Progressive Restriction Research Articles

A history-dependent integrase recorder of plant gene expression with single-cell resolution

During development, most cells experience a progressive restriction of fate that ultimately results in a fully differentiated mature state. Understanding more about the gene expression patterns that underlie developmental programs can inform engineering efforts for new or optimized forms. Here, we present a four-state integrase-based recorder of gene expression history and demonstrate its use in tracking gene expression events in Arabidopsis thaliana in two developmental contexts: lateral root initiation and stomatal differentiation. The recorder uses two serine integrases to mediate sequential DNA recombination events, resulting in step-wise, history-dependent switching between expression of fluorescent reporters. By using promoters that express at different times along each of the two differentiation pathways to drive integrase expression, we tie fluorescent status to an ordered progression of gene expression along the developmental trajectory. In one snapshot of a mature tissue, our recorder is able to reveal past gene expression with single cell resolution. In this way, we are able to capture heterogeneity in stomatal development, confirming the existence of two alternate paths of differentiation.

Atrial flow regulator in transposition of the great arteries, ventricular septal defect, and pulmonary stenosis: a case report.

A 5-month-old girl with transposition of the great arteries, ventricular septal defect, and pulmonary stenosis underwent the implantation of a 6-mm M Atrial Flow Regulator (Occlutech) over an 8-French delivery sheath for significant cyanosis and progressive restriction of the atrial septal defect, without adverse event for 6 months. The Atrial Flow Regulator device could improve blood mixing as a bridge to surgery.

Are increased symptoms of orthorexia nervosa linked to self-perceived body image and nutritional adequacy of Turkish adults?

ABSTRACT This cross-sectional study, conducted on 4003 participants aged between 18 and 45, aims to contribute to orthorexia nervosa (ON) research by examining the relationship between ON, body image and nutritional adequacy. The Orthorexia Nervosa-11 scale (ORTO-11) and body perception scale were applied to individuals, and food consumption records were taken with a 24-hour dietary recall method. The study found that more individuals with orthorexia nervosa (ON) considered themselves overweight compared to non-ON individuals. Evaluating diet quality, the mean adequacy ratio was significantly higher in ON individuals. Nutrient adequacy ratios for total fiber, magnesium, zinc, thiamine, folic acid, and vitamin C were higher, while those for carbohydrate and iron were lower in ON individuals. Additionally, increasing the number of snacks, protein, and total fiber adequacy decreased the ORTO-11 score. Distorted body image perception may be a risk factor for ON, but healthy eating fixation does not lead to nutrient inadequacy unless it involves progressive food restriction.

THE POTENTIAL OF TEQUIL, A PLANT EXTRACT BASED ON QUILLAJA SAPONARIA, IN SUSTAINABLE AGRICULTURE

More attention is being given to researches of eco-sustainable solutions to be implemented in agriculture, particularly in the presence of plant parasitic nematodes, whose damages have significant global importance. Unsustainable practices, such as fumigation and monoculture, have led to depletion of biodiversity, allowing harmful trophic groups (bacteria, fungi, and nematodes) to prevail, and their negative synergistic action further exacerbating yield losses. Considering the notable and progressive restriction of usable molecules, nematode control strategies must necessarily consider the appropriate integration of methods. The main objective of control is to limit pathogen populations below the damage threshold, rather than aiming at their eradication as mistakenly pursued in the past. This goal can be achieved with the help of solutions that promote plant development through biostimulation of root systems, which are often affected by various organisms in the biosphere. Tequil, through its well-documented synergy of saponins, tannins, and polyphenols, produces invigorating, biostimulating, and strengthening effects on the root system. Indeed, in vitro tests and field trials have highlighted Tequil’s appreciable activity in containing trophic groups, particularly root-knot nematodes of the Meloidogyne genus. Therefore, its use could indirectly contribute to nematode control and limit yield losses. Key Words: Quillaja saponaria, nematodes, bio stimulation, biocontrol, abiotic stresses resistance.

