Mature Population Research Articles

Genetic diversity and mating system of Euterpe precatoria in three localities along the lower Solimões River in Central Amazonia

Abstract Euterpe precatoria is a Neotropical palm from South and Central America and is hyperdominant in Amazonia, where it is increasingly important in the Brazilian market for açaí. Genetic diversity, population structure and mating system of E. precatoria were characterized with 10 microsatellite markers in three localities (Codajás, Manacapuru, and Manaquiri) along the lower Solimões River, Amazonas, Brazil. Leaves of 63 mature palms were collected, as well as fruits from 30 of these to analyze 20 seedlings per progeny. Genetic differentiation across localities was substantial (G S ′ = 0.304) for mature palms, suggesting that gene flow is restricted between localities due to isolation by distance. Inbreeding was significant in progenies from all populations (ranging from 0.059–0.076), but not for mature palms, suggesting selection for heterozygosity during maturation to the adult stage. The outcrossing rate was high (0.917–1.0), confirming that the species is predominantly allogamous. Matings were not random due to the occurrence of biparental inbreeding (0.021–0.079) and correlated matings (0.059–0.424), so open-pollinated progenies present mixtures of self-sibs, half-sibs, full-sibs, and self-half-sibs, resulting in mean effective population size within progenies (2.23–3.06) lower than expected for a random mating population. The mating system’s characteristics are those expected in a predominantly allogamous hyper-abundant palm and suggest that human management of these often-anthropogenic populations is unlikely to reduce genetic diversity in the short term if done in situ, as practiced by Indigenous Peoples and local communities. Intensification will require careful attention to maintain genetic diversity.

Gradual transitions in genetics and songs between coastal and inland populations of Setophaga townsendi

Abstract Setophaga townsendi is a species of wood warbler (family Parulidae) in northwestern North America that has geographic structure in the mitochondrial and nuclear genomes: while interior populations have differentiated mitonuclear ancestry from the sister species S. occidentalis, coastal populations have a mix of inland and S. occidentalis mitonuclear ancestries. This coastal to inland transition in genomic ancestry raises the possibility of similar geographic structure in phenotypic traits, especially those involved in mate choice. Using qualitative and multivariate approaches, we investigated whether there is a sharp transition between coastal and inland populations in both song and in nuclear DNA. We find there is a shallow geographic cline in Type I song but not in Type II song. Nuclear DNA shows a gradient between coast and inland. There is little correlation between variation in song and the isolation-by-distance pattern in the nuclear DNA. Learned songbird song is shaped by both genetic and cultural processes. There has been a debate on whether song learning promotes or slows down population differentiation. By comparing the within-species variation in song and genetic structures, we can expand our understanding of the dynamic interplay between mating signals and population differentiation.

Circulating CD22+/CD19-/CD24- progenitors and CD22+/CD19+/CD24- mature B cells: Diagnostic pitfalls for minimal residual disease detection in B-lymphoblastic leukemia.

Multiparametric flow cytometry (MFC) has become a powerful tool in minimal residual disease (MRD) detection in B-lymphoblastic leukemia/lymphoma (B-ALL). In the setting of targeted immunotherapy, B-ALL MRD detection often relies on alterative gating strategies, such as the utilization of CD22 and CD24. It is important to depict the full diversity of normal cell populations included in the alternative B-cell gating methods to avoid false-positive results. We describe two CD22-positive non-neoplastic cell populations in the peripheral blood (PB), including one progenitor population of uncertain lineage and one mature B-cell population, which are immunophenotypic mimics of B-ALL. Using MFC, we investigated the prevalence and phenotypic profiles of both CD22-positive populations in 278 blood samples from 52 patients with B-ALL; these were obtained pre- and post-treatment with CD19 and/or CD22 CAR-T therapies. We further assessed whether these two populations in the blood were exclusively associated with B-ALL or recent anticancer therapies, by performing the same analysis on patients diagnosed with other hematological malignancies but in long-term MRD remission. The progenitor population and mature B-cell population were detected at low levels in PB of 61.5% and 44.2% of B-ALL patients, respectively. Both cell types showed distinctive and highly consistent antigen expression patterns that are reliably distinguishable from B-ALL. Furthermore, their presence is not restricted solely to B-ALL or recent therapy. Our findings aid in building a complete immunophenotypic profile of normal cell populations in PB, thereby preventing misdiagnosis of B-ALL MRD and inappropriate management.

