Development of a molecular marker for rust resistance genes Sr39 and Lr35 in wheat breeding lines

Polymorphic DNA bands were identified between a near iso-isogenic line of wheat carrying both stem (Sr39) and leaf (Lr35) rust resistance genes and the recurrent line Thatcher (Tc) which lacks these genes. Both resistance genes are located on a translocated chromosomal segment derived from Aegilops speltoides and thus are genetically linked. The primers used to generate polymorphic bands were 3'-anchored inter-simple sequence repeat primers which identified genomic microsatellites with a repeated motif of 3 nucleotides in length. The primers were used singly to amplify genomic segments which were flanked by inversely orientated, closely spaced, identical microsatellite sequences. One of the polymorphic bands, a 900 base pair band, was completely linked to the Sr39 and Lr35 rust resistance genes in the segregating population used in this study. After cloning and sequencing this polymorphic band, the inter-simple sequence repeat marker was converted to a sequence characterized amplified region marker by designing primer sets which amplify a single, easily resolved band from DNA of plants with Sr39/Lr35 genes. This marker is present in six wheat lines carrying the Sr39 and Lr35 genes on the translocated chromosome segment from Ae. speltoides, The marker has facilitated efforts to breed Canada Prairie Spring and Canada Western Extra Strong lines with these rust resistance genes

The specter of empty countrysides and wetlands—Impact of hunting take on birds in Indo-Burma

Hunting for the wild meat trade, medicines and other human uses has decimated Indo-Burma's vertebrate biota and has led to widespread defaunation. Yet, there is surprisingly little data on how hunting impacts wild bird assemblages in different landscapes here. Based on concurrent snapshot surveys of bird hunting, food markets and hunting attitudes across six Indo-Burma countries, we found that hunting threatens species not only in forested landscapes but also wetlands and farmlands such as orchards and paddy fields—ecosystems overlooked by past studies, with at least 47 species associated with wetlands and agricultural lands identified from market surveys across the region. High rates of mortality are suffered when hunting tools such as nets are used to exclude perceived bird pests in both aquaculture and agricultural landscapes, with over 300 individual carcasses of at least 29 identifiable species detected in one aquaculture landscape sampled in Thailand. We warn that the potentially unsustainable trapping of species for consumption and trade in Indo-Burma, coupled with high incidental mortalities, could decimate the populations of erstwhile common and/or legally unprotected species. There is an urgent need for stronger regulatory oversight on the hunting take of wild birds and the use of hunting tools such as nets. Alongside this, conservation practitioners need to better engage with rural communities to address unsustainable hunting practices, especially outside of protected areas

Regulation of alpha-dioxygenase expression and functional analyses in salt-stressed Arabidopsis thaliana

Alpha-dioxygenase (α-DOX) catalyzes the oxygenation of fatty acids to produce a newly identified group of oxylipins. In Arabidopsis, α-DOX is represented by a small gene family comprised of two members, Atα-DOX1 and Atα-DOX2. Both α-DOX genes were constitutively expressed but in distinct locations. Atα-DOX1 was expressed in roots, stamens and Atα-DOX2 was expressed in shoots, sepals, siliques and developing seeds. The expression of both α-DOX genes was responsive to salt in the roots and shoots and this salt-responsive expression was accompanied by increased α-DOX activity in both root and shoot tissues of salt stressed Arabidopsis. 2-Hydroxylinolenic acid (2HOT) and heptadecatrienal (C17 aldehyde) were the major products detected in in-vitro α-DOX assays using linolenic acid as a substrate. The role of hormones in regulating salt-induced changes in Atα-DOX expression was explored using exogenous application of hormones and hormone mutants. Abscisic acid (ABA) and salicylic acid (SA) were major hormone signals that up-regulated Atα-DOX expression in roots, whereas ABA, SA and ethylene up-regulated Atα-DOX expression in shoots. The functional significance of α-DOX in salt-stressed Arabidopsis plants was explored using lines with altered Atα-DOX1 and/or Atα-DOX2 expression. Knockout lines lacking Atα-DOX1 or Atα-DOX2 expression were more sensitive to the damaging effects of salt than wild type suggesting that α-DOX products contribute to salt tolerance. In the same lines, increased levels of H2O2 were detected in the roots indicating that α-DOX may suppress the accumulation of reactive oxygen species or promote their removal. An unanticipated function for α-DOX in regulating root system architecture was discovered whereby Atα-DOX1 and Atα-DOX2 play a role in checking LR emergence under salt stressed conditions. Such a role is consistent with the spatial expression of Atα-DOX in roots, which occurred in the zone of cell differentiation within which LR primordia are known to develop. The expression of both Atα-DOX genes was ABA and salt-responsive; it is therefore possible that the resulting α-DOX products contribute to the known ability of ABA to check LR emergence in osmotically-stressed plants. The α-DOX products contribute to salt tolerance in Arabidopsis by protecting cells against oxidative stress and checking LR production

