Biology subjects

Peters, K.

Publications and source records attributed to Peters, K..

At least 19 recordsLinked to original sources

bioRxiv2026

A data-driven approach to integrative taxonomy

Central to understanding biodiversity is the systematic classification of biological taxa where concepts on integrating omics data have not yet been comprehensively executed. The data-driven approach is aiming at integrating phylogenetic data from three or more scales aiming at enriching the robustness of species delimitations while also revealing evolutionary drivers of diversification and speciation. This study investigates complex-thallose liverworts as reference and combines the analysis of DNA marker sequencing, morphometrics utilizing bioimaging measurements and chemometrics using liquid chromatography high-resolution mass-spectrometry (UPLC/ESI-QTOF-MS) with data-dependent acquisition of tandem mass-spectra (DDA-MS), with character variation evaluated with dendrograms and data mining. The comparative analysis revealed similar tree topologies albeit with diverging positions of taxa that were attributed to flavonoid-glycosides, auronidins and phenanthrenes resulting from evolutionary radiation and adaptations to stressful bioclimatic conditions, whereas unique fatty acyls in Riccia link to ecological causes of speciation. Characteristic amino acid motifs confirm the intermediary position of liverworts between algae and land plants. By functionally attributing and mapping chemometric markers to the taxonomy, the data-driven approach integrating omics into integrative taxonomy is opening opportunities for plant systematics to identify evolutionary drivers and form new hypotheses on the diversification and speciation of species.

plant biology↗

bioRxiv2026

Essential Molecular Variables of liverworts in biological soil crusts

(1) In plant ecology, functional traits are widely used to predict plant performance in ecosystems. Little is known on molecular traits and how they integrate with the classical trait spectrum, in particular in non-vascular land plants. We conceptualize Essential Molecular Variables (EMVs) using complex-thallose liverworts in biocrusts as reference. (2) We combined morphometry and bioimaging with liquid chromatography high- resolution mass-spectrometry (UPLC/ESI-QTOF-MS) with data-dependent acquisition of tandem mass-spectra (DDA-MS). To identify EMVs, data mining was performed including regression trees, random forest and redundancy analysis combined with manual filtering and functional annotation using literature and chemical libraries. (3) We found the molecular trait spectrum to be highly structured and largely orthogonal to classical traits. We identified six major categories of EMVs: molecule structure, carbon metabolism, amino acids and peptides, shikimates and phenylpropanoids, terpenoids and alkaloids that were functionally related to biotic interactions and bioclimatic properties. (4) We find EMVs to be indicators that characterize plant performance in ecosystems. Molecular traits and EMVs represent the mechanistic link to form and function and extend the functional trait concept. They provide mechanistic insights into how global changes destabilize liverworts in biocrusts and represent a new tool set by informing functional ecology on molecular mechanisms.

ecology↗

bioRxiv2025

Spatiotemporal proteomics reveals dynamic antagonistic gradients shaping signalling waves

Embryonic development is driven by dynamic protein networks, yet how these dynamics shape morphogenesis remains incompletely understood. Somitogenesis, the rhythmic segmentation of vertebrate embryos, is governed by signalling gradients and oscillations in the presomitic mesoderm (PSM)1,2, but the corresponding protein dynamics are largely unknown. Perturbations in this process cause congenital spine disorders and can result in embryonic lethality3. Here, we introduce an integrated proteomics and microfluidics approach to resolve spatiotemporal protein expression in the developing mouse tail. To this end, we established a microfluidic system to synchronize oscillations in embryo tails grown in 3D, which we combined with mass-spectrometry and RNA sequencing. We uncover novel oscillatory proteins and differentially expressed genes along the anteroposterior axis. Building on this dataset, we identify a previously unrecognized antagonistic, dynamic ligand-receptor expression pattern in R-Spondin/LGR signalling explaining how Wnt-oscillation amplitude increases despite decreasing ligand levels in anterior PSM. Dynamic ligand expression was validated in mouse gastruloids. Perturbation of ligand dynamics reduced oscillation amplitude and impaired somite formation. Our study reveals a novel regulatory strategy in which dynamic antagonistic gradients fine-tune signalling strength, providing new mechanistic insight into how protein dynamics control tissue patterning. We anticipate our dataset to serve as foundation for mechanistic investigations of mammalian somitogenesis including the role of mechanics and metabolism. More broadly, our approach combining microfluidics-based synchronization of signalling in multicellular systems with omics analyses can be applied to study dynamics in other contexts such as in tissue homeostasis4 and regeneration5.

