A survey of apomixis and ploidy levels among Poa L. (Poaceae) using flow cytometry

Poa is a complex genus taxonomically and genetically. As a result, relatively little information exists for this economically important genus with regards to reproductive mode and variability in chromosome number. We examined apomixis frequency and ploidy levels in 83 Poa accessions representing 33 species from the National Plant Germplasm System using flow cytometric techniques. In reproductive mode analysis, we analyzed at least three preparations of 50 seeds each from the accessions. In ploidy level analysis, at least three plants of each accession were analyzed. Sixty percent of the species had at least one apomictic or facultative apomictic accession; 40% were sexual. Thirty-three percent of the species had no sexual accessions. Autonomous apomixis was newly identified in P. bactriana and P. bulbosa in addition to it being previously reported in P. nervosa. Poa annua and P. trivialis were identified as obligate sexual, and P. nervosa as obligate apomictic. Two of four P. palustris accessions exhibited facultative apomixis. Ploidy levels among sexually reproducing Poa accessions ranged from 2n = 2x = 14 to 2n = 12x = 84, with most accessions between 2n = 3x = 21 to 2n = 8x = 56. Among apomictic accessions, ploidy levels ranged from 2n = 3x = 21 to 2n = 10x = 70, with most between 2n = 4x = 28 and 2n = 10x = 70. These results emphasize the wide variability in Poa, both among and within species

Genetic Decomposition of the Heritable Component of Reported Childhood Maltreatment

BACKGROUND: Decades of research have shown that environmental exposures, including self-reports of trauma, are partly heritable. Heritable characteristics may influence exposure to and interpretations of environmental factors. Identifying heritable factors associated with self-reported trauma could improve our understanding of vulnerability to exposure and the interpretation of life events. METHODS: We used genome-wide association study summary statistics of childhood maltreatment, defined as reporting of abuse (emotional, sexual, and physical) and neglect (emotional and physical) (N = 185,414 participants). We calculated genetic correlations (rg) between reported childhood maltreatment and 576 traits to identify phenotypes that might explain the heritability of reported childhood maltreatment, retaining those with |rg| > 0.25. We specified multiple regression models using genomic structural equation modeling to detect residual genetic variance in childhood maltreatment after accounting for genetically correlated traits. RESULTS: In 2 separate models, the shared genetic component of 12 health and behavioral traits and 7 psychiatric disorders accounted for 59% and 56% of heritability due to common genetic variants (single nucleotide polymorphism–based heritability [h2SNP]) of childhood maltreatment, respectively. Genetic influences on h2SNP of childhood maltreatment were generally accounted for by a shared genetic component across traits. The exceptions to this were general risk tolerance, subjective well-being, posttraumatic stress disorder, and autism spectrum disorder, identified as independent contributors to h2SNP of childhood maltreatment. These 4 traits alone were sufficient to explain 58% of h2SNP of childhood maltreatment. CONCLUSIONS: We identified putative traits that reflect h2SNP of childhood maltreatment. Elucidating the mechanisms underlying these associations may improve trauma prevention and posttraumatic intervention strategies

Trajectories of depression and anxiety symptom severity during psychological therapy for common mental health problems

BACKGROUND: There is substantial variation in patient symptoms following psychological therapy for depression and anxiety. However, reliance on endpoint outcomes ignores additional interindividual variation during therapy. Knowing a patient's likely symptom trajectories could guide clinical decisions. We aimed to identify latent classes of patients with similar symptom trajectories over the course of psychological therapy and explore associations between baseline variables and trajectory class. METHODS: Patients received high-intensity psychological treatment for common mental health problems at National Health Service Improving Access to Psychological Therapies services in South London (N = 16 258). To identify trajectories, we performed growth mixture modelling of depression and anxiety symptoms over 11 sessions. We then ran multinomial regressions to identify baseline variables associated with trajectory class membership. RESULTS: Trajectories of depression and anxiety symptoms were highly similar and best modelled by four classes. Three classes started with moderate-severe symptoms and showed (1) no change, (2) gradual improvement, and (3) fast improvement. A final class (4) showed initially mild symptoms and minimal improvement. Within the moderate-severe baseline symptom classes, patients in the two showing improvement as opposed to no change tended not to be prescribed psychotropic medication or report a disability and were in employment. Patients showing fast improvement additionally reported lower baseline functional impairment on average. CONCLUSIONS: Multiple trajectory classes of depression and anxiety symptoms were associated with baseline characteristics. Identifying the most likely trajectory for a patient at the start of treatment could inform decisions about the suitability and continuation of therapy, ultimately improving patient outcomes

Long‐term trends in the distribution, abundance and impact of native “injurious” weeds