Developmental pharmacokinetics of indomethacin in preterm neonates: Severely decreased drug clearance in the first week of life.

Indomethacin is used commonly in preterm neonates for the prevention of intracranial hemorrhage and closure of an abnormally open cardiac vessel. Due to biomedical advances, the infants who receive this drug in the neonatal intensive care unit setting have become younger, smaller, and less mature (more preterm) at the time of treatment. To develop a pharmacokinetics (PK) model to aid future dosing, we designed a prospective cohort study to characterize indomethacin PK in a dynamically changing patient population. A population PK base model was created using NONMEM, and a covariate model was developed in a primary development cohort and subsequently was tested for accuracy in a validation cohort. Postnatal age was a significant covariate for hepatic clearance (CLH ) and renal clearance (CLR ). The typical value of the total clearance (CL, the sum of CLR and CLH ) was 3.09 ml/h and expressed as CL/WTmedian =3.96 ml/h/kg, where WTmedian is the median body weight. The intersubject variability of CLR and CLH were 61% and 207%, respectively. The typical value of the volume of distribution Vp =366 ml (Vp /WTmedian =470 ml/kg), and its intersubject variability was 38.8%. Half-life was 82.1h. Compared with more mature and older preterm populations studied previously, indomethacin CL is considerably lower in this contemporary population. Model-informed precision dosing incorporating important covariates other than weight alone offers an opportunity to individualize dosing in a susceptible patient undergoing rapid change.

Pursuing the Clonal Dynamics of Minimal Residual Disease (MRD) in Relapsed and Refractory Acute Myeloid Leukemia

Acute Myeloid Leukemia (AML) is a myelogenous malignancy that frequently relapses despite complete remission (CR) and elicits non-responsiveness (refractory) to treatment. Recent studies have emphasized that acquiring resistance to treatment and/or residual subclones bearing drug persistency such as Cancer stem cells (CSCs) or Minimal residual disease (MRD) clones can lead to relapse and treatment-refractory in AML. However, due to the AML's cytogenetic clonal heterogeneity, drug persistent MRD having leukemogenic properties and its clinical relevance have not yet been fully explained. In this study, we investigate the clonal dynamics of AML MRD by pursuing their genotypic/phenotypic changes in the individual AML patient's Bone Marrow (BM) niche. To investigate, we collected longitudinal BM samples at diagnosis (Dx), remission (CR), relapse (Rel), and treatment-refractory (Per) from two patients of relapsed/refractory AML. By bulk Whole Exome Sequencing (WES), somatic variants were analyzed, and selected four oncogenic variants (Patient #01: FLT3 D835E, WT1 R375Pfs; Patient #02: KIT D816Y, ASXL1 A722L) showing a significant change according to the treatment process. Seven blood cell fractions (4 HSPCs, Hematopoietic Stem and Progenitors: HSC/MPP, LMPP, CMP/MEP, GMP, LSC-like populations; 3 Mature leukocytes: Myeloid cells, T/B Lymphocytes) from AML patient's bone marrow samples were sorted by cell surfaces antigens. Selected AML-associated variants were detected by droplet digital PCR (ddPCR) in DNA of each sorted seven single cell fractions. In the AML patient BM, we found that the clones with an oncogenic (or likely oncogenic) variant were distributed in not only primitive cell populations with the HSPC (LSC-like) phenotype, but also mature (differentiated) cell populations such as leukocytes. These clones were not completely disappeared even after intense AML chemotherapy, and remained in minimal quantities. In our sequential analysis, some residual clones distributed in LSC-like populations exhibited the traditionally well-known MRD's character, such as repopulating LSC proportions. Furthermore, some other residual clones only in mature populations also seemed to be played a role in functional MRD resulting in the repopulation of LSCs. However, whether these residual clones in LSC-like populations or mature populations eventually induced repopulating of LSC-like fractions during AML relapse, and particularly in the relapse before an endpoint, these clones also tended to be highly enriched in LSC-like populations by 30% (based on the VAF). While the variant clones in mature populations may be the temporal salvages of AML-MRD clones (functional MRD) to survive against treatment, the variant clones in LSC-like populations might be the AML-MRDs practically contributing to AML recurrence and treatment-refractory. This approach suggests the methodology for specifying AML-MRD and pursuing its clonal evolution according to the treatment progress. This will help to improve AML risk stratification and the diagnostic methodology, enabling the preemptive detection of AML MRD at the initial diagnosis/treatment. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Phytocenological Structure and Biological Reserves of Helichrysum aurantiacum Boiss. & A. Huet in Gazakh-Tovuz Economic Region (Azerbaijan)

