Search bioRxiv⌕ Search

Biology subjects

Jones, K.

Publications and source records attributed to Jones, K..

At least 19 recordsLinked to original sources

Spatially-resolved multimodal profiling identifies functionally-heterogeneous cancer-associated fibroblasts associated with poor radiotherapy outcomes in muscle-invasive bladder cancer.

Background: Cancer-associated fibroblasts (CAFs) contribute to systemic therapy resistance in muscle-invasive bladder cancer (MIBC), but their functional heterogeneity and relevance to curative bladder-preserving radiotherapy, are poorly understood. Methods: Transcriptomic analysis was performed on 279 tumours from BC2001, a phase 3 radiotherapy clinical trial. To study CAF heterogeneity, we integrated bulk RNA-seq, single-cell spatial analysis of multiplex immunofluorescence images and quantification of extracellular matrix (ECM) features in 155 MIBC biopsies. The functional heterogeneity of distinct CAF populations was evaluated by single-nuclear RNA-seq. Spatial interactions between CAF populations and CD8+ T-cells was assessed and the relevance of lymphocytes to radiation responses was evaluated in a CAF-enriched murine bladder cancer model (BBN963). Results: BC2001 patients with CAF-enriched tumours had worse overall survival (HR=1.671, 95% CI 1.221-2.287, Log-rank p=0.0012). CAF abundance and antigen expression was highly heterogenous. Podoplanin (PDPN) was expressed on the majority of CAFs and was associated with inflammatory pathways. Enrichment of CAF gene signatures was associated with a significant increase in CAFs expressing fibroblast activation protein (FAP) (p=0.004) and dense ECM features (p=0.0004). Fifty-three percent of tumours exhibited stromal CD8+ T-cell exclusion with significant enrichment in FAP-dominant neighbourhoods (p<0.001). In vivo, lymphocytes were critical for radiation-induced tumour control, indicating that immune cold or excluded tumours may have limited radiotherapy responses. Conclusion: In MIBC, CAFs are associated with poor radiotherapy outcomes. Multiple mechanisms are deployed by functionally-heterogeneous CAFs, including promotion of chronic inflammation by PDPN+ CAFs and ECM remodelling by FAP+ CAFs which impact CD8+ T-cell distribution and radiation responses.

cancer biology↗

Lipoproteins modulate the uptake and biological functionof cationic cell-penetrating peptides across the animal lineage.

Cationic cell-penetrating peptides (+CPPs) are pervasive killer peptides produced by all animals and found in innate immune systems, venoms and neurodegenerative diseases. Despite their ubiquity, the mechanisms underlying their uptake remain opaque and intensely debated. Here, we interrogate +CPPs spanning 600 million years of animal evolution and identify endocytosis as a conserved/convergent uptake mechanism across cell types and organisms, at physiological concentrations. By combining multiplex imaging, genetic screening, cryo-electron tomography, and biophysical methods, we uncover that +CPPs seemingly universally enter eukaryote cells via 'hitchhiking' on lipoproteins. We further show that the interaction of +CPPs with lipoproteins modulates their antimicrobial function. Combined, our findings establish a unified molecular framework describing a pan-eukaryote cell penetrance mechanism. As hyperlipidemia is a common comorbidity, our findings have direct implications for human health. Lastly, the insights gleaned from this work highlight design principles that may inform the future engineering of peptide-based therapeutics and delivery vehicles.

cell biology↗

A patient-derived xenograft model of FUS::TFCP2 intraosseous rhabdomyosarcoma reveals chemoresistance and differential sensitivity to ALK inhibitors

