2008/09/23 by Moriya Ohkuma, Satoko Noda, Yuichi Hongoh +2 · 2 citations
Biochemistry, Genetics and Molecular Biology · Agricultural and Biological Sciences · #Insect and Arachnid Ecology and Behavior #Plant and animal studies #Nematode management and characterization studies #Biology #Obligate #Sister group #Monophyly #Most recent common ancestor #Evolutionary biology #Phylum #Zoology #Cockroach #Phylogenetic tree #Phylogenetics #Ecology #Clade #Gene #Genetics
paper · doi:10.1098/rspb.2008.1094
openalex publication_date 2008/09/23 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Cryptocercus cockroaches and lower termites harbour obligate, diverse and unique symbiotic cellulolytic flagellates in their hindgut that are considered critical in the development of social behaviour in their hosts. However, there has been controversy concerning the origin of these symbiotic flagellates. Here, molecular sequences encoding small subunit rRNA and glyceraldehyde-3-phosphate dehydrogenase were identified in the symbiotic flagellates of the order Trichonymphida (phylum Parabasalia) in the gut of Cryptocercus punctulatus and compared phylogenetically to the corresponding species in termites. In each of the monophyletic lineages that represent family-level groups in Trichonymphida, the symbionts of Cryptocercus were robustly sister to those of termites. Together with the recent evidence for the sister-group relationship of the host insects, this first comprehensive study comparing symbiont molecular phylogeny strongly suggests that a set of symbiotic flagellates representative of extant diversity was already established in an ancestor common to Cryptocercus and termites, was vertically transmitted to their offspring, and subsequently became diversified to distinct levels, depending on both the host and the symbiont lineages.