The article presents the phytocenological and bioecological analyzes of Helichrysum aurantiacum Boiss. et Huet., an endemic species of the Asteraceae family and assessments in plant coenopopulations of the plant. The studies were carried out in 3 districts of Gazakh-Tovuz Economic Region of Azerbaijan. Ten natural populations where H. aurantiacum species are distributed were selected. In the selected populations, the integral characteristics of the demographic structure of the plant, age and efficiency indices were studied. The formations and associations were determined, the project cover of the areas was calculated, and the abundance was determined. In the H. aurantiacum species, the highest indicator is observed in the generative development stages (225-243 individuals were counted in the g1-g3 period). The efficiency coefficient of H. aurantiacum species in mature populations was ω=0.52-0.76. The high value of the efficiency coefficient in CP 7, 6 and 10 is related to the high number dynamics of plants belonging to the juvenile and immature phases before the generative development phases, and the small number of individuals belonging to the aging (s, ss) phases. The resource potential of the plant was determined and the biological reserve in the districts was 1241.1 centners, and the annual supply was 498.6 centners. This allows the supply of H. aurantiacum species in Tovuz, Agstafa and Gazakh districts located in the north-east of the Lesser

Dysregulation of neuroprotective astrocytes, a spectrum of microglial activation states, and altered hippocampal neurogenesis are revealed by single-cell RNA sequencing in prion disease

Prion diseases are neurodegenerative disorders with long asymptomatic incubation periods, followed by a rapid progression of cognitive and functional decline culminating in death. The complexity of intercellular interactions in the brain is challenging to unravel and the basis of disease pathobiology remains poorly understood. In this study, we employed single cell RNA sequencing (scRNAseq) to produce an atlas of 147,536 single cell transcriptomes from cortex and hippocampus of mice infected with prions and showing clinical signs. We identified transcriptionally distinct populations and sub-populations of all the major brain cell-types. Disease-related transcription was highly specific to not only overarching cell-types, but also to sub-populations of glia and neurons. Most striking was an apparent decrease in relative frequency of astrocytes expressing genes that are required for brain homeostasis such as lipid synthesis, glutamate clearance, synaptic modulation and regulation of blood flow. Additionally, we described a spectrum of microglial activation states that suggest delineation of phagocytic and neuroinflammatory functions in different cell subsets. Differential responses of immature and mature neuron populations were also observed, alongside abnormal hippocampal neurogenesis. Our scRNAseq library provides a new layer of knowledge on single cell gene expression in prion disease, and is a basis for a more detailed understanding of cellular interplay that leads to neurodegeneration.

NATIONAL TRENDS IN THE PREVALENCE OF DISEASES AMONG RESIDENTS OF UKRAINE AND KHARKIV REGION

Introduction: the relevance of determining national trends in prevalence of diseases among the adult population in Ukraine is high, as it solves several important medical, social and economic problems of society.
 The aim: to determine national trends in prevalence of diseases among the adult population in Ukraine and Kharkiv region.
 Materials and methods: data from official sources of statistical information of Ukraine (State Institution "Center for Medical Statistics of the Ministry of Health of Ukraine") were used to determine national trends in prevalence of diseases among the adult population in Ukraine and Kharkiv region. A systematic analysis and generalization of the obtained data was performed and trends in prevalence of diseases among the adult population in Ukraine and Kharkiv region.
 Results: a decrease in the prevalence of diseases among the adult population of Ukraine over the 2010-2017 years with trends of -18.3% (general morbidity) and -25.9% (diseases detected for the first time in life) has been determined. Over the 2010-2019 years, the dynamics of reducing the prevalence of diseases and morbidity of adult residents of the Kharkiv region with trends of -12.6% and -23.0% has been established. For 2018-2019, progressive trends in reducing the prevalence of most diseases were noted, except for eating disorders and metabolic disorders (trends of increase, respectively, + 2.2% and + 2.9%) and symptoms, signs and deviations from the norm, which were found in clinical and laboratory studies (trends + 2.8% and + 3.5%) and neoplasms (only in terms of 100 thousand people) — + 0.1%.
 Discussion: the obtained results of the general dynamics of trends in the prevalence of diseases of the population in Ukraine completely coincide with the data of other world studies.
 Conclusions: there was a significant decrease in the spread of prevalence of diseases and morbidity among the mature population of Ukraine and the Kharkiv region.

