2025 Hyper Recent •CC0 1.0 Universal

This work is dedicated to the public domain. No rights reserved.

Access Preprint From Server
July 17th, 2025
Version: 2
UMR7141: Chloroplast Biology and Light Sensing in Microalgae, Institut de Biologie Physico-Chimique, Sorbonne University, CNRS, Paris, France
biophysics
biorxiv

Interplay between high-energy quenching and state transitions in Chlamydomonas reinhardtii: a single-cell approach

Lahlou, A.Open in Google Scholar•Orlando, M.Open in Google Scholar•Bujaldon, S.Open in Google Scholar•Gaultier, W.Open in Google Scholar•Israelievitch, E.Open in Google Scholar•Hanappe, P.Open in Google Scholar•Le Saux, T.Open in Google Scholar•Jullien, L.Open in Google Scholar•Colliaux, D.Open in Google Scholar•Bailleul, B.Open in Google Scholar

Studying cell-to-cell heterogeneity is essential to understand how unicellular organisms respond to stresses. We introduce a single-cell framework that enables the study of interactions between photosynthetic traits within individuals with the same genotype and cellular context, along with common histories. Our approach combines single-cell imaging of chlorophyll a fluorescence with machine learning and we study light stress responses in Chlamydomonas reinhardtii as a proof-of-concept. This framework allows us to score the extent of high-light responses such as state transitions (qT) and high-energy quenching (qE), and reveals significant cell-to-cell response heterogeneity. We uncover a strong correlation between qT and qE at the individual level, an interaction that cannot be detected by bulk measurements. Our study highlights the value of single-cell phenotypic analysis for uncovering relationships between traits. We detail the key aspects that come into play to generalize the method to other multi-trait systems.

Similar Papers

biorxiv
Thu Jul 17 2025
Cell-substrate friction controls biofilm development
Bacteria often live in biofilms, surface-attached communities that can form on nearly any surface, from coarse sands to smooth glass. It is often hypothesized that cell-substrate friction can impact biofilm growth and development on these disparate surfaces. However, the experimental difficulty in measuring the friction between a biofilm and its surface has limited our understanding of how frictio...
Pokhrel, A.
•
Copeland, R.
•
Hejri, M.
•
Belpaire, T. E. R.
...•
Yunker, P. J.
biorxiv
Thu Jul 17 2025
Label-Free Fluorescence Microscopy Reveals Multiphase Organization in Biomolecular Condensates
Phase transitions of proteins and nucleic acids (NA) leading to the formation of biomolecular condensates have been linked to various biological functions. Given the growing number of proteins/NA predicted to undergo liquid-liquid phase separation (LLPS), efficient tools to investigate this behavior are critical to advancing our understanding of biomolecular condensate function. The current standa...
Acharya, B.
•
Castillo, S.
•
Kodirov, R.
•
Shakya, A.
biorxiv
Thu Jul 17 2025
Robust Estimation of Rotational Diffusion Tensors of Proteins from Molecular Dynamics Simulations
Rotational diffusion is a fundamental physical process that determines the rotational motion of proteins in solution. It plays a role, for example, in molecular association processes and in theories of spectroscopic experiments in solution. In addition to experimental methods, molecular dynamics (MD) simulations have emerged as a powerful method to investigate rotational diffusion. Thereby, diffus...
Holtbrügge, S. L.
•
Schäfer, L. V.
biorxiv
Thu Jul 17 2025
Fluid flow induced biomechanical origin of collagen architecture in articular cartilage
The zonal collagen architecture of articular cartilage (AC) is essential for its mechanical function and long-term homeostasis. While its structural organization is well established, the mechanistic basis for the emergence and maintenance of this architecture remains unresolved. In this study, we propose a fluid flow - driven mechanism for the evolution of collagen fiber orientation in AC, using b...
Mech, D. J.
•
Rizvi, M. S.
biorxiv
Thu Jul 17 2025
Detecting directed motion and confinement in single-particle trajectories using hidden variables
Single-particle tracking is a powerful tool for understanding protein dynamics and characterizing microenvironments. As the motion of unconstrained nanoscale particles is governed by Brownian diffusion, deviations from this behavior are biophysically insightful. However, the stochastic nature of particle movement and the presence of localization error posea challenge for the robust classification ...
Simon, F.
•
Ramadier, G.
•
Fonquernie, I.
•
Zsok, J.
...•
Weiss, L. E.
biorxiv
Thu Jul 17 2025
Quality control AAA+ machines: Stochastic mechanism and translocation dynamics
How biological machines harness ATP to drive mechanical work remains a crucial question. Structural studies of protein-translocating AAA+ machines proposed a coupled and sequential translocation process, whereby ATP hydrolysis events lead to short threading steps. Yet, direct real-time observation of these events remains elusive. Here, we employ single-molecule FRET spectroscopy to track substrate...
Casier, R.
•
Levy, D.
•
Riven, I.
•
Barak, Y.
•
Haran, G.
biorxiv
Wed Jul 16 2025
Calicivirus assembly and stability are mediated by the N-terminal domain of the capsid protein with the involvement of the viral genome
Caliciviruses are important human and animal pathogens that cause varying clinical signs including gastroenteritis, respiratory illness, and hepatitis. Despite the availability of numerous calicivirus structures, relatively little is known about the mechanisms of capsid assembly and stability, or about genome packaging. Here we present the atomic structure of the RHDV virion and several related no...
Novoa, G.
•
Mata, C. P.
•
Mertens, J.
•
Zamora-Ceballos, M.
...•
Caston, J. R.
biorxiv
Wed Jul 16 2025
Immunologic insights into the critical epitopes of HIV-1 and structure-based characterization of cross-reactive antibodies
HIV-1 escape from neutralizing antibodies even in the presence of strong host immunity is associated with variations in envelope proteins that drive antigenic diversification. The virus exploits the error-prone nature of reverse transcriptase and the high mutation rate as key survival strategies. However, the rate of production of new variations occurs at relatively slow pace. Interestingly, the i...
Jaiswal, D.
•
Verma, S.
•
Madni, Z. K.
•
Kaur, G.
...•
Salunke, D. M.
biorxiv
Wed Jul 16 2025
Marker-independent imaging reveals a correlation of fibrotic and epigenetic alterations in endometriosis
Endometriosis describes the presence of endometrial glands outside of the uterus and can cause various symptoms such as chronic pelvic pain, hypermenorrhea and infertility. These complications pose an extreme burden on the patients, especially as up to date, the average time until diagnosis can consume several years and requires invasive laparoscopy. The aim of this study is to molecularly charact...
Beyer, T.
•
Becker, L.
•
Demir, S.
•
Liebscher, S.
...•
Marzi, J.