We try to contribute to the construction of a sustainable society by conducting research on the life sciences from the basics to the applications to address the various issues faced by modern society. Much of our research is carried out in collaboration with universities, research institutes and private companies in Japan and abroad.


Exploiting Unused Biological Resources



  Fig.1 Teleogryllus occipitalis


Fig.2 Crickets whose genome have been ever sequenced
As the world's population grows rapidly, the demand for animal protein will be increasing, and the supply will not be able to keep up (Protein crisis). Animal protein is not only important for human food, but also for a key feed ingredient for livestock and aquaculture. We are therefore focusing on crickets as an alternative animal protein source. Crickets (1) have a relatively short developmental period, (2) are omnivorous, and (3) can be raised at a high density, (4) have low risks for zoonotic diseases. Nevertheless, its production costs are still high, requiring efficient and low environmental impact production.

As a first step towards achieving highly efficient and stable production of crickets, we have been the first in the world to successfully sequence the whole genome of Asian edible crickets (Figure 1). This makes it possible to efficiently search for genes that can be targeted for breeding improvement. Currently, we are developing a reverse genetic approach to achieve highly efficient production of this species. We are also conducting basic research based on genome evolutionary studies using the entire genome information of crickets from around the world (Figure 2).

Homeostatic mechanism of the endocannabinoid system


Fig.3 Cannabinoid CB1 receptor regulates
mitochondrial dynamics and autophagy
in hippocampal neuron

Aging research is becoming increasingly important as the aging population accelerates in developed countries. Aging is viewed as a breakdown in the mechanisms that maintain biological homeostasis, thus understanding of its mechanisms is important for solving various problems in the super-aging society. The endocannabinoid system (ECS) is responsible for the regulation of biological homeostasis in organs and tissues throughout the body, including the central nervous system and muscles. The ECS has been reported to change with age. However, how the ECS is involved in age-related changes in central nervous system is not clear.

Therefore, we focused on the type 1 cannabinoid (CB1) receptor, a component of the ECS. The CB1 receptor is thought to be one of the most highly expressed G-protein-coupled receptor in the central nervous system. Interestingly, mice that knocked out the CB1 receptor showed a rapid increase in age-related memory deficits. We asked how CB1 receptors are involved in age-related memory changes, and found that the CB1 receptor plays an important role in mitochondrial quality control in hippocampal neurons. This provides clues to the mechanisms linking the intrinsic cannabinoid system and age-related changes in the central nervous system. Currently, we are exploring further molecular
mechanisms and biological functions in other organs.

References

[1] Kataoka, K., Minei, R., Ide, K., Ogura, A., Takeyama, H., Takeda, M., Suzuki, T., Yura, K., Asahi, T. (2020) The Draft Genome Dataset of the Asian Cricket Teleogryllus occipitalis for Molecular Research Toward Entomophagy. Front. Genet. 11, 470. DOI: 10.3389/fgene.2020.00470

[2] Kataoka, K., Bilkei-Gorzo, A., Nozaki, C., Togo, A., Nakamura, K., Ohta, K., Zimmer, A., Asahi, T. (2020) Age-dependent Alteration in Mitochondrial Dynamics and Autophagy in Hippocampal Neuron of Cannabinoid CB1 Receptor-deficient Mice. Brain Res. Bull. 160, 40-49. DOI: 10.1016/j.brainresbull.2020.03.014

[3] Kataoka, K., Bilkei-Gorzo, A., Zimmer, A., Asahi, T. (2020) Immunohistochemical Characterization of Phosphorylated Ubiquitin in the Mouse Hippocampus. bioRxiv, DOI: 10.1101/2020.01.20.912238