High outcrossing rates in a self-compatible and highly aggregated host-generalist mistletoe.

Plants have evolved various strategies to avoid inbreeding, but the mass flowering displayed by many plants predisposes them to within-plant pollen movements and self-pollination. Mistletoes often aggregate at multiple spatial scales. Their bird pollinators often visit several flowers of the same individual and of others on the same host tree. We hypothesized that hermaphroditic mistletoes have self-incompatibility mechanisms that reduce or prevent selfing. Whether their spatial distribution, affected by host specificity, host distribution, and the behaviour of seed dispersers, influences their mating system and population genetic structure remains unclear. We studied how mating system and spatial distribution affect genetic structure in four populations of the host-generalist mistletoe Dendrophthoe pentandra in southwestern China using microsatellite markers and progeny arrays. We also characterized the fine-scale spatial genetic structure among 166 mistletoes from four host trees in one population. Prevalence and intensity of infection both appeared to vary among host species, strongly affecting the degree of aggregation. Host tree size had a strong effect on infection intensity. Surprisingly, manual pollination experiments indicated that D. pentandra is self-compatible, but genetic analyses revealed that outcrossing rates were higher than expected in all four populations (MLTR tm 0.83-1.20, Bayesian tm 0.772-0.952). Spatial genetic structure was associated with distance between host trees but not at shorter scales (within hosts). Our results demonstrate that the combination of bird pollination, bird-mediated seed dispersal, and post-dispersal processes result in outcrossing and maintain relatively high diversity in the presence of biparental inbreeding, despite very high local densities and possible self-compatibility.

Reserves and Nutritive Value of Species of the Medicago L. Genus in Pastures of the Shirvan (Azerbaijan)

31 are species of the MedicagoL. genus — alfalfa common in the Caucasus, 21 in Azerbaijan. 1 of them is cultivated, 7 are distributed directly in the Shirvan territory. As a result of the studies carried out in 10 cenopopulations in different phytocenological arrays, it was revealed that the M. caerulea species is characteristic of all CPs, and at the same time is effective. In terms of age indices and efficiency indices in 2, 3, 5, 6, 7 populations, individuals belonging to the juvenile and immature periods of ontogenesis mainly dominate (Δ=0.08–0.28; ω=0.21–0,54). In 8 and 9 fully mature populations, the spread rate of the species, as well as their indices, were high (Δ=0.39–0.55; ω=0.82–0.89). Only in 5 and 6 populations were no individuals found belonging to the senile (s) and subsenile (ss) periods, which is one of the signs confirming the constant development of plant populations. The largest reserve for the annual exploitation of the M. caerulea species falls on the Kura-Araz lowland and the Pirgulu massif of the Shamakhi district. Thus, from the results obtained, it can be concluded that the supply and use of the plant in natural resources as food can be carried out continuously.

