The microbiota regulate neuronal function and fear extinction learning.

Multicellular organisms have co-evolved with complex consortia of viruses, bacteria, fungi and parasites, collectively referred to as the microbiota1. In mammals, changes in the composition of the microbiota can influence many physiologic processes (including development, metabolism and immune cell function) and are associated with susceptibility to multiple diseases2. Alterations in the microbiota can also modulate host behaviours-such as social activity, stress, and anxiety-related responses-that are linked to diverse neuropsychiatric disorders3. However, the mechanisms by which the microbiota influence neuronal activity and host behaviour remain poorly defined. Here we show that manipulation of the microbiota in antibiotic-treated or germ-free adult mice results in significant deficits in fear extinction learning. Single-nucleus RNA sequencing of the medial prefrontal cortex of the brain revealed significant alterations in gene expression in excitatory neurons, glia and other cell types. Transcranial two-photon imaging showed that deficits in extinction learning after manipulation of the microbiota in adult mice were associated with defective learning-related remodelling of postsynaptic dendritic spines and reduced activity in cue-encoding neurons in the medial prefrontal cortex. In addition, selective re-establishment of the microbiota revealed a limited neonatal developmental window in which microbiota-derived signals can restore normal extinction learning in adulthood. Finally, unbiased metabolomic analysis identified four metabolites that were significantly downregulated in germ-free mice and have been reported to be related to neuropsychiatric disorders in humans and mouse models, suggesting that microbiota-derived compounds may directly affect brain function and behaviour. Together, these data indicate that fear extinction learning requires microbiota-derived signals both during early postnatal neurodevelopment and in adult mice, with implications for our understanding of how diet, infection, and lifestyle influence brain health and subsequent susceptibility to neuropsychiatric disorders.

Early Detection of Optic Nerve Changes on Optical Coherence Tomography Using Deep Learning for Risk-Stratification of Papilledema and Glaucoma.

BACKGROUND: The use of artificial intelligence is becoming more prevalence in medicine with numerous successful examples in ophthalmology. However, much of the work has been focused on replicating the works of ophthalmologists. Given the analytical potentials of artificial intelligence, it is plausible that artificial intelligence can detect microfeatures not readily distinguished by humans. In this study, we tested the potential for artificial intelligence to detect early optic coherence tomography changes to predict progression toward papilledema or glaucoma when no significant changes are detected on optical coherence tomography by clinicians. METHODS: Prediagnostic optical coherence tomography of patients who developed papilledema (n = 93, eyes = 166) and glaucoma (n = 187, eyes = 327) were collected. Given discrepancy in average cup-to-disc ratios of the experimental groups, control groups for papilledema (n = 254, eyes = 379) and glaucoma (n = 441, eyes = 739) are matched by cup-to-disc ratio. Publicly available Visual Geometry Group-19 model is retrained using each experimental group and its respective control group to predict progression to papilledema or glaucoma. Images used for training include retinal nerve fiber layer thickness map, extracted vertical tomogram, ganglion cell thickness map, and ILM-RPE thickness map. RESULTS: Trained model was able to predict progression to papilledema with a precision of 0.714 and a recall of 0.769 when trained with retinal nerve fiber layer thickness map, but not other image types. However, trained model was able to predict progression to glaucoma with a precision of 0.682 and recall of 0.857 when trained with extracted vertical tomogram, but not other image types. Area under precision-recall curve of 0.826 and 0.785 were achieved for papilledema and glaucoma models, respectively. CONCLUSIONS: Computational and analytical power of computers have become an invaluable part of our lives and research endeavors. Our proof-of-concept study showed that artificial intelligence (AI) algorithms have the potential to detect early changes on optical coherence tomography for prediction of progression that is not readily observed by clinicians. Further research may help establish possible AI models that can assist with early diagnosis or risk stratification in ophthalmology.

Facilitating deep learning through preprocessing of optical coherence tomography images.

