Biology subjects

Ishiguro, A.

Publications and source records attributed to Ishiguro, A..

3 recordsLinked to original sources

bioRxiv2026

Removing head ganglia in amphibious centipedes unveils descending contribution to versatile locomotor repertoire

Understanding how animals produce a versatile locomotor repertoire requires unraveling the interplay between higher centers, decentralized locomotor circuits, and sensory feedback. However, the principles governing their integration remain elusive. We investigated amphibious centipedes through stepwise neural lesions and neuromechanical modeling. Behavioral experiments revealed that while decentralized circuits autonomously generate coordination, the brain and subesophageal ganglion provide situational flexibility, such as modulating trunk undulation and initiating leg folding. Integrating these findings, our model demonstrated how higher centers selectively inhibit or release lower circuit dynamics. Simulations verified that varying only a few descending control parameters reproduces transitions between slow walking, fast walking, and swimming. This work may capture the essence of the locomotor circuitry that harnesses decentralized self-organization to coordinate the bodys large degrees of freedom.

neuroscience↗

bioRxiv2025

Discovery of a wide variety of α-1,6-cyclized β-1,2-glucan synthases: a new entrance for host-microbe interactions.

-1,6-Cyclized {beta}-1,2-glucans (C{beta}G) are established virulence factors in Xanthomonas, yet functional breadth and distribution of C{beta}Gs in nature have remained unclear. Here, we biochemically identified enzymes synthesizing C{beta}Gs with specific chain lengths, exhibiting potential natural occurrence of various C{beta}Gs. Structural analyses identify subtle variations in a loop, named Loop X, as a key determinant of product size, leading to understanding of the whole picture of the mechanism that controls the sizes. We further demonstrated that C{beta}G composed of 13 glucose units contributes to plant-virulence in Ralstonia pseudosolanacearum, expanding the functional scope of virulence-associated cyclic glucans. Overall, it provides the potential targets for regulating various plant-microbe interactions and also serves as a vital lead to discovering unknown host-microbe interactions with significant potential for agricultural applications.

biochemistry↗

bioRxiv2022

FUS regulates RAN translation through modulating the G-quadruplex structure of GGGGCC repeat RNA in C9orf72-linked ALS/FTD

Abnormal expansions of GGGGCC repeat sequence in the noncoding region of the C9orf72 gene is the most common cause of familial amyotrophic lateral sclerosis and frontotemporal dementia (C9-ALS/FTD). The expanded repeat sequence is translated into dipeptide repeat proteins (DPRs) by noncanonical repeat-associated non-AUG (RAN) translation. Since DPRs play central roles in the pathogenesis of C9-ALS/FTD, we here investigate the regulatory mechanisms of RAN translation, focusing on the effects of RNA-binding proteins (RBPs) targeting GGGGCC repeat RNAs. Using C9-ALS/FTD model flies, we demonstrated that the ALS/FTD-linked RBP FUS suppresses RAN translation and neurodegeneration in an RNA-binding activity-dependent manner. Moreover, we found that FUS directly binds to and modulates the G-quadruplex structure of GGGGCC repeat RNA as an RNA chaperone, resulting in the suppression of RAN translation in vitro. These results reveal a previously unrecognized regulatory mechanism of RAN translation by G-quadruplex-targeting RBPs, providing therapeutic insights for C9-ALS/FTD and other repeat expansion diseases.

neuroscience↗