Biology subjects

Miyagi, H.

Publications and source records attributed to Miyagi, H..

4 recordsLinked to original sources

bioRxiv2026

Individual leadership in cattle persists when collective movement is induced by robotic herding

In social species, some individuals consistently lead collective movements while others follow, but whether these roles persist when movement is externally induced remains unknown. Robotic herding offers a way to address this: animals are displaced by an approaching device, yet retain the option to stay, to move or to follow a conspecific that has moved. We recorded spontaneous group departures in a herd of 18 Japanese Black cows on three days, then recorded which individuals initiated movement away from a quadruped robot, which followed and which remained, across an eight-day herding trial. Cows that frequently initiated spontaneous departures and attracted followers also initiated movement away from the robot more often and drew more followers, whereas habitual followers tended to be less effective initiators. Follower frequency during herding was unrelated to any characteristic measured. Individual leadership therefore persists when movement is induced by a robot. Behavioural roles may thus be expressed under moderate external constraint, provided animals retain some freedom of choice. Identifying leaders from spontaneous departures offers a practical route to more efficient robotic herding.

animal behavior and cognition↗

bioRxiv2026

Animal-robot interaction in the field: stronger responses and slower habituation of grazing cattle to a quadruped robot than to a drone

Robotic herding offers a promising off-animal approach to controlling the spatial distribution of grazing livestock. Nevertheless, the habituation of cattle to herding stimuli remains a critical obstacle to its practical use. This study presents the first field investigation of behavioral responses of grazing cattle to herding by a quadruped robot. We compared the herding efficacy of a drone and a quadruped robot, and tracked daily changes in responsiveness during continuous herding. Trials were conducted in a 1.1-ha pasture with Japanese Black breeding cows from June to October 2023. The quadruped robot elicited stronger avoidance responses with shorter latencies than the drone, and herding was more successful with the robot. During consecutive daily herding with the robot, behavioral responsiveness declined progressively over the initial 5 days, at a markedly slower rate than previously reported for drone herding. Following a 24-day interruption, responsiveness partially increased, but declined rapidly again over the subsequent two days. These results indicate that the quadruped robot constitutes a more persistent aversive stimulus than a drone for grazing cattle, although habituation management strategies (such as diversifying stimuli or combining sensory modalities) will be necessary for sustained control of grazing distribution.

animal behavior and cognition↗

bioRxiv2020

Origin of diverse phosphorylation patterns in the ERBB system

Intercellular signals induce various cellular responses, including growth, proliferation, and differentiation, via the dynamic processes of signal transduction pathways. For cell-fate decisions, ligand-binding induces the phosphorylation of ERBB receptors, which in turn activate downstream molecules. The ERBB family includes four subtypes, which diverged through two gene duplications from a common ancestor, of different kinetic properties. Differences in the expression patterns of the subtypes have been reported between different organs in the human body. However, how these different kinetic and expression properties influence the diverse phosphorylation dynamics of ERBB proteins is not well understood. Here we study the phosphorylation dynamics by experimental and mathematical analyses. The experimental measurements clarified that the phosphorylation dynamics heavily depend on the ERBB expression profiles. We developed a mathematical model consisting of the four subtypes as monomers, homodimers and heterodimers and estimated the rate constants governing the phosphorylation dynamics from the experimental data. To understand the origin of the diversity of the phosphorylation responses of the ERBB system, we analyzed the expression profiles and reaction rates of the ERBB subtypes. The difference in phosphorylation rates between ERBB subtypes showed a much larger contribution to the diversity of the phosphorylation responses than did the dimerization rates. This result implies that divergent evolution in phosphorylation reactions rather than in dimerization reactions after whole genome duplications was essential for increasing the diversity of the phosphorylation responses. Statement of SignificanceIt is known that the expression patterns of a protein family are different between different organs in the human body. This difference is considered essential for the functional diversity between organs. However, the dynamical processes that translate expression patterns into function are not well understood. Here we study the origin of the diversity in ERBB phosphorylation patterns by combining experimental and mathematical methods. We confirmed experimentally that phosphorylation patterns depend on the ERBB expression profiles. Our mathematical model found that differences in phosphorylation rates made the largest contribution to the diversity of phosphorylation patterns between ERBB subtypes.

systems biology↗

bioRxiv2019

Cell-to-cell diversification in ERBB-RAS-MAPK signal transduction that produces cell-type specific growth factor responses

Growth factors regulate cell fates, including their proliferation, differentiation, survival, and death, according to the cell type. Even when the response to a specific growth factor is deterministic for collective cell behavior, significant levels of fluctuation are often observed between single cells. Statistical analyses of single-cell responses provide insights into the mechanism of cell fate decisions but very little is known about the distributions of the internal states of cells responding to growth factors. Using multi-color immunofluorescent staining, we have here detected the phosphorylation of seven elements in the early response of the ERBB-RAS-MAPK system to two growth factors. Among these seven elements, five were analyzed simultaneously in distinct combinations in the same single cells. Although principle component analysis suggested cell-type and input specific phosphorylation patterns, cell-to-cell fluctuation was large. Mutual information analysis suggested that cells use multitrack (bush-like) signal transduction pathways under conditions in which clear cell fate changes have been reported. The clustering of single-cell response patterns indicated that the fate change in a cell population correlates with the large entropy of the response, suggesting a bet-hedging strategy is used in decision making. A comparison of true and randomized datasets further indicated that this large variation is not produced by simple reaction noise, but is defined by the properties of the signal-processing network. Author SummaryHow extracellular signals, such as growth factors (GFs), induce fate changes in biological cells is still not fully understood. Some GFs induce cell proliferation and others induce differentiation by stimulating a common reaction network. Although the response to each GF is reproducible for a cell population, not all single cells respond similarly. The question that arises is whether a certain GF conducts all the responding cells in the same direction during a fate change, or if it initially stimulates a variety of behaviors among single cells, from which the cells that move in the appropriate direction are later selected. Our current statistical analysis of single-cell responses suggests that the latter process, which is called a bet-hedging mechanism is plausible. The complex pathways of signal transmission seem to be responsible for this bet-hedging.

systems biology↗