Anatomy of the late Famennian Dasberg event in a deep shelf of southern Euramerica: Oxygenation and productivity in a restricted basin during a progressive long-term cooling

The late Famennian Dasberg event is described as a series of global hypoxic and transgressive events associated with global faunal turnover. The event, recorded on a deep shelf of the Rhenohercynian basin from southern Euramerica, was investigated in the Holy Cross Mountains of Poland using integrated high-resolution geochemical, mineralogical, and palynological studies. The data revealed the progressive restriction of the intrashelf basin resulting from intense regional block tectonics likely connected with the Late Devonian Variscan tectonic activity. This led to weak chemocline ventilation, the development of anoxic conditions, and the deposition of two organic-rich Dasberg black shale (DBS) horizons. The DBS was deposited in an environment characterized by the constant contribution of detrital components from a common source area. A slight change in terrestrial input may have been driven by modest bathymetric changes associated with the tectonics and stronger winds delivering charcoal and terrestrial components (i.e., miospores and phytoclasts). A supply of nutrients from land and delivery of crucial biolimiting elements (i.e., nitrogen and phosphorus) from deeper waters stimulated primary productivity, as recorded in phytoplankton blooms. The δ13Corganic values in the DBS reflect the incorporation of primary biomass from mainly marine photoautotrophs into sedimentary organic matter. Episodic delivery of toxic sulphides to the photic zone was detected by small-sized framboids and biomarkers, which record the appearance of green sulphur bacteria that photosynthesized in euxinic water column. The activity of phototrophic sulphide-oxidizing bacteria could have led to hyper-enrichment of Zn (715–1002 ppm) in the Lower DBS. The diachronous appearance of the DBS horizons in Euramerica and Gondwana, and regionally marked extinction of benthic fauna, suggest that anoxia developed in restricted Black Sea–like basins formed by intensive tectonic activity and continental plate convergence.

Exploring Molecular Mechanisms and Biomarkers in COPD: An Overview of Current Advancements and Perspectives.

Chronic obstructive pulmonary disease (COPD) plays a significant role in global morbidity and mortality rates, typified by progressive airflow restriction and lingering respiratory symptoms. Recent explorations in molecular biology have illuminated the complex mechanisms underpinning COPD pathogenesis, providing critical insights into disease progression, exacerbations, and potential therapeutic interventions. This review delivers a thorough examination of the latest progress in molecular research related to COPD, involving fundamental molecular pathways, biomarkers, therapeutic targets, and cutting-edge technologies. Key areas of focus include the roles of inflammation, oxidative stress, and protease-antiprotease imbalances, alongside genetic and epigenetic factors contributing to COPD susceptibility and heterogeneity. Additionally, advancements in omics technologies-such as genomics, transcriptomics, proteomics, and metabolomics-offer new avenues for comprehensive molecular profiling, aiding in the discovery of novel biomarkers and therapeutic targets. Comprehending the molecular foundation of COPD carries substantial potential for the creation of tailored treatment strategies and the enhancement of patient outcomes. By integrating molecular insights into clinical practice, there is a promising pathway towards personalized medicine approaches that can improve the diagnosis, treatment, and overall management of COPD, ultimately reducing its global burden.

Provision of palliative care for people with chronic obstructive pulmonary disease: a narrative review.