Short-term exposure to norethisterone affected swimming behavior and antioxidant enzyme activity of medaka larvae, and led to masculinization in the adult population

Norethisterone (NET), one of the synthetic progestins, is detected with increasing frequency in the water environment and distributed in the ocean, with a potential toxicity risk to marine organisms. However, current studies on the adverse effects of progestins (including NET) in aquatic environments have focused on freshwater organisms, mainly fish. In the present, marine medaka (Oryzias melastigma) larvae were exposed to 91.31 ng/L NET for 10 days, and then the swimming behavior, oxidation-antioxidant-related enzyme activities, sex and thyroid hormone levels, and the gene transcription patterns of the larvae were measured. After NET treatment, medaka larvae were raised in artificial seawater until 5 months of age, and the sex ratio was counted. Ten-day exposure to 91.31 ng/L NET inhibited swimming behavior, of marine medaka larvae, which showed that the time in the resting state was significantly prolonged, while the time in the large motor state was significantly reduced; disrupted oxidative-antioxidant system, significantly up-regulated the enzymatic activities of reactive oxygen species (ROS), malondialdehyde (MDA), and glutathione peroxidase (GSH-Px); affected the hormone levels of larvae, lowered 11- keto testosterone (11-KT) and triiodothyronine (T3) concentrations. RNA-seq results showed that 91.31 ng/L NET exposure for 10 days changed the transcript levels of 275 genes, of which 28 were up-regulated and 247 were down-regulated. Differentially expressed genes (DEGs) were mainly significantly enriched in piwi interacting RNA (piRNA), gonadal development, gametogenesis, and steroidogenesis biological processes, etc. After removing NET exposure and returning to breeding for 140 days, a significant increase in male proportions (69.67%) was observed in sexually mature medaka populations in the NET-treated group. These results show that exposure to 91.31 ng/L NET for 10 days can lead to various adverse effects on marine medaka larvae. These findings shed light on the potential ecological risks of synthetic progestins to marine organisms.

Осмотическая резистентность эритроцитов у девушек с гиподинамией в зависимости от полиморфизма I/D гена АСЕ

The purpose of this paper was to study erythrocyte osmotic resistance (EOR) and its relationship with the quantitative and morphofunctional parameters of red blood cells in young women with limited physical activity depending on the I/D polymorphism of the ACE gene. Materials and methods. The study involved 200 healthy women aged 18–22 years leading a sedentary lifestyle. Their blood samples were taken for genotyping and to determine the haemoglobin (HGB) level and red blood cell count (RBC), their mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) as well as haematocrit (HCT). EOR was studied by measuring the optical density of haemoglobin solutions after erythrocyte destruction in a series of hypotonic NaCl solutions with the concentration decreasing from 0.8 % to 0.1 %. Based on the results of osmotic haemolysis, erythrograms were produced and the NaCl concentrations were determined, at which 10, 50 and 90 % of the red blood cells were destroyed. Results. Carriers of the DD genotype were characterized by the lowest resistance to haemolysis in all three erythrocyte populations. According to the analysis of factor structures, in girls with the DD genotype only relationships between the total and individual parameters of erythrocytes were established. In carriers of the I allele (ID and II genotypes) the dominant factor combined the total red blood cell parameters (RBC, HGB, HCT) and the EOR of old, mature, and young erythrocytes. Thus, carriers of the I allele (ID and II genotypes) of the ACE gene are characterized by a higher resistance of mature and old cell populations than those of the DD genotype, while EOR variations in the former are interconnected with changes in the quantitative parameters of red blood cells. At the same time, an increase in EOR is combined with an increase in erythrocyte functional activity. DD genotype carriers showed no correlations between EOR and the quantitative and morphofunctional parameters of red blood cells.

Human fetal membrane-mesenchymal stromal cells generate functional spinal motor neurons in vitro

SummaryHuman fetal membrane mesenchymal stromal cells (hFM-MSCs) are a cell population easily isolable from the amniochorionic membrane of term placentas, without ethical issues or safety limitations. We previously reported that hFM-MSCs share some epigenetic characteristics with pluripotent stem cells and can overcome the mesenchymal commitment. Here, we demonstrated that hFM-MSCs can give rise to spinal motor neurons by the sequential exposure to specific factors that induced a neuralization, caudalization and ventralization of undifferentiated cells, leading to a gradual gene and protein upregulation of early and late MN markers. Also, spontaneous electrical activity (spikes and bursts) was recorded. Finally, when co-cultured with myotubes, differentiated MNs were able to create functional neuromuscular junctions that induced robust skeletal muscle cell contractions. These data demonstrated the hFM-MSCs can generate a mature and functional MN population that may represent an alternative source for regenerative medicine, disease modeling or drug screening.

