Scientific article
Open access

SSU rRNA-based Phylogenetic Position of the Genera Amoeba and Chaos (Lobosea, Gymnamoebia): the Origin of Gymnamoebae Revisited

Published inMolecular biology and evolution, vol. 18, no. 12, p. 2306-2314
Publication date2001-12-01
First online date2001-12

Naked lobose amoebae (gymnamoebae) are among the most abundant group of protists present in all aquatic and terrestrial biotopes. Yet, because of lack of informative morphological characters, the origin and evolutionary history of gymnamoebae are poorly known. The first molecular studies revealed multiple origins for the amoeboid lineages and an extraordinary diversity of amoebae species. Molecular data, however, exist only for a few species of the numerous taxa belonging to this group. Here, we present the small-subunit (SSU) rDNA sequences of four species of typical large gymnamoebae: Amoeba proteus, Amoeba leningradensis, Chaos nobile, and Chaos carolinense. Sequence analysis suggests that the four species are closely related to the species of genera Saccamoeba, Leptomyxa, Rhizamoeba, Paraflabellula, Hartmannella, and Echinamoeba. All of them form a relatively well-supported clade, which corresponds to the subclass Gymnamoebia, in agreement with morphology-based taxonomy. The other gymnamoebae cluster in small groups or branch separately. Their relationships change depending on the type of analysis and the model of nucleotide substitution. All gymnamoebae branch together in Neighbor-Joining analysis with corrections for among-site rate heterogeneity and proportion of invariable sites. This clade, however, is not statistically supported by SSU rRNA gene sequences and further analysis of protein sequence data will be necessary to test the monophyly of gymnamoebae.

  • Amoebae
  • RRNA
  • Phylogeny
Citation (ISO format)
BOLIVAR, Ignacio et al. SSU rRNA-based Phylogenetic Position of the Genera <i>Amoeba</i> and <i>Chaos</i> (Lobosea, Gymnamoebia): the Origin of Gymnamoebae Revisited. In: Molecular biology and evolution, 2001, vol. 18, n° 12, p. 2306–2314. doi: 10.1093/oxfordjournals.molbev.a003777
Main files (1)
Article (Published version)
ISSN of the journal0737-4038

Technical informations

Creation09/13/2023 9:03:34 AM
First validation09/15/2023 12:22:53 PM
Update time09/15/2023 12:22:53 PM
Status update09/15/2023 12:22:53 PM
Last indexation02/12/2024 12:33:20 PM
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack