Assessment of the Clinical Presentations and Ultrasonographic Features of Uterine Fibroids in Adult Africans: A Retrospective Study

Objectives

We sought to determine the clinical presentations and ultrasonographic features of uterine fibroids in adult Ghanaians.

Methods

Between 1 January 2018 and 31 December 2021, 4279 ultrasound-confirmed cases of uterine fibroids were retrieved. The data obtained, which included age, clinical presentations, and sonographic features were analyzed. A chi-squared test was done to assess for possible associations between the clinical indications, age distribution, and ultrasonographic features of uterine fibroids.

Results

The mean age of the patients diagnosed with uterine fibroids was 37.1±11.5 years (range = 16-69 years). Routine checkup (n = 1310, 28.1%), menorrhagia (n = 1104, 23.7%), and lower abdominal mass (n = 801, 17.2%) were the leading clinical indications. Dysmenorrhea, amenorrhea, menorrhagia, and routine checkup were significantly noted in the younger patients (p ≤ 0.001). The majority of the fibroid nodules had smooth regular outline (n = 4125, 96.4%) and were mostly heterogeneous (n = 3282, 76.7%). The echo pattern of the nodules was predominantly hypoechoic (n = 3358, 51.1%) followed by hyperechoic nodules (n = 2554, 38.9%). Degenerative changes accounted for less than one-third of the total fibroid nodules, with the least recorded degenerative change being nodules with cystic areas (n = 55, 5.4%) and the most observed degenerative feature being nodules with rim of calcification and areas of calcified degeneration (n = 965, 94.6%). Almost all the sonographic features were significantly seen in the 30-44 years age category.

Conclusions

Sonographically, uterine fibroids were mostly hypoechoic heterogeneous nodules with a smooth regular outline with a predominant occurrence within women in the fourth to fifth decade of life.

Curved Mirror Arrays for Light Extraction in Top-Emitting Organic Light-Emitting Diodes

The light outcoupling efficiency of a top-emitting organic light-emitting diode (OLED) is only about 20%, and the majority of the light is trapped in the waveguide modes and surface plasmon polariton (SPP) modes. Extracting the trapped modes can reduce the device power consumption and improve the operating lifetime. In this study, we demonstrate a top-emitting OLED structure with a dielectric spacer to suppress the SPP mode and with a patterned back mirror to extract the waveguide modes. We examine and compare several curved mirror arrays and conclude that a micromirror array (μMA) can efficiently extract the waveguide modes while minimizing the absorption loss. The optimized μMA device with a semi-transparent top electrode shows a 36% external quantum efficiency, 2 times higher than the referenced device. This optical design can be easily incorporated into a top-emitting device and has a great potential for displays and lighting applications.

High-density DArT-based SilicoDArT and SNP markers for genetic diversity and population structure studies in cassava (Manihot esculenta Crantz)

Cassava (Manihot esculenta Crantz) is an important industrial and staple crop due to its high starch content, low input requirement, and resilience which makes it an ideal crop for sustainable agricultural systems and marginal lands in the tropics. However, the lack of genomic information on local genetic resources has impeded efficient conservation and improvement of the crop and the exploration of its full agronomic and breeding potential. This work was carried out to obtain information on population structure and extent of genetic variability among some local landraces conserved at the Plant Genetic Resources Research Institute, Ghana and exotic cassava accessions with Diversity Array Technology based SilicoDArT and SNP markers to infer how the relatedness in the genetic materials can be used to enhance germplasm curation and future breeding efforts. A total of 10521 SilicoDArT and 10808 SNP markers were used with varying polymorphic information content (PIC) values. The average PIC was 0.36 and 0.28 for the SilicoDArT and SNPs respectively. Population structure and average linkage hierarchical clustering based on SNPs revealed two distinct subpopulations and a large number of admixtures. Both DArT platforms identified 22 landraces as potential duplicates based on Gower's genetic dissimilarity. The expected heterozygosity which defines the genetic variation within each subpopulation was 0.008 for subpop1 which were mainly landraces and 0.391 for subpop2 indicating the homogeneous and admixture nature of the two subpopulations. Further analysis upon removal of the duplicates increased the expected heterozygosity of subpop1 from 0.008 to 0.357. A mantel test indicated strong interdependence (r = 0.970; P < 0.001) between SilicoDArT and DArTSeq SNP genotypic data suggesting both marker platforms as a robust system for genomic studies in cassava. These findings provide important information for efficient ex-situ conservation of cassava, future heterosis breeding, and marker-assisted selection (MAS) to enhance cassava improvement.