BACKGROUND: While deep learning has delivered promising results in the field of ophthalmology, the hurdle to complete a deep learning study is high. In this study, we aim to facilitate small scale model trainings by exploring the role of preprocessing to reduce computational burden and accelerate learning. METHODS: A small subset of a previously published dataset containing optical coherence tomography images of choroidal neovascularization, drusen, diabetic macula edema, and normal macula was modified using Fourier transformation and bandpass filter, producing high frequency images, original images, and low frequency images. Each set of images was trained with the same model, and their performances were compared. RESULTS: Compared to that with the original image dataset, the model trained with the high frequency image dataset achieved an improved final performance and reached maximum performance much earlier (in fewer epochs). The model trained with low frequency images did not achieve a meaningful performance. CONCLUSION: Appropriate preprocessing of training images can accelerate the training process and can potentially facilitate modeling using artificial intelligence when limited by sample size or computational power.

Sympatric speciation of wild emmer wheat driven by ecology and chromosomal rearrangements.

In plants, the mechanism for ecological sympatric speciation (SS) is little known. Here, after ruling out the possibility of secondary contact, we show that wild emmer wheat, at the microclimatically divergent microsite of "Evolution Canyon" (EC), Mt. Carmel, Israel, underwent triple SS. Initially, it split following a bottleneck of an ancestral population, and further diversified to three isolated populations driven by disruptive ecological selection. Remarkably, two postzygotically isolated populations (SFS1 and SFS2) sympatrically branched within an area less than 30 m at the tropical hot and dry savannoid south-facing slope (SFS). A series of homozygous chromosomal rearrangements in the SFS1 population caused hybrid sterility with the SFS2 population. We demonstrate that these two populations developed divergent adaptive mechanisms against severe abiotic stresses on the tropical SFS. The SFS2 population evolved very early flowering, while the SFS1 population alternatively evolved a direct tolerance to irradiance by improved ROS scavenging activity that potentially accounts for its evolutionary fate with unstable chromosome status. Moreover, a third prezygotically isolated sympatric population adapted on the abutting temperate, humid, cool, and forested north-facing slope (NFS), separated by 250 m from the SFS wild emmer wheat populations. The NFS population evolved multiple resistant loci to fungal diseases, including powdery mildew and stripe rust. Our study illustrates how plants sympatrically adapt and speciate under disruptive ecological selection of abiotic and biotic stresses.

Correlations between Clinical and Histopathologic Characteristics in Idiopathic Epiretinal Membrane.

PURPOSE: To investigate correlations between clinical and histopathologic characteristics of idiopathic epiretinal membrane (ERM). DESIGN: Retrospective interventional case series. PARTICIPANTS: In total, 87 eyes from 87 patients with idiopathic ERM who underwent pars plana vitrectomy with peeling of the ERM from 2019 to 2020 were included. METHODS: The outcomes of clinical ophthalmic examination, including measurement of best-corrected visual acuity (BCVA) and spectral-domain OCT (SD-OCT), before and after surgery were reviewed. Surgical specimens were fixed in formalin and embedded in paraffin for histologic and immunohistochemical analysis. MAIN OUTCOMES MEASURES: The association between morphological characteristics revealed on SD-OCT images and the cellular composition of the surgically excised ERM demonstrated with immunohistochemical staining were the main outcome measures. Changes in the BCVA and central macular thickness (CMT) were assessed through a comparison of preoperative and postoperative measurements. RESULTS: Based on SD-OCT morphological characteristics in the foveal area, 15 cases were classified into group 1A (mainly outer retinal thickening), 39 into group 1B (more tenting of the outer retina and distorted inner retina), and 33 into group 1C (prominent inner retina thickening). Overall, postoperative final BCVA and CMT at 1 year improved in all groups. Patients who presented with a better initial BCVA exhibited a more favorable final BCVA. Epiretinal membranes in group 1C demonstrated the greatest decrease in CMT compared with those in groups 1B and 1A, but the final CMT did not differ among the groups. A negative correlation between the density of hyalocytes (P = 0.003) and myofibroblasts (P = 0.047) was noted between the 3 groups. Total cell density and glial cell density of the ERMs were strongly associated with poor final BCVA and BCVA improvement. CONCLUSIONS: The present study provides new histopathologic information regarding the formation and progression of idiopathic ERM. Glial cell proliferation plays a predominant role in these processes. Epiretinal membranes with high cellularity and glial cell density may cause damage to the retina structure, resulting in poor postoperative visual outcomes. These findings provide additional evidence supporting early surgical intervention in patients with idiopathic ERM reported with visual disturbance.

