Genomic analyses elucidate S-locus evolution in response to intra-specific losses of distyly in Primula vulgaris.

Distyly, a floral dimorphism that promotes outcrossing, is controlled by a hemizygous genomic region known as the S-locus. Disruptions of genes within the S-locus are responsible for the loss of distyly and the emergence of homostyly, a floral monomorphism that favors selfing. Using whole-genome resequencing data of distylous and homostylous individuals from populations of Primula vulgaris and leveraging high-quality reference genomes of Primula we tested, for the first time, predictions about the evolutionary consequences of transitions to selfing on S-genes. Our results reveal a previously undetected structural rearrangement in CYPᵀ associated with the shift to homostyly and confirm previously reported, homostyle-specific, loss-of-function mutations in the exons of the S-gene CYPᵀ. We also discovered that the promoter and intronic regions of CYPᵀ in distylous and homostylous individuals are conserved, suggesting that down-regulation of CYPᵀ via mutations in its promoter and intronic regions is not a cause of the shift to homostyly. Furthermore, we found that hemizygosity is associated with reduced genetic diversity in S-genes compared with their paralogs outside the S-locus. Additionally, the shift to homostyly lowers genetic diversity in both the S-genes and their paralogs, as expected in primarily selfing plants. Finally, we tested, for the first time, long-standing theoretical models of changes in S-locus genotypes during early stages of the transition to homostyly, supporting the assumption that two copies of the S-locus might reduce homostyle fitness.

Skewed morph ratios lead to lower genetic diversity of the heterostylous Primula veris in fragmented grasslands.

Populations of heterostylous plant species are ideally composed of equal frequencies of two (distylous) or three (tristylous) morphologically different floral morphs. Intra-morph incompatibility helps to avoid inbreeding and to maintain genetic diversity, supporting plant fitness and long-term viability. Habitat fragmentation can lead to skewed morph ratios and thereby reduce the abundance of compatible mates. This, in turn, can result in a loss of genetic diversity. We tested whether the genetic diversity of heterostylous plants is affected by morph ratio bias using populations of the distylous grassland plant Primula veris in recently fragmented grasslands. We recorded morph frequencies and population sizes in 30 study populations of P. veris on two Estonian islands characterised by different degrees of habitat fragmentation. Examining variation of thousands of single nucleotide polymorphisms (SNPs) and heterostyly-specific genetic markers, we quantified overall and morph-specific genetic diversity and differentiation in these populations. Morph frequencies deviated more in smaller populations. Skewed morph ratios had a negative effect on the genetic diversity of P. veris in more fragmented grasslands. In the populations of better-connected grassland systems, genetic differentiation among S-morphs was higher than among L-morphs. Our study shows that deviations from morph balance are stronger in small populations and have a negative impact on the genetic diversity of the distylous plant P. veris. Together with the direct negative effects of habitat loss and decreased population size on the genetic diversity of plants, morph ratio bias may intensify the process of genetic erosion, thus exacerbating the local extinction of heterostylous species.

Three cases of spontaneous major bleeding in patients with a COVID-19 infection.

In addition to the respiratory compromise typical for COVID-19 many papers reported on the thromboembolic complications in these often critically ill patients. In this report, three cases of patients that developed spontaneous major bleeding following treatment with therapeutic anticoagulation for thromboembolic complications of COVID-19 were described. Two cases were treated with coil-embolization and one patient could be treated conservatively. These cases illustrate the presence of a relevant bleeding risk against the background of the well-known thromboembolic complications associated with COVID-19. The increased risks of thromboembolic complications in COVID-19 warrant adequate prophylactic anticoagulation. The optimal dose to obtain a significant risk reduction without a significant increase in the incidence of major bleeding requires further research.

A Systematic Review and Meta-Analysis on Perioperative Cerebral and Hemodynamic Monitoring Methods during Carotid Endarterectomy.

