– Mother stinkbugs produce symbiont capsules to their offspring at the expense of their own survival –
Researchers) KOGA Ryuichi, Group Leader, TANAHASHI Masahiko, former AIST Post-Doctoral Research Scientist (currently a Researcher at National Taiwan Normal University), MORIYAMA Minoru, Senior Researcher, FUKATSU Takema, Prime Senior Researcher, Symbiotic Evolution and Biological Functions Research Group, Bioproduction Research Institute
- Discovery of novel secretion protein contained in large quantities in the symbionts capsules of plataspid stinkbugs
- This protein protects vulnerable symbiotic bacteria from the harsh conditions outside of the host body and ensures maternal transmission of the symbiont to the next generation.
- Mother stinkbugs produce the symbiont capsules to their offspring at the expense of their own survival.
Dorsal (left) and ventral (right) sides of Megacopta. punctatissimum laying eggs.
The brown pellets deposited between the eggs are symbiont capsules.
In an ecosystem a great variety of organisms have not only adapted to their habitats but also co-evolved while interacting with each other. The elaborate biological functions arisen from the interactions between organisms amidst such biodiversity are of quite interest from a viewpoint of basic biology and have also been applied in various ways as biogenetic resources that lead to novel bioactive substances and pharmaceutical lead compounds, etc. However, biodiversity is enormous and unexplored frontiers are still everywhere.
Researchers in AIST analyzed the contents of the symbiont capsules produced by adult females of the plataspid stinkbug Megacopta punctatissima and identified a novel secretion protein as the major protein component of the capsules. This protein was shown to protect fragile essential symbiotic bacteria from the harsh condition outside the host and ensure the maternal transmission of the bacteria to the next generation. It was also found that capsule production shortened the female’s lifespan. This indicates mother stinkbugs produce the symbiont capsules to their offspring “at the expense of their own survival.”
This is a new discovery identifying the host factor essential for symbiosis with microorganisms and leading to the elucidation of the molecular mechanism underling the maintenance of symbiosis. This discovery will give a great insight how symbioses with microorganisms shape the evolution of dependencies between generations of hosts.