developmental biology↗

bioRxiv2024

Honey bee egg composition changes seasonally and after acute maternal virus infection

Honey bee (Apis mellifera) colonies depend on the reproductive output of their queens, which in turn is contingent on the care provided by worker bees. Viral infections in queens can compromise reproductive output, while worker infections can inhibit the successful functioning of a colony and its ability to care for the queen. Transgenerational immune priming (TGIP) occurs when queens transfer immune-related compounds or immune elicitors to their offspring, enhancing the ability of subsequent generations to resist infections. These maternal effects on offspring could positively impact colony health and resilience to viral infections, but little is currently known about TGIP for viruses. In this study, we investigate how viral infections affect the proteomic composition of eggs laid by virus-challenged queens (injected with a mixture of black queen cell virus and deformed wing virus B), both in controlled experimental settings and natural field conditions. Our results showed that virus-challenged queens upregulated immune effectors in their eggs and ovaries. In contrast, naturally infected queens from field surveys did not; there were no significant differences in egg protein, lipid, or metabolite composition related to maternal viral load or ovary size. However, egg collection date strongly influenced egg composition, likely reflecting seasonal variations in pollen resources. These findings highlight that while viral infections can induce transgenerational effects on egg proteomes under short-term experimental conditions, such effects are less apparent in natural settings and can be overshadowed by seasonal and other ecological factors.

zoology↗

bioRxiv2024

Global thermal tolerance of freshwater invertebrates and fish

Scientists have investigated the thermal tolerance of organisms for centuries, yet the field has not lost relevance as the environmental threats of thermal pollution and global change sharpen the need to understand the thermal vulnerability of organisms in landscapes increasingly subjected to multiple stressors. Freshwater fish and especially invertebrates are greatly underrepresented in recent large-scale compilations of thermal tolerance, despite the importance of freshwater habitats as a crucial resource and biodiversity havens. This inspired us to create a thermal tolerance database for these organisms that includes literature from 1900 until the present day sourced from five languages to counteract geographic bias, and 395 thermal tolerance tests conducted with additional stressors present. The database contains over 5000 records for over 800 species, including 452 invertebrates, providing a valuable resource to test hypotheses on thermal risks to freshwater organisms in present and future environments, and how these might change in multiple stressor scenarios.

ecology↗

bioRxiv2024

Drivers of recovery and degradation of riverine benthic macroinvertebrate communities: A nationwide analysis of time series

In response to the global freshwater biodiversity crisis this study examines the drivers, influencing recovery and degradation in riverine benthic macroinvertebrate communities across Germany. Utilizing the Asymmetric Response Concept (ARC), which posits that species tolerances to stressors, dispersal capacity, and biotic interactions are critical drivers in aquatic ecosystem recovery, we analyzed a comprehensive dataset from 1568 sites, sampled between 2004 and 2022. Our findings indicate that abiotic stress consistently influences ecological status in both recovery and degradation phases. Interspecific competition shows a stronger positive relationship with ecological status improvements during recovery phases than during degradation, underscoring its importance in the recovery process. Additionally, land use intensity has a nuanced impact: catchments with higher proportions of cropland and urban areas are more likely to recover, while forested catchments are more prone to degradation. This study supports the ARC and highlights the complex interplay of biotic and abiotic variables in shaping ecological outcomes, underscoring the importance of integrated management approaches in freshwater conservation and restoration efforts.

ecology↗

bioRxiv2024

Transferability of stream benthic macroinvertebrate distribution models to drought-related conditions