BACKGROUND: To compare outcomes between different strategies of perioperative cerebral and hemodynamic monitoring during carotid endarterectomy. DATA SOURCES: MEDLINE, EMBASE, CINAHL, and Cochrane CENTRAL databases were searched. METHODS: This review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and prospectively registered in the international prospective register of systematic reviews (CRD42021241891). The Grading of Recommendations, Assessment, Development and Evaluation approach was used to describe the methodological quality of the studies and certainty of the evidence. The primary outcome was 30-day stroke rate. Secondary outcomes measures are 30-day ipsilateral stroke, 30-day mortality, shunt rate, and complication rates. RESULTS: The search identified 3,460 articles. Seventeen randomized controlled trials (RCTs), three prospective observational studies and seven registries were included, reporting on 236,983 patients. The overall pooled 30-day stroke rate is 1.8% (95% CI 1.4-2.2%), ranging from 0 to 12.6%. In RCT's the pooled 30-day stroke rate is 2.7% (95% CI 1.6-3.7%) compared to 1.3% (95% CI 0.8-1.8%) in the registries. The overall stroke risk decreased from 3.7% before the year 2000 to 1.6% after 2000. No significant differences could be identified between different monitoring and shunting strategies, although a trend to higher stroke rates in routine no shunting arms of RCTs was observed. Overall, 30-day mortality, myocardial infarction and nerve injury rates are 0.6% (95% CI 0.4-0.8), 0.8% (95% CI 0.6-1.0) and 1.3% (95% CI 0.4-2.2), respectively. CONCLUSIONS: No significant differences between the compared shunting and monitoring strategies are found. However, routine no shunting is not recommended. The available data are too limited to prefer 1 method of neuromonitoring over another method when selective shunting is applied.

Why Cell-Free DNA Can Be a "Game Changer" for Lung Allograft Monitoring for Rejection and Infection.

Purpose of Review: Although there has been improvement in short-term clinical outcomes for patients following lung transplant (LT), advances have not translated into longer-term allograft survival. Furthermore, invasive biopsies are still standard of practice for monitoring LT recipients for allograft injury. We review the relevant literature supporting the role of using plasma donor-derived cell-free DNA (dd-cfDNA) as a non-invasive biomarker for LT allograft injury surveillance and discuss future research directions. Recent Findings: Accumulating data has demonstrated that dd-cfDNA is associated with molecular and cellular injury due to acute (cellular and antibody-mediated) rejection, chronic lung allograft dysfunction, and relevant infectious pathogens. Strong performance in distinguishing rejection and allograft injury from stable patients has set the stage for clinical trials to assess dd-cfDNA utility for surveillance of LT patients. Research investigating the potential role of dd-cfDNA methylation signatures to map injured tissue and cell-free DNA in detecting allograft injury-related pathogens is ongoing. Summary: There is an amassed breadth of clinical data to support a role for dd-cfDNA in monitoring rejection and other forms of allograft injury. Rigorously designed, robust clinical trials that encompass the diversity in patient demographics are paramount to furthering our understanding and adoption of plasma dd-cfDNA for surveillance of lung allograft health.

Path probability ratios for Langevin dynamics-Exact and approximate.

Path reweighting is a principally exact method to estimate dynamic properties from biased simulations-provided that the path probability ratio matches the stochastic integrator used in the simulation. Previously reported path probability ratios match the Euler-Maruyama scheme for overdamped Langevin dynamics. Since molecular dynamics simulations use Langevin dynamics rather than overdamped Langevin dynamics, this severely impedes the application of path reweighting methods. Here, we derive the path probability ratio ML for Langevin dynamics propagated by a variant of the Langevin Leapfrog integrator. This new path probability ratio allows for exact reweighting of Langevin dynamics propagated by this integrator. We also show that a previously derived approximate path probability ratio Mapprox differs from the exact ML only by O(ξ4Δt4) and thus yields highly accurate dynamic reweighting results. (Δt is the integration time step, and ξ is the collision rate.) The results are tested, and the efficiency of path reweighting is explored using butane as an example.

Genetic analyses of the parasitic nematode, Parelaphostrongylus tenuis, in Missouri and Kentucky reveal unexpected levels of diversity and population differentiation.

Wildlife translocations, which involve the introduction of naive hosts into new environments with novel pathogens, invariably pose an increased risk of disease. The meningeal worm Parelaphostrongylus tenuis is a nematode parasite of the white-tailed deer (Odocoileus virginianus), which serves as its primary host and rarely suffers adverse effects from infection. Attempts to restore elk (Cervus canadensis) to the eastern US have been hampered by disease caused by this parasite. Using DNA sequence data from mitochondrial and nuclear genes, we examined the hypothesis that elk translocated within the eastern US could be exposed to novel genetic variants of P. tenuis by detailing the genetic structure among P. tenuis taken from white-tailed deer and elk at a source (Kentucky) and a release site (Missouri). We found high levels of diversity at both mitochondrial and nuclear DNA in Missouri and Kentucky and a high level of differentiation between states. Our results highlight the importance of considering the potential for increased disease risk from exposure to novel strains of parasites in the decision-making process of a reintroduction or restoration.

From laboratory to the field: biological control of Fusarium graminearum on infected maize crop residues.

AIM: To evaluate biological control agents (BCAs) against Fusarium graminearum on infected maize stalks as a means to reduce Fusarium head blight (FHB) in subsequently grown wheat. METHODS AND RESULTS: In the laboratory, BCAs were applied against F. graminearum on maize stalk pieces. Clonostachys rosea inhibited the perithecia development and ascospore discharge when applied before, simultaneously with and after the pathogen. In the field, we simulated a system with high disease pressure, that is, a maize-wheat rotation under no-tillage, by preparing maize stalks inoculated with F. graminearum. The infected stalks were treated with formulations of C. rosea selected in vitro or the commercial BCA strain Trichoderma atrobrunneum ITEM908 and exposed to field conditions over winter and spring between winter wheat rows. Monitoring with spore traps and of FHB symptoms, as well as quantification of F. graminearum incidence and DNA in harvested grain revealed significant reductions by C. rosea by up to 85, 91, 69 and 95% compared with an inoculated but untreated positive control, respectively. Deoxynivalenol (DON) and zearalenone (ZEN) contents were reduced by up to 93 and 98%, respectively. Treatments with T. atrobrunneum were inconsistent, with significant reductions of DON and ZEN under warm and wet climatic conditions only. CONCLUSIONS: The findings support the application of C. rosea against F. graminearum on residues of maize to suppress the primary inoculum of FHB. SIGNIFICANCE AND IMPACT OF THE STUDY: As sustainable agriculture requires solutions to control FHB, hence, the application of C. rosea during the mulching of maize crop residues should be evaluated in on-farm experiments.

Changes in Pulmonary Function in Patients With Advanced Heart Failure Listed for Heart Transplantation.

BACKGROUND: Pulmonary function tests (PFTs) are often impaired in patients with advanced heart failure. There is limited data about their impact on survival after heart transplantation (HT). We sought to assess the prevalence and type of PFT abnormalities in patients on HT waiting list and their impact on outcomes. METHODS: We performed a retrospective analysis of a prospective registry of consecutive patients undergoing HT between 2012 and 2018. Patients were classified into 4 groups according to pre-HT PFT results: 1. normal pattern: forced vital capacity (FVC) ≥ 80% and forced expiratory volume in 1 second (FEV1) to FVC ratio (FEV1/FVC) ≥ 0.7; 2. obstructive: FEV1/FVC < 0.7; 3. nonobstructive: FEV1/FVC ≥ 0.7 and FVC < 80% when total lung capacity value was not available; and 4. restrictive: FEV1/FVC ≥ 0.7 and total lung capacity < 80%. The prevalence of impaired carbon monoxide diffusing capacity corrected for hemoglobin < 80% and FEV1 < 70% was also analyzed. High-urgency HT patients and those referred from other centers without quantitative pulmonary evaluation were excluded. RESULTS: Among 123 patients who underwent HT, 83 patients with complete PFT were included. Median follow-up was 2.7 ± 1.9 years. Of these, 29 (34.9%) had an obstructive pattern, 20 (24.1%) a nonobstructive, 18 (21.7%) a restrictive, and 16 (19.3%) a normal pattern. Fifty-one (61.4%) patients had FEV1 < 70% and 58 (69.9%) a carbon monoxide diffusing capacity corrected for hemoglobin < 80%. There was a tendency to lower survival in all altered PFT groups compared with normal (P = .054) but not within the other groups. Patients with an impaired FEV1 had significantly higher mortality than patients with normal values (P = .008). Area under receiver operating characteristic curve for FEV1 was 0.73 (95% confidence interval [0.60-0.86]). A cutoff value of FEV1 (60.5) predicts mortality with 66% sensitivity and 64% specificity. CONCLUSIONS: PFT alterations have a very high prevalence on HT waiting list patients. Patients with impaired FEV1 had worse outcomes after heart transplantation.

Convergent evolution of a metabolic switch between aphid and caterpillar resistance in cereals.