TFCP2-rearranged rhabdomyosarcoma is an exceptionally rare and highly aggressive malignancy driven by TFCP2 gene fusions and associated with a dismal clinical prognosis. Because standardized treatment regimens are lacking, developing representative preclinical models is critical for identifying effective therapies. Here, we present a case of a 29-year-old male with rapidly progressive, metastatic pelvic intraosseous rhabdomyosarcoma (iRMS) harboring a FUS::TFCP2 fusion and anaplastic lymphoma kinase (ALK) overexpression. To evaluate therapeutic vulnerabilities, we established a patient-derived xenograft (PDX) model that faithfully recapitulated the histologic, immunohistochemical, and molecular hallmarks of the primary tumor. High-throughput in vitro pharmacological screening of PDX-derived cells demonstrated notable resistance to standard cytotoxic chemotherapies and revealed a paradoxical and selective sensitivity profile across ALK inhibitors. The PDX-derived cells were susceptible to crizotinib, brigatinib, and ceritinib, yet resistant to the more selective second- and third-generation inhibitors alectinib and lorlatinib. Notably, next-generation ROS1/pan-TRK inhibitors (entrectinib, repotrectinib, and taletrectinib) demonstrated superior efficacy compared to the fourth-generation ALK inhibitor NVL-655. Our findings establish a validated preclinical PDX model for FUS::TFCP2 iRMS and suggest that multi-targeted tyrosine kinase inhibition may offer a more viable therapeutic strategy than narrow-spectrum ALK targeting or conventional chemotherapy.

cancer biology↗

Recommendations for the ethical and accurate use of population descriptors: a trainee-led survey of early-career researchers

Despite the importance of population descriptors in human genomics research, many scientists struggle to translate evolving ethical guidelines into their computational workflows. To characterize this gap between recommendations and implementation, we conducted a mixed-methods survey of early-career researchers to assess how they understand and implement the landmark 2023 NASEM report on the use of population descriptors in human genetics research. We show that while exposure to the report fosters ethical awareness, fundamental misconceptions about race and ancestry persist across academic disciplines, and trainees face structural bottlenecks, including legacy data constraints and a lack of technical confidence. To address this gap, we offer actionable, stakeholder-specific recommendations across the research lifecycle ranging from decision-support tools to "bring-your-own-data" workshops to leadership from academic journals, scientific societies, and trainee mentors. Ultimately, we argue that to promote scientific rigor and reduce bias in genetic discoveries, the scientific ecosystem must invest in the infrastructure necessary to empower the next generation of researchers.

genetics↗

Visual uncertainty and task demands shape active sensing strategies in mice

In natural environments, animals actively sample visual information to guide behavior. Sensory feedback is dynamic and often requires active movements, whether saccading across the lines of this page or walking through a park. From high-acuity vision in hawks to low-acuity mice, many animals actively navigate to seek information, which can be called infotaxis. Although mice have relatively low-acuity vision, they still rely on sight for critical behaviors including navigation and prey capture. Yet, how sensitive they are to visual information and performing infotaxis has not been established. Here, we develop a virtual reality object discrimination task to investigate visual decision-making under naturalistic conditions. We show that mice perform infotaxis by actively seeking out informative views to guide their choices. Stimulus manipulations confirm that this strategy is modulated by the amount of available visual information. These results reveal that mice use principled active strategies to resolve visual uncertainty, highlighting a key role for information-seeking in natural vision. HighlightsO_LIMice perform active visual sensing in a free-range VR object discrimination task. C_LIO_LIThey perform infotaxis and select the correct object under variable visibility. C_LIO_LIDecisions decoded from head-body movements and speed reflect occlusion sensitivity. C_LI

neuroscience↗

Lake ecosystem responses to runoff variability across time and space

Inland waters in the Northern Hemisphere are experiencing increased annual runoff due to higher overall precipitation as well as intensified short-term events such as heavy rainfall, floods and storms. These events affect the total loading and variability of inputs of allochthonous, coloured dissolved organic matter (cDOM) and inorganic nutrients into lakes. Previous studies have shown that increased total cDOM and inorganic nutrient loads affect phytoplankton biomass and metabolic rates, but it is unknown how the effects of different cDOM and nutrient pulse scenarios are modified by spatial and seasonal differences in lake characteristics. Here, we conducted a coordinated, standardized mesocosm experiment across three lakes with different ambient cDOM and nutrient concentrations. In two of these lakes, the experiment was implemented in two seasons. The same total amounts of cDOM, nitrate and phosphate were added to all mesocosms, but in pulses that differed in intensity and frequency. We found that pulse intensity and frequency affected chlorophyll a and phycocyanin concentrations and metabolic rates, i.e. gross primary production and respiration, differently. Specifically, more pronounced effects were found in response to the extreme pulse scenario compared to those with more frequent, smaller pulse additions. Furthermore, the effects were mainly temporary and varied more among lakes than between seasons. The clearest differences between the extreme and more gradual runoff scenarios were found in the lake with the lowest background cDOM and nitrate concentrations, likely because lower light limitation and possibly stronger initial N-limitation caused a faster response to the nutrient addition. Our results highlight that both antecedent lake conditions and characteristics of runoff events can affect phytoplankton biomass and metabolic rates and that comparative experimental approaches are needed to reveal the complexity of the responses.

ecology↗

Migratory connectivity of pelagic predators between tropical Atlantic islands and seamounts revealed through passive acoustic telemetry

BACKGROUNDOceanic islands and seamounts are recognised as hotspots of abundance and diversity for marine top predators, such as sharks and large teleosts, and are hypothesised to function as migratory stepping stones for mobile, pelagic species. However, while movements of pelagic predators between such features have been documented in some oceans, evidence from the tropical Atlantic remains limited. RESULTSHere, we report on long-distance migrations of three species of pelagic predator between oceanic islands and seamounts in the tropical south Atlantic recorded via independent passive acoustic telemetry arrays. These include the first recorded trans-Atlantic migration of a Galapagos shark (Carcharhinus galapagensis) from Ascension Island (UK) to the Sao Pedro and Sao Paul Archipelago (Brazil) (minimum distance 1,930 km); the longest documented oceanic migration of an Almaco jack (Seriola rivoliana) from St Helena (UK) to Ascension Island (minimum 1,300 km); and multiple movements of Galapagos and silky sharks (C. falciformis) between two Mid-Atlantic Ridge seamounts and Ascension Island (minimum 265-325 km). These detections are notable given the limited duration, sample sizes, and temporal overlap of acoustic tracking studies in the region, suggesting substantial connectivity across large spatial scales. CONCLUSIONSOur findings provide empirical support for the role of oceanic islands and seamounts as connectivity hubs for pelagic predators in the tropical Atlantic, underscoring their importance as key nodes in marine protected area networks. More broadly, this study demonstrates the value of collaborative regional tracking networks in resolving large-scale movement patterns and informing marine management at ecologically relevant scales.

ecology↗

Vision guides directed orienting movements during obstacle avoidance in mice

In natural environments, animals must effectively maneuver around obstacles to reach goals such as food or shelter. Recent work has demonstrated that laboratory mice use vision for naturalistic behavior such as prey capture, escape, and distance estimation. However, it is unknown to what extent mice use vision relative to other senses such as touch for obstacle avoidance, a critical natural behavior. In this study we developed an obstacle avoidance task in freely moving mice to investigate how vision is used to guide paths around an obstacle obstructing a goal. We found that mice clearly use vision to avoid an obstacle, steering around the obstacle at distances where tactile information isnt available. By comparing trajectories for mice performing obstacle avoidance in the light versus the dark, we found that vision contributes to more spatially efficient trajectories and paths directed to the open edge of the obstacle. When vision is available, mice make large orienting movements towards the opening of the obstacle at about 10 cm from its edge, suggesting that mice are actively using visual information to direct these movements. Finally, by occluding one eye, we found that mice were still able to avoid obstacles with primarily monocular information. Taken together, these results demonstrate that laboratory mice use vision to avoid an obstacle, taking directed paths that are initiated by large orienting movements. In addition to demonstrating the visual behavioral capabilities of the mouse, this paradigm can serve as a foundation to study the neural circuits that mediate visually guided orienting and locomotion. HighlightsO_LIWe developed a simple obstacle avoidance task for freely moving mice that requires minimal training C_LIO_LIVision is necessary for efficient and directed paths around an obstacle C_LIO_LIMice steer around obstacles by performing directed head movements towards clear paths C_LIO_LIMice do not require binocular vision for obstacle avoidance C_LI

neuroscience↗

Machine perfusion and single-cell spatial transcriptome mapping identifies novel immune escape mechanisms in colorectal cancer liver metastasis

Liver metastasis is the terminal stage of colorectal cancer. Immune checkpoint blockade (ICB) has heralded remarkable clinical success across a range of cancer types, but with limited efficacy in replacement-type colorectal liver metastasis (CRLM), the most common and lethal histological subtype. Using a novel human normothermic perfusion model, we demonstrate for the first time, that T-cells preferentially extravasate within the peri-tumoural liver rather than the CRLM. We use single-cell spatial transcriptomics and multiplexed immunofluorescence to validate CRLM T-cell exclusion and show that CRLM endothelia are anergic, lacking key receptors required for T-cell extravasation. CD4 T-cells that extravasate within the peri-tumoural liver are TCR-reactive, yet exhausted, whilst CD4 T-cells within the CRLM demonstrate a stress response, impaired cytokine expression and lack of TCR reactivity. We identify the spatial cellular and molecular interactions underlying these observations, providing novel targets for future attempts to sensitise to immunotherapeutics and a justification for failed ICB efficacy in CRLM.

cancer biology↗

Sampling Microbial Dynamics in the Salish Sea Estuary: Evaluating Methods to Capture Cyanobacteria and Cyanophage

Picocyanobacteria from the genera Prochlorococcus and Synechococcus thrive across the globe in aqueous environments, have relatively small genomes, and have growth dynamics regulated by both viral interactions and abiotic conditions, making them excellent model organisms for exploring host-pathogen coevolution. The Salish Sea, located in the Western coastal waters bordering the USA and Canada, is at the current northern boundary (defined by Prochlorococcus versus Synechococcus prevalence ratios) of the range of Prochlorococcus. Predictions suggest that this boundary will shift northward as warmer waters move northward, providing an excellent system to study host-pathogen dynamics and coevolution in a changing environmental context. In preparation for such studies, we developed and refined methods to sample and sequence cyanobacteria, cyanophages, and their abiotic environment. In addition to basic methodological questions focused on the physical sampling, filtering, viral precipitation, DNA extraction, and technical replicability, we explored how well our filtering and extraction protocols enrich for our main target, picocyanobacteria. The protocol described herein can successfully discriminate large-cell eukaryotic organisms, but size fractionation of picocyanobacteria appears to be affected by the presence of free DNA, multicellular structures, and abundant tycheposons. Our preferred final protocol at the conclusion of these experiments based on yield and processing time is presented. We recovered substantial Prochlorococcus, Synechococcus and amoeba-like sequences in most samples, and preliminary exploration of relative taxon sequence read recoveries across locations, over time, and tidal conditions are also discussed. Approaches described here may be useful to other efforts such as harmful algal bloom monitoring, species isolation and enrichment, water quality assessments, anti-viral discovery, and understanding picocyanobacterial population changes over space and time.

microbiology↗

Sustainable cattle management by communities supports African wildlife

Community-based conservation (CBC) initiatives aim to reconcile biodiversity protection with local livelihoods, yet their effectiveness in protecting wildlife remains uncertain, often hinging on local management1,2. We evaluated a globally significant CBC model in Kenyas Greater Maasai Mara Ecosystem (GME), where conservancies, run jointly by Maasai landowners and the tourism sector, employ rotational cattle grazing to support both wildlife and pastoralism3,4. Using a [~]1200 km2 grid of 180 camera traps across gradients of livestock pressure in Maasai Mara National Reserve and three conservancies in 2018, we collected and analysed over 2 million images with a customised AI-powered pipeline. We found a positive impact of observed cattle pressure on mammal community occupancy and species richness, except for at the highest levels of cattle grazing. However, sheep and goat grazing and proximity to infrastructure had a negative impact. These results provide evidence that wildlife and pastoralism can coexist under community-led stewardship5, but only with active management and targeted control of emerging threats. AI tools such as our image classifier may contribute to more adaptive community-led management of these areas6. As conservation policy shifts beyond formal protected areas, our findings support CBC as a scalable model for conserving biodiversity within working landscapes, offering a pathway to meet global targets while maintaining local livelihoods7.

ecology↗

Rats Exposed to a Low Resource Environment in Early Life Display Sex Differences in Blood Pressure, Autonomic Activity, and Brain and Kidney Pro-inflammatory Markers During Adulthood

Introduction: Poverty, a low resource state, is a common adverse childhood experience (ACE) and early life stress (ELS). People who experienced childhood poverty are at greater risk for developing hypertension during adulthood, with sex differences. To determine the possible mechanisms of these sex differences, we investigated the alterations in blood pressure (BP), autonomic activity, and inflammation in the brain and kidneys of rats exposed to an impoverished environment during the early postnatal period, by using the limited bedding and nesting (LBN) model. Methods: The LBN model mimics childhood poverty by creating a low resource environment on postnatal days 2-9. After weaning, offspring were separated by sex and LBN exposure and were evaluated at 16-18 weeks of age (Adulthood). Results: LBN males displayed an increase in BP compared to the control (CON), whereas LBN females showed no changes. Sympathetic nerve activity (SNA) was increased in LBN males and females compared to the CON, while only parasympathetic nerve activity (PNA) was increased in LBN vs. CON females. Pro-inflammatory cytokines, IL-17 and TNF-, were decreased in the brains of LBN vs. CON males, with no alterations in females. Conclusion: Adult LBN males have elevated BP, due to increased SNA, while LBN females may be protected from increased BP due to a simultaneous increase in SNA and PNA. The reduction in IL-17 and TNF- in LBN males may serve as a compensatory mechanism to lower BP. This study provides insights into sex differences in BP for adults who experienced childhood poverty.

physiology↗

Modular adaptation of the ribcage in response to artificial selection for endurance running

The capability for sustained running has convergently evolved multiple times in mammals, and involves myriad anatomical, physiological, and behavioural adaptations. The ribcage plays a critical role in both respiration and locomotion but its adaptations to running are largely unexplored. Robustly testing adaptation in wild populations is challenging, so we use artificial selection for voluntary wheel-running behaviour (i.e., High Runner or HR mice) to directly test form-function relationships associated with sustained running. We compared ribcage configuration and shape of HR (males: 52, females: 47) to control (males: 48, females: 48) mice using rib counts and 3D Geometric Morphometrics. Two of four HR lines had an additional rib and increased variation in the proportion of true to false ribs, suggesting that ribcage patterning has been impacted by selection. This variability among lines suggests that selection for wheel running has resulted in adaptations that are expressed variably among the selected lines, resulting in "multiple solutions" to selection. Total ribcage shape did not vary significantly between HR and Control mice. Instead, the effect of selection varied along the ribcage, with significant effects in the caudal ribs. Further, the caudal ribcage of HR mice showed increased disparity, within-rib, and among-rib integration compared to controls. The strong response of caudal ribs indicates a modular pattern of adaptation, with cranial ribs possibly constrained by their role in ventilation. This study demonstrates that adaptation in the mammalian ribcage is likely shaped by a complex interplay of selection and craniocaudal integration and may result in variation at multiple anatomical levels (count, shape, modularity).

evolutionary biology↗

A prognostic signature for lung adenocarcinoma in people who have never smoked

Knowledge of tumor cell dynamics can inform prognosis and treatment yet is largely lacking for lung adenocarcinoma in people who have never smoked (NS-LUAD). With RNA-seq data from 684 NS-LUAD and validation in an independent dataset, we identified three subtypes with distinct phenotypic traits and cell compositions. Additional genomic and histological data further characterized the subtypes. Steady, marked by low proliferation, high alveolar cell fraction, moderate-to-well differentiation, and fewer driver genes alterations, is linked to prolonged survival and low immune evasion. Proliferative shows high proliferation markers, TP53 mutations, and gene fusions. Chaotic, with high epithelial-to-mesenchymal transition markers, has the worst prognosis even within stage I tumors. Lacking known molecular or histological characteristics, this aggressive subtype is solely identified by transcriptomic data. A 60-gene signature recapitulates the overall classification and strongly predicts survival even within subgroups based on tumor stage or known genomic features, emphasizing its potential for improving NS-LUAD prognostication in clinical settings. SignificanceThe transcriptome of 684 lung adenocarcinomas in people who have never smoked (NS-LUAD) identifies three subtypes with different cellular dynamics, and genomic and morphologic features. A 60-gene signature accurately stratifies subjects for mortality risk, even in stage I, offering a clinically applicable tool for treatment decision making in NS-LUAD patients.

genomics↗

Non-redundant cardiolipin synthases support membrane integrity and stress resilience in Bacteroides fragilis

Gut-resident bacteria must tolerate diverse membrane-disrupting agents, including bile acids, to maintain colonization. Cardiolipin is an anionic phospholipid that supports membrane integrity and stress resilience in many bacteria. However, cardiolipin synthases remain poorly characterized in the Bacteroidota, a dominant phylum of the human gut microbiota. The prevalent gut commensal Bacteroides fragilis encodes two predicted cardiolipin synthases, ClsA and ClsB. We previously identified both cls genes as bile-acid fitness factors in B. fragilis P207, but the individual contributions of ClsA and ClsB to cell physiology had remained undefined. Here we combine targeted gene deletion with high-resolution lipidomics, metabolomics, and elemental mass spectrometry to show that the two enzymes have non-redundant functions in the cell. Cardiolipin is a minor lipid in the B. fragilis membrane, and both Cls enzymes contribute to its production. clsA and clsB differ in growth-phase expression, in their effects on cell morphology, and in their associated cardiolipin species. Loss of each enzyme also produces distinct changes in fitness under several membrane-perturbing stresses and in the broader cellular metabolome, including compound classes with documented bioactivity in mammalian hosts. In contrast to the acute ion-gradient disruption caused by the secondary bile acid deoxycholate, deletion of both synthases did not measurably alter steady-state intracellular ion levels under standard growth conditions, indicating that cardiolipin loss does not perturb basal ion homeostasis under these conditions. Together, these results define non-redundant roles for two cardiolipin synthases in a common member of the human gut microbiota. ImportanceInflammatory bowel diseases affect millions of people worldwide. The gut bacterium Bacteroides fragilis is a normal member of the human intestinal microbiota that can also bloom to high abundance in inflamed guts. To survive within the gut, B. fragilis must maintain the integrity and function of its cell membrane. In this study, we characterize the functional role of two B. fragilis genes that contribute to the synthesis of the membrane lipid, cardiolipin. We find that the two cardiolipin synthase genes are not functionally interchangeable; each impacts the cells lipid pool in distinct ways and contributes differently to how B. fragilis responds to membrane stress. Our work provides insight into how a common gut bacterium adapts to conditions encountered in the intestine, and improves understanding of membrane biology in this important group of gut microbes.

microbiology↗

Th9-endothelial cell crosstalk promotes inflammatory atherosclerotic cardiovascular disease