Freshwater ecosystems increasingly face pressures from climate change induced extreme events, like droughts, posing significant threats to biodiversity. While Species Distribution Models (SDMs) serve as vital tools for predicting species responses to environmental shifts, their transferability to novel environmental conditions, especially during and after drought remains poorly understood. In this study, we delve into the transferability of SDMs for freshwater macroinvertebrates from drought-free to drought-influenced conditions. We examine how sensitive the transferability is to traits such as tolerance scores according to their distribution along longitudinal gradients, as well as the used modelling method. We constructed and validated SDMs for freshwater macroinvertebrates in a central German catchment under drought-free conditions using four different algorithms (Generalised linear models; GLM, Spatial Stream Networks; SSN, Random Forests; RF, and Maximum Entropy; MaxEnt). We then projected these models to environmental conditions influenced by drought, and obtained their transferability by computing the difference in accuracy when predicting under drought-free and drought-influenced conditions (AUCgap). Our findings reveal a marked reduction in SDM accuracy under drought conditions, illustrating the challenges of accurately predicting species distributions into novel environmental conditions. Our results show a slightly better transferability when using SSN and RF. In addition, we observed that SDM transferability can be influenced by species tolerance, with sensitive and tolerant species presenting higher AUCgap (i.e. lower transferability). Furthermore, we found that when sensitive species were modelled using SSNs, the AUCgap was reduced. Our study underscores the limitations of SDMs in capturing species responses to drought and advocates for integrating ecologically relevant predictors and modelling methods that account for the stream connectivity to allow for robust predictions. These considerations could enhance the ability of SDMs to effectively estimate the impacts of extreme events on freshwater biodiversity.

ecology↗

bioRxiv2024

Common viral infections inhibit egg laying in honey bee queens and are linked to premature supersedure

With their long lives and extreme reproductive output, social insect queens have escaped the classic trade-off between fecundity and lifespan but evidence for a trade-off between fecundity and immunity has been inconclusive. This is in part because pathogenic effects are seldom decoupled from effects of immune induction. We conducted parallel, blind virus infection experiments in the laboratory and in the field to interrogate the idea of a reproductive immunity trade-off and better understand how these ubiquitous honey bee stressors affect queen health. We found that queens injected with infectious virus had smaller ovaries and were less likely to recommence egg-laying than controls, while queens injected with UV-inactivated virus displayed an intermediate phenotype. In the field, heavily infected queens had smaller ovaries and infection was a meaningful predictor of whether supersedure cells were observed in the colony. Immune responses in queens receiving live virus were similar to queens receiving inactivated virus, and several of the same immune proteins were negatively associated with ovary mass in the field. This work solidifies the relationship between virus infection and symptoms associated with queen failure and suggests that a reproductive-immunity trade-off is partially, but not wholly responsible for these effects.

zoology↗

bioRxiv2024

Estimating essential phenotypic and molecular traits from integrative biodiversity data

In the context of biodiversity, only few functional traits and mechanisms are known from underrepresented groups such as mosses (bryophytes). Here, we use 16 field samples of complex thallose liverworts (order Marchantiales) collected from biological soil crusts as reference data for the reusable computational framework iESTIMATE that integrates and extracts phenotypic and molecular traits; and estimates Essential Molecular Variables (EMV). Our reference data involves (1) bioimaging, (2) metabolomics, and (3) DNA marker sequencing. These data are used to demonstrate the systematic and standardized extraction of phenotypic and molecular traits. To demonstrate the reusability of our framework, we propose naming schemes, apply Random Forest to estimate EMVs, phylogenetic dendrograms and partitioning around medoids to connect evolutionary relationships with ecological hypotheses and to document knowledge gains across domains. With this work we want to encourage the combined assessment, reuse and integration of phenotypic and molecular traits into functional ecology, biodiversity and related disciplines.

ecology↗

bioRxiv2023

Analysis of Metabolomics and Transcriptomics Data to Assess Interactions in Microalgal Co-culture of Skeletonema marinoi and Prymnesium parvum

In marine ecosystems, microbial communities often interact using specialised metabolites, which play a central role in shaping the dynamics of the ecological networks and maintaining the balance of the ecosystem. With metabolomics and transcriptomics analyses, this study explores the interactions between two marine microalgae, Skeletonema marinoi and Prymnesium parvum, grown in mono-cultures and non-contact co-cultures. As a growth indicator, the photosynthetic potential, measured via fluorescence, suggested chemical interaction between S. marinoi and P. parvum. Using Liquid Chromatography-Mass Spectrometry (LC-MS) data, we identified 346 and 521 differentially produced features in the endo- and exometabolome of S. marinoi and P. parvum, respectively. Despite limited tandem mass spectrometry data (MS2) for these features, we structurally annotated 14 compounds, most of which were previously under-studied specialised metabolites. Differential gene expression analysis was then performed on the transcriptomes of the microalgae, which uncovered differentially expressed genes involved in energy metabolism and cellular repair for both species. These metabolic and transcriptomics changes depict the adaptation of both species in the co-culture. However, further data acquisition and investigation will be necessary to confirm the type of interaction and the underlying mechanisms. ImportanceMarine microalgae have great ecological importance and biochemical potential. Among these microbes are the diatom Skeletonema marinoi, known for its marine biogeochemical cycling, and the haptophyte Prymnesium parvum, which poses adverse environmental consequences. Given these opposing roles for the two cosmopolitan microalgae, we designed a study using untargeted metabolomics and transcriptomics to acquire a comprehensive snapshot of their interactions, grown as mono-cultures and co-cultures. The statistical analysis of the chlorophyll a fluorescence levels, and the metabolomics and transcriptomics dataset revealed metabolic communication occurring among the two species via specialised metabolites and activated cellular repair mechanisms. These findings reveal the complexity of the interactions within marine microbial ecosystems, offering a foundation for future research to understand and harness marine ecological systems.