Role of BDNF in the development of an OFC-amygdala circuit regulating sociability in mouse and human.

Social deficits are common in many psychiatric disorders. However, due to inadequate tools for manipulating circuit activity in humans and unspecific paradigms for modeling social behaviors in rodents, our understanding of the molecular and circuit mechanisms mediating social behaviors remains relatively limited. Using human functional neuroimaging and rodent fiber photometry, we identified a mOFC-BLA projection that modulates social approach behavior and influences susceptibility to social anxiety. In humans and knock-in mice with a loss of function BDNF SNP (Val66Met), the functionality of this circuit was altered, resulting in social behavioral changes in human and mice. We further showed that the development of this circuit is disrupted in BDNF Met carriers due to insufficient BDNF bioavailability, specifically during a peri-adolescent timeframe. These findings define one mechanism by which social anxiety may stem from altered maturation of orbitofronto-amygdala projections and identify a developmental window in which BDNF-based interventions may have therapeutic potential.

Ventral hippocampus interacts with prelimbic cortex during inhibition of threat response via learned safety in both mice and humans.

Heightened fear and inefficient safety learning are key features of fear and anxiety disorders. Evidence-based interventions for anxiety disorders, such as cognitive behavioral therapy, primarily rely on mechanisms of fear extinction. However, up to 50% of clinically anxious individuals do not respond to current evidence-based treatment, suggesting a critical need for new interventions based on alternative neurobiological pathways. Using parallel human and rodent conditioned inhibition paradigms alongside brain imaging methodologies, we investigated neural activity patterns in the ventral hippocampus in response to stimuli predictive of threat or safety and compound cues to test inhibition via safety in the presence of threat. Distinct hippocampal responses to threat, safety, and compound cues suggest that the ventral hippocampus is involved in conditioned inhibition in both mice and humans. Moreover, unique response patterns within target-differentiated subpopulations of ventral hippocampal neurons identify a circuit by which fear may be inhibited via safety. Specifically, ventral hippocampal neurons projecting to the prelimbic cortex, but not to the infralimbic cortex or basolateral amygdala, were more active to safety and compound cues than threat cues, and activity correlated with freezing behavior in rodents. A corresponding distinction was observed in humans: hippocampal-dorsal anterior cingulate cortex functional connectivity-but not hippocampal-anterior ventromedial prefrontal cortex or hippocampal-basolateral amygdala connectivity-differentiated between threat, safety, and compound conditions. These findings highlight the potential to enhance treatment for anxiety disorders by targeting an alternative neural mechanism through safety signal learning.

Genetic mapping of a novel powdery mildew resistance gene in wild emmer wheat from "Evolution Canyon" in Mt. Carmel Israel.