Tailoring defense responses to different attackers is important for plant performance. Plants can use secondary metabolites with dual functions in resistance and defense signaling to mount herbivore-specific responses. To date, the specificity and evolution of this mechanism are unclear. Here, we studied the functional architecture, specificity, and genetic basis of defense regulation by benzoxazinoids in cereals. We document that DIMBOA-Glc induces callose as an aphid resistance factor in wheat. O-methylation of DIMBOA-Glc to HDMBOA-Glc increases plant resistance to caterpillars but reduces callose inducibility and resistance to aphids. DIMBOA-Glc induces callose in wheat and maize, but not in Arabidopsis, while the glucosinolate 4MO-I3M does the opposite. We identify a wheat O-methyltransferase (TaBX10) that is induced by caterpillar feeding and converts DIMBOA-Glc to HDMBOA-Glc in vitro. While the core pathway of benzoxazinoid biosynthesis is conserved between wheat and maize, the wheat genome does not contain close homologs of the maize DIMBOA-Glc O-methyltransferase genes, and TaBx10 is only distantly related. Thus, the functional architecture of herbivore-specific defense regulation is similar in maize and wheat, but the regulating biosynthetic genes likely evolved separately. This study shows how two different cereal species independently achieved herbivore-specific defense activation by regulating secondary metabolite production.

["My Home, my Car, my Boat" - Satisfaction with One's Own Standard of Living as a Predictor of Gender-Specific Mortality]. / "Mein Haus, mein Auto, mein Boot". Zufriedenheit mit dem Lebensstandard als geschlechtsspezifischer Mortalitätsprädiktor.

BACKGROUND: Men have a higher risk of mortality than women and react much more sensitively to status-related stressors. The relationship between hierarchical rank and health, mediated on the HPA axis, delivers possible explanations for the more pronounced male sensitivity. In this context, the construct of status unease has attracted a lot of attention in recent years. It links social comparison with a reduced general wellbeing and considers it to be a major risk factor for various diseases. METHODS: An analysis of secondary data from the Socio-Economic Panel (SOEP) was used to analyze the extent to which subjective dissatisfaction with one's own standard of living is associated with an increased gender-related mortality risk. The statistical modeling of the question was carried out by performing gender-disaggregated Cox proportional hazard models. The unbalanced sub-sample consisted of 6 454 men (685 deaths) and 6 908 women (618 deaths). RESULTS: Dissatisfaction with one's standard of living has a significant influence on the mortality risk of men but not women: Men with low satisfaction have nearly a twice as high risk of mortality than the reference group (HR=1,95, 95% CI 1,48-2,58), men with moderate satisfaction a 25% higher mortality risk (HR=1,26, 95% CI 1,08-1,49). Furthermore, subjective status shows stronger dose-response relationships than objective status parameters. CONCLUSION: Dissatisfaction with one's standard of living turns out to be a clear predictor for male mortality. Stress reactions due to disparaging social comparison processes triggered by the HPA-axis could be a central cause. The results indicate that the standardized inclusion of subjective status indicators should be considered in social-epidemiological analysis. The distinctive gender difference also points out that gender-sensitive epidemiological data analysis is reasonable.

Neural correlates of proactive and reactive motor response inhibition of gambling stimuli in frequent gamblers.

We used functional magnetic resonance imaging to examine whether motivational-salient cues could exert a differential impact on proactive (the restrain of actions in preparation for stopping) and reactive (outright stopping) inhibition. Fourteen high-frequency poker players, and 14 matched non-gambler controls, performed a modified version of the stop-signal paradigm, which required participants to inhibit categorization of poker or neutral pictures. The probability that a stop-signal occurs (0%, 17%, 25%, 33%) was manipulated across blocks of trials, as indicated by the color of the computer screen. Behavioral analyses revealed that poker players were faster than controls in categorizing pictures across all levels of proactive motor response inhibition (go trials). Brain imaging analyses highlighted higher dorsal anterior cingulate cortex activation in poker players, as compared to controls, during reactive inhibition. These findings suggest that, due to their faster rates of stimulus discrimination, poker players might have recruited more cognitive resources than controls when required to stop their response (reactive inhibition). Nevertheless, no main effect of stimulus type was found, on either proactive or reactive inhibition. Additional studies are, therefore, needed in order to confirm that investigating the dynamics between reactive and proactive inhibition offers a discriminative analysis of inhibitory control toward motivational-salient cues.

Girsanov reweighting for path ensembles and Markov state models.