Questions: How can we quantify changes in the distribution and abundance of injurious weed species (Senecio jacobaea, Cirsium vulgare, Cirsium arvense, Rumex obtusifolius, Rumex crispus and Urtica dioica), over long time periods at wide geographical scales? What impact do these species have on plant communities? To what extent are changes driven by anthropogenically induced drivers such as disturbance, eutrophication and management? Location: Great Britain. Methods: Data from national surveys were used to assess changes in the frequency and abundance of selected weed species between 1978 and 2007. This involved novel method development to create indices of change, and to relate changes in distribution and abundance of these species to plant community diversity and inferred changes in resource availability, disturbance and management. Results: Three of the six weed species became more widespread in GB over this period and all of them increased in abundance (in grasslands, arable habitats, roadsides and streamsides). Patterns were complex and varied by landscape context and habitat type. For most of the species, there were negative relationships between abundance, total plant species richness, grassland, wetland and woodland indicators. Each individual species responds to a different combination of anthropogenic drivers but disturbance, fertility and livestock management significantly influenced most species. Conclusions: The increase in frequency and abundance of weeds over decades has implications for landscape‐scale plant diversity, fodder yield and livestock health. This includes reductions in plant species richness, loss of valuable habitat specialists and homogenisation of vegetation communities. Increasing land‐use intensity, excessive nutrient input, overgrazing, sward damage, poaching and bare ground in fields and undermanagement or too frequent cutting on linear features may have led to increases in weeds. These weeds do have conservation value so we are not advocating eradication, rather co‐existence, without dominance. Land management policy needs to adapt to benefit biodiversity and agricultural productivity

Genetics of environmental sensitivity and its association with variations in emotional problems, autistic traits, and wellbeing

Greater environmental sensitivity has been associated with increased risk of mental health problems, especially in response to stressors, and lower levels of subjective wellbeing. Conversely, sensitivity also correlates with lower risk of emotional problems in the absence of adversity, and in response to positive environmental influences. Additionally, sensitivity has been found to correlate positively with autistic traits. Individual differences in environmental sensitivity are partly heritable, but it is unknown to what extent the aetiological factors underlying sensitivity overlap with those on emotional problems (anxiety and depressive symptoms), autistic traits and wellbeing. The current study used multivariate twin models and data on sensitivity, emotional problems, autistic traits, and several indices of psychological and subjective wellbeing, from over 2800 adolescent twins in England and Wales. We found that greater overall sensitivity correlated with greater emotional problems, autistic traits, and lower subjective wellbeing. A similar pattern of correlations was found for the Excitation and Sensory factors of sensitivity, but, in contrast, the Aesthetic factor was positively correlated with psychological wellbeing, though not with emotional problems nor autistic traits. The observed correlations were largely due to overlapping genetic influences. Importantly, genetic influences underlying sensitivity explained between 2 and 12% of the variations in emotional problems, autistic traits, and subjective wellbeing, independent of trait-specific or overlapping genetic influences. These findings encourage incorporating the genetics of environmental sensitivity in future genomic studies aiming to delineate the heterogeneity in emotional problems, autistic traits, and wellbeing

Age and sex‐related variability in the presentation of generalized anxiety and depression symptoms

Background: Generalized anxiety and depression are extremely prevalent and debilitating. There is evidence for age and sex variability in symptoms of depression, but despite comorbidity it is unclear whether this extends to anxiety symptomatology. Studies using questionnaire sum scores typically fail to address this phenotypic complexity. Method: We conducted exploratory and confirmatory factor analyses on Generalized Anxiety Disorder (GAD‐7) and Patient Health Questionnaire (PHQ‐9) items to identify latent factors of anxiety and depression in participants from the Genetic Links to Anxiety and Depression Study (N = 35,637; 16–93 years). We assessed age‐ and sex‐related variability in latent factors and individual symptoms using multiple logistic regression. Results: Four factors of mood, worry, motor, and somatic symptoms were identified (comparative fit index [CFI] = 0.99, Tucker–Lewis Index [TLI] = 0.99, root mean square error of approximation [RMSEA] = 0.07, standardized root mean square residuals [SRMR] = 0.04). Symptoms of irritability (odds ratio [OR] = 0.81) were most strongly associated with younger age, and sleep change (OR = 1.14) with older age. Males were more likely to report mood and motor symptoms (p < .001) and females to report somatic symptoms (p < .001). Conclusion: Significant age and sex variability suggest that classic diagnostic criteria reflect the presentation most commonly seen in younger males. This study provides avenues for diagnostic adaptation and factor‐specific interventions

Comparison of depression and anxiety symptom networks in reporters and non-reporters of lifetime trauma in two samples of differing severity

Background: Reported trauma is associated with differences in the course and outcomes of depression and anxiety. However, no research has explored the association between reported trauma and patterns of clinically relevant symptoms of both depression and anxiety. Methods: We used network analysis to investigate associations between reported trauma and depression and anxiety symptom interactions in affected individuals from the Genetic Links to Anxiety and Depression (GLAD) Study (n = 17720), and population volunteers from the UK Biobank (n = 11120). Participants with current moderate symptoms of depression or anxiety were grouped into reporters and non-reporters of lifetime trauma. Networks of 16 depression and anxiety symptoms in the two groups were compared using the network comparison test. Results: In the GLAD Study, networks of reporters and non-reporters of lifetime trauma did not differ on any metric. In the UK Biobank, the symptom network of reporters had significantly greater density (7.80) than the network of non-reporters (7.05). Limitations: The data collected in the GLAD Study and the UK Biobank are self-reported with validated or semi-validated questionnaires. Conclusions: Reported lifetime trauma was associated with stronger interactions between symptoms of depression and anxiety in population volunteers. Differences between reporters and non-reporters may not be observed in individuals with severe depression and/or anxiety due to limited variance in the presentation of disorder