Updated on 2026/09/15

Information

 

写真a

 
FUKAI YOHSUKE
 
Organization
Faculty of Science Department of Physics Associate Professor
Title
Associate Professor
Contact information
メールアドレス
Profile
A researcher in biophysics and nonequilibrium physics. After obtaining a Ph.D. from the Department of Physics, the University of Tokyo, worked as a research scientist at RIKEN, and has held the current position since September 2026.

Research Areas

  • Life Science / Biophysics

  • Natural Science / Biophysics, chemical physics and soft matter physics

  • Natural Science / Mathematical physics and fundamental theory of condensed matter physics

Research History

  • Kyushu University Faculty of Sciences Associate Professor 

    2026.9 - Present

      More details

    Country:Japan

    researchmap

  • 特定国立研究開発法人理化学研究所 開拓研究所 川口生体非平衡物理学研究室 研究員 

    2025.4 - 2026.8

      More details

    Country:Japan

    researchmap

  • 特定国立研究開発法人理化学研究所 生命機能科学研究センター 生体非平衡物理学理研白眉研究チーム 研究員 

    2022.9 - 2025.3

      More details

    Country:Japan

    researchmap

  • 特定国立研究開発法人理化学研究所 生命機能科学研究センター 生体非平衡物理学理研白眉研究チーム 基礎科学特別研究員 

    2019.4 - 2022.9

      More details

    Country:Japan

    researchmap

Education

  • The University of Tokyo   Graduate School of Science   Department of Physics, Ph. D. Course

    2016.4 - 2019.3

      More details

  • The University of Tokyo   Graduate School of Science   Department of Physics, Master Course

    2014.4 - 2016.3

      More details

  • The University of Tokyo   Faculty of Science   Department of Physics

    2012.4 - 2014.3

      More details

  • The University of Tokyo   Collage of Arts and Sciences  

    2010.4 - 2012.3

      More details

Research Interests・Research Keywords

  • Research theme: Interface growth

    Keyword: Interface growth

    Research period: 2026

  • Research theme: 生物物理学

    Keyword: 生物物理学

    Research period: 2026

  • Research theme: Liquid crystla electroconvection

    Keyword: Liquid crystla electroconvection

    Research period: 2026

  • Research theme: Universality classes

    Keyword: Universality classes

    Research period: 2026

  • Research theme: 再構成クロマチン

    Keyword: 再構成クロマチン

    Research period: 2026

  • Research theme: Scale invariance

    Keyword: Scale invariance

    Research period: 2026

  • Research theme: クロマチン修飾

    Keyword: クロマチン修飾

    Research period: 2026

Awards

  • SFS2015 Best Poster Award for Young Researcher

    2015.8   International Symposium on Fluctuation and Structure out of Equilibrium 2015  

    Yohsuke T. Fukai

     More details

Papers

  • Universal interface fluctuations in absorbing-state phase transitions

    Yohsuke T. Fukai, Keiichi Tamai, Tetsuya Hiraiwa

    2026.5

     More details

    Authorship:Lead author, Corresponding author   Publisher:arXiv  

    Despite similarities between models exhibiting absorbing phase transitions (APTs) and those showing Kardar-Parisi-Zhang (KPZ) growth, the relationship between these universal fluctuations has remained elusive. We numerically study (1+1)-dimensional interfaces of (2+1)-dimensional models showing APTs of directed percolation (DP) and compact directed percolation (CDP) classes with an active boundary, finding a universal crossover from short-time APT-governed fluctuations to long-time KPZ fluctuations. Upon rescaling time and length by the APT correlation time and length, the cumulants of the interface height distributions collapse onto a single scaling function. The fluctuation properties of the discrete Domany-Kinzel model and the continuum stochastic Fisher-Kolmogorov-Petrovsky-Piskunov (sFKPP) equation coincide, indicating that the KPZ growth parameters are determined solely by fundamental properties of the APT. For the CDP sFKPP equation, a dimensionless parameter tunes both the critical interface distribution and the KPZ parameters, with the interface properties of the biased voter model recovered in a limiting case. These results uncover a universal crossover in which KPZ fluctuations emerge from APT fluctuations at long times, linking paradigmatic universality classes of nonequilibrium scale-invariant phenomena.

    DOI: 10.48550/ARXIV.2605.17781

    arXiv

    researchmap

    Other Link: https://arxiv.org/pdf/2605.17781v1

  • Gene-scale in vitro reconstitution reveals histone acetylation directly controls chromatin architecture Reviewed

    Lisa Yamauchi, Satoshi Morita, Tomoya Kujirai, Kyogo Kawaguchi, Mitsutaka Kadota, Somayeh Zeraati, Setsuko Kanamura, Masatoshi Wakamori, Chiharu Tanegashima, Yohsuke T. Fukai, Mikako Shirouzu, Hitoshi Kurumizaka, Takashi Umehara

    Science Advances   11 ( 47 )   1 - 13   2025.11   ( eISSN:2375-2548 )

     More details

    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Cold Spring Harbor Laboratory  

    Chromatin organization plays a crucial role in gene regulation [1, 2, 3], but disentangling the contributions of various epigenetic components to gene-scale chromatin structure remains challenging. Whilein vitrochromatin reconstitution enables controlled studies on the effect of bio-chemical factors on the structure, current methods are either limited to short arrays or lack control over histone modification patterns. Here we directly test how histone modification affects higher-order chromatin architecture by characterizing gene-scale reconstituted chromatin using single-molecule microscopy andin vitroHi-C. We reconstitute 20-kilobase chromatin arrays with histone modification patterns controlled at 12-nucleosome resolution, achieving complete assembly of 96 nucleosomes in the designed order as confirmed by atomic force microscopy and longread sequencing. Observing end-to-end fluctuations of the reconstituted arrays, we find that increasing the density of acetylated nucleosomes leads to larger structural fluctuations with longer relaxation times, consistent with the predictions of a polymer model with hydrodynamic interactions. We demonstrate throughin vitroHi-C how acetylation reduces contact frequency between nucleosomes and induces open conformations. In heterogeneously modified arrays, differential contact probabilities between acetylated and unmodified regions lead to distinct structural domains. The results establish the physical principles by which histone modifications directly modulate chromatin architecture through altered nucleosome-nucleosome interactions, providing a quantitative framework for understanding and engineering genome organization.

    DOI: 10.1126/sciadv.adx9282

    Web of Science

    Scopus

    PubMed

    researchmap

  • Initial perturbation matters: implications of geometry-dependent universal Kardar-Parisi-Zhang statistics for spatiotemporal chaos Reviewed

    Fukai, Yohsuke T., Takeuchi, Kazumasa A.

    Chaos: An Interdisciplinary Journal of Nonlinear Science   31 ( 11 )   111103 - 111103   2021.11   ( ISSN:1054-1500 eISSN:1089-7682 )

     More details

    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:{American Institute of Physics}  

    Infinitesimal perturbations in various systems showing spatiotemporal chaos (STC) evolve following the power laws of the Kardar-Parisi-Zhang (KPZ) universality class. While universal properties beyond the power-law exponents, such as distributions and correlations, and their geometry dependence, are established for random growth and related KPZ systems, the validity of these findings to deterministic chaotic perturbations is unknown. Here we fill this gap between stochastic KPZ systems and deterministic STC perturbations by conducting extensive simulations of a prototypical STC system, namely the logistic coupled map lattice. We show that the perturbation interfaces, defined by the logarithm of the modulus of the perturbation vector components, exhibit the universal, geometry-dependent statistical laws of the KPZ class, despite the deterministic nature of STC. We demonstrate that KPZ statistics for three established geometries arise for different initial profiles of the perturbation, namely point (l ocal), uniform, and "pseudo-stationary" initial perturbations, the last being the statistically stationary state of KPZ interfaces given independently of the Lyapunov vector. This geometry dependence lasts until the KPZ correlation length becomes comparable to the system size. Thereafter, perturbation vectors converge to the unique Lyapunov vector, showing characteristic meandering, coalescence, and annihilation of borders of piece-wise regions that remain different from the Lyapunov vector. Our work implies that the KPZ universality for stochastic systems generally characterizes deterministic STC perturbations, providing new insights for STC, such as the universal dependence on initial perturbation and beyond.

    DOI: 10.1063/5.0071658

    researchmap

  • Kardar-Parisi-Zhang Interfaces with Curved Initial Shapes and Variational Formula Reviewed

    Fukai, Yohsuke T., Takeuchi, Kazumasa A.

    Physical Review Letters   124 ( 6 )   060601 - 060601   2020.2   ( ISSN:0031-9007 eISSN:1079-7114 )

     More details

    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:{American Physical Society}  

    DOI: 10.1103/PhysRevLett.124.060601

    arXiv

    researchmap

    Other Link: https://link.aps.org/article/10.1103/PhysRevLett.124.060601

  • GEFF: Graph Exchange File Format Reviewed

    Morgan Schwartz, Caroline Malin-Mayor, Talley Lambert, Teun Huijben, Jan Funke, Laura Xénard, Mark Kittisopikul, Draga Doncila Pop, Yohsuke Fukai, Jordão Bragantini, Melisande Croft, Anniek Stokkermans, Georgeos Hardo, Benjamin Gallusser, Kasia Kedziora, Jean-Yves Tinevez, Ko Sugawara, Tobias Pietzsch, Ilan Theodoro

    Journal of Open Source Software   2026.4

     More details

    Publishing type:Research paper (scientific journal)  

    DOI: 10.21105/joss.10143

    researchmap

  • Optical microscopic imaging, manipulation, and analysis methods for morphogenesis research Invited

    Takanobu A Katoh, Yohsuke T Fukai, Tomoki Ishibashi

    Microscopy   73 ( 3 )   226 - 242   2023.12   ( ISSN:20505698 eISSN:20505701 )

     More details

    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Oxford University Press (OUP)  

    Abstract

    Morphogenesis is a developmental process of organisms being shaped through complex and cooperative cellular movements. To understand the interplay between genetic programs and the resulting multicellular morphogenesis, it is essential to characterize the morphologies and dynamics at the single-cell level and to understand how physical forces serve as both signaling components and driving forces of tissue deformations. In recent years, advances in microscopy techniques have led to improvements in imaging speed, resolution and depth. Concurrently, the development of various software packages has supported large-scale, analyses of challenging images at the single-cell resolution. While these tools have enhanced our ability to examine dynamics of cells and mechanical processes during morphogenesis, their effective integration requires specialized expertise. With this background, this review provides a practical overview of those techniques. First, we introduce microscopic techniques for multicellular imaging and image analysis software tools with a focus on cell segmentation and tracking. Second, we provide an overview of cutting-edge techniques for mechanical manipulation of cells and tissues. Finally, we introduce recent findings on morphogenetic mechanisms and mechanosensations that have been achieved by effectively combining microscopy, image analysis tools and mechanical manipulation techniques.

    DOI: 10.1093/jmicro/dfad059

    Web of Science

    Scopus

    PubMed

    CiNii Research

    researchmap

    Other Link: https://academic.oup.com/jmicro/article-pdf/73/3/226/58122776/dfad059.pdf

  • LapTrack: linear assignment particle tracking with tunable metrics

    Yohsuke T Fukai, Kyogo Kawaguchi

    Bioinformatics   39 ( 1 )   2022.12   ( ISSN:1367-4803 eISSN:13674811 )

     More details

    Authorship:Lead author, Corresponding author   Language:English   Publishing type:Research paper (scientific journal)   Publisher:Cold Spring Harbor Laboratory  

    Motivation

    Particle tracking is an important step of analysis in a variety of scientific fields, and is particularly indispensable for the construction of cellular lineages from live images. Although various supervised machine learning methods have been developed for cell tracking, the diversity of the data still necessitates heuristic methods that require parameter estimations from small amounts of data. For this, solving tracking as a linear assignment problem (LAP) has been widely applied and demonstrated to be efficient. However, there has been no implementation that allows custom connection costs, parallel parameter tuning with ground truth annotations, and the functionality to preserve ground truth connections, limiting the application to datasets with partial annotations.