Benthic community zonation from mesophotic to deep sea: Description of first deep-water kelp forest and coral gardens in the Madeira archipelago (central NE Atlantic)

The Madeira archipelago has a unique underwater landscape that is characterised by narrow shelves, steep slopes and a large submarine tributary system that boosts primary productivity in oligotrophic waters and thus offers a potential for hotspots of biodiversity. Despite this, there have been limited deep-water exploration activities with less than five expeditions since the 1960s. Here, we investigated the seabed on the southern side of the Madeira-Desertas Ridge using a manned submersible along a 3.8 km long transect starting at 366 m depth up the ridge shelf until its top at 73 m. Benthic habitats and community composition were documented with video along a depth gradient from mesophotic to deep sea. Six distinct biotopes were recognised (three deeper, and three shallower than 115 m depth). Our results showed a rich biodiversity with deep biotopes characterised by sponges and non-reef-building corals (e.g., Pachastrella monilifera, Viminella flagellum, Eunicella verrucosa) and shallow biotopes comprising macroalgae and the gorgonian Paramuricea cf. grayi. The pronounced benthic zonation reflects the steep environmental gradient that includes high topographic variation, heterogeneous substrates, and bidirectional regular wave-motion at the shallow mesophotic part. Together with biotic factors, such as low density of sea urchins and presence of predatory fish, this environment with unusual deep light penetration, a mesoscale cyclonic eddy, and deep wave-motion, has allowed the establishment of a mature deep-water kelp population of Laminaria ochroleuca in the plateau (max. >100 individuals p/100 m2). At the same time, a conspicuous coral fauna was observed on a wide range of soft to hard bottoms with several species taking advantage of the favourable hydrodynamic regime and seawater properties together with substratum availability to create coral gardens. These habitats were previously not known from Madeira, and their newfound discovery in the archipelago merit further investigation and protection.

Trends and Outcomes in Management of Thoracic Aortic Injury in Children, Adolescent, and Mature Pediatric Patients Using Data from the National Trauma Data Bank

Thoracic aortic injury (TAI) is rare in the pediatric population. Thoracic endovascular aortic repair (TEVAR) is the recommended standard of care for treatment in the adult population given its association with lower rates of mortality and morbidity than traditional open repairs for treatment of TAI. However, there are unique anatomic challenges in treating pediatric patients with TEVAR which may impact the outcomes and pediatric guidelines. We aimed to compare current management trends and outcomes between different pediatric age groups using data from the National Trauma Data Bank (NTDB). We analyzed the NTDB from 2007 to 2019 using International Classification of Diseases (ICD)-9 and -10 codes to identify patients with a TAI. We excluded patients older than 21years and any patients who died in the emergency department. The pediatric patients were stratified by age group: children (1-11years), adolescent (12-17years), and mature (18-21years) patients. Patient characteristics compared included injury mechanism and severity, TAI intervention, and outcomes between the 3 groups using bivariate analysis (analysis of variance for parametric and Kruskal-Wallis for nonparametric variables). These characteristics and outcomes were also compared by TAI intervention and injury mechanism. ICD-9 and -10 procedural codes were used to identify patients who underwent TEVAR, open aortic repair (OAR), or both. The modified Poisson regression was performed with relative risk (RR) to evaluate our primary outcome measure-mortality during the trauma admission. A total of 2,431 pediatric TAI were identified in the NTDB that met the inclusion criteria. This included 134 children (5.5%), 733 adolescent (30.2%), and 1,564 mature (64.3%) patients. Children had significantly lower median Injury Severity Scores (34.1) than the adolescent (38) or mature population (36.1) (P=0.001). The mechanism of injury differed between age groups. Children had higher rates of blunt trauma (90.3% children, 89.6% adolescent, and 86.8% mature patients) and mature patients had higher rates of penetrating trauma (6% children, 10.1% adolescent, and 12.5% mature patients) (P<0.001). TAI management also differed significantly between pediatric age groups. Mature patients had significantly higher rates of TEVAR (3% children, 25.2% adolescent, and 29.2% mature patients) and children were most likely to be treated with nonoperative management (NOM) (94% children, 67.9% adolescent, and 64.8% mature patients) (P<0.001). Patients who were treated with TEVAR were discharge home most frequently (31.8% NOM, 54.1% TEVAR, 44.3% OAR, 22.2% both TEVAR and OAR). Upon modified Poisson regression analysis, patient age was not associated with an increased risk of in-hospital mortality. Intervention with TEVAR (RR: 0.22, 95% CI: 0.15-0.33, P<0.001) and OAR (RR: 0.58, 95% CI: 0.36-0.93, P=0.024) were associated with a lower risk of mortality than NOM. TAI is less prevalent in children compared to adults. TEVAR for TAI is associated with lower risk of in-hospital mortality compared to both NOM and OAR without differences between pediatric subgroups. Further studies should be completed to determine the most appropriate management guidelines.

