Biology subjects

Fukuoka, M.

Publications and source records attributed to Fukuoka, M..

4 recordsLinked to original sources

bioRxiv2024

Symbiotic Bacterial Partners for Chemical Defense are Vertically Transmitted in a Marine Sponge

Marine sponges host diverse symbiotic bacteria, some of which are essential for chemical defense. However, the mechanisms governing the inheritance of these defensive symbionts remain elusive. Here we report the first case of a transmission mechanism for symbionts producing cytotoxins in the sponge Mycale nullarosette, for which we established the full life-cycle cultivation method. The identification of Candidatus Synechomycale tutelaris as the cytotoxins producer enabled us to unveil their vertical transmission to offspring via bacteriocyte-like structures from the embryonic stage. This study demonstrates that sponges have evolved a sophisticated system to ensure the inheritance of significant bacterial partners crucial for host defense, which is likely one of the reasons that sponges have survived throughout the long history of multicellular organisms.

microbiology↗

bioRxiv2023

Wnt5a-Ror2 signaling activates p62-Nrf2 axis in reactive astrocytes after brain injury

In the brains under pathological conditions, astrocytes become reactive astrocytes that exhibit various context-dependent functions through the regulation of specific signaling pathways and transcriptional mechanisms in response to environmental changes. Reactive astrocytes induced in injured brains begin proliferating and play a role in promoting protection and repair of damaged tissues, but the relationship between the proliferative characteristics and tissue-protective and repair functions of reactive astrocytes remains unclear. Here, we show that growth factor signaling elicited by bFGF and HB-EGF, whose expression is up-regulated in the injured brains, acts synergistically with inflammatory cytokine signaling in astrocytes, thereby markedly up-regulating gene expression of the Ror-family protein Ror2, a receptor for Wnt5a. Activation of Wnt5a-Ror2 signaling in astrocytes results in intracellular accumulation of phosphorylated p62, thereby activating antioxidative transcription factor Nrf2. Finally, we provide evidence demonstrating that forced activation of Wnt5a-Ror2-p62-Nrf2 signaling axis in astrocytes reduces cellular damage caused by hemin, a degradation product of hemoglobin, and promotes repair of the damaged blood brain barrier after brain hemorrhage.

molecular biology↗

bioRxiv2022

Embodiment of Supernumerary Robotic Limbs in Virtual Reality

The supernumerary robotic limb system expands the motor function of human users by adding extra artificially designed limbs. It is important for us to embody the system as if it is a part of ones own body and to maintain cognitive transparency in which the cognitive load is suppressed. Embodiment studies have been conducted with an expansion of bodily functions through a "substitution" and "extension." However, there have been few studies on the "addition" of supernumerary body parts. In this study, we developed a supernumerary robotic limb system that operates in a virtual environment, and then evaluated whether the extra limb can be regarded as a part of ones own body using a questionnaire and whether the perception of peripersonal space changes with a visuotactile crossmodal congruency task. We found that the participants can embody the extra-limbs after using the supernumerary robotic limb system. We also found a positive correlation between the perceptual change in the crossmodal congruency task and the subjective feeling that the number of ones arms had increased (supernumerary limb sensation). These results suggest that the addition of an extra body part may cause the participants to feel that they had acquired a new body part that differs from their original body part through a functional expansion.

neuroscience↗

bioRxiv2020

Canopy micrometeorology monitoring in diverse climates innovatively improves the evaluation heat-induced sterility of rice under climate change

This study is the first and unique of open-field studies to assess the determination process of heat-induced spikelet sterility (HISS) of rice by using the same variety and the same monitoring system, MINCER (Micrometeorological Instrument for Near Canopy Environment of Rice), covering the major-rice growing regions from Sub-Saharan Africa, South, Southeast, and East Asia, and USA. Applying the observation data from the monitoring network, MINCERnet, to the canopy heat balance model, IM2PACT, it was quantitatively corroborated in open-field conditions worldwide that the canopy and panicle transpiration and their evaporative cooling effect played a great role on the micrometeorological gap between the ambient air temperature and the panicle temperature, and that the sterility rate due to HISS in open-fields can be evaluated accurately in diverse climates by the mean panicle temperature at flowering hours in the flowering period. The heat balance structure suggested that the risk of HISS should be higher in high humidity climates rather than in dry climates also in the future, which lead to the importance of the humidity accuracy as well as of the air temperature in climate scenarios and their spatial downscaling for future prediction of rice heat stress and production. Applying the heat-tolerant variety was suggested to be able to keep the sterility due to HISS low in all climates. It is needed of the approach using the panicle temperature as indicator of HISS by intervening sub-model and/or monitoring of micrometeorology inside the canopy to reduce uncertainties in future rice yield prediction under various adaptation measures.

plant biology↗