KEY MESSAGE: A single dominant powdery mildew resistance gene MlNFS10 was identified in wild emmer wheat and mapped within a 0.3cM genetic interval spanning a 2.1Mb physical interval on chromosome arm 4AL. Wheat powdery mildew caused by Blumeria graminis forma specialis tritici (Bgt) is a globally devastating disease. The use of powdery mildew resistance genes from wild relatives of wheat is an effective method of disease management. Our previous research has shown that disruptive ecological selection has driven the discrete adaptations of the wild emmer wheat population on the south facing slope (SFS) and north facing slope (NFS) at the microsite of "Evolution Canyon" at Mount Carmel, Israel and demonstrated that 16 accessions in the NFS population display high resistance to 11 powdery mildew isolates (collected from different wheat fields in China). Here, we constructed bi-parental population by crossing the accession NFS-10 (resistant to 22 Bgt races collected from China in seedling resistance screen) and the susceptible line SFS2-12. Genetic analysis indicated that NFS-10 carries a single dominant gene, temporarily designated MlNFS10. Ultimately, 13 markers were successfully located within the long arm of chromosome 4A, thereby delineating MlNFS10 to a 0.3 cM interval covering 2.1 Mb (729275816-731365462) in the Chinese Spring reference sequence. We identified disease resistance-associated genes based on the RNA-seq analysis of both parents. The tightly linked InDel marker XWsdau73447 and SSR marker XWsdau72928 were developed and used for marker-assisted selection when MlNFS10 was introgressed into a hexaploid wheat background. Therefore, MlNFS10 can be used for improvement of germplasm in breeding programs for powdery mildew resistant cultivars.

High-resolution genome-wide association study and genomic prediction for disease resistance and cold tolerance in wheat.

KEY MESSAGE: High-resolution genome-wide association study (GWAS) facilitated QTL fine mapping and candidate gene identification, and the GWAS based genomic prediction models were highly predictive and valuable in wheat genomic breeding. Wheat is a major staple food crop and provides more than one-fifth of the daily calories and dietary proteins for humans. Genome-wide association study (GWAS) and genomic selection (GS) for wheat stress resistance and tolerance related traits are critical to understanding their genetic architecture for improvement of breeding selection efficiency. However, the insufficient marker density in previous studies limited the utility of GWAS and GS in wheat genomic breeding. Here, we conducted a high-resolution GWAS for wheat leaf rust (LR), yellow rust (YR), powdery mildew (PM), and cold tolerance (CT) by genotyping a panel of 768 wheat cultivars using genotyping-by-sequencing. Among 153 quantitative trait loci (QTLs) identified, 81 QTLs were delimited to ≤ 1.0 Mb intervals with three validated using bi-parental populations. Furthermore, 837 stress resistance-related genes were identified in the QTL regions with 12 showing induced expression by YR and PM pathogens. Genomic prediction using 2608, 4064, 3907, and 2136 pre-selected SNPs based on GWAS and genotypic correlations between the SNPs showed high prediction accuracies of 0.76, 0.73, and 0.78 for resistance to LR, YR, and PM, respectively, and 0.83 for resistance to cold damage. Our study laid a solid foundation for large-scale QTL fine mapping, candidate gene validation and GS in wheat.

Orbital Apex Syndrome Secondary to Invasive Aspergillus Infection: A Case Series and Literature Review.