microbiology↗

bioRxiv2023

Untargeted Metabolomics to Expand the Chemical Space of the Marine Diatom Skeletonema marinoi

Diatoms (Bacillariophyceae) are aquatic photosynthetic microalgae with an ecological role as primary producers in the aquatic food web. They account substantially for global carbon, nitrogen, and silicon cycling. Elucidating the chemical space of diatoms is crucial to understanding their physiology and ecology. To expand the known chemical space of a cosmopolitan marine diatom, Skeletonema marinoi, we performed High-Resolution Liquid Chromatography-Tandem Mass Spectrometry (LC-MS2) for untargeted metabolomics data acquisition. The spectral data from LC-MS2 was used as input for the Metabolome Annotation Workflow (MAW) to obtain putative annotations for all measured features. A suspect list of metabolites previously identified in the Skeletonema spp. was generated to verify the results. These known metabolites were then added to the putative candidate list from LC-MS2 data to represent an expanded catalogue of 1970 metabolites estimated to be produced by S. marinoi. The most prevalent chemical superclasses, based on the ChemONT ontology in this expanded dataset, were "Organic acids and derivatives", "Organoheterocyclic compounds", "Lipids and lipid-like molecules", and "Organic oxygen compounds". The metabolic profile from this study can aid the bioprospecting of marine microalgae for medicine, biofuel production, agriculture, and environmental conservation. The proposed analysis can be applicable for assessing the chemical space of other microalgae, which can also provide molecular insights into the interaction between marine organisms and their role in the functioning of ecosystems. ImportanceDiatoms are abundant marine phytoplankton members and have great ecological importance and biochemical potential. The cosmopolitan diatom Skeletonema marinoi has become an ecological and environmental research model organism. In this study, we used untargeted metabolomics to acquire a general metabolic profile of S. marinoi to assess its chemical diversity and expand the known metabolites produced by this diatom. S. marinoi produces a chemically diverse set of secondary metabolites with potential therapeutic properties, such as anti-cancer, antioxidant, and anti-inflammatory. Such metabolites are highly significant due to their potential role in drug discovery and bioeconomy. Lipids from S. marinoi also have potential in the biofuel industry. Furthermore, the environmental fluctuations in the water bodies directly affect the production of different secondary metabolites from diatoms, which can be key indicators of climate change.

microbiology↗

bioRxiv2023

Leaf metabolic traits reveal hidden dimensions of plant form and function

The plant metabolome encompasses the biochemical mechanisms through which evolutionary and ecological processes shape plant form and function1,2. However, while the metabolome should thus be an important component of plant life-history variation3, we know little about how it varies across the plant kingdom. Here, we use the plant functional trait concept4 - a powerful framework for describing plant form and function5-7 - to interpret leaf metabolome variation among 457 tropical and 339 temperate plant species. Distilling metabolite chemistry into five discriminant metabolic functional traits reveals that plants vary along two major axes of leaf metabolic specialization - a leaf chemical defense spectrum and an expression of leaf longevity. These axes are qualitatively consistent for tropical and temperate species, with many trait combinations being viable. However, axes of leaf metabolic specialization vary orthogonally to life-history strategies described by widely used functional traits5-7, while being at least equally important to them. Our findings question classical trait6 and plant defense8 theory that predicts relationships between the leaf chemical phenotype, plant productivity, and pace of life. Moreover, we show that metabolic functional traits describe unique dimensions of plant life-history variation that are complementary to, and independent from, those captured by existing plant functional traits.

ecology↗

bioRxiv2022

MAW - The Reproducible Metabolome Annotation Workflow for Untargeted Tandem Mass Spectrometry

