ZusammenfassungPhosphodiestergruppen sind in der Natur weit verbreitet. Sie kommen z. B. in Nukleinsäuren oder in für die Signaltransduktion wichtigen zyklischen (Di‐)Nukleotiden vor. Proteine verwenden häufig polare oder positiv geladene Aminosäuren, um über Wasserstoffbrücken und Salzbrücken mit den negativ geladenen Phosphodiestergruppen zu interagieren. Im Gegensatz dazu werden die sauren Aminosäuren Aspartat und Glutamat generell nicht als wichtig für die Bindung an Phosphodiestergruppen angesehen. Stattdessen wird oft angenommen, dass die Ladungsabstoßung zwischen ihren deprotonierten, negativ geladenen Seitenkettencarboxylatgruppen und den Phosphodiestergruppen solche Wechselwirkungen verhindert oder zumindest abschwächt. Dementsprechend werden in funktionellen Studien saure Aminosäuren oft gezielt in Proteine eingeführt, um Nukleinsäure‐Protein‐Interaktionen zu stören. Hier zeigen wir am Beispiel eines c‐di‐GMP‐bindenden Proteins, der GSPII‐B‐Domäne von PilF aus Thermus thermophilus, dass Glutamat‐Seitenketten in einem passenden strukturellen Kontext sogar bei neutralem pH‐Wert protoniert werden können und dann als Wasserstoffbrückenbindungsdonorgruppen für Phosphodiestergruppen dienen können. Bei der Analyse bereits bekannter Strukturen von RNA‐Protein‐ und DNA‐Protein‐Komplexen aus der PDB haben wir beobachtet, dass Wasserstoffbrückenbindungen zwischen offensichtlich protonierten Carboxylatgruppen von Glutamat und Aspartat und Phosphodiestergruppen relativ häufig und in vielen verschiedenen funktionellen Proteinklassen vorkommen. Die funktionelle Rolle von sauren Aminosäuren bei der Erkennung von Phosphodiestergruppen sollte daher neu bewertet werden.

Biophotonics-the interdisciplinary fusion of light-based technologies with biology and medicine-is rapidly transforming research, diagnostics, and therapy across various domains. This white paper, developed in conjunction with the International Congress on Biophotonics 2024, offers a comprehensive overview of the current landscape and future potential of biophotonics. It discusses core technologies such as bioimaging, biosensing, and photonic-based therapies, while highlighting novel applications in oncology, infectious diseases, neurology, cardiovascular health, agriculture, food safety, and environmental monitoring. The document also explores key enablers, including artificial intelligence, novel materials, and quantum biophotonics, along with critical challenges related to standardization, regulation, and clinical translation. A SWOT analysis and recommendations are provided to guide future research, commercialization, and interdisciplinary collaboration, underscoring biophotonics as a cornerstone of next-generation precision medicine and the One Health approach.

AbstractWe report a biomimetic system for light‐driven CO2 conversion in lipid bilayers using a [FeFe]‐hydrogenase‐inspired molecular dyad (PS‐CAT) acting simultaneously as photosensitizer and catalyst. The molecular design of PS‐CAT consists of both light‐harvesting and catalytically active moieties in a single molecule. This structure allows for efficient charge transfer between these two moieties. The PS‐CAT consists of only an organic chromophore and an iron complex. Photocatalytic reduction of CO2 to CO (CO2RR) as well as H2 production (HER) was traced over 56 h to determine CO2RR/HER selectivity. The presence of water in the lipid bilayer system allows for CO2RR selectivity >99 % over the competitive HER, outperforming previous molecular, and liposome‐based systems for light‐driven CO2 to CO conversion. The product selectivity in CO2RR (e.g., CO, HCOO−, and CH4) was determined via gas chromatography and NMR spectroscopy with 13C‐labeled carbon sources. The Stern–Volmer quenching studies on the initial light‐driven electron‐transfer revealed static quenching and indicated a preassembly of the PS‐CAT with the electron donor at the membrane‐water interface.

BackgroundGenomic repetitive DNA sequences (Repeatomes, REPs) are widespread in eukaryotes, influencing biological form and function. In Cnidaria, an early-diverging animal lineage, these sequences remain largely uncharacterized. This study investigates sea anemone REPs (Cnidaria: Actiniaria) in a phylogenetic context. We sequenced and assembled de novo the genome of Actinostella flosculifera and analyzed a total of 38 nuclear genomes to create the first ActiniariaREP library (Actiniaria-REPlib). We compared Actiniaria-REPlib with Repbase and RepeatModeler2 libraries, and used dnaPipeTE to annotate REPs from genomic short-read datasets of 36 species for divergence landscapes.ResultsOur study assembled and annotated the mitochondrial genomes, including 27 newly assembled ones. We re-annotated ~92% of the unknown sequences from the initial nuclear genome library, finding that 6.4–30.6% were DNA transposons, 2.1–11.6% retrotransposons, 1–28.4% tandem repeat sequences, and 1.2–7% unclassifiable sequences. Actiniaria-REPlib recovered 9.4x more REP sequences from actiniarian genomes than Dfam and 10.4x more than Repbase. It yielded 79,903 annotated TE consensus sequences (74,643 known, 5,260 unknown), compared to Dfam with 7,697 (3,742 known, 3,944 unknown) and Repbae (763 known).ConclusionsOur study significantly enhances the characterization of sea anemone repetitive DNA, assembling mitochondrial genomes, re-annotating nuclear sequences, and identifying diverse repeat elements. Actiniaria-REPlib vastly outperforms existing databases, recovering significantly more REP sequences and providing a comprehensive resource for future genomic and evolutionary studies in Actiniaria.

Angst fühlt sich zwar oft negativ an, ist aber lebensnotwendig. In ihrem Buch geht Barbara Schmidt den verschiedenen Aspekten von Angst auf den Grund. Sie erklärt, woher Angst kommt, wie sie im Körper wirkt und wie man eine Angststörung klassifiziert. Außerdem zeigt sie, wie sich Angstreaktionen verändern lassen. Damit ist das Buch für Studierende aller Fachrichtungen ein wertvoller Ratgeber! Frag doch einfach! Die utb-Reihe geht zahlreichen spannenden Themen im Frage-Antwort-Stil auf den Grund. Ein Must-have für alle, die mehr wissen und verstehen wollen.

PurposeThis narrative review systematically compiles and analyzes existing literature on the use of helical plates in orthopaedic trauma surgery. By synthesizing data across various study types, it provides a comprehensive overview of the biomechanical characteristics, clinical outcomes, and anatomical advantages of helical plating.MethodsA systematic search was performed using PubMed and Web of Science databases, employing defined search terms to identify relevant studies. Single case reports were excluded, while structured case series were included. Retrieved studies were categorized into five groups: simulation studies, biomechanical studies, case series, clinical comparative studies, and anatomical studies.ResultsThe review identified studies from 1992 to 2023, with most of the research focusing on the femur (7 studies) and humerus (6 studies). Biomechanical studies (7) were the most common, followed by clinical case series (7), comparative studies (4), and finite element analyses (3). European institutions contributed to the majority of research, with additional studies from Asia and South America. No randomized controlled trials were found. Helical plates demonstrated comparable stability to straight plates, with distinct biomechanical advantages: superior torsional resistance in femoral fractures and improved neurovascular safety in humeral fractures.ConclusionHelical plates offer a viable alternative to straight plates in long bone fractures, particularly for protecting neurovascular structures. Optimal designs vary by location, with 45° helical plates recommended for humeral minimally invasive plate osteosynthesis, 180° helical plates for young patients with femoral fractures, and 90° helical plates in geriatric double plating constructs. Further high-quality research is needed to establish definitive clinical guidelines.

BackgroundThe evolution of differences in gamete size and number between sexes is a cornerstone of sexual selection theories. The green macroalga Ulva, with incipient anisogamy and parthenogenetic gametes, provides a unique system to investigate theoretical predictions regarding the evolutionary pressures that drive the transition from isogamy to anisogamy, particularly in relation to gamete size differentiation and sexual selection. Its minimal gamete dimorphism and facultative parthenogenesis enable a rare window into early evolutionary steps toward anisogamy.ResultsBy analyzing the expression profiles of sex-biased genes (SBGs) during gametogenesis, we found that SBGs evolve faster than unbiased genes, driven by higher rates of non-synonymous substitution (dN), indicating that SBGs are under stronger selective pressures. Mating type minus-biased genes (mt-BGs) exhibit higher dN/dS values than mating type plus-biased genes (mt+BGs), suggesting stronger selective pressures on mt-BGs, although this difference was not statistically significant (P = 0.08). Using branch-site and RELAX models, we found positive selection and relaxed purifying selection acting on a significant proportion of SBGs, particularly those associated with flagella function.ConclusionsThis study highlights the selective pressures shaping anisogamy and provides insights into the molecular mechanisms underlying its evolution. The faster evolution of SBGs, particularly mt-BGs, and the positive selection on genes associated with motility, such as those related to flagella function, suggest the importance of enhanced gamete motility in the transition to anisogamy. These findings contribute to our understanding of sexual selection and the evolutionary forces that drive the differentiation of gamete size and number between sexes.