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Biology subjects

Vogt, H.

Publications and source records attributed to Vogt, H..

5 recordsLinked to original sources

13CO2 pulse labelling reveals species-specific alterations in carbon allocation and volatile organic compound emissions under heat stress

Temperate forests increasingly face extreme air temperature, but plant physiological responses, particularly alterations in carbon allocation or protection via volatile organic compound (VOC) emissions, remain poorly understood. We pulse-labelled well-watered saplings of Fagus sylvatica and Pseudotsuga menziesii in a controlled heat stress experiment with 13CO2 to quantify heat-induced shifts in CO2, VOC and C pool exchange, specifically analyzing compound-specific {delta}13C of terpenoids, water-soluble organic matter (WSOM) and dark respiration. Under heat stress, up to 50% of fresh assimilates were directed to maintenance respiration and 1-2% to VOC emissions, while net assimilation and water use efficiency decreased by 50-75% in both species. Heat directly affected metabolic processes and reduced turnover rates of fresh assimilates in F. sylvatica, but accelerated them in P. menziesii. Strong 13C labelling of some compounds, particularly acyclic ones, suggested increased de novo synthesis of specific terpenoids for heat stress protection. By tracing the fate of recently assimilated 13CO2 we demonstrate that heat stress reduces net carbon uptake and water use efficiency, disrupts turnover of C pools and increases carbon loss via respiration and de novo synthesis of specific VOCs, potentially diminishing net carbon uptake of forests under future heat extremes.

plant biology↗

Pubertal maturation and chemotherapy-associated disruption of the pediatric ovary revealed by multimodal single-cell profiling

Ovarian tissue cryopreservation enables fertility preservation in females undergoing gonadotoxic therapies, restoring fertility in adults. Although offered even before puberty, the childhood ovary and its vulnerability to therapy remain poorly characterized. Here, ovarian tissue from 16 patients undergoing fertility preservation (aged 1-16 years) and 11 adult controls (aged 22-32 years) was analyzed using single-cell RNA sequencing, spatial transcriptomics, and multiplex immunostaining. In chemotherapy-naive samples, 13 somatic cell populations underwent extracellular matrix remodeling, vascular, neural, and stromal maturation during puberty, whereas changes in germline related to chromatin remodeling. Spatial transcriptomics resolved 23 clusters across, revealing distinct tissue organization and follicular niche composition between children and adults. Chemotherapy exposure depleted perifollicular and vascular cells, suppressed intercellular signaling, and dysregulated over half of puberty-associated genes, converging on stress responses and extracellular matrix remodeling, with SEPTIN7 as a potential biomarker. These findings uncover critical developmental vulnerabilities of the pediatric ovary relevant to fertility preservation.

developmental biology↗

A novel pipeline for the validation of manganese chelators for the treatment of manganese overload

Manganese neurotoxicity, arising from environmental overexposure or inherited transporter disorders due to pathogenic variants in SLC30A10 and SLC39A14, leads to manganism, a debilitating Parkinsonian movement disorder. Alhtough chelation therapy can partially reverse neuropathology, current clinical practice relies on intravenous CaNa2EDTA, which is burdensome and poorly suited for long-term use. Consequently, there remains a significant unmet need for more effective, orally bioavailable chelators. This study aimed to establish and validate a pipeline for identifying and assessing novel ligands that attenuate manganese neurotoxicity and support preclinical translational development. Based on the structural features of manganese-based MRI contrast agents, we selected two chelators, N-picolyl-N,N',N'-trans-1,2-cyclohexylenediaminetriacetic acid (H3PyC3A) and ethylenediaminetetraacetic acid-benzothiazole aniline (H4EDTA-BTA), and their methyl ester derivatives, Me3PyC3A and Me4EDTA-BTA. These were evaluated in vivo using zebrafish (slc39a14U801/U801) and mouse (Slc30a10KO/KO) models of manganese overload. H3PyC3A and Me3PyC3A demonstrated greater manganese-mobilizing efficacy than CaNa2EDTA, improving locomotor behavior in slc39a14U801/U801 zebrafish. In Slc30a10KO/KO mice, intravenous administration confirmed selective in vivo chelation of excess manganese over physiological concentrations of zinc and copper. Although oral bioavailability was low (<1%), long-term oral administration of H3PyC3A modestly reduced liver and brain Mn accumulation, suggesting an added benefit of oral administration via gastrointestinal chelation. This integrated in vitro to in vivo pipeline provides a robust and scaleable approach for the development of next-generation Mn chelators. Slc39a14U801 loss-of-function zebrafish enable high throughput identification of candidate compounds while Slc30a10KO/KO mice offer a clinically relevant disease model for pharmacokinetic profiling and proof-of-concept validation.

pharmacology and toxicology↗

A whole-genome scan for association with invasion success in the fruit fly Drosophila suzukii using contrasts of allele frequencies corrected for population structure

Evidence is accumulating that evolutionary changes are not only common during biological invasions but may also contribute directly to invasion success. The genomic basis of such changes is still largely unexplored. Yet, understanding the genomic response to invasion may help to predict the conditions under which invasiveness can be enhanced or suppressed. Here we characterized the genome response of the spotted wing drosophila Drosophila suzukii during the worldwide invasion of this pest insect species, by conducting a genome-wide association study to identify genes involved in adaptive processes during invasion. Genomic data from 22 population samples were analyzed to detect genetic variants associated with the status (invasive versus native) of the sampled populations based on a newly developed statistic, we called C2, that contrasts allele frequencies corrected for population structure. This new statistical framework has been implemented in an upgraded version of the program BO_SCPLOWAYC_SCPLOWPO_SCPLOWASSC_SCPLOW. We identified a relatively small set of single nucleotide polymorphisms (SNPs) that show a highly significant association with the invasive status of populations. In particular, two genes RhoGEF64C and cpo, the latter contributing to natural variation in several life-history traits (including diapause) in Drosophila melanogaster, contained SNPs significantly associated with the invasive status in the two separate main invasion routes of D. suzukii. Our methodological approaches can be applied to any other invasive species, and more generally to any evolutionary model for species characterized by non-equilibrium demographic conditions for which binary covariables of interest can be defined at the population level.

evolutionary biology↗

A reassessment of DNA immunoprecipitation-based genomic profiling

DNA immunoprecipitation sequencing (DIP-seq) is a common enrichment method for profiling DNA modifications in mammalian genomes. However, DIP-seq profiles often exhibit significant variation between independent studies of the same genome and from profiles obtained by alternative methods. Here we show that these differences are primarily due to intrinsic affinity of IgG for short unmodified DNA repeats. This pervasive experimental error accounts for 50 - 99% of regions identified as enriched for DNA modifications in DIP-seq data. Correction of this error profoundly alters DNA modification profiles for numerous cell types, including mouse embryonic stem cells, and subsequently reveals novel associations between DNA modifications, chromatin modifications and biological processes. We propose new methodological guidelines that minimize the impact of these errors on future DIP-seq experiments and allow new insights to be made from the wealth of existing DIP-seq data.

genetics↗