Mapping the chemical space of compounds to chemical structures remains a challenge in metabolomics. Despite the advancements in untargeted liquid chromatography-mass spectrometry (LC-MS) to achieve a high-throughput profile of metabolites from complex biological resources, only a small fraction of these metabolites can be annotated with confidence. Many novel computational methods and tools have been developed to enable chemical structure annotation to known and unknown compounds such as in silico generated spectra and molecular networking. Here, we present an automated and reproducible Metabolome Annotation Workflow (MAW) for untargeted metabolomics data to further facilitate and automate the complex annotation by combining tandem mass spectrometry (MS2) input data pre-processing, spectral and compound database matching with computational classification, and in silico annotation. MAW takes the LC-MS2 spectra as input and generates a list of putative candidates from spectral and compound databases. The databases are integrated via the R package Spectra and the metabolite annotation tool SIRIUS as part of the R segment of the workflow (MAW-R). The final candidate selection is performed using the cheminformatics tool RDKit in the Python segment (MAW-Py). Furthermore, each feature is assigned a chemical structure and can be imported to a chemical structure similarity network. MAW is following the FAIR (Findable, Accessible, Interoperable, Reusable) principles and has been made available as the docker images, maw-r and mawpy. The source code and documentation are available on GitHub (https://github.com/zmahnoor14/MAW). The performance of MAW is evaluated on two case studies. MAW can improve candidate ranking by integrating spectral databases with annotation tools like SIRIUS which contributes to an efficient candidate selection procedure. The results from MAW are also reproducible and traceable, compliant with the FAIR guidelines. Taken together, MAW could greatly facilitate automated metabolite characterization in diverse fields such as clinical metabolomics and natural product discovery.

bioinformatics↗

bioRxiv2022

Reference BioImaging to assess the phenotypic trait diversity of bryophytes within the family Scapaniaceae

Macro- and microscopic images of organisms are pivotal in biodiversity research. Despite that bioimages have manifold applications such as for assessing the diversity of form and function, FAIR bioimaging data in the context of biodiversity are still very scarce, especially for difficult taxonomic groups such as bryophytes. Here, we present a high-quality reference dataset containing macroscopic and bright-field microscopic images documenting various phenotypic attributes of the species belonging to the family of Scapaniaceae occurring in Europe. To encourage data reuse in biodiversity and adjacent research areas, we annotated the imaging data with machine-actionable meta-data using community-accepted semantics. Furthermore, raw imaging data are retained and any contextual image processing like multi-focus image fusion and stitching were documented to foster good scientific practices through source tracking and provenance. The information contained in the raw images are also of particular interest for machine learning and image segmentation used in bioinformatics and computational ecology. We expect that this richly annotated reference dataset will encourage future studies to follow our principles.

bioinformatics↗

bioRxiv2021

The VarA-CsrA regulatory pathway influences cell shape in Vibrio cholerae

Despite extensive studies on the curve-shaped bacterium Vibrio cholerae, the causative agent of the diarrheal disease cholera, its virulence-associated regulatory two-component signal transduction system VarS/VarA is not well understood. This pathway, which mainly signals through the downstream protein CsrA, is highly conserved among gamma-proteobacteria, indicating there is likely a broader function of this system beyond virulence regulation. In this study, we investigated the VarA-CsrA signaling pathway and discovered a previously unrecognized link to the shape of the bacterium. We observed that varA-deficient V. cholerae cells showed an abnormal spherical morphology during late-stage growth. Through peptidoglycan (PG) composition analyses, we discovered that these mutant bacteria contained an increased content of disaccharide dipeptides and reduced peptide crosslinks, consistent with the atypical cellular shape. The spherical shape correlated with the CsrA-dependent overproduction of aspartate ammonia lyase (AspA) in varA mutant cells, which likely depleted the cellular aspartate pool; therefore, the synthesis of the PG precursor amino acid meso-diaminopimelic acid was impaired. Importantly, this phenotype, and the overall cell rounding, could be prevented by means of cell wall recycling. Collectively, our data provide new insights into how V. cholerae use the VarA-CsrA signaling system to adjust its morphology upon unidentified external cues in its environment. Significance StatementResponsible for the diarrheal disease cholera, the bacterium Vibrio cholerae tightly regulates its virulence program according to external stimuli. Here, we discovered that a sensing-response mechanism involved in the regulation of virulence also controls bacterial shape. We show that V. cholerae lacking this system lose their normal comma shape and become spherical due to an abnormal cell wall composition caused by metabolic changes that reduce available cell wall building blocks. Our study therefore sheds new light on how V. cholerae modulates its morphology based on environmental changes.

