeba has aroused people’s interest in its evolutionary status for a long time. Lacking mitochondrion and other intracellular organelles common to typical eu- karyotes, Entamoeba and several other amitochondrial pro- tozoans have been recognized as ancient pre-mitochondriate eukaryotes and named “archezoa”, the most primitive extant eukaryotes. It was suggested that they might be living fossils that remained in a primitive stage of evolution before acqui- sition of organelles, lying close to the transition between prokaryotes and eukaryotes. However, recent studies re- vealed that Entamoeba contained an organelle, “crypton” or “mitosome”, which was regarded as specialized or reductive mitochondrion. Relative molecular phylogenetic analyses also indicated the existence or the probable existence of mi- tochondrion in Entamoeba. Our phylogenetic analysis based on DNA topoisomerase II strongly suggested its divergence after some mitchondriate eukaryotes. Here, all these recent researches are reviewed and the evolutionary status of En- tamoeba is discussed.展开更多
文摘In addition to its medical importance as para- sitic pathogen, Entamoeba has aroused people’s interest in its evolutionary status for a long time. Lacking mitochondrion and other intracellular organelles common to typical eu- karyotes, Entamoeba and several other amitochondrial pro- tozoans have been recognized as ancient pre-mitochondriate eukaryotes and named “archezoa”, the most primitive extant eukaryotes. It was suggested that they might be living fossils that remained in a primitive stage of evolution before acqui- sition of organelles, lying close to the transition between prokaryotes and eukaryotes. However, recent studies re- vealed that Entamoeba contained an organelle, “crypton” or “mitosome”, which was regarded as specialized or reductive mitochondrion. Relative molecular phylogenetic analyses also indicated the existence or the probable existence of mi- tochondrion in Entamoeba. Our phylogenetic analysis based on DNA topoisomerase II strongly suggested its divergence after some mitchondriate eukaryotes. Here, all these recent researches are reviewed and the evolutionary status of En- tamoeba is discussed.
