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Pedersen, K.

Publications and source records attributed to Pedersen, K..

4 recordsLinked to original sources

GESTURE: unsupervised genotype-specific behavioral phenotyping in rodents via graph-based representation learning

Objective quantification of complex animal behavior is fundamental to neuroscience and pharmacology, yet extracting biologically meaningful insights from high-dimensional pose data remains challenging. This is especially true for subtle phenotypic differences caused by genetic mutations, which frequently evade conventional evaluation metrics. Here, we introduce GESTURE, an unsupervised, graph-based deep generative framework that autonomously discovers and quantifies behavioral structure from raw pose dynamics. Analyzing mice with motor dysfunction alongside wild-type controls, GESTURE identifies a shared vocabulary of behavioral motifs. We show that genotype-specific differences arise from the differential usage of these motifs, yielding distinct "behavioral fingerprints" that reliably separate genotypes without supervision. By modeling behavior as a sequence rather than a static partition, GESTURE measures temporal organization directly: affected animals held motifs longer and transitioned more predictably, revealing a slowing and stereotyping of behavioral sequences rather than a simple reduction in activity. Importantly, GESTUREs graph-based representation enables training across multiple recordings and embedding behaviors into a shared latent space, supporting robust cross-animal comparisons and future cross-experiment alignment. Furthermore, automatically derived metrics of behavioral divergence track the temporal dynamics of expert-annotated disability scores, reaching agreement comparable to independent human raters. Finally, node- and edge-level explainability analyses indicate that the models latent representations are shaped by a biologically plausible focus on the animals core motor scaffold. Together, these results position GESTURE as an interpretable and scalable framework for automated behavioral phenotyping, linking genetic perturbation to quantitative behavioral phenotypes. Author summaryHow can we measure, objectively, the subtle changes in behavior caused by a disease-causing mutation? Such changes are hard for human observers to judge consistently, and scoring them by hand is slow and does not scale. We studied mice carrying a mutation in a calcium-channel gene. In people, mutations in the same gene cause episodic ataxia and related movement disorders. We developed GESTURE, which learns recurring patterns of movement directly from video of a freely moving mouse, without being told what to look for. It treats the body as a set of connected landmarks and follows how their arrangement changes over time, discovering a shared vocabulary of movements. Affected and healthy mice drew on the same vocabulary but used it differently. Each animals pattern of use formed a distinctive "behavioral fingerprint", and these fingerprints alone identified which animals carried the mutation --in every case. They also revealed something a simple activity measure would miss: affected mice hold each movement longer, and string movements together more predictably. A severity score read automatically from them matched expert judgement as closely as two trained raters matched each other, and returned the same answer every time.

neuroscience↗

Experimental inoculation of pigs with porcine respirovirus type 1 revealed pathological manifestations in the upper respiratory tract

Several pathogens are known to affect the respiratory tract of pigs resulting in decreased health and welfare. Virological investigations and the use of metagenomic sequencing of samples allowed the identification of new viruses in pigs, such as porcine respirovirus type 1 (PRV1) and swine orthopneumovirus (SOV). The pathogenicity of PRV1 has been investigated experimentally by one research group, whereas SOV is yet to be studied. In this experimental trial, groups of weaners were inoculated with a European isolate of PRV1 (n = 8), a pool of SOV RNA-positive clinical nasal swab material (n = 8) or culture medium serving as controls (n = 4). Four days post inoculation (DPI), two controls and four pigs from each of the PRV1 and SOV groups were euthanized and necropsied. All SOV inoculated pigs tested negative for SOV at DPI 4 and therefore four of these pigs were transferred to the stable with the PRV1- infected pigs to assess direct-contact transmission. Nasal swab samples were collected at regular intervals after challenge and blood samples were collected at DPI 0, 4, and 14. At 14 DPI, the remaining pigs (n = 10) were euthanized and necropsied. Nasal swab samples and tissues from the respiratory tract were examined for PRV1 RNA by reverse transcriptase real- time PCR and blood samples were investigated for PRV1 antibodies by ELISA. Respiratory tissues were also evaluated macro- and microscopically and selected tissues were investigated for in situ detection of PRV1 mRNA by RNAscope. No clinical signs, except for nasal discharge, were observed in any of the pigs. PRV1-shedding was observed from DPI 2 to 11 with peaks between DPI 4 and 7, and PRV1 was transmitted horizontally to all direct-contact pigs. The highest viral load was detected in the upper respiratory tract, i.e. nose, upper and lower trachea compared to the lower respiratory tract, i.e., bronchioles, and alveoli. Generally, a chronic tracheitis at 4 DPI, developing into chronic, erosive tracheitis at 14 DPI was observed in the PRV1 groups and was supported by in situ detection of PRV1 by RNAscope. Three pigs also developed mild, bronchointerstitial pneumonia at 14 DPI. In conclusion, these results showed that PRV1 is a primary porcine respiratory pathogen. Author summaryRespiratory diseases in pigs impair porcine health and welfare and are often caused by a complex interaction between pathogens. We investigated the pathogenesis of two recently discovered viruses: porcine respirovirus type 1 (PRV1) and swine orthopneumovirus (SOV). An experimental model in weaner pigs showed that PRV1 is capable of efficient replication, horizontal transmission and caused pathological manifestations mainly in the upper respiratory tract. The lesions consisted of chronic, erosive tracheitis in all PRV1 infected pigs, resulting in a breakage of the tracheal epithelial barrier, and a few pigs developed bronchointerstitial pneumonia. These findings confirm that PRV1 should be considered a primary porcine respiratory pathogen, but in contrast, SOV did not result in a successful infection, and the reasons why remain to be elucidated. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=100 SRC="FIGDIR/small/666573v1_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@d93a11org.highwire.dtl.DTLVardef@17341e9org.highwire.dtl.DTLVardef@1ec4ca4org.highwire.dtl.DTLVardef@9bd42f_HPS_FORMAT_FIGEXP M_FIG C_FIG Graphical abstract created with Biorender.com

microbiology↗

Lock, Protect, and Bind: In Vitro Selection of LNA-modified Aptamers Using a Mutant T7 RNA Polymerase

RNA therapeutics are powerful tools for gene modulation and targeted therapies, but their clinical application is hindered by nuclease degradation and immunogenicity. Incorporating chemical modifications, like locked nucleic acids (LNAs), can enhance nuclease resistance, targeting properties, and thermal stability. Traditionally, LNA incorporation has relied on solid-phase synthesis of short RNAs. Engineered polymerases capable of incorporating xenonucleic acids (XNAs), including LNA, into longer RNAs have been described. However, their XNA yield is limited by primer and template copy numbers, and the generated DNA-XNA duplexes can be difficult to purify. We present a novel approach for incorporating LNA-ATP and LNA-TTP alongside 2Fluoro (2F)-modified pyrimidines via in vitro transcription using a mutant T7 RNA polymerase. This method enables efficient, primer-independent synthesis and amplification of LNA-modified RNA with low error rates. To demonstrate its utility, we performed in vitro selection (SELEX) of LNA- and 2F-modified aptamers targeting Influenza hemagglutinin (HA) and human CD40 ligand (hCD40L), two therapeutically relevant proteins. Iterative SELEX cycles yielded aptamers with low-nanomolar affinities, high specificity, and high nuclease resistance. Overall, this approach provides a scalable and versatile platform for generating chemically stabilized RNAs, fully compatible with SELEX, and holds potential for developing next-generation RNA-based therapeutics with improved pharmacokinetics.

molecular biology↗

Defining the scope of the European Antimicrobial Resistance Surveillance network in Veterinary medicine (EARS-Vet): a bottom-up and One Health approach

BackgroundBuilding the European Antimicrobial Resistance Surveillance network in Veterinary medicine (EARS-Vet) was proposed to strengthen the European One Health antimicrobial resistance (AMR) surveillance approach. ObjectivesThe objectives were to (i) define the combinations of animal species, production types, age categories, bacterial species, specimens and antimicrobials to be monitored in EARS-Vet and to (ii) determine antimicrobial test panels able to cover most combinations. MethodsThe EARS-Vet scope was defined by consensus between 26 European experts. Decisions were guided by a survey of the combinations that are relevant and feasible to monitor in diseased animals in 13 European countries (bottom-up approach). Experts also considered the One Health approach and the need for EARS-Vet to complement existing European AMR monitoring systems coordinated by the European Centre for Disease Prevention and Control (ECDC) and the European Food Safety Authority (EFSA). ResultsEARS-Vet would monitor AMR in six animal species (cattle, swine, chicken (broiler and laying hen), turkey, cat and dog), for 11 bacterial species (Escherichia coli, Klebsiella pneumoniae, Mannheimia haemolytica, Pasteurella multocida, Actinobacillus pleuropneumoniae, Staphylococcus aureus, Staphylococcus pseudintermedius, Staphylococcus hyicus, Streptococcus uberis, Streptococcus dysgalactiae and Streptococcus suis). Relevant antimicrobials for their treatment were selected (e.g. tetracyclines) and complemented with antimicrobials of more specific public health interest (e.g. carbapenems). Three test panels of antimicrobials were proposed covering most EARS-Vet combinations of relevance for veterinary antimicrobial stewardship. ConclusionsWith this scope, EARS-Vet would enable to better address animal health in the strategy to mitigate AMR and better understand the multi-sectoral AMR epidemiology in Europe.

microbiology↗