The sensitivity of molecular dynamics on changes in the potential energy function plays an important role in understanding the dynamics and function of complex molecules. We present a method to obtain path ensemble averages of a perturbed dynamics from a set of paths generated by a reference dynamics. It is based on the concept of path probability measure and the Girsanov theorem, a result from stochastic analysis to estimate a change of measure of a path ensemble. Since Markov state models (MSMs) of the molecular dynamics can be formulated as a combined phase-space and path ensemble average, the method can be extended to reweight MSMs by combining it with a reweighting of the Boltzmann distribution. We demonstrate how to efficiently implement the Girsanov reweighting in a molecular dynamics simulation program by calculating parts of the reweighting factor "on the fly" during the simulation, and we benchmark the method on test systems ranging from a two-dimensional diffusion process and an artificial many-body system to alanine dipeptide and valine dipeptide in implicit and explicit water. The method can be used to study the sensitivity of molecular dynamics on external perturbations as well as to reweight trajectories generated by enhanced sampling schemes to the original dynamics.

Assessment of disease extent on contrast-enhanced MRI in breast cancer detected at digital breast tomosynthesis versus digital mammography alone.

AIM: To compare the utility of breast magnetic resonance imaging (MRI) in determining the extent of disease in patients with newly diagnosed breast cancer detected on combination digital breast tomosynthesis (DBT) versus digital screening mammography (DM). MATERIALS AND METHODS: Review of 24,563 DBT-screened patients and 10,751 DM-screened patients was performed. Two hundred and thirty-five DBT patients underwent subsequent MRI examinations; 82 to determine extent of disease after newly diagnosed breast cancer. Eighty-three DM patients underwent subsequent MRI examinations; 23 to determine extent of disease. MRI examinations performed to assess disease extent were considered true positives if additional disease was discovered in the contralateral breast or >2 cm away from the index malignancy. Differences in cancer subtypes and MRI outcomes between the DM and DBT cohorts were compared using chi-squared tests and post-hoc Bonferroni-adjusted tests for equal proportions. RESULTS: No differences in cancer subtype findings were observed between the two cohorts; however, MRI outcomes were found to differ between the DBT and DM cohorts (p=0.024). Specifically, the DBT cohort had significantly (p=0.013) fewer true-positive findings (7/82, 8.5%) than did the DM cohort (7/23; 30%), whereas the false-positive rate was similar between the cohorts (not statistically significant). When stratifying by breast density, this difference in true-positive rates was primarily observed when evaluating women with non-dense breasts (p=0.001). CONCLUSION: In both the DM- and DBT-screened populations with new cancer diagnoses, MRI is able to detect additional cancer; however, in those patients who have DBT screen-detected cancers the positive impact of preoperative MRI is diminished, particularly in those women with non-dense breasts.

Who Should Bear the Cost of Convenience? A Cost-effectiveness Analysis Comparing External Beam and Brachytherapy Radiotherapy Techniques for Early Stage Breast Cancer.

AIMS: Standard treatment for early breast cancer includes whole breast irradiation (WBI) after breast-conserving surgery. Recently, accelerated partial breast irradiation (APBI) has been proposed for well-selected patients. A cost and cost-effectiveness analysis was carried out comparing WBI with two APBI techniques. MATERIALS AND METHODS: An activity-based costing method was used to determine the treatment cost from a societal perspective of WBI, high dose rate brachytherapy (HDR) and permanent breast seed implants (PBSI). A Markov model comparing the three techniques was developed with downstream costs, utilities and probabilities adapted from the literature. Sensitivity analyses were carried out for a wide range of variables, including treatment costs, patient costs, utilities and probability of developing recurrences. RESULTS: Overall, HDR was the most expensive ($14 400), followed by PBSI ($8700), with WBI proving the least expensive ($6200). The least costly method to the health care system was WBI, whereas PBSI and HDR were less costly for the patient. Under cost-effectiveness analyses, downstream costs added about $10 000 to the total societal cost of the treatment. As the outcomes are very similar between techniques, WBI dominated under cost-effectiveness analyses. CONCLUSIONS: WBI was found to be the most cost-effective radiotherapy technique for early breast cancer. However, both APBI techniques were less costly to the patient. Although innovation may increase costs for the health care system it can provide cost savings for the patient in addition to convenience.

Cyanobacteria facilitate parasite epidemics in Daphnia.

The seasonal dominance of cyanobacteria in the phytoplankton community of lake ecosystems can have severe implications for higher trophic levels. For herbivorous zooplankton such as Daphnia, cyanobacteria have poor nutritional value and some species can produce toxins affecting zooplankton survival and reproduction. Here we present another, hitherto largely unexplored aspect of cyanobacteria, namely that they can increase Daphnia susceptibility to parasites. In a 12-yr monthly time-series analysis of the Daphnia community in Greifensee (Switzerland), we observed that cyanobacteria density correlated significantly with the epidemics of a common gut parasite of Daphnia, Caullerya mesnili, regardless of what cyanobacteria species was present or whether it was colonial or filamentous. The temperature from the previous month also affected the occurrence of Caullerya epidemics, either directly or indirectly by the promotion of cyanobacterial growth. A laboratory experiment confirmed that cyanobacteria increase the susceptibility of Daphnia to Caullerya, and suggested a possible involvement of cyanotoxins or other chemical traits of cyanobacteria in this process. These findings expand our understanding of the consequences of toxic cyanobacterial blooms for lake ecosystems and might be relevant for epidemics experienced by other aquatic species.

Live volumetric (4D) visualization and guidance of in vivo human ophthalmic surgery with intraoperative optical coherence tomography.

Minimally-invasive microsurgery has resulted in improved outcomes for patients. However, operating through a microscope limits depth perception and fixes the visual perspective, which result in a steep learning curve to achieve microsurgical proficiency. We introduce a surgical imaging system employing four-dimensional (live volumetric imaging through time) microscope-integrated optical coherence tomography (4D MIOCT) capable of imaging at up to 10 volumes per second to visualize human microsurgery. A custom stereoscopic heads-up display provides real-time interactive volumetric feedback to the surgeon. We report that 4D MIOCT enhanced suturing accuracy and control of instrument positioning in mock surgical trials involving 17 ophthalmic surgeons. Additionally, 4D MIOCT imaging was performed in 48 human eye surgeries and was demonstrated to successfully visualize the pathology of interest in concordance with preoperative diagnosis in 93% of retinal surgeries and the surgical site of interest in 100% of anterior segment surgeries. In vivo 4D MIOCT imaging revealed sub-surface pathologic structures and instrument-induced lesions that were invisible through the operating microscope during standard surgical maneuvers. In select cases, 4D MIOCT guidance was necessary to resolve such lesions and prevent post-operative complications. Our novel surgical visualization platform achieves surgeon-interactive 4D visualization of live surgery which could expand the surgeon's capabilities.

Molecular dynamics simulations data of the twenty encoded amino acids in different force fields.

We present extensive all-atom Molecular Dynamics (MD) simulation data of the twenty encoded amino acids in explicit water, simulated with different force fields. The termini of the amino acids have been capped to ensure that the dynamics of the Φ and ψ torsion angles are analogues to the dynamics within a peptide chain. We use representatives of each of the four major force field families: AMBER ff-99SBILDN [1], AMBER ff-03 [2], OPLS-AA/L [3], CHARMM27 [4] and GROMOS43a1 [5], [6]. Our data represents a library and test bed for method development for MD simulations and for force fields development. Part of the data set has been previously used for comparison of the dynamic properties of force fields (Vitalini et al., 2015) [7] and for the construction of peptide basis functions for the variational approach to molecular kinetics [8].

Identification and genetic mapping of PmAF7DS a powdery mildew resistance gene in bread wheat (Triticum aestivum L.).

KEY MESSAGE: Gene PmAF7DS confers resistance to wheat powdery mildew (isolate Bgt#211 ); it was mapped to a 14.6-cM interval ( Xgwm350 a- Xbarc184 ) on chromosome 7DS. The flanking markers could be applied in MAS breeding. Wheat powdery mildew (Pm) is caused by the biotrophic pathogen Blumeria graminis tritici (DC.) (Bgt). An ongoing threat of breakdown of race-specific resistance to Pm requires a continuous effort to discover new alleles in the wheat gene pool. Developing new cultivars with improved disease resistance is an economically and environmentally safe approach to reduce yield losses. To identify and characterize genes for resistance against Pm in bread wheat we used the (Arina × Forno) RILs population. Initially, the two parental lines were screened with a collection of 61 isolates of Bgt from Israel. Three Pm isolates Bgt#210 , Bgt#211 and Bgt#213 showed differential reactions in the parents: Arina was resistant (IT = 0), whereas Forno was moderately susceptible (IT = -3). Isolate Bgt#211 was then used to inoculate the RIL population. The segregation pattern of plant reactions among the RILs indicates that a single dominant gene controls the conferred resistance. A genetic map of the region containing this gene was assembled with DNA markers and assigned to the 7D physical bin map. The gene, temporarily designated PmAF7DS, was located in the distal region of chromosome arm 7DS. The RILs were also inoculated with Bgt#210 and Bgt#213. The plant reactions to these isolates showed high identity with the reaction to Bgt#211, indicating the involvement of the same gene or closely linked, but distinct single genes. The genomic location of PmAF7DS, in light of other Pm genes on 7DS is discussed.