BACKGROUND: Invasive fungal sinusitis carries high morbidity and mortality and often poses a diagnostic challenge. Orbital apex syndrome (OAS) is not an uncommon presentation in the setting of invasive fungal sinusitis. Delays in diagnosis and appropriate treatment can result in permanent visual dysfunction and, potentially, death. We present 2 cases of OAS secondary to invasive sinus aspergillosis, detailing the diagnostic process, treatment, and outcome for both patients. Subsequently, we present a review of the literature and combined analysis of our 2 patients plus 71 cases from previously published reports. METHODS: Literature review was performed to identify demographic, diagnostic, clinical, and treatment data of patients with OAS caused by Aspergillus species. RESULTS: The review resulted in 52 included articles with 71 patients, plus our 2 reported patients, leading to a total of 73 subjects included in the analysis. The average age of patients at presentation was 59.9 years. A combination of visual disturbance and pain (headache and/or periocular pain) was the most common presentation reported (46 cases; 63%). Diabetes mellitus was reported in 15 cases (21%), with more than half specifically noted to have poorly controlled diabetes. After diabetes, the second most common cause of immunocompromise was chronic steroid use (n = 13; 18%). Empiric antifungal treatment was started in 10 patients (14%), while 25 patients (34%) were first treated with systemic steroids due to a concern for an inflammatory etiology. Time to diagnosis from initial presentation was on average 7.4 weeks (range of 0.3-40 weeks). Approximately 78% of the cases (57 of 73) had biopsies with histology that confirmed Aspergillus fungal morphology, and 30/73 (41%) had diagnostic fungal cultures. The majority of the cases received monotherapy with intravenous (IV) amphotericin B (36 patients; 49%) and IV voriconazole (19 patients; 26%), with a combination of the 2 or more antifungal agents being used in 11 patients (15%). Forty patients (55%) showed signs of clinical improvement with treatment, while 33 (45%) patients did not experience any improvement or continued to deteriorate, and 23 (32%) died in the course of their reported follow-up. CONCLUSIONS: The present cases illustrate well the challenge in the diagnosis and treatment of OAS due to invasive sinus aspergillosis. Our review and analysis of 73 cases support the notion that a high index of suspicion leading to early biopsy with histology and fungal culture is paramount for diagnosis. Early empiric antifungal treatment and debridement can potentially reduce morbidity and mortality.

Integrated metabolo-transcriptomics and functional characterization reveals that the wheat auxin receptor TIR1 negatively regulates defense against Fusarium graminearum.

Fusarium head blight (FHB) caused by Fusarium graminearum Schwabe (teleomorph Gibberella zeae (Schw.) Perch) results in large yield losses in annual global wheat production. Although studies have identified a number of wheat FHB resistance genes, a deeper understanding of the mechanisms underlying host plant resistance to F. graminearum is required for the control of FHB. Here, an integrated metabolomics and transcriptomics analysis of infected wheat plants (Triticum aestivum L.) enabled identification of 789 differentially accumulated metabolites, including flavonoids, phenolamides, tryptamine derivatives, and phytohormones, and revealed altered expression of more than 100 genes that function in the biosynthesis or regulation of these pathways. Our data regarding the effects of F. graminearum infection on flavonoids and auxin signaling led to follow-up experiments that showed that exogenous kaempferide and apigenin application on spikes increased wheat resistance to FHB, while exogenous auxin treatment increased FHB susceptibility. RNAi-mediated knockdown of the gene encoding the auxin receptor, TaTIR1, increased FHB resistance. Our data supported the use of TaTIR1 knockdown in controlling FHB. Our study provides insights on the wheat response to F. graminearum infection and its FHB resistance mechanisms while illustrating the potential of TaTIR1 knockdown in increasing FHB resistance during crop improvement programs.

A member of wheat class III peroxidase gene family, TaPRX-2A, enhanced the tolerance of salt stress.

