Analysis of wood decomposition mechanisms by termites

Termites and their symbiotic microorganisms digest almost withered plants in subtropical and tropical areas. Effective decomposer systems constructed by both host and symbiont relationships are being analyzed from the viewpoints of molecular biology, biochemistry, morphology, and spaciotemporal metabolomics. The outcome would give a useful insight into a molecular basis of carbon recycle in the tropical ecosystem and is expected to be applied for bio-ethanol production as an important bio-resource.

Evolutionary and genetic analyses of insect-endosymbiont mutualisms.

Many insects harbor obligate mutualistic endosymbionts. We are studying mechanisms and diversity of insect-symbiont interactions focusing on the intracellular symbionts of cockroaches, termites, stinkbugs and cicadas. In termites, the loss of intracellular symbioses and gain of gut symbioses can be considered as an evolutionary transition based on genetic and metabolic conflicts between two different symbiotic systems. Thus, we conduct comparative genomics among several strains of cockroach endosymbiont Blattabacterium cuenoti and its metabolic diversity of the endoymbiont and gut to elucidate their conflicts. We also work on the insect genes regulating intracellular symbioses in a seed bug Nysius plebeius, with a special focus on the development of its bacteriocytes and incorporation of the endosymbiont cells.

  • Gut of termite and their symbiotic protists
Green signals indicate methnogens.
    Gut of termite and their symbiotic protists
    Green signals indicate methnogens.
  • Left: Wood-feeding cockroach, Cryptocercus punctulatus, Right: Juveniles of C. punctulatus, which resemble termites.
    Left: Wood-feeding cockroach, Cryptocercus punctulatus
    Right: Juveniles of C. punctulatus, which resemble termites.
  • Left: Lygaeid seed bug, Nysius plebeius, 
Right: A bacteriocyte of N. plebeius, harboring numerous symbiont cells.
    Left: Lygaeid seed bug, Nysius plebeius 
    Right: A bacteriocyte of N. plebeius, harboring numerous symbiont cells.
  • Left: Sugar cane cicada , Mogannia minuta.
    Left: Sugar cane cicada , Mogannia minuta.

Member

Position Name
Professor Gaku TOKUDA
Assistant Prof. Yu MATSUURA