Carbohydrate-dense snacks are a key feature of the nutrition transition among Ghanaian adults - findings from the RODAM study

BACKGROUND

African populations in sub-Saharan Africa and African migrants in Europe are facing a rapid upsurge in obesity. This trend has been related to urbanization, migration and associated shifts in lifestyle, including dietary habits. Whether changes in eating patterns contribute to the rising burden of obesity among African populations is currently unknown.

OBJECTIVE

Our aims in conducting this study were to characterize eating patterns among Ghanaian adults living in their country of origin and in Europe and to explore associations of meal patterns with body mass index (BMI).

DESIGN

Within the cross-sectional RODAM (Research on Obesity and Diabetes among African Migrants) study, data of single 24-h dietary recalls from Ghanaian adults in rural Ghana (n = 20), urban Ghana (n = 42), and Europe (n = 172) were recorded. Eating frequencies, energy intake, and macronutrient composition of eating occasions (EOs, i.e. meals or snacks) were compared between study sites based on descriptive statistics and χ 2-/Kruskal-Wallis tests.

RESULTS

A rising gradient of EO frequencies from rural Ghana through urban Ghana to Europe was observed, mainly reflecting the differences in snacking frequencies (≥1 snack per day: 20 vs. 48 vs. 52%, P = 0.008). Meal frequencies were similar across study sites (≥3 meals per day: 30 vs. 33 vs. 38%, P = 0.80). Meals were rich in carbohydrates (median 54.5, interquartile range (IQR): 43.2-64.0 energy%) and total fats (median: 27.0, IQR: 19.9-34.4 energy %); their protein content was lowest in rural Ghana, followed by urban Ghana and Europe (P = 0.0005). Snacks mainly contained carbohydrates (median: 75.7, IQR: 61.0-89.2 energy%). In linear regression analyses, there was a non-significant trend for an inverse association between snacking frequencies and BMI.

DISCUSSION AND CONCLUSIONS

The observed integration of carbohydrate-dense snacks into the diet supports the growing evidence for a nutrition transition among African populations undergoing socioeconomic development. This analysis constitutes a starting point to further investigate the nutritional implications of increased snacking frequencies on obesity and metabolic health in these African populations.

Feasibility of a Culturally Adapted Dietary Weight-Loss Intervention among Ghanaian Migrants in Berlin, Germany: The ADAPT Study

Background: Dietary weight-loss interventions often fail among migrant populations. We investigated the practicability and acceptability of a culturally adapted dietary weight-loss intervention among Ghanaian migrants in Berlin. Methods: The national guidelines for the treatment of adiposity were adapted to the cultural characteristics of the target population, aiming at weight-loss of ≥2.5 kg in 3 months using food-based dietary recommendations. We invited 93 individuals of Ghanaian descent with overweight or obesity to participate in a 12-weeks intervention. The culturally adapted intervention included a Ghanaian dietician and research team, one session of dietary counselling, three home-based cooking sessions with focus on traditional Ghanaian foods, weekly smart-phone reminders, and monthly monitoring of diet and physical activity. We applied a 7-domains acceptability questionnaire and determined changes in anthropometric measures during clinic-based examinations at baseline and after the intervention. Results: Of the 93 invitees, five participants and four family volunteers completed the study. Reasons for non-participation were changed residence (13%), lack of time to attend examinations (10%), and no interest (9%); 64% did not want to give any reason. The intervention was highly accepted among the participants (mean range: 5.3–6.0 of a 6-points Likert scale). Over the 12 weeks, median weight-loss reached −0.6 kg (range: +0.5, −3.6 kg); the diet was rich in meats but low in convenience foods. The median contribution of fat to daily energy intake was 24% (range: 16–40%). Conclusions: Acceptance of our invitation to the intervention was poor but, once initiated, compliance was good. Assessment centers in the participants’ vicinity and early stakeholder involvement might facilitate improved acceptance of the invitation. A randomized controlled trial is required to determine the actual effects of the intervention.