BACKGROUND: Salt and drought are the main abiotic stresses that restrict the yield of crops. Peroxidases (PRXs) are involved in various abiotic stress responses. Furthermore, only few wheat PRXs have been characterized in the mechanism of the abiotic stress response. RESULTS: In this study, a novel wheat peroxidase (PRX) gene named TaPRX-2A, a member of wheat class III PRX gene family, was cloned and its response to salt stress was characterized. Based on the identification and evolutionary analysis of class III PRXs in 12 plants, we proposed an evolutionary model for TaPRX-2A, suggesting that occurrence of some exon fusion events during evolution. We also detected the positive selection of PRX domain in 13 PRXs involving our evolutionary model, and found 2 or 6 positively selected sites during TaPRX-2A evolution. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) results showed that TaPRX-2A exhibited relatively higher expression levels in root tissue than those exhibited in leaf and stem tissues. TaPRX-2A expression was also induced by abiotic stresses and hormone treatments such as polyethylene glycol 6000, NaCl, hydrogen peroxide (H2O2), salicylic acid (SA), methyljasmonic acid (MeJA) and abscisic acid (ABA). Transgenic wheat plants with overexpression of TaPRX-2A showed higher tolerance to salt stress than wild-type (WT) plants. Confocal microscopy revealed that TaPRX-2A-eGFP was mainly localized in cell nuclei. Survival rate, relative water content, and shoot length were higher in TaPRX-2A-overexpressing wheat than in the WT wheat, whereas root length was not significantly different. The activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were enhanced in TaPRX-2A-overexpressing wheat compared with those in the WT wheat, resulting in the reduction of reactive oxygen species (ROS) accumulation and malondialdehyde (MDA) content. The expression levels of downstream stress-related genes showed that RD22, TLP4, ABAI, GST22, FeSOD, and CAT exhibited higher expressions in TaPRX-2A-overexpressing wheat than in WT under salt stress. CONCLUSIONS: The results show that TaPRX-2A plays a positive role in the response to salt stress by scavenging ROS and regulating stress-related genes.

Using a Developmental Ecology Framework to Align Fear Neurobiology Across Species.

Children's development is largely dependent on caregiving; when caregiving is disrupted, children are at increased risk for numerous poor outcomes, in particular psychopathology. Therefore, determining how caregivers regulate children's affective neurobiology is essential for understanding psychopathology etiology and prevention. Much of the research on affective functioning uses fear learning to map maturation trajectories, with both rodent and human studies contributing knowledge. Nonetheless, as no standard framework exists through which to interpret developmental effects across species, research often remains siloed, thus contributing to the current therapeutic impasse. Here, we propose a developmental ecology framework that attempts to understand fear in the ecological context of the child: their relationship with their parent. By referring to developmental goals that are shared across species (to attach to, then, ultimately, separate from the parent), this framework provides a common grounding from which fear systems and their dysfunction can be understood, thus advancing research on psychopathologies and their treatment.

Individual differences in frontolimbic circuitry and anxiety emerge with adolescent changes in endocannabinoid signaling across species.

Anxiety disorders peak in incidence during adolescence, a developmental window that is marked by dynamic changes in gene expression, endocannabinoid signaling, and frontolimbic circuitry. We tested whether genetic alterations in endocannabinoid signaling related to a common polymorphism in fatty acid amide hydrolase (FAAH), which alters endocannabinoid anandamide (AEA) levels, would impact the development of frontolimbic circuitry implicated in anxiety disorders. In a pediatric imaging sample of over 1,000 3- to 21-y-olds, we show effects of the FAAH genotype specific to frontolimbic connectivity that emerge by ∼12 y of age and are paralleled by changes in anxiety-related behavior. Using a knock-in mouse model of the FAAH polymorphism that controls for genetic and environmental backgrounds, we confirm phenotypic differences in frontoamygdala circuitry and anxiety-related behavior by postnatal day 45 (P45), when AEA levels begin to decrease, and also, at P75 but not before. These results, which converge across species and level of analysis, highlight the importance of underlying developmental neurobiology in the emergence of genetic effects on brain circuitry and function. Moreover, the results have important implications for the identification of risk for disease and precise targeting of treatments to the biological state of the developing brain as a function of developmental changes in gene expression and neural circuit maturation.

Cloning and characterization of a specific UDP-glycosyltransferase gene induced by DON and Fusarium graminearum.