RESEARCH ARTICLE - Development of a molecular marker for rust resistance genes Sr39 and Lr35 in wheat breeding lines

Polymorphic DNA bands were identified between a near iso-isogenic line of wheat carrying both stem (Sr39) and leaf (Lr35) rust resistance genes and the recurrent line Thatcher (Tc) which lacks these genes. Both resistance genes are located on a translocated chromosomal segment derived from Aegilops speltoides and thus are genetically linked. The primers used to generate polymorphic bands were 3'-anchored inter-simple sequence repeat primers which identified genomic microsatellites with a repeated motif of 3 nucleotides in length. The primers were used singly to amplify genomic segments which were flanked by inversely orientated, closely spaced, identical microsatellite sequences. One of the polymorphic bands, a 900 base pair band, was completely linked to the Sr39 and Lr35 rust resistance genes in the segregating population used in this study. After cloning and sequencing this polymorphic band, the inter-simple sequence repeat marker was converted to a sequence characterized amplified region marker by designing primer sets which amplify a single, easily resolved band from DNA of plants with Sr39/Lr35 genes. This marker is present in six wheat lines carrying the Sr39 and Lr35 genes on the translocated chromosome segment from Ae. speltoides. The marker has facilitated efforts to breed Canada Prairie Spring and Canada Western Extra Strong lines with these rust resistance gene

HIV, hypertension and diabetes care and all-cause mortality in rural South Africa in the HIV antiretroviral therapy era: a longitudinal cohort study

Introduction South Africa is in the midst of rapid epidemiological transition from extremely high HIV and tuberculosis (TB) mortality to one characterised increasingly non-communicable disease-related deaths. However, longitudinal data linking modifiable risk factors and disease care indices to mortality in the country are extremely rare, and a prerequisite to appropriately prioritise health system responses.Methods Individuals in the Africa Health Research Institute Southern Demographic Health Surveillance area were invited to health fairs to collect data on modifiable risk factors and HIV, TB, diabetes and hypertension disease status and control. Individuals are then followed longitudinally through routine surveillance to detect deaths. We fit Cox proportional hazards models and estimated population-attributable fractions (PAFs) to identify modifiable risk factors and disease control indicators associated with all-cause mortality.Results A total of 18 041 individuals completed health screening and were followed for 114 692 person-years. Men had higher mortality rates than women across all age bands. The median follow-up time was 3.3 years (IQR: 3.0–3.5 years). For men, communicable diseases accounted for a higher PAF of mortality (PAF=13.7% for HIV and 8.3% for TB) than non-communicable diseases (6.6% for hypertension and 1.9% for diabetes). By contrast, despite extremely high HIV prevalence, non-communicable diseases with comorbid communicable disease accounted for the greatest share of deaths. In both sexes, having a chronic disease with poor control was most predictive of all-cause mortality. For example, among men, compared with those without each condition, adjusted HRs of all-cause mortality for people with uncontrolled disease were 3.47 (95% CI 2.10 to 5.72) for HIV, 1.52 (95% CI 1.05 to 2.20) for hypertension and 2.34 (95% CI 1.75 to 6.79) for diabetes. Among women, these same ratios were 5.32 (95% CI 3.54 to 7.99) for HIV, 1.73 (95% CI 1.31 to 2.28) for hypertension and 3.11 (95% CI 2.02 to 4.77) for diabetes.Discussion Poor control of chronic, treatable diseases predicts all-cause mortality in rural South Africa in the HIV antiretroviral therapy era. Health system strengthening to improve chronic disease and multimorbidity care should be prioritised

1498. Geographic differences in weight change on dolutegravir: a prospective cohort study

Background: People with HIV (PWH) on integrase inhibitors may be at increased risk of excess weight gain, but it is unclear if this risk is consistent across settings. Our study objective was to compare weight change over 48 weeks among PWH in Uganda and South Africa.Figure 1.Mean weight change (kg) over 48 weeks among DISCO participants overall (A), among men (B), and among women (C). Methods: The Population Effectiveness of Dolutegravir Implementation in Sub-Saharan Africa (DISCO) study is a prospective observational cohort of PWH in routine clinical care at public-sector HIV clinics in Uganda and South Africa. Inclusion criteria were as follows: PWH >18 years old, on NNRTI-based first-line ART for >6 months, and switched to tenofovir disoproxil fumarate, lamivudine, and dolutegravir) by clinic staff. We measured the primary outcomes of weight (in kilograms [kg]) and waist circumference (WC, in centimeters [cm]) at enrollment, 24 weeks, and 48 weeks after switch. The primary outcomes were (1) weight change (kg) and (2) change in WC (cm). We used a linear mixed-effect regression model, adjusted for age, sex, education, duration on ART, and the interaction of study site and visit, to estimate weight. Results: 428 individuals in Uganda and 387 in South Africa had data available. The mean weight change over 48 weeks was 0.6 kg [95% CI: 0.1-1.0] in Uganda compared to 2.9 kg [2.4-3.4] in South Africa (p< 0.001); men had significantly smaller mean weight changes than women did in both countries (Figure 1). After adjustment, PWH in South Africa gained significantly more weight than those in Uganda. In participants with available waist data (277 in Uganda and 402 in South Africa), the mean change in WC was significantly greater among those in South Africa (2.3 cm [1.4-3.2]) than those in Uganda (0.8 cm [0.0-1.5]) (p< 0.017). Conclusion: PWH in South Africa experienced greater weight gain than in Uganda, suggesting substantial heterogeneity in this risk across settings. Strategies to address obesity risk in PWH should account for regionality. Disclosures: W D Francois Venter, MD, FCP, PhD, Gilead Sciences: Grant/Research Support|South African Medical Research Council: Grant/Research Support|Unitaid: Grant/Research Support|USAID: Grant/Research Support|ViiV Healthcare: Grant/Research Support Mark J Siedner, MD, MPH, Viiv Healthcare: Grant/Research Suppor

Population Effectiveness of Dolutegravir Implementation in Uganda - A Prospective Observational Cohort Study (DISCO): 48-week Results.

BACKGROUND: Tenofovir/lamivudine/dolutegravir (TLD) is the preferred first-line antiretroviral therapy (ART) regimen for people with HIV (PWH), including those who were previously virologically suppressed on non-nucleoside reverse transcriptase inhibitors (NNRTIs). We sought to estimate the real-world effectiveness of the TLD transition in Ugandan public-sector clinics. METHODS: We conducted a prospective cohort study of PWH ≥18 years who were transitioned from NNRTI-based ART to TLD. Study visits were conducted on the day of TLD transition and 24- and 48- weeks later. The primary endpoint was viral suppression (500 copies/mL. RESULTS: We enrolled 500 participants (median age of 47 years; 41% women). At 48-weeks after TLD transition, 94% of participants were in care with a VL 500 copies/mL. No incident resistance to DTG was identified. Few participants (2%, n = 9/500) discontinued TLD due to adverse events. CONCLUSIONS: High rates of viral suppression, high tolerability, and lack of emergent drug resistance support use of TLD as the preferred first-line regimen in the region