Recovering cavity effects in corrugated organic light emitting diodes

Cavity effects play an important role in determining the out-coupling efficiency of an OLED. By fabricating OLEDs on corrugated substrates, the waveguide and SPP modes can be extracted by diffraction. However, corrugation does not always lead to an enhancement in out-coupling efficiency due to the reduction of the electrode reflectance and hence the cavity effects. Based on the results of our rigorous couple-wave analysis (RCWA) simulation, we found that the cavity effects can be partially recovered using a low index Teflon layer inserted between the ITO anode and the substrate due to the enhancement of the reflectance of the corrugated electrodes. To verify the simulation results, we fabricated corrugated OLEDs having a low-index Teflon interlayer with an EQE of 36%, which is 29% higher than an optimized planar OLED. By experimentally measuring the OLED air mode dispersion, we confirm the cavity emission of a corrugated OLED is enhanced by the low index layer.

Multi-mode Organic Light-Emitting Diode to Suppress the Viewing Angle Dependence

A typical top-emitting organic light-emitting diode (OLED) has a strong microcavity effect because of the two reflective electrodes. The cavity effect causes a serious color shift with the viewing angles and restricts the organic layer thickness. To overcome these drawbacks, we design a multi-mode OLED structure with dual-dielectric spacer layers, which extend the cavity length by more than 10 times. This design completely eliminates the intrinsic cavity effect caused by the top and bottom boundaries and provides freedom for the organic layer thickness. We demonstrate these effects in a white multi-mode OLED using a white emitter, which shows a negligible angular chromaticity shift of Δuv = 0.006 from 0 to 70° and a Lambertian emission profile. The simple design and the perfect angular color profiles make the multi-mode OLED structure promising in large-area displays and solid-state lighting applications.

Knowledge, information needs and behavior regarding HIV and sexually transmitted infections among migrants from sub-Saharan Africa living in Germany: Results of a participatory health research survey

BACKGROUND

A total of 3,419 new HIV diagnoses were reported in Germany in 2016, with migrants from sub-Saharan Africa (misSA) accounting for 14.1%. To understand the driving factors behind the epidemiological situation, we conducted a quantitative cross-sectional survey on knowledge, attitudes, behavior, and practices regarding HIV and sexually transmitted infections (STIs) among misSA living in six German cities utilizing participatory health research.

METHODS

Participants were recruited by peer researchers. Levels of knowledge, information needs, and preferred methods of information dissemination were analyzed to inform future prevention planning. Additionally, we analyzed sexual behavior and other risk factors for contracting HIV and STIs. The results may facilitate the formulation of targeted prevention messages in the future.

RESULTS

We included 2,432 participants in the analysis. General knowledge about HIV was adequate, as 86.9% were aware of the presented information. Statements about HIV co-infections were prior knowledge for 53.4% of the participants and about German HIV policies and HIV testing for 54.7%. Knowledge about other STIs differed, ranging from 69.6% who have ever heard of gonorrhea to 23.8% who have ever heard of genital warts. Groups with particular knowledge gaps were i) younger misSA, ii) recent migrants, iii) misSA without regular access to the German health care system, iv) misSA of lower socioeconomic status, and v) misSA with Muslim religious affiliation. The majority of participants reported information needs (72.8%), and 71.3% wanted to obtain this information from health professionals. Male misSA were more likely to report five or more sexual partners compared to females. Less than half of participants reported always using condoms with non-steady sexual partners (46.8%). Reasons for not using condoms differed between males and females. A considerable proportion of females (16.3%) and males (6.8%) experienced sexualized violence. More than one fourth of women (26.9%) were affected by female genital mutilation/cutting.

DISCUSSION

Future prevention planning should focus on sub-groups with particular knowledge gaps, recognizing their preferred methods of information dissemination. Prevention messages for male misSA should focus on their own risk perception and for female misSA on empowerment, e.g. to negotiate condom use.

Bambara groundnut: an exemplar underutilised legume for resilience under climate change

Bambara groundnut has the potential to be used to contribute more the climate change ready agriculture. The requirement for nitrogen fixing, stress tolerant legumes is clear, particularly in low input agriculture. However, ensuring that existing negative traits are tackled and demand is stimulated through the development of markets and products still represents a challenge to making greater use of this legume. World agriculture is currently based on very limited numbers of crops, representing a significant risk to food supplies, particularly in the face of climate change which is expected to increase the frequency of extreme events. Minor and underutilised crops can help to develop a more resilient and nutritionally dense future agriculture. Bambara groundnut [Vigna subterranea (L.) Verdc.[, as a drought resistant, nitrogen-fixing, legume has a role to play. However, as with most underutilised crops, there are significant gaps in knowledge and also negative traits such as 'hard-to-cook' and 'photoperiod sensitivity to pod filling' associated with the crop which future breeding programmes and processing methods need to tackle, to allow it to make a significant contribution to the well-being of future generations. The current review assesses these factors and also considers what are the next steps towards realising the potential of this crop.