KEY MESSAGE: TaUGT5: can reduce the proliferation and destruction of F. graminearum and enhance the ability of FHB resistance in wheat. Deoxynivalenol (DON) is one of the most important toxins produced by Fusarium species that enhances the spread of the pathogen in the host. As a defense, the UDP-glycosyltransferase (UGT) family has been deduced to transform DON into the less toxic form DON-3-O-glucoside (D3G), but the specific gene member in wheat that is responsible for Fusarium head blight (FHB) resistance has been little investigated and proved. In this study, a DON and Fusarium graminearum responsive gene TaUGT5, which is specific for resistant cultivars, was cloned with a 1431 bp open reading frame (ORF) encoding 476 amino acids in Sumai3. TaUGT5 is located on chromosome 2B, which has been confirmed in nulli-tetrasomic lines of Chinese Spring (CS) and is solely expressed among three homologs on the A, B and D genomes. Over-expression of this gene in Arabidopsis conferred enhanced tolerance when grown on agar plates that contain DON. Similarly, the coleoptiles of wheat over-expressing TaUGT5 showed more resistance to F. graminearum, evidencing reduced proliferation and destruction of plant tissue by the pathogen. However, the disease resistance in spikes was not as significant as that on coleoptile compared with wild-type plants. A subcellular localization analysis revealed that TaUGT5 was localized on the plasma membrane of tobacco leaf epidermal cells. It is possible that TaUGT5 could enhance tolerance to DON, protect the plant cell from the pathogen infection and result in better maintenance of the cell structure, which slows down pathogen proliferation in plant tissue.

Combined effects of peer presence, social cues, and rewards on cognitive control in adolescents.

Developmental scientists have examined the independent effects of peer presence, social cues, and rewards on adolescent decision-making and cognitive control. Yet, these contextual factors often co-occur in real world social situations. The current study examined the combined effects of all three factors on cognitive control, and its underlying neural circuitry, using a task to better capture adolescents' real world social interactions. A sample of 176 participants ages 13-25, was scanned while performing an adapted go/no-go task alone or in the presence of a virtual peer. The task included brief positive social cues and sustained periods of positive arousal. Adolescents showed diminished cognitive control to positive social cues when anticipating a reward in the presence of peers relative to when alone, a pattern not observed in older participants. This behavioral pattern was paralleled by enhanced orbitofrontal activation. The results demonstrate the synergistic impact of social and reward influences on cognitive control in adolescents.

Endoplasmic reticulum and oxidant stress mediate nuclear factor-κB activation in the subfornical organ during angiotensin II hypertension.

Endoplasmic reticulum (ER) stress and reactive oxygen species (ROS) generation in the brain circumventricular subfornical organ (SFO) mediate the central hypertensive actions of Angiotensin II (ANG II). However, the downstream signaling events remain unclear. Here we tested the hypothesis that angiotensin type 1a receptors (AT1aR), ER stress, and ROS induce activation of the transcription factor nuclear factor-κB (NF-κB) during ANG II-dependent hypertension. To spatiotemporally track NF-κB activity in the SFO throughout the development of ANG II-dependent hypertension, we used SFO-targeted adenoviral delivery and longitudinal bioluminescence imaging in mice. During low-dose infusion of ANG II, bioluminescence imaging revealed a prehypertensive surge in NF-κB activity in the SFO at a time point prior to a significant rise in arterial blood pressure. SFO-targeted ablation of AT1aR, inhibition of ER stress, or adenoviral scavenging of ROS in the SFO prevented the ANG II-induced increase in SFO NF-κB. These findings highlight the utility of bioluminescence imaging to longitudinally track transcription factor activation during the development of ANG II-dependent hypertension and reveal an AT1aR-, ER stress-, and ROS-dependent prehypertensive surge in NF-κB activity in the SFO. Furthermore, the increase in NF-κB activity before a rise in arterial blood pressure suggests a causal role for SFO NF-κB in the development of ANG II-dependent hypertension.

Molecular and Cytological Comparisons of Chromosomes 7el1, 7el2, 7E(e), and 7E ⁱ Derived from Thinopyrum.