Chronic obstructive pulmonary disease (COPD) is characterized by persistent and progressive airflow restriction and is the third leading cause of death and disability, globally. People with severe COPD generally experience long-term functional decline punctuated by periods of acute exacerbation. Symptom burden can be severe and debilitating, and typically includes breathlessness, cough, fatigue, pain, anxiety, depression, and overall reduced quality of life. Understanding current palliative care needs and provisions in this group is an essential step to expanding access in future. A narrative review of specialist and generalist (primary) palliative care provisions for people with COPD, with an emphasis on breathlessness symptom management. This paper aims to examine the current landscape of palliative care provision and highlight barriers and facilitators to palliative care access for people with severe COPD. People living with severe COPD, as well as the people who care for them, are routinely under-serviced in best-practice end-of-life care, despite having symptom burden that is comparable to that of people with advanced cancer. Barriers to palliative care in this group include lack of specialist palliative care resources, uncertainty surrounding prognostication, and poor recognition of need from both patients and clinicians. Routine early palliative care involvement, including integration of specialist palliative care into respiratory services and upskilling of other healthcare providers to adopt palliative care principals within usual care (primary palliative care), have been shown to improve outcomes indicative of high-quality end-of-life care in this group, including symptom control, place of death, and legal preparations. Ongoing integration of specialist palliative care and professional education for generalist and non-palliative care specialist healthcare providers in the recognition and management of unmet palliative care needs is required to increase capacity beyond traditional specialist palliative care models. Despite high level of symptom burden, many people with COPD miss out on palliative care. Expanding capacity of traditional specialist palliative care by upskilling generalist healthcare providers and integrating specialist palliative care into existing respiratory services is necessary to improve access for people with COPD.

Chondromyxoid fibroma of the temporomandibular joint - a rare case.

Chondromyxoid fibroma (CMF) is a rare cartilaginous tumor, accounting for < 1% of benign bone tumors. We report a case of temporomandibular joint (TMJ)-CMF, involving the pterygopalatine space and skull base and discuss its epidemiology, clinical characteristics, and management. A 56-year-old woman presented with facial asymmetry and progressive mouth opening restriction due to a mass expanding upwardly to the auriculotemporal region. Using digital techniques to determine the lesion's boundary and reconstruct the normal glenoid fossa, the temporalis myofascial flap was transplanted between the titanium mesh and condyle to reconstruct the disc after tumor resection. This case highlights the importance of identifying patients with TMJ-CMF.

Early transcriptional similarities between two distinct neural lineages during ascidian embryogenesis

In chordates, the central nervous system arises from precursors that have distinct developmental and transcriptional trajectories. Anterior nervous systems are ontogenically associated with ectodermal lineages while posterior nervous systems are associated with mesoderm. Taking advantage of the well-documented cell lineage of ascidian embryos, we asked to what extent the transcriptional states of the different neural lineages become similar during the course of progressive lineage restriction. We performed single-cell RNA sequencing (scRNA-seq) analyses on hand-dissected neural precursor cells of the two distinct lineages, together with those of their sister cell lineages, with a high temporal resolution covering five successive cell cycles from the 16-cell to neural plate stages. A transcription factor binding site enrichment analysis of neural specific genes at the neural plate stage revealed limited evidence for shared transcriptional control between the two neural lineages, consistent with their different ontogenies. Nevertheless, PCA analysis and hierarchical clustering showed that, by neural plate stages, the two neural lineages cluster together. Consistent with this, we identified a set of genes enriched in both neural lineages at the neural plate stage, including miR-124, Celf3.a, Zic.r-b, and Ets1/2. Altogether, the current study has revealed genome-wide transcriptional dynamics of neural progenitor cells of two distinct developmental origins. Our scRNA-seq dataset is unique and provides a valuable resource for future analyses, enabling a precise temporal resolution of cell types not previously described from dissociated embryos.

Spatially distinct epithelial and mesenchymal cell subsets along progressive lineage restriction in the branching embryonic mammary gland

How cells coordinate morphogenetic cues and fate specification during development remains a fundamental question in organogenesis. The mammary gland arises from multipotent stem cells (MaSCs), which are progressively replaced by unipotent progenitors by birth. However, the lack of specific markers for early fate specification has prevented the delineation of the features and spatial localization of MaSC-derived lineage-committed progenitors. Here, using single-cell RNA sequencing from E13.5 to birth, we produced an atlas of matched mouse mammary epithelium and mesenchyme and reconstructed the differentiation trajectories of MaSCs toward basal and luminal fate. We show that murine MaSCs exhibit lineage commitment just prior to the first sprouting events of mammary branching morphogenesis at E15.5. We identify early molecular markers for committed and multipotent MaSCs and define their spatial distribution within the developing tissue. Furthermore, we show that the mammary embryonic mesenchyme is composed of two spatially restricted cell populations, and that dermal mesenchyme-produced FGF10 is essential for embryonic mammary branching morphogenesis. Altogether, our data elucidate the spatiotemporal signals underlying lineage specification of multipotent MaSCs, and uncover the signals from mesenchymal cells that guide mammary branching morphogenesis.

The single-cell chromatin landscape in gonadal cell lineage specification

Gonad development includes sex determination and divergent maturation of the testes and ovaries. Recent advances in measuring gene expression in single cells are providing new insights into this complex process. However, the underlying epigenetic regulatory mechanisms remain unclear. Here, we profiled chromatin accessibility in mouse gonadal cells of both sexes from embryonic day 11.5 to 14.5 using single-cell assay for transposase accessible chromatin by sequencing (scATAC-seq). Our results showed that individual cell types can be inferred by the chromatin landscape, and that cells can be temporally ordered along developmental trajectories. Integrative analysis of transcriptomic and chromatin-accessibility maps identified multiple putative regulatory elements proximal to key gonadal genes Nr5a1, Sox9 and Wt1. We also uncover cell type-specific regulatory factors underlying cell type specification. Overall, our results provide a better understanding of the epigenetic landscape associated with the progressive restriction of cell fates in the gonad.

Psychometric properties of the Disability of Arm Shoulder and Hand (DASH) in subjects with frozen shoulder: a reliability and validity study

BackgroundFrozen Shoulder (FS) is a painful condition characterized by severe pain and progressive restriction of shoulder movement, leading to functional impairment and reduced quality of life. While different Patient Reported Outcome Measurements (PROMs) tools exist for assessing shoulder diseases, few specific PROMs are validated for FS patients.PurposeThis study aims to assess the psychometric properties of the Disability of Arm, Shoulder, and Hand (DASH) questionnaire in FS patients.MethodsOne hundred and twenty-four subjects (mean ± SD age = 55.4 ± 7.9 years; 55.6% female) diagnosed with FS were included and completed the DASH questionnaire, the Numerical Pain Rating Scale (NPRS), the Shoulder Pain and Disability Index (SPADI), and the Short-Form Health Survey 36 (SF-36). Floor or ceiling effects were investigated. Structural validity was analysed through a unidimensional Confirmatory Factor Analysis (CFA), internal consistency through Cronbach’s alpha, test-retest reliability through the Intraclass Correlation coefficient (ICC), measurement error through the Standard Error of Measurement (SEM), and the Minimum Detectable Change (MDC), and construct validity through the hypothesis testing with the correlation with the other outcome measures used.ResultsNo floor or ceiling effects were observed. CFA confirmed a one-factor structure after addressing local item dependency (Root Mean Square Error of Approximation = 0.055; Standardized Root Mean Square Residual = 0.077; Comparative Fit Index = 0.970; Tucker-Lewis Index = 0.968). Cronbach’s alpha was high (= 0.951), and test-retest reliability was excellent (ICC = 0.999; 95% CI: 0.998-1.000). SEM was equal to 0.5 points, and MDC to 1.5 points. Construct validity was considered satisfactory as 80% of the a-priori hypotheses were met.ConclusionThe DASH questionnaire demonstrated good psychometric properties in FS patients, supporting its use as a valuable tool for assessing the impact of FS in clinical and research settings.

Cell fate decision in erythropoiesis: Insights from multiomics studies

Every second, the body produces 2 million red blood cells through a process called erythropoiesis. Erythropoiesis is hierarchical in that it results from a series of cell fate decisions whereby hematopoietic stem cells progress toward the erythroid lineage. Single-cell transcriptomic and proteomic approaches have revolutionized the way we understand erythropoiesis, revealing it to be a gradual process that underlies a progressive restriction of fate potential driven by quantitative changes in lineage-specifying transcription factors. Despite these major advances, we still know very little about what cell fate decision entails at the molecular level. Novel approaches that simultaneously measure additional properties in single cells, including chromatin accessibility, transcription factor binding, and/or cell surface proteins are being developed at a fast pace, providing the means to exciting new advances in the near future. In this review, we briefly summarize the main findings obtained from single-cell studies of erythropoiesis, highlight outstanding questions, and suggest recent technological advances to address them.

A prospective research on depression among chronic obstructive pulmonary disease patients in a tertiary care hospital

Background: Chronic obstructive pulmonary disease (COPD) indicates chronic lung disorders presented by a gradually progressive irrevocable bronchial obstruction (progressive restriction of the enforced expiratory capacity in 1 s forced expiratory volume-1) and manifestation compound of recurring bronchial cough and breathlessness. The patient’s life enters into a vicious cycle due to the complications of concurrent depressive disorder. Aims and Objectives: This research was conducted to evaluate the occurrence of despair among COPD patients in an advanced care hospital using a patient health questionnaire (PHQ-9) scale. Materials and Methods: This research was led subsequently receiving authorization from Institutional Ethical Board and inscribed well-versed agreement from the patients in the department of respiratory medicine. The PHQ-9 scale was employed for screening and assessment of despair yielding relevant details. No intervention was administered for the research. The analysis was based on the information obtained from the investigation reports. Results: Reddy et al. suggested the arbitrary classification of PHQ-9 scores: 0–4 indicates negligible misery, 5–9 minor misery, 10 and higher than indicates reasonable to acute misery. In our research, 39 patients scored PHQ-9 score between 0 and 4, 46 patients scored PHQ-9 score between 5 and 9, and 15 patients scored PHQ-9 score 10 and above. Conclusion: The occurrence of depression among COPD patients is significantly excessive so validated screening tool for depression is required in COPD management.

Adenovirus IgG and respiratory syncytial virus IgG seroprevalence in chronic obstructive pulmonary disease

Objectives: Chronic obstructive pulmonary disease (COPD) is the inflammatory response of the airways against harmful gases and particles in the lungs. It is an important cause of morbidity and mortality in all countries of the world due to progressive airway restriction. The acute exacerbation phase of COPD is usually triggered by bacterial or viral infections of the airway. The aim of this study was to determine the seroprevalence of respiratory syncytial virus (RSV)-immunoglobulin G (IgG) and adenovirus-IgG in COPD patients. Materials and Methods: Seroprevalence of RSV-IgG and adenovirus-IgG was investigated by enzyme-linked immunosorbent assay method in serum samples taken from 172 (107 male/65 female) patients being treated for COPD. Results: In the RSV-IgG study, 42.5% of the samples were positive, 49.4% were negative, and 8.1% gray-zone. In the adenovirus IgG study, 30.2% of the samples were positive, 61.6% negative, and 8.2% gray-zone. In addition, 13.4% (n = 23) of 172 patients were found to have both RSV and adenovirus coexistence. There was a statistically significant difference (P &lt; 0.05) in terms of gender in viral positive patients. Conclusion: In this thesis study, the prevalence of specific immune responses developed in individuals against RSV and adenovirus, which play a role in COPD attacks and exacerbations has been revealed. We suggest that it will be effective to use virus-specific vaccines as a treatment modality for the elimination of viral agents that increase the severity of exacerbations in unvaccinated COPD patients.

Sensitivity of the thermohaline circulation during the Messinian: Toward constraining the dynamics of Mediterranean deoxygenation

During the Messinian, the sensitivity of the Mediterranean Basin to ecosystem perturbation was enhanced in response to the progressive restriction of water exchange with the Atlantic Ocean. The widespread deposition of organic-rich layers (i.e. sapropel) during the Messinian testifies the perturbation of the carbon and oxygen cycles; indeed, these sediments were deposited under conditions of oxygen starvation, presumably in response to a periodic deterioration of the thermohaline circulation strength. Disentangling the causes, the effect and magnitude of the thermohaline circulation weakening during the geological past is crucial for better constraining present and near-future deoxygenation dynamics in the Mediterranean region under the current climate warming. For this purpose, we investigate a Messinian sapropel-bearing succession cropping out at Monte dei Corvi (Ancona, central Italy) with mineralogical, petrographic, micropaleontological and stable Carbon and Oxygen isotopic analyses. We show that sapropel layers were deposited in response to an increase of the sea surface buoyancy, which hampered the thermohaline circulation and thus the oxygenation of bottom water, in turn affecting the bioturbating organisms. Within the lithological cycle, the recovery of an efficient thermohaline circulation is recorded by thin packstone layers underlying the marly limestone/marlstone, which record intense bottom currents. The marly limestone/marlstone accumulated during periods of intense primary productivity and organic carbon export to the sea bottom, which promoted bottom hypoxia but not organic matter preservation. We infer that these lithological changes resulted from variations in the Adriatic Deep Water formation system, controlled by precession-driven climatic and oceanographic changes.By integrating previously published Sea Surface Temperature (SST) with new isotopic and mineralogical data, we show that variations in Sea Surface Salinity (SSS) were the leading factor controlling sapropel deposition, minimizing the role of primary productivity. The SSTs characterizing the sapropel deposits are close to the range of those projected in the Eastern Mediterranean at the end of this century under climate warming. In this scenario, future warming will be coupled with SSS increase, which will counteract the density loss provided by temperature, making the bottom deoxygenation in the Eastern Mediterranean abysses unlikely. However, additional forcing, such as winter heat waves and eutrophication, could contribute to negatively affecting the Mediterranean oxygen balance and should be considered in model-based projections.

Signs of local adaptation by genetic selection and isolation promoted by extreme temperature and salinity in the Mediterranean seagrass Posidonia oceanica.

Adaptation to local conditions is known to occur in seagrasses; however, knowledge of the genetic basis underlying this phenomenon remains scarce. Here, we analysed Posidonia oceanica from six sites within and around the Stagnone di Marsala, a semi-enclosed coastal lagoon where salinity and temperature exceed the generally described tolerance thresholds of the species. Sea surface temperatures (SSTs) were measured and plant samples were collected for the assessment of morphology, flowering rate and for screening genome-wide polymorphisms using double digest restriction-site-associated DNA sequencing. Results demonstrated more extreme SSTs and salinity levels inside the lagoon than the outer lagoon regions. Morphological results showed significantly fewer and shorter leaves and reduced rhizome growth of P. oceanica from the inner lagoon and past flowering events were recorded only for a meadow farthest away from the lagoon. Using an array of 51,329 single nucleotide polymorphisms, we revealed a clear genetic structure among the study sites and confirmed the genetic isolation and high clonality of the innermost site. In all, 14 outlier loci were identified and annotated with several proteins including those relate to plant stress response, protein transport and regulators of plant-specific developmental events. Especially, five outlier loci showed maximum allele frequency at the innermost site, likely reflecting adaptation to the extreme temperature and salinity regimes, possibly due to the selection of more resistant genotypes and the progressive restriction of gene flow. Overall, this study helps us to disentangle the genetic basis of seagrass adaptation to local environmental conditions and may support future works on assisted evolution in seagrasses.