Smoking prevalence differs by location of residence among Ghanaians in Africa and Europe: The RODAM study

BACKGROUND

Although the prevalence of smoking is low in Ghana, little is known about the effect of migration on smoking. Comparing Ghanaians living in their country of origin to those living in Europe offers an opportunity to investigate smoking by location of residence and the associations between smoking behaviours and migration-related factors.

METHODS

Data on a relatively homogenous group of Ghanaians living in London (n = 949), Amsterdam (n = 1400), Berlin (n = 543), rural Ghana (n = 973) and urban Ghana (n = 1400) from the cross-sectional RODAM (Research on Obesity & Diabetes in African Migrants) study were used. Age-standardized prevalence rates of smoking by location of residence and factors associated with smoking among Ghanaian men were estimated using prevalence ratios (PR: 95% CIs).

RESULTS

Current smoking was non-existent among women in rural and urban Ghana and London but was 3.2% and 3.3% in women in Amsterdam and Berlin, respectively. Smoking prevalence was higher in men in Europe (7.8%) than in both rural and urban Ghana (4.8%): PR 1.91: 95% CI 1.27, 2.88, adjusted for age, marital status, education and employment. Factors associated with a higher prevalence of smoking among Ghanaian men included European residence, being divorced or widowed, living alone, Islam religion, infrequent attendance at religious services, assimilation (cultural orientation), and low education.

CONCLUSION

Ghanaians living in Europe are more likely to smoke than their counterparts in Ghana, suggesting convergence to European populations, although prevalence rates are still far below those in the host populations.

Lipid Profile and High Maternal Body Mass Index is Associated with Preeclampsia: A Case-Control Study of the Cape Coast Metropolis

Background:

Preeclampsia is a leading cause of maternal mortality worldwide and a serious health problem that affects the majority of women.

Aim:

We investigated the association between lipid profile and maternal obesity among preeclamptic women in the Cape Coast Metropolis.

Subject and Methods:

This case–control study involved 60 preeclamptics and 50 healthy pregnant controls matched for age and gestational weeks consecutively recruited from two major hospitals in the Cape Coast Metropolis. Blood samples were collected after overnight fasting and enzymatic spectrophotometric tests used to estimate lipid concentrations. The independent samples t-test, Chi-square, and Pearson's correlation were used in the analysis of data gathered.

Results:

Serum triglyceride (TG) (P = 0.04), very low density lipoprotein (VLDL) (P = 0.02), TC (P = 0.01) and low density lipoprotein (LDL) (P = 0.03) levels were higher in preeclamptic participants than in the controls. High density lipoprotein concentration showed no significant variation between the two groups (P = 0.83). Preeclamptic women were more obese (P = 0.07). High body mass index (OR = 1.501; CI = 0.926-2.106, P = 0.01), high TG level (OR = 5.026; CI = 0.794-31.818, P = 0.01), were associated with preeclampsia.

Conclusion:

Lipid abnormalities, mostly elevated levels of TG, TC, LDL, and VLDL are present in preeclamptics. High TG levels and maternal obesity are associated with preeclampsia among pregnant women in the Cape Coast Metropolis.

A hypomethylated population of Brassica rapa for forward and reverse epi-genetics

BACKGROUND

Epigenetic marks superimposed on the DNA sequence of eukaryote chromosomes provide agility and plasticity in terms of modulating gene expression, ontology, and response to the environment. Modulating the methylation status of cytosine can generate epialleles, which have been detected and characterised at specific loci in several plant systems, and have the potential to generate novel and relatively stable phenotypes. There have been no systematic attempts to explore and utilise epiallelic variation, and so extend the range of phenotypes available for selection in crop improvement. We developed an approach for generating novel epialleles by perturbation of the DNA methylation status. 5- Azacytidine (5-AzaC) provides selective targeting of 5 mCG, which in plants is associated with exonic DNA. Targeted chemical intervention using 5-AzaC has advantages over transgenic or mutant modulation of methyltransferases, allowing stochastic generation of epialleles across the genome.