Thinopyrum chromosomes 7el1, 7el2, 7E(e), and 7E(i), homoeologous to group 7 chromosomes of common wheat (Triticum aestivum), were determined to have many useful agronomical traits for wheat improvement. To analyze the genetic relationships among the 4 Thinopyrum 7E chromosomes, the conserved orthologous set markers, genomic in situ hybridization (GISH), and meiotic chromosome pairing were used in this study. The unweighted pair-group method with arithmetical averages (UPGMA) analysis indicated that 7el1, derived from T. ponticum, and 7E(i), derived from T. intermedium, were the most closely related. 7el2, derived from T. ponticum, was relatively distant from the 7el1-7E(i) complex. While 7E(e), derived from T. elongatum, was more distantly related to 7el1, 7el2, and 7E(i). This is the first report showing that 7el1 and 7E(i) may be similar, which could be explained by the similar chromosome signal distribution revealed by GISH as well as UPGMA analysis revealed by both molecular markers and the highest frequency of meiotic pairing. The newly developed genome-specific molecular markers may be useful for marker-assisted selection of Lr19, Bdv3, and Fhblop.

High-density mapping of the major FHB resistance gene Fhb7 derived from Thinopyrum ponticum and its pyramiding with Fhb1 by marker-assisted selection.

KEY MESSAGE: Wheat lines with shortened Th. ponticum chromatin carrying Fhb7 and molecular markers linked to Fhb7 will accelerate the transfer of Fhb7 to breeding lines and provide an important resource for future map-based cloning of this gene. Fusarium head blight is a major wheat disease globally. A major FHB resistance gene, designated as Fhb7, derived from Thinopyrum ponticum, was earlier transferred to common wheat, but was not used in wheat breeding due to linkage drag. The aims of this study were to (1) saturate this FHB resistance gene region; (2) develop and characterize secondary translocation lines with shortened Thinopyrum segments carrying Fhb7 using ph1b; (3) pyramid Fhb7 and Fhb1 by marker-assisted selection. Fhb7 was mapped in a 1.7 cM interval that was flanked by molecular markers XsdauK66 and Xcfa2240 with SSR, diversity arrays technology, EST-derived and conserved markers. KS24-2 carrying Fhb7 was analyzed with molecular markers and genomic in situ hybridization, confirming it was a 7DS.7el2L Robertsonian translocation. To reduce the Thinopyrum chromatin segments carrying Fhb7, a BC1F2 population (Chinese Spring ph1bph1b*2/KS24-2) was developed and genotyped with the markers linked to Fhb7. Two new translocation lines (SDAU1881 and SDAU1886) carrying Fhb7 on shortened alien segments (approximately 16.1 and 17.3% of the translocation chromosome, respectively) were developed. Furthermore, four wheat lines (SDAU1902, SDAU1903, SDAU1904, and SDAU1906) with the pyramided markers flanking Fhb1 and Fhb7 were developed and the FHB responses indicated lines with mean NDS ranging from 1.3 to 1.6 had successfully combined Fhb7 and Fhb1. Three new molecular markers associated with Fhb7 were identified and validated in 35 common wheat varieties. The translocation lines with shortened alien segments carrying Fhb7 (and Fhb1) and the markers closely linked to Fhb7 will be useful for improving wheat scab resistance.

Shotgun Analysis of the Secretome of Fusarium graminearum.

Fusarium head blight, caused predominately by Fusarium graminearum, is one of the most destructive diseases of wheat (Triticum aestivum L.) worldwide. To characterize the profile of proteins secreted by F. graminearum, the extracellular proteins were collectively obtained from F. graminearum culture supernatants and evaluated using one-dimensional SDS-PAGE and liquid chromatography-tandem mass spectrometry. A total of 87 proteins have been identified, of which 63 were predicted as secretory proteins including those with known functions. Meanwhile, 20 proteins that are not homologous to genomic sequences with known functions have also been detected. Some of the identified proteins are possible virulence factors and may play extracellular roles during F. graminearum infection. This study provides a valuable dataset of F. graminearum extracellular proteins, and a better understanding of the virulence mechanisms of the pathogen.