Phylogenetic Identification of Hypermastigotes, Pseudotrichonympha, Spirotrichonympha, Holomastigotoides, and Parabasalian Symbionts in the Hindgut of Termites

Abstract

The phylogenetic diversity of parabasalian flagellates was examined based on the sequences of small subunit ribosomal RNA genes amplified directly from the mixed population of flagellates in the hindgut of lower termites. In total, 33 representative sequences of parabasalids were recovered from eight termite species. Fluorescent-labeled oligonucleotide probes specific for certain sequences were designed and used for the in situ identification of parabasalian species by whole-cell hybridization. The hypermastigotes, Pseudotrichonympha grassii, Spirotrichonympha leidyi, and Holomastigotoides mirabile in the hindgut of Coptotermes formosanus, and Spirotrichonympha sp. and Trichonympha spp. in Hodotermopsis sjoestedti were identified. In the phylogenetic tree constructed, the sequences from the termites were dispersed within the groups of known members of parabasalids, reflecting the presence of diverse parabasalids in the hindgut of termites. There were three paraphyletic lineages of hypermastigotes represented by Pseudotrichonympha, Trichonympha, and Spirotrichonympha, in agreement with the morphology-based taxonomic groups. The analysis of the tree-root suggested that the Pseudotrichonympha group is the most probable ancient lineage of parabasalids and that the Trichonympha group is the secondly deep-branching lineage. The Spirotrichonympha group and the Trichomonadida may have emerged later.

Diverse Bacteria Related to the Bacteroides Subgroup of the CFB Phylum within the Gut Symbiotic Communities of Various Termites

“…Furthermore, approximately 18z of the clones cannot be readily assigned to any recognized group of Bacteria. The analogous culture-independent approaches have been successfully applied, in various termite species, to the studies of their gut microbial community of ‰agellated protists, 3) spirochetes, 4,5) methanogenic Archaea, [6][7][8] and diazotrophs. 9,10) These studies revealed that the majority of the gut community consists of novel and yet-uncultured species previously unknown to microbiologists.…”

Hydrogen Production by Termite Gut Protists: Characterization of Iron Hydrogenases of Parabasalian Symbionts of the Termite Coptotermes formosanus

“…Culture-independent molecular studies, however, have been successfully applied to the gut dwellers of termites (for reviews, see reference 26); these studies were mainly molecular phylogenetic analyses. They revealed unexpected diversity among termite gut protists (12,(27)(28)(29). Genes involved in cellulose decomposition have also been identified previously (references 18 and 36 and references therein).…”

“…The flagellated protists in the gut of C. formosanus comprise exclusively the three parabasalian species P. grassii, Holomastigotoides mirabile, and Spirotrichonympha leidyi (28,29). P. grassii belongs to the family Eucomonymphidae, while the latter two belong to the family Spirotrichonymphidae.…”

“…All of the following manipulations were performed anaerobically. Termite guts were dissected using a fine-tipped forceps and gently crushed in the solution described previously (28). After the release of the gut contents and the removal of the gut tissues, the P. grassii cells were concentrated by low-speed centrifugation at 18 ϫ g for 5 min in a Kubota 1-13 centrifuge and the pellet was resuspended and washed three times.…”

“…The termite C. formosanus is a globally distributed and economically important pest of wood houses. It harbors only three species of gut protists, all of which belong to the phylogenetically monophyletic phlyum Parabasalia but are distantly related to the cultivated Parabasalia representatives Trichomonas vaginalis and Tritrichomonas foetus (28,29). Among the three, the largest protist, Pseudotrichonympha grassii, is maximally responsible for the decomposition of highly polymerized cellulose (40).…”