    Results

    We developed LapTrack, a LAP-based tracker which allows including arbitrary cost functions and inputs, parallel parameter tuning, and ground-truth track preservation. Analysis of real and artificial datasets demonstrates the advantage of custom metric functions for tracking score improvement. The tracker can be easily combined with other Python-based tools for particle detection, segmentation, and visualization.

    Availability and implementation

    LapTrack is available as a Python package on PyPi, and the notebook examples are shared at https://github.com/yfukai/laptrack. The data and code for this publication are hosted at https://github.com/NoneqPhysLivingMatterLab/laptrack-optimization.

    Contact

    ysk@yfukai.net

    DOI: 10.1093/bioinformatics/btac799

    Web of Science

    Scopus

    PubMed

    CiNii Research

    researchmap

  • Direct Evidence for Universal Statistics of Stationary Kardar-Parisi-Zhang Interfaces Reviewed

    Iwatsuka, Takayasu, Fukai, Yohsuke T., Takeuchi, Kazumasa A.

    Physical Review Letters   124 ( 25 )   250602 - 250602   2020.6   ( ISSN:0031-9007 eISSN:1079-7114 )

     More details

    Publishing type:Research paper (scientific journal)   Publisher:{American Physical Society}  

    The nonequilibrium steady state of the one-dimensional (1D)
    Kardar-Parisi-Zhang (KPZ) universality class is studied in-depth by exact
    solutions, yet no direct experimental evidence of its characteristic
    statistical properties has been reported so far. This is arguably because, for
    an infinitely large system, infinitely long time is needed to reach such a
    stationary state and also to converge to the predicted universal behavior. Here
    we circumvent this problem in the experimental system of growing liquid-crystal
    turbulence, by generating an initial condition that possesses a long-range
    property expected for the KPZ stationary state. The resulting interface
    fluctuations clearly show characteristic properties of the 1D stationary KPZ
    interfaces, including the convergence to the Baik-Rains distribution. We also
    identify finite-time corrections to the KPZ scaling laws, which turn out to
    play a major role in the direct test of the stationary KPZ interfaces. This
    paves the way to explore unsolved properties of the stationary KPZ interfaces
    experimentally, making possible connections to nonlinear fluctuating
    hydrodynamics and quantum spin chains as recent studies unveiled relation to
    the stationary KPZ.

    DOI: 10.1103/PhysRevLett.124.250602

    arXiv

    researchmap

    Other Link: http://harvest.aps.org/v2/journals/articles/10.1103/PhysRevLett.124.250602/fulltext

  • Experimental and Numerical Investigation of Universal Fluctuations in Out-of-Equilibrium Interface Growth Reviewed

    Yohsuke T. Fukai

    2018.12

     More details

    Publishing type:Doctoral thesis  

    researchmap

  • Kardar-Parisi-Zhang Interfaces with Inward Growth Reviewed

    Yohsuke T. Fukai

    Physical Review Letters   119 ( 3 )   030602 - 030602   2017.7   ( ISSN:0031-9007 )

     More details

    Authorship:Lead author, Corresponding author   Publishing type:Research paper (scientific journal)   Publisher:American Physical Society ({APS})  

    We study the $(1+1)$-dimensional Kardar-Parisi-Zhang (KPZ) interfaces growing
    inward from ring-shaped initial conditions, experimentally and numerically,
    using growth of a turbulent state in liquid-crystal electroconvection and an
    off-lattice Eden model, respectively. To realize the ring initial condition
    experimentally, we introduce a holography-based technique that allows us to
    design the initial condition arbitrarily. Then, we find that fluctuation
    properties of ingrowing circular interfaces are distinct from those for the
    curved or circular KPZ subclass and, instead, are characterized by the flat
    subclass. More precisely, we find an asymptotic approach to the Tracy-Widom
    distribution for the Gaussian orthogonal ensemble and the $\text{Airy}_1$
    spatial correlation, as long as time is much shorter than the characteristic
    time determined by the initial curvature. Near this characteristic time,
    deviation from the flat KPZ subclass is found, which can be explained in terms
    of the correlation length and the circumference. Our results indicate that the
    sign of the initial curvature has a crucial role in determining the universal
    distribution and correlation functions of the KPZ class.