microbiology↗

bioRxiv2021

Commensal Streptococcus mitis produces two different lipoteichoic acids of type I and type IV

The opportunistic pathogen Streptococcus mitis possesses, like other members of the Mitis group of viridans streptococci, phosphorylcholine (P-Cho)-containing teichoic acids (TAs) in its cell wall. Bioinformatic analyses predicted the presence of TAs that are almost identical with those identified in the pathogen S. pneumoniae, but a detailed analysis of S. mitis lipoteichoic acid (LTA) was not performed to date. Here we determined the structures of LTA from two S. mitis strains, the high-level beta-lactam and multiple antibiotic resistant strain B6 and the penicillin-sensitive strain NCTC10712. In agreement with bioinformatic predictions we found that the structure of one LTA (type IV) was like pneumococcal LTA, except the exchange of a glucose moiety with a galactose within the repeating units. Further genome comparisons suggested that the majority of S. mitis strains should contain the same type IV LTA as S. pneumoniae, providing a more complete understanding of the biosynthesis of these P-Cho-containing TAs in members of the Mitis group of streptococci. Remarkably, we observed besides type IV LTA an additional polymer belonging to LTA type I in both investigated S. mitis strains. This LTA consists of {beta}-galactofuranosyl-(1,3)-diacylglycerol as glycolipid anchor and a poly-glycerol-phosphate chain at the O-6 position of the furanosidic galactose. Hence, these bacteria are capable of synthesizing two different LTA polymers, most likely produced by distinct biosynthesis pathways. Our bioinformatics analysis revealed the prevalence of the LTA synthase LtaS, most probably responsible for the second LTA version (type I), amongst S. mitis and S. pseudopneumoniae strains.

microbiology↗

bioRxiv2021

Sahul's megafauna were vulnerable to extinction due to their position in the trophic network

Extinctions stemming from environmental change often trigger trophic cascades and coextinctions. However, it remains unclear whether trophic cascades were a large contributor to the megafauna extinctions that swept across several continents in the Late Pleistocene. The pathways to megafauna extinctions are particularly unclear for Sahul (landmass comprising Australia and New Guinea), where extinctions happened earlier than on other continents. We investigated the role of bottom-up trophic cascades in Late Pleistocene Sahul by constructing pre-extinction (~ 80 ka) trophic network models of the vertebrate community of Naracoorte, south-eastern Australia. These models allowed us to predict vertebrate species vulnerability to cascading extinctions based on their position in the network. We tested whether the observed extinctions could be explained by bottom-up cascades, or if they should be attributed to other external causes. Species that disappeared from the community were more vulnerable, overall, to bottom-up cascades than were species that survived. The position of extinct species in the network - having few or no predators - also suggests they might have been particularly vulnerable to a new predator. These results provide quantitative evidence that trophic cascades and naivety to predators could have contributed to the megafauna extinction event in Sahul.

ecology↗

bioRxiv2020

HIV-1 uncoating by release of viral cDNA from capsid-like structures in the nucleus of infected cells.

HIV-1 replication commences inside the cone-shaped viral capsid, but timing, localization and mechanism of uncoating are under debate. We adapted a strategy to visualize individual reverse-transcribed HIV-1 cDNA molecules and their association with viral and cellular proteins using fluorescence and correlative-light-and-electron-microscopy (CLEM). We specifically detected HIV-1 cDNA inside nuclei, but not in the cytoplasm. Nuclear cDNA initially co-localized with a fluorescent integrase fusion (IN-FP) and the viral CA (capsid) protein, but cDNA-punctae separated from IN-FP/CA over time. This phenotype was conserved in primary HIV-1 target cells, with nuclear HIV-1 complexes exhibiting strong CA-signals in all cell types. CLEM revealed cone-shaped HIV-1 capsid-like structures and apparently broken capsid-remnants at the position of IN-FP signals and elongated chromatin-like structures in the position of viral cDNA punctae lacking IN-FP. Our data argue for nuclear uncoating by physical disruption rather than cooperative disassembly of the CA-lattice, followed by physical separation from the pre-integration complex.

microbiology↗