• Analysis of wood decomposition mechanisms by 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 bioresource.

  • Evolutionary and genetic analyses of insectendosymbiont mutualisms.

    Many insects harbor obligate mutualistic endosymbionts. We are studying mechanisms and diversity of insectsymbiont 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 study various singing cicada species for their microbial symbioses, having discovered repeated evolutionary transitions of fungal parasites into beneficial symbionts for compensating the loss of ancient bacterial symbiont lineage.

  • 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
  • (左)イワサキクサゼミオス成虫と(右)共生真菌 (黄色は細胞壁)多くのセミ類は冬虫夏草に由来する真菌類と共生している
    Sugar cane cicada, Mogannia minutaand its fungal symbiont cells

Member

Position Name
Professor Gaku TOKUDA
Assistant Prof. Yu MATSUURA