Pest defences under weak selection exert a limited influence on the evolution of height growth and drought avoidance in marginal pine populations.

While droughts, intensified by climate change, have been affecting forests worldwide, pest epidemics are a major source of uncertainty for assessing drought impacts on forest trees. Thus far, little information has documented the adaptability and evolvability of traits related to drought and pests simultaneously. We conducted common-garden experiments to investigate how several phenotypic traits (i.e. height growth, drought avoidance based on water-use efficiency inferred from δ13C and pest resistance based on defence traits) interact in five mature lodgepole pine populations established in four progeny trials in western Canada. The relevance of interpopulation variation in climate sensitivity highlighted that seed-source warm populations had greater adaptive capability than cold populations. In test sites, warming generated taller trees with higher δ13C and increased the evolutionary potential of height growth and δ13C across populations. We found, however, no pronounced gradient in defences and their evolutionary potential along populations or test sites. Response to selection was weak in defences across test sites, but high for height growth particularly at warm test sites. Response to the selection of δ13C varied depending on its selective strength relative to height growth. We conclude that warming could promote the adaptability and evolvability of growth response and drought avoidance with a limited evolutionary influence from pest (biotic) pressures.

Abstract 011: Epigenetic Determinants Of Renin Cell Identity

Renin secreting cells are restricted in adult mammals within the walls of renal arterioles near the entrance to the glomeruli and are therefore known as juxtaglomerular (JG) cells. These JG cells are critical for survival through the maintenance of homeostasis via the release of the peptide hormone renin in response to changes in blood pressure. By performing independently paired scATAC-seq and scRNA-seq during mouse kidney development, we sought to identify epigenetic markers of renin cell identity. While we lack spatial information, we identified putative JG cells through the identification of cells enriched in canonical markers (Ren1 and Akr1b7) of JG cell identity using both expression and accessibility derived measures of gene activity. We constructed a pseudotime trajectory of cells that lead to the mature JG population and performed pairwise comparisons of cell populations to identify the genomic regions and transcription factors (TFs) contributing to JG cell identity. As JG cells form along this trajectory, significantly different (Log2FC&gt;0.5 and FDR&lt;0.1) regions of accessible chromatin define the JG cell population. Within these open regions, the MEF2 family of TF motifs are significantly enriched (log10Padj &gt; 20). We further identify a specific region of accessible chromatin (chr1:133345385-133345885) unique to the initial population of JG cells located within a Ren1 super enhancer previously identified by our group. This region is co-accessible with several regions of open chromatin within the greater Ren1 gene region (correlation &gt; 0.75) where we identify putative binding sites for Mef2b, 2c, and 2d at these co-accessible regions. As the mature renin-expressing cells further differentiate into terminally differentiated cell populations including pericytes and mesangial cells, we continue to see significant enrichment of the MEF2 TF family within the JG cell population compared to downstream populations (log10Padj &gt; 646.6891). Overall, we have presented the first investigation and finding using single-cell -omics of the JG cell population and uncover the importance of the MEF2 family of TFs as significant drivers of JG cell formation and identity.

Dopaminergic Neurons Differentiated from LRRK2 I1371V-Induced Pluripotent Stem Cells Display a Lower Yield, α-Synuclein Pathology, and Functional Impairment.