Atherosclerotic cardiovascular disease (ASCVD) is a leading cause of death, and understanding its pathogenic drivers is critical for effective prevention and treatment. Inflammation has a critical role in ASCVD, and patients with inflammatory diseases are at increased risk. However, the key inflammatory mediator promoting ASCVD are incompletely understood, a major barrier when targeting inflammation to prevent ASCVD. Here, we found that interleukin-9 (IL-9) producing T helper cells (Th9) were significantly associated with ASCVD in patients with the autoimmune disease psoriasis. Th9 cells were poised to migrate to coronary vessels and were identified in atherosclerotic plaque. In vivo, murine inflammatory atherogenesis was prevented by IL-9 blockade and by IL-9 receptor (IL-9R) deletion in endothelial cells. In human arterial endothelial cells, IL-9R/STAT3 signaling promoted endothelial dysfunction, angiogenesis, and release of leukocyte chemoattractants. These findings suggest that in autoimmune diseases like psoriasis, Th9/IL-9 promote atherosclerosis by directly targeting endothelial cells, and that IL-9R/STAT3 signaling could be a promising therapeutic target for ASCVD. eTOC SummaryBaral et. al. investigate individuals who are at high risk for atherosclerosis due to underlying inflammatory disease and use mouse models of cardiovascular disease to uncover a role for interleukin-9-producing T helper 9 cells in the pathogenesis of inflammatory atherosclerosis.

immunology↗

Neural dynamics in superior colliculus of freely moving mice

Vision is an active process that depends on head and eye movements to explore the visual environment. Superior colliculus (SC) is known for its role in generating these movements, as well as processing visual information, but has not been studied extensively during free movement in complex visual environments. To determine the impact of active vision, we recorded neural activity across the depth of SC during free movement while simultaneously recording eye and head position. We find that superficial SC (sSC) neurons respond to visual input following gaze-shifting saccadic movements, whereas deep SC (dSC) neurons respond to the movements themselves, as demonstrated by their sustained response in darkness. Additionally, we find motor responses in dSC are more correlated to head movements rather than eye movements. Furthermore, we compared sSC gaze shift responses to known gaze shift responses in primary visual cortex (V1), finding similarities in key response types, although the temporal sequences following gaze shifts differ between the regions. Our results demonstrate distinct visual processing differences between SC and V1 as well as highlighting the various roles SC plays during active vision. HighlightsO_LIWe recorded neural activity across the depths of superior colliculus (SC) in freely moving mice while measuring head and eye movements. C_LIO_LINeurons in mouse SC respond strongly to gaze shifts, and these responses differ between superficial (sSC) and deep (dSC) layers. C_LIO_LIsSC neurons respond primarily to the visual input during a saccadic movement. C_LIO_LIdSC neurons generally represent the head movement more than the eye movement, independent of visual input. C_LIO_LIWhile sSC gaze shift responses share similarities with V1 there are unique response profiles in SC that suggest differences in the role of visual processing between SC and V1 during free movement. C_LI

neuroscience↗

Short-term alterations in dietary amino acids override host genetic susceptibility and reveal mechanisms of Salmonella Typhimurium small intestine colonization

In addition to individual genetics, environmental factors (e.g., dietary changes) may influence host susceptibility to gastrointestinal infection through unknown mechanisms. Herein, we developed a model in which CBA/J mice, a genetically resistant strain that tolerates intestinal colonization by the enteric pathogen Salmonella Typhimurium (S. Tm), rapidly succumb to infection after exposure to a diet rich in L-amino acids (AA). In mice, S. Tm-gastroenteritis is restricted to the large intestine (cecum), limiting their use to understand S. Tm small intestine (ileum) colonization, a feature of human Salmonellosis. Surprisingly, CBA mice fed AA diet developed ileitis with enhanced S. Tm ileal colonization. Using germ-free mice and ileal-fecal slurry transplant, we found diet-mediated S. Tm ileal expansion to be microbiota-dependent. Mechanistically, S. Tm relied on Fructosyl-asparagine utilization to expand in the ileum during infection. We demonstrate how AA diet overrides host genetics by altering the gut microbiotas ability to prevent S. Tm ileal colonization.

microbiology↗