Realizing a healthy, active, aged society and creating a sustainable society

New Research Results

Discovery That Oxidative Stress Shortens Life Span Under Social Isolation

Researchers at AIST, in collaboration with Mitsubishi Tanabe Pharma America and the University of Lausanne, have used ants, social insects, to reveal part of the mechanism by which social isolation cause behavioral abnormalities and shortened individual life spans.
Various living creatures, including humans, live in groups with a social structure. While we experience in our daily lives that social interactions with family and friends influence our behaviors and physiological states, the actual situation and mechanisms of social interactions have remained largely unknown. This is because only a limited number of species are socially active, and most social organisms have long individual life spans, making it difficult to evaluate them and conduct manipulation experiments.
In this study, we used an ant, a social insect that lives in a complex social structure and has a relatively short individual life span of approximately one year, as a research model and found that social isolation environments induce a high oxidative stress response. By alleviating the oxidative stress in the isolated environment through drug administration, we succeeded in alleviating the behavioral abnormalities and shortened life span of ants in the isolated environment. This is an important achievement that will provide a basis for future research to understand social isolation stress responses in other species and to mitigate and solve problems related to social environment and health.

Using ants, a social insect, to elucidate one aspect of the mechanism of life span shortening in an isolated environment.
*Revised figure from Koto et al. (2023)

Insects Switch the Form and Function of Their Gut Symbionts and Their Habitats Through "Metamorphosis"

AIST Researchers, in collaboration with the University of Tokyo, have shown that in the stinkbug Plautia stali, for which the gut symbiotic bacteria are essential for survival, (i) the morphology and function of the symbiotic organ developed at the posterior end of the digestive tract differ between nymphs before metamorphosis and adults after metamorphosis, (ii) the transition of the symbiotic organ from the nymphal to adult form is controlled by metamorphosis-regulating genes, (iii) the nymphal symbiont is specialized for retention of the gut symbiotic bacteria, whereas the adult symbiont is, in addition, involved in food digestion and absorption, (iv) the adult symbiont synthesizes large amounts of amino acids necessary for eggshell formation, and (v) these metamorphosis-associated changes of both the stinkbug host and the bacterial symbiont support the vigorous reproductive capacity of adult stinkbugs, which consume large amounts of food and lay an egg mass every few days.
This study demonstrates that metamorphosis, one of the factors that support insect diversity and prosperity, regulates the function of not only the insects themselves but also the symbiotic bacteria therein. This is an important achievement that uncovers a high degree of functional integration of different organisms in a symbiotic relationship, and may contribute to the development of pest control technologies targeting the mechanisms of metamorphosis and symbiosis.

The brown-winged green stinkbugs Plautia stali used in this study.
From left to right: 5^th instar normal nymph; 6^th instar nymph-like insect (= supernumerary nymph) induced by suppression of E93 gene; 5^th instar adult-like insect (= precocious adult) induced by suppression of Kr-h1 gene; 6^th instar normal adult.

Open Innovation Laboratory

Since FY 2016, as a part of the “Open Innovation Arena concept” promoted by the Ministry of Economy, Trade and Industry (METI), AIST has created the concept of “open innovation laboratories” (OILs), collaborative research bases located on university campuses, and has been engaged in their provision. We are planning to establish more than ten OILs by FY 2020.

AIST will merge the basic research carried out at universities, etc. with AISTʼs goal-oriented basic research and applied technology development, and will promote bridging research and evelopment and industry by the establishment of OILs.