Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
Is Full-Text AvailableIs Full-Text Available
-
YearFrom:-To:
-
More FiltersMore FiltersSubjectPublisherSourceLanguagePlace of PublicationContributors
Done
Filters
Reset
316
result(s) for
"Barker, Gary"
Sort by:
High‐density SNP genotyping array for hexaploid wheat and its secondary and tertiary gene pool
by
Benbow, Harriet R
,
Allen, Alexandra M
,
Winfield, Mark O
in
agronomic traits
,
Agronomy
,
Arrays
2016
In wheat, a lack of genetic diversity between breeding lines has been recognized as a significant block to future yield increases. Species belonging to bread wheat's secondary and tertiary gene pools harbour a much greater level of genetic variability, and are an important source of genes to broaden its genetic base. Introgression of novel genes from progenitors and related species has been widely employed to improve the agronomic characteristics of hexaploid wheat, but this approach has been hampered by a lack of markers that can be used to track introduced chromosome segments. Here, we describe the identification of a large number of single nucleotide polymorphisms that can be used to genotype hexaploid wheat and to identify and track introgressions from a variety of sources. We have validated these markers using an ultra‐high‐density Axiom® genotyping array to characterize a range of diploid, tetraploid and hexaploid wheat accessions and wheat relatives. To facilitate the use of these, both the markers and the associated sequence and genotype information have been made available through an interactive web site.
Journal Article
Analysis of the bread wheat genome using whole-genome shotgun sequencing
by
McKenzie, Neil
,
Kay, Suzanne
,
D’Amore, Rosalinda
in
631/208/514/1948
,
631/449/2491
,
Agronomy. Soil science and plant productions
2012
Bread wheat (
Triticum aestivum
) is a globally important crop, accounting for 20 per cent of the calories consumed by humans. Major efforts are underway worldwide to increase wheat production by extending genetic diversity and analysing key traits, and genomic resources can accelerate progress. But so far the very large size and polyploid complexity of the bread wheat genome have been substