Lysosome-related organelles (LROs) are cell-type-specific organelles derived from the endosomal system. Their lack of ubiquity requires that they be created during cell differentiation. To investigate how LROs are first formed, we characterized the biogenesis of Caenorhabditis elegans gut granules and found that these intestinally restricted LROs are generated de novo during a short period of early embryogenesis. Intriguingly, we found that gut granule number and size remain unchanged throughout the rest of embryonic development. The transition from formation to maintenance coincides with the loss of the GLO-1/Rab32 guanine nucleotide exchange factor (GEF) subunit CCZ-1 from gut granules. Our investigations manipulating the presence and activity of GLO-1/ Rab32 reveal that LRO biogenesis remains active during embryogenesis when the steady-state number of gut granules does not change. These studies define a system where the de novo formation of LROs can be investigated and provide insights into the mechanisms maintaining LROs once they have been generated.
Cellular oxygen consumption rate (OCR) is a widely used readout of mitochondrial respiration and oxidative metabolism. However, many OCR assay workflows are limited by short assay durations, expensive specialized instrumentation, and reduced flexibility under controlled low-oxygen conditions. Here, we describe an in-incubator method for continuous, non-disruptive OCR measurement in adherent cell cultures using the PreSens OxoDish optical oxygen-sensing system. OCR is estimated by applying the steady-state solution of Fick's law to pericellular oxygen measurements acquired at well bottoms. This approach enables OCR monitoring over several hours to 24 hours without removing plates from a standard cell-culture incubator. Using MCF-7 breast cancer cells cultured in DMEM, we calculated basal OCR values of 20.07-32.79 amol cell−1s−1, similar to published values obtained using other methods. We also demonstrate a respiration profiling approach analogous to SeahorseXF Mito Stress Tests by quantifying OCR in parallel wells exposed to oligomycin, FCCP, or antimycin A/rotenone. Importantly, we demonstrate that the method remains functional under hypoxia (1.5% O2) without modification. Benchmarking the PreSens system against the SeahorseXF yielded values within the expected reported range. The approach we describe provides an accessible option for continuous OCR measurements in adherent cell cultures under a range of oxygen levels.
ABSTRACT In most animals, detection of light depends on G-protein-coupled receptors termed opsins. Accordingly, opsins can be found expressed in the retina of many animals. However, opsins constitute a relatively large phylogenetic group of proteins with several members that are not involved in image-forming vision or light sensing at all, while the functions of others remain unknown. The transcriptome of zebrafish includes over 30 nonvisual opsins distributed over all major opsin families. Several of these sequences have been found and phylogenetically analyzed only recently. Most analyses of opsin expression and function in zebrafish focused on adult eye tissue. The goal of this study was to provide an expression catalog for nonvisual opsins in developing zebrafish larvae at three developmental stages: 24, 72 and 120 hpf. Using in situ hybridization, we observe that, early in development, nonvisual opsins exhibit dynamic expression patterns that narrow as development proceeds. We also observe commonality in expression patterns within functional opsin groups and document potential novel expression in ear and neuromast tissues. Our observations suggest that based on expression patterns, nonvisual opsin function during early development may be widely distributed before they become restricted in fully differentiated adult tissues.
Music exposure may alter affect-related behavior in rodents, but findings vary among studies and little is known about effects on behavioral variability. We conducted a preregistered systematic review and multilevel meta-analysis of 20 experimental studies (298 effect sizes) of music exposure in laboratory rodents. We quantified changes in average anxiety- and depression-like behavior using the log response ratio (lnRR) and changes in between-animal variability using the log variability ratio (lnVR), while accounting for non-independence among effects. We also assessed reporting, methodological quality, and risk of bias using CRIME-Q. Music exposure was associated with about a 20% reduction in anxiety- and depression-like behavior relative to controls, but no overall change in behavioral variability. Average responses differed among behavioral assays, while exploratory analyses of variability suggested context-dependent effects: anxiety-like outcomes tended toward greater variability and depression-like outcomes toward lower variability, and behavioral assay and music meta-genre explained comparatively larger shares of heterogeneity in lnVR. Reporting of sample-size justification, allocation, blinding, attrition, and acoustic delivery was often incomplete in the primary studies. Evidence was limited to 20 studies and predominantly to young adult rodents and short-term exposures, constraining inference about variability and generalization beyond the laboratory contexts studied.
ABSTRACT The annual symposia of the German Young Physiologists are defined by a ‘No PI’ philosophy, being organized and attended by early-career researchers in physiology, from undergraduates to post-docs. A defining characteristic of this setup is a pressure-free environment with open scientific discourse during the events. The 15th Symposium of Young Physiologists took place in Berlin, Germany, on April 8-10, 2026, and marked a significant transformation from a predominantly German-speaking national gathering to an international platform, attracting participants from 19 countries across all early career stages. Under the motto ‘Homeostasis is overrated. Let's push the limits’, the symposium featured oral sessions, poster presentations, and keynote lectures covering diverse physiological topics. The meeting demonstrated strong demand for dedicated platforms supporting young physiologists and international early-career scientific exchange in physiology.