Being a large multidomain protein, LRRK2 has several confirmed pathological mutant variants for PD, and the incidence of these variants shows ethnicity biases. I1371V, a mutation in the GTPase domain, has been reported in East-Asian populations, but there are no studies reported on dopaminergic (DA) neurons differentiated from this variant. The aim here was to assess the yield, function, and α-synuclein pathology of DA neurons differentiated from LRRK2 I1371V iPSCs. FACS analysis of neural progenitors (NPs) showed a comparable immunopositive population of cells for neural and glial progenitor markers nestin and S100β; however, NPs from I1371V iPSCs showed lower clonogenic and proliferative capacities than healthy control NPs as determined by the neurosphere assay and Ki67 expression. Floor plate cells obtained from I1371V NPs primed with FGF8 showed distinctly lower immunopositivity for FOXA2 and CLIC5 than healthy control FPCs and similar DOC2B expression. On SHH addition, a similar mature neuronal population was obtained from both groups; however, the yield of TH-immunopositive cells was significantly lower in I1371V, with lower expression of mature DA neuronal markers En1, Nurr1, and DAT. Vesicular dopamine release and intracellular Ca2+ response with KCl stimulation were lower in I1371V DA neurons, along with a significantly reduced expression of resting vesicle marker VMAT2. A concurrently lower expression of PSD95/Syn-I immunopositive puncta was observed in I1371V differentiated cells. Further, higher phosphorylation of α-synuclein and aggregation of oligomeric α-synuclein in I1371V DA neurons were observed. Our data demonstrated conclusively for the first time that mutations in the I1371V allele of LRRK2 showed developmental deficit from the FPC stage and generated a lower yield/number of TH-immunopositive neurons with impairment in their function and synapse density along with increased α-synuclein pathology.

In situ single particle classification reveals distinct 60S maturation intermediates in cells.

Previously, we showed that high-resolution template matching can localize ribosomes in two-dimensional electron cryo-microscopy (cryo-EM) images of untilted Mycoplasma pneumoniae cells with high precision (Lucas et al., 2021). Here, we show that comparing the signal-to-noise ratio (SNR) observed with 2DTM using different templates relative to the same cellular target can correct for local variation in noise and differentiate related complexes in focused ion beam (FIB)-milled cell sections. We use a maximum likelihood approach to define the probability of each particle belonging to each class, thereby establishing a statistic to describe the confidence of our classification. We apply this method in two contexts to locate and classify related intermediate states of 60S ribosome biogenesis in the Saccharomyces cerevisiae cell nucleus. In the first, we separate the nuclear pre-60S population from the cytoplasmic mature 60S population, using the subcellular localization to validate assignment. In the second, we show that relative 2DTM SNRs can be used to separate mixed populations of nuclear pre-60S that are not visually separable. 2DTM can distinguish related molecular populations without the need to generate 3D reconstructions from the data to be classified, permitting classification even when only a few target particles exist in a cell.

Ubiquitin E3 ligase FBXO21 regulates cytokine-mediated signaling pathways, but is dispensable for steady-state hematopoiesis

Hematopoietic cell fate decisions such as self-renewal and differentiation are highly regulated through multiple molecular pathways. One pathway, the ubiquitin proteasome system (UPS), controls protein levels by tagging them with polyubiquitin chains and promoting their degradation through the proteasome. Ubiquitin E3 ligases serve as the substrate-recognition component of the UPS. By investigating the FBOX family of E3 ligases, we discovered that Fbxo21 was highly expressed in the hematopoietic stem and progenitor cell (HSPC) population, and exhibited low to no expression in mature myeloid populations. To determine the role of FBXO21 on HSPC maintenance, self-renewal, and differentiation, we generated shRNAs against FBXO21 and a hematopoiesis-specific Fbxo21 conditional knockout (cKO) mouse model. We found that silencing FBXO21 in HSPCs led to a loss in colony formation and an increase in cell differentiation in vitro. Additionally, stressing the HSPC populations in our Fbxo21 cKO mouse with 5-fluorouracil injections resulted in a decrease in survival, despite these populations exhibiting minimal alterations during steady-state hematopoiesis. Although FBXO21 has previously been proposed to regulate cytokine signaling via ASK and p38, our results indicate that depletion of FBXO21 led to altered ERK signaling in vitro. Together, these findings suggest ubiquitin E3 ligase FBXO21 regulates HSPCs through cytokine-mediated pathways.