RESULTS

We demonstrate the potential of stochastic chemically-induced hypomethylation to generate novel and valuable variation for crop improvement. Systematic analysis of dose-response to 5-AzaC in B. rapa guided generation of a selfed stochastically hypomethylated population, used for forward screening of several agronomic traits. Dose-response was sigmoidal for several traits, similar to that observed for chemical mutagens such as EMS. We demonstrated transgenerational inheritance of some phenotypes. BraRoAZ is a unique hypomethylated population of 1000 E2 sib lines. When compared to untreated controls, 5-Aza C-treated lines exhibited reduced immuno-staining of 5mC on pachytene chromosomes, and Methylation Sensitive Amplified Polymorphism (MSAP) profiles that were both divergent and more variable. There was coincident phenotypic variation among these lines for a range of seed yield and composition traits, including increased seed protein content and decreased oil content, as well as decreased erucic acid and corresponding increases in linoleic and/or palmitic acid. Each 5-AzaC-treated line represents a unique combination of hypomethylated epialleles.

CONCLUSIONS

The approach and populations developed are available for forward and reverse screening of epiallelic variation and subsequent functional and inheritance studies. The generation of stochastically hypomethylated populations has utility in epiallele discovery for a wide range of crop plants, and has considerable potential as an intervention strategy for crop improvement.

A hypomethylated population of Brassica rapa for forward and reverse epi-genetics

BACKGROUND

Epigenetic marks superimposed on the DNA sequence of eukaryote chromosomes provide agility and plasticity in terms of modulating gene expression, ontology, and response to the environment. Modulating the methylation status of cytosine can generate epialleles, which have been detected and characterised at specific loci in several plant systems, and have the potential to generate novel and relatively stable phenotypes. There have been no systematic attempts to explore and utilise epiallelic variation, and so extend the range of phenotypes available for selection in crop improvement. We developed an approach for generating novel epialleles by perturbation of the DNA methylation status. 5- Azacytidine (5-AzaC) provides selective targeting of 5 mCG, which in plants is associated with exonic DNA. Targeted chemical intervention using 5-AzaC has advantages over transgenic or mutant modulation of methyltransferases, allowing stochastic generation of epialleles across the genome.

RESULTS

We demonstrate the potential of stochastic chemically-induced hypomethylation to generate novel and valuable variation for crop improvement. Systematic analysis of dose-response to 5-AzaC in B. rapa guided generation of a selfed stochastically hypomethylated population, used for forward screening of several agronomic traits. Dose-response was sigmoidal for several traits, similar to that observed for chemical mutagens such as EMS. We demonstrated transgenerational inheritance of some phenotypes. BraRoAZ is a unique hypomethylated population of 1000 E2 sib lines. When compared to untreated controls, 5-Aza C-treated lines exhibited reduced immuno-staining of 5mC on pachytene chromosomes, and Methylation Sensitive Amplified Polymorphism (MSAP) profiles that were both divergent and more variable. There was coincident phenotypic variation among these lines for a range of seed yield and composition traits, including increased seed protein content and decreased oil content, as well as decreased erucic acid and corresponding increases in linoleic and/or palmitic acid. Each 5-AzaC-treated line represents a unique combination of hypomethylated epialleles.

CONCLUSIONS

The approach and populations developed are available for forward and reverse screening of epiallelic variation and subsequent functional and inheritance studies. The generation of stochastically hypomethylated populations has utility in epiallele discovery for a wide range of crop plants, and has considerable potential as an intervention strategy for crop improvement.

High Resolution Melt (HRM) analysis is an efficient tool to genotype EMS mutants in complex crop genomes

BACKGROUND

Targeted Induced Loci Lesions IN Genomes (TILLING) is increasingly being used to generate and identify mutations in target genes of crop genomes. TILLING populations of several thousand lines have been generated in a number of crop species including Brassica rapa. Genetic analysis of mutants identified by TILLING requires an efficient, high-throughput and cost effective genotyping method to track the mutations through numerous generations. High resolution melt (HRM) analysis has been used in a number of systems to identify single nucleotide polymorphisms (SNPs) and insertion/deletions (IN/DELs) enabling the genotyping of different types of samples. HRM is ideally suited to high-throughput genotyping of multiple TILLING mutants in complex crop genomes. To date it has been used to identify mutants and genotype single mutations. The aim of this study was to determine if HRM can facilitate downstream analysis of multiple mutant lines identified by TILLING in order to characterise allelic series of EMS induced mutations in target genes across a number of generations in complex crop genomes.