    DOI: 10.1103/PhysRevLett.119.030602

    PubMed

    arXiv

    researchmap

▼display all

Presentations

▼display all

Professional Memberships

  • 日本生物物理学会

    2025.11 - Present

      More details

  • 日本分子生物学会

    2023.10 - Present

      More details

  • THE PHYSICAL SOCIETY OF JAPAN

    2015.7 - Present

      More details

Research Projects

  • 長鎖クロマチンの3D構造観察に基づく物理モデル推定

    Grant number:JPMJAX24LF  2024.9 - 2027.3

    科学技術振興機構   戦略的な研究開発の推進 戦略的創造研究推進事業 ACT-X  

      More details

    Authorship:Principal investigator  Grant type:Competitive funding other than Grants-in-Aid for Scientific Research

  • オミックス計測技術から比較する、細胞内と人工環境のヒストンリサイクリング動態

    Grant number:25K24823  2024.4 - 2027.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Transformative Research Areas (B)

    三浦 尚, 大野 雅恵, 深井 洋佑

      More details

    Grant type:Scientific research funding

    真核生物のD N A 複製では、鋳型D N A 鎖上のヒストンが新生DNA鎖へ再利用され、クロマチン状態は細胞分裂を経て娘細胞へ継承される。近年、次世代シーケンス(N G S)技術を用いたオミックス解析により、このヒストンリサイクリング動態の理解が進んだ。その一方で、従来のN G S 解析は細胞内動態の記述にとどまることが多く、分子機構の解明には課題が残る。そこで本研究では、再構成した人工染色体D N A 複製系にオミックス計測技術を組み合わせ、細胞内と人工環境下の比較から、ヒストンリサイクリング動態を再現する最小要素を明らかにし、エピゲノム継承の基本原理に迫る。

    CiNii Research

  • Studying modification-pattern-dependent structure and function of long chromatin array via reconstitution and single molecule observation

    Grant number:22K14016  2022.4 - 2026.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Early-Career Scientists

    深井 洋佑

      More details

    Grant type:Scientific research funding

    化学修飾依存的なヌクレオソーム間の相互作用がクロマチン構造形成に重要な役割を果たすという視点が広く認められていること、高分子物理学的な視点が大規模構造の理解に重要であると考えられることを踏まえ、研究代表者らは、ヌクレオソーム修飾のパターンを自在に制御した長鎖クロマチンの再構成系を初めて構築した。本研究では、この再構成クロマチンの様々な条件での一分子観察を通して、修飾パターン依存的な構造・動態の変化や力学的特性・修飾の変化による非平衡ダイナミクスを明らかにすることを目指す。

    CiNii Research

  • オミックス計測技術から比較する、細胞内と人工環境のヒストンリサイクリング動態

    Grant number:24H00886 

    三浦 尚, 大野 雅恵, 深井 洋佑

      More details

    Grant type:Scientific research funding

    真核生物のD N A 複製では、鋳型D N A 鎖におけるヒストンがリーディング鎖およびラギング鎖に再利用され、クロマチンは細胞分裂後の娘細胞に受け継がれる。最近、次世代シーケンス(N G S)技術を用いたオミックス解析により、このヒストンリサイクリング動態が明らかにされた。しかし、従来のN G S 解析では、主に細胞内の動態に関する記述的研究が行われ、分子機構の解明には多くの課題がある。そのため、本研究では、再構成した人工染色体のD N A 複製系において、オミックス計測技術を活用し、細胞内(in vivo)と人工環境(in vitro)におけるヒストンリサイクリング動態の類似点や相違点を明らかにする。

    CiNii Research