Abstract
The symbiotic protists of the lower termite have been regarded as a model of early-branched eukaryotes because of their simple cellular systems and morphological features. However, cultivation of these symbiotic protists is very difficult. For this reason, these interesting protists have not been well characterized in terms of their molecular biology. In research on these organisms which have not yet been cultivated, we developed a method for retrieving specific genes from a small number of cells, through micromanipulation without axenic cultivation, and we obtained EF-1α and α-tubulin genes from members of the Hypermastigida—the parabasalid protist Trichonympha agilis and the oxymonad protists Pyrsonympha grandis and Dinenympha exilis—from the termite Reticulitermes speratus gut community. Results of phylogenetic analysis of the amino acid sequences of both proteins, EF-1α and α-tubulin, indicate that the hypermastigid, parabasalid, and oxymonad protists do not share a close common ancestor. In addition, although the EF-1α phylogeny indicates that these two groups of protists branched at an early stage of eukaryotic evolution, the α-tubulin phylogeny indicates that these protists can be assigned to two diversified clades. As shown in a recent investigation of α-tubulin phylogeny, eukaryotic organisms can be divided into three classes: an animal–parabasalids clade, a plant–protists clade, and the diplomonads. In this study, we show that parabasalids, including hypermastigids, can be classified as belonging to the animal–parabasalids clade and the early-branching eukaryote oxymonads can be classified as belonging to the plant–protists clade. Our findings suggest that these protists have a cellular microtubule system that has diverged considerably, and it seems that such divergence of the microtubule system occurred in the earliest stage of eukaryotic evolution.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Author information
Authors and Affiliations
Additional information
Received: 1 May 2000 / Accepted: 10 August 2000
Rights and permissions
About this article
Cite this article
Moriya, S., Tanaka, K., Ohkuma, M. et al. Diversification of the Microtubule System in the Early Stage of Eukaryote Evolution: Elongation Factor 1α and α-Tubulin Protein Phylogeny of Termite Symbiotic Oxymonad and Hypermastigote Protists. J Mol Evol 52, 6–16 (2001). https://doi.org/10.1007/s002390010129
Published:
Issue Date:
DOI: https://doi.org/10.1007/s002390010129