RESULTS

We demonstrate that HRM can be used to genotype allelic series of mutations in two genes, BraA.CAX1a and BraA.MET1.a in Brassica rapa. We analysed 12 mutations in BraA.CAX1.a and five in BraA.MET1.a over two generations including a back-cross to the wild-type. Using a commercially available HRM kit and the Lightscanner™ system we were able to detect mutations in heterozygous and homozygous states for both genes.

CONCLUSIONS

Using HRM genotyping on TILLING derived mutants, it is possible to generate an allelic series of mutations within multiple target genes rapidly. Lines suitable for phenotypic analysis can be isolated approximately 8-9 months (3 generations) from receiving M3 seed of Brassica rapa from the RevGenUK TILLING service.

Exploring and exploiting epigenetic variation in crops

This review addresses the mechanisms by which epigenetic variation modulates plant gene regulation and phenotype. In particular we explore the scope for harnessing such processes within the context of crop genetic improvement. We focus on the role of DNA methylation as an epigenetic mark that contributes to epiallelic diversity and modulation of gene regulation. We outline the prevalence and distribution of epigenetic marks in relation to eukaryote developmental processes, and in particular identify where this may be relevant to crop traits both in terms of specific developmental stages and in relation to physiological responses to environmental change. Recent whole genome surveys have identified specific characteristics of the distribution of DNA methylation within plant genomes. Together with greater understanding of the mode of action of different maintenance and de novo methyltransferases, this provides an opportunity to modulate DNA methylation status at specific loci as an intervention strategy in crop genetic improvement. We discuss alternative approaches that may be suitable for harnessing such induced epiallelic variation. Most of the discussion is associated with Brassica crops, which demonstrate considerable morphological plasticity, segmental chromosomal duplication, and polyploidy.

A rich TILLING resource for studying gene function in Brassica rapa

BACKGROUND

The Brassicaceae family includes the model plant Arabidopsis thaliana as well as a number of agronomically important species such as oilseed crops (in particular Brassica napus, B. juncea and B. rapa) and vegetables (eg. B. rapa and B. oleracea). Separated by only 10-20 million years, Brassica species and Arabidopsis thaliana are closely related, and it is expected that knowledge obtained relating to Arabidopsis growth and development can be translated into Brassicas for crop improvement. Moreover, certain aspects of plant development are sufficiently different between Brassica and Arabidopsis to warrant studies to be carried out directly in the crop species. However, mutating individual genes in the amphidiploid Brassicas such as B. napus and B. juncea may, on the other hand, not give rise to expected phenotypes as the genomes of these species can contain up to six orthologues per single-copy Arabidopsis gene. In order to elucidate and possibly exploit the function of redundant genes for oilseed rape crop improvement, it may therefore be more efficient to study the effects in one of the diploid Brassica species such as B. rapa. Moreover, the ongoing sequencing of the B. rapa genome makes this species a highly attractive model for Brassica research and genetic resource development.

RESULTS

Seeds from the diploid Brassica A genome species, B. rapa were treated with ethyl methane sulfonate (EMS) to produce a TILLING (Targeting Induced Local Lesions In Genomes) population for reverse genetics studies. We used the B. rapa genotype, R-o-18, which has a similar developmental ontogeny to an oilseed rape crop. Hence this resource is expected to be well suited for studying traits with relevance to yield and quality of oilseed rape. DNA was isolated from a total of 9,216 M2 plants and pooled to form the basis of the TILLING platform. Analysis of six genes revealed a high level of mutations with a density of about one per 60 kb. This analysis also demonstrated that screening a 1 kb amplicon in just one third of the population (3072 M2 plants) will provide an average of 68 mutations and a 97% probability of obtaining a stop-codon mutation resulting in a truncated protein. We furthermore calculated that each plant contains on average approximately 10,000 mutations and due to the large number of plants, it is predicted that mutations in approximately half of the GC base pairs in the genome exist within this population.

CONCLUSIONS

We have developed the first EMS TILLING resource in the diploid Brassica species, B. rapa. The mutation density in this population is approximately 1 per 60 kb, which makes it the most densely mutated diploid organism for which a TILLING population has been published. This resource is publicly available through the RevGenUK reverse genetics platform http://revgenuk.jic.ac.uk.