Phylogenetic Analysis of the Gut Bacterial Microflora of the Fungus-Growing TermiteOdontotermes formosanus

Abstract

We constructed a bacterial 16S rRNA gene clone library from the gut microbial community of O. formosanus and phylogenetically analyzed it in order to contribute to the evolutional study of digestive symbiosis and method development for termite control. After screening by restriction fragment length polymorphism (RFLP) analysis, 56 out of 280 clones with unique RFLP patterns were sequenced and phylogenetically analyzed. The representative phylotypes were affiliated to four phylogenetic groups, Firmicutes, the Bacteroidetes/ Chlorobi group, Proteobacteria, and Actinobacteria of the domain Bacteira. No one clone affiliated with the phylum Spirochaetes was identified, in contrast to the case of wood-feeding termites. The phylogenetic analysis revealed that nearly half of the representative clones (25 phylotypes) formed monophyletic clusters with clones obtained from other termite species, especially with the sequences retrieved from fungus-growing termites. These results indicate that the presence of termitespecific bacterial lineages implies a coevolutional relationship of gut microbes and host termites.Key words: termite; bacteria; symbiosis; 16S rRNA; restriction fragment length polymorphismTermites live in the area from tropical to temperate zones in great abundance, and are capable of degrading various derivatives of plant materials (woods, leaves, and humus). They have a great impact on the decomposition of plant matter in nature, and play an important role, especially in the carbon cycle. On the other hand, termites are known to be a harmful insect causing damage to farm products, wooden houses, etc. The xylophagy of termites depends on digestive symbiosis established in their hindgut, which consists of both eukaryotes (protozoa and fungi) and prokaryotes (bacteria and archaea). The microbial symbionts in termite guts play an important role in lignocellulose digestion and termite nutrition, and this mutualism has been referred to as a representative model of symbiotic association between animals and microorganisms.1)The microflora of termite guts are commonly exchanged between colony members and transmitted to the next generation via trophallaxis (proctodeal feeding), which can promote coevolutional diversification of symbiotic microbes along with the host phylogeny. Protozoan symbionts residing in classificatory lower termites are responsible for lignocellulose digestion in this termite group. They are basically host termite specific in phylogeny and composition, reflecting the obligate (mutualistic) symbiotic association between the protists and termites.2) However, the evolutional relationships between symbiotic prokaryotes and host termites have not yet been adequately addressed, because of their enormous population and diversity.For the last decade, microbial communities of termite guts have been investigated by rRNA gene-based molecular techniques, and our knowledge of this symbiosis has been expanded considerably. [3][4][5][6][7][8] Recently, Hongoh et al. 9) performed comparative analysis of the b...

The gut microbiota of the wood-feeding termite Reticulitermes lucifugus (Isoptera; Rhinotermitidae)

“…Spirochaetes are a major constituent of wood-feeding termite gut microbiota (Lilburn et al 1999;Leadbetter et al 1999), both in lower (Yang et al 2005) and higher termites (Paster et al 1996;Warnecke et al 2007). In contrast, the population of Spirochaetes in the gut of fungus-growing and soil-feeding termites is lower SchmittWagner et al 2003) or absent (Shinzato et al 2007). Most Spirochaetes are free-living in the gut fluid, and they have also been found as ectosymbionts attached to the surface of protists (Wenzel et al 2002b).…”

The Bacterial Community in the Gut of the Cockroach Shelfordella lateralis Reflects the Close Evolutionary Relatedness of Cockroaches and Termites

“…When the bacterial community in the colon of S. lateralis is compared to that of termites, it most closely resembles the hindgut microbiota of a fungus-growing species (62). A predominance of Bacteroidetes and Firmicutes is not typical for wood-feeding termites, but is a common feature of omnivorous mammals (29,42).…”

The protective role of endogenous bacterial communities in chironomid egg masses and larvae

“…The closest relatives of the dominant larval OTU ( Figure 3) were: a clone (AB231068) identified from the gut wall of termites (Nakajima et al, 2006), a clone (AJ576412) identified from the hindgut of Pachnoda ephippiata larvae (Egert et al, 2003) and a clone (AB288878) identified from a fungus-growing termite (Shinzato et al, 2007). It has been suggested that these bacteria have symbiotic relationships with their hosts and may have a role in their nutrition digestion (Egert et al, 2003;Nakajima et al, 2006;Shinzato et al, 2007). More research is needed to verify the hypothesis regarding the symbiotic relationships between chironomids' larvae and this unclassified Firmicutes.…”