Impact of tiered measures on social contact and mixing patterns of in Italy during the second wave of COVID-19

BackgroundMost countries around the world enforced non-pharmaceutical interventions against COVID-19. Italy was one of the first countries to be affected by the pandemic, imposing a hard lockdown, in the first epidemic wave. During the second wave, the country implemented progressively restrictive tiers at the regional level according to weekly epidemiological risk assessments. This paper quantifies the impact of these restrictions on contacts and on the reproduction number.MethodsRepresentative (with respect to age, sex, and region of residence) longitudinal surveys of the Italian population were undertaken during the second epidemic wave. Epidemiologically relevant contact patterns were measured and compared with pre-pandemic levels and according to the level of interventions experienced by the participants. Contact matrices were used to quantify the reduction in the number of contacts by age group and contact setting. The reproduction number was estimated to evaluate the impact of restrictions on the spread of COVID-19.ResultsThe comparison with the pre-pandemic baseline shows a significant decrease in the number of contacts, independently from the age group or contact settings. This decrease in the number of contacts significantly depends on the strictness of the non-pharmaceutical interventions. For all levels of strictness considered, the reduction in social mixing results in a reproduction number smaller than one. In particular, the impact of the restriction on the number of contacts decreases with the severity of the interventions.ConclusionsThe progressive restriction tiers implemented in Italy reduced the reproduction number, with stricter interventions associated with higher reductions. Readily collected contact data can inform the implementation of mitigation measures at the national level in epidemic emergencies to come.

Brain Derived Neurotrophic Factor (BDNF) modifies endothelial Ca2+ signaling

BACKGROUND: Preventing or reversing endothelial dysfunction is essential for preserving vascular homeostasis and staving off vascular disease. Previous findings from our lab suggest that maintaining a distinct profile of calcium (Ca 2+ ) signals along the endothelial network is crucial for sustaining normal vascular function and structure, and progressive restriction of dynamic Ca 2+ signals under chronic low-flow conditions precedes impaired vasodilation and vascular remodeling. Brain Derived Neurotrophic Factor (BDNF) plays a key role in maintaining brain plasticity and has recently been implicated in cardiovascular health, perhaps through direct action on the endothelial TrkB receptors. The goal of this study was to determine whether BDNF might exert its effects by altering the endothelial Ca 2+ signaling profile. METHODS: Using confocal imaging, we assessed endothelial Ca 2+ in Cal-520-loaded open mouse carotid arteries. RESULTS: Two concentrations of Both BDNF (2.2M x 10-9 and 2.2M x 10-6) and the selective TrkB agonist LM22A-4 (4.8 x 10-9 and 4.8 x 10-6) increased Ca 2+ dynamics beyond baseline; LM22A-4 increased frequency of events while BDNF increased the amplitude of events. TrKB receptor inhibition with the antagonist ANA-12 appeared to reduce TrkB dependent Ca 2+ changes. These findings suggest that activation of the TrkB receptor alters Ca 2+ dynamics in ex vivo carotid arteries. Future work will aim to elucidate the contribution of internal and external sources of Ca 2+ and determine the role of shear stress in BDNF release. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Zebrafish pigment cells develop directly from persistent highly multipotent progenitors

Neural crest cells are highly multipotent stem cells, but it remains unclear how their fate restriction to specific fates occurs. The direct fate restriction model hypothesises that migrating cells maintain full multipotency, whilst progressive fate restriction envisages fully multipotent cells transitioning to partially-restricted intermediates before committing to individual fates. Using zebrafish pigment cell development as a model, we show applying NanoString hybridization single cell transcriptional profiling and RNAscope in situ hybridization that neural crest cells retain broad multipotency throughout migration and even in post-migratory cells in vivo, with no evidence for partially-restricted intermediates. We find that leukocyte tyrosine kinase early expression marks a multipotent stage, with signalling driving iridophore differentiation through repression of fate-specific transcription factors for other fates. We reconcile the direct and progressive fate restriction models by proposing that pigment cell development occurs directly, but dynamically, from a highly multipotent state, consistent with our recently-proposed Cyclical Fate Restriction model.