糖心TV

Shefeeq M. Theparambil, Olga Kopach, Alice Braga, Shereen Nizari, Patrick S. Hosford, Virag Sagi-Kiss, Anna Hadjihambi, Christos Konstantinou, Noemi Esteras, Ana Gutierrez Del Arroyo, Gareth L. Ackland, Anja G. Teschemacher, Nicholas Dale, Tobias Eckle, Petros Andrikopoulos, Dmitri A. Rusakov, Sergey Kasparov & Alexander V. Gourine

Brain computation performed by billions of nerve cells relies on a sufficient and uninterrupted nutrient and oxygen supply. Astrocytes, the ubiquitous glial neighbours of neurons, govern brain glucose uptake and metabolism, but the exact mechanisms of metabolic coupling between neurons and astrocytes that ensure on-demand support of neuronal energy needs are not fully understood. Here we show, using experimental in vitro and in vivo animal models, that neuronal activity-dependent metabolic activation of astrocytes is mediated by neuromodulator adenosine acting on astrocytic A2B receptors. The data identifies the adenosine A2B receptor as an astrocytic sensor of neuronal activity and show that cAMP signalling in astrocytes tunes brain energy metabolism to support its fundamental functions such as sleep and memory.

Michael Hymas, Sopida Wongwas, Simin Roshan, Abigail L. Whittock, Christophe Corre, Reza Omidyan and Vasilios G. Stavros

Mycosporine glycine (MyG) was produced by the fermentation of a purposely engineered bacterial strain and isolated from this sustainable source. The ultrafast spectroscopy of MyG was then investigated in its native, zwitterionic form (MyG_zwitter), via femtosecond transient electronic absorption spectroscopy. Complementary nonadiabatic (NAD) simulations suggest that, upon photoexcitation to the lowest excited singlet state (S₁), MyG_zwitter undergoes efficient nonradiative decay to repopulate the electronic ground state (S₀). We propose an initial ultrafast ring-twisting mechanism toward an S₁/S₀ conical intersection, followed by internal conversion to S₀ and subsequent vibrational cooling. This study illuminates the workings of the archetype mycosporine, providing photoprotection, in the UV–B range, to organisms such as corals, macroalgae, and cyanobacteria. This study also contributes to our growing understanding of the photoprotection mechanisms of life.

Joshua C. Macdonald, Hayriye Gulbudak, Brianna Beechler, Erin E. Gorsich, Simon Gubbins, Eva P茅rez-Martin and Anna E. Jolles

We investigated within-host dynamics and among-host transmission of three strains (SAT-1, -2, -3) of foot-and-mouth disease viruses (FMDVs) in their wildlife host, African buffalo. Our data reveals contrasting within-host dynamics among viral strains, with SAT-2 eliciting more rapid and effective immune responses than SAT-1 and SAT-3. Within-host viral fitness was overwhelmingly determined by variation among hosts in immune response activation rates but not by variation among individual hosts in viral growth rate. Our analyses investigating across-scale linkages indicate that viral replication rate in the host correlates with transmission rates among buffalo and that adaptive immune activation rate determines the infectious period. These parameters define the virus鈥檚 relative basic reproductive number (鈩�₀), suggesting that viral invasion potential may be predictable from within-host dynamics.

Nicole Pereira, Kathryn R. Hales, Andrew Mead, Lauren H. K. Chappell, Guy C. Barker, John P. Clarkson

In Europe, cavity spot disease continues to have a major impact on marketable yield. The lack of reliable inoculation methods for these Pythium pathogens has, for many years, hampered the identification of new effective crop protection products or carrot varieties that are resistant to the disease. In this research, inoculation methods were developed for P. violae using mycelium or oospores, each of which successfully induced typical cavity spot symptoms in both pot- and field-grown carrots as well as consistent root stunting in the former. These methods were also used to successfully identify carrot cultivars with resistance to cavity spot and confirmed the efficacy of the fungicide metalaxylM against the disease. Results therefore demonstrated that the inoculation methods should be reliable for identifying the efficacy of crop protection products, assessing cavity spot resistance and for further studies investigating the biology and epidemiology of the pathogen.

Jing An, Rim Brik Chaouche, Leonardo I Pereyra-Bistra铆n, Hugo Zalzal茅, Qingyi Wang, Ying Huang, Xiaoning He, Chlo茅 Dias Lopes, Javier Antunez-Sanchez, Catherine Bergounioux, Claire Boulogne, Cynthia Dupas, Cynthia Gillet, Jos茅 Manuel P茅rez-P茅rez, Olivier Mathieu, Nicolas Bouch茅, Sotirios Fragkostefanakis, Yijing Zhang, Shaojian Zheng, Martin Crespi, Magdy M Mahfouz, Federico Ariel, Jose Gutierrez-Marcos, C茅cile Raynaud, David Latrasse, Moussa Benhamed

In recent years, the exploration of genome three-dimensional (3D) conformation has yielded profound insights into the regulation of gene expression and cellular functions in both animals and plants. Employing advanced high-throughput sequencing and microscopy techniques, we investigated the landscape of 26 histone modifications and RNA polymerase II distribution in tomato (Solanum lycopersicum). Our study unveiled a rich and nuanced epigenetic landscape, shedding light on distinct chromatin states associated with heterochromatin formation and gene silencing. Moreover, we elucidated the intricate interplay between these chromatin states and the overall topology of the genome. Employing a genetic approach, we delved into the role of the histone modification H3K9ac in genome topology. Notably, our investigation revealed that the ectopic deposition of this chromatin mark triggered a reorganization of the 3D chromatin structure, defining different TAD-like borders. Our work emphasizes the critical role of H3K9ac in shaping the topology of the tomato genome, providing valuable insights into the epigenetic landscape of this agriculturally significant crop species.

Perioperative stroke deteriorates white matter integrity by enhancing cytotoxic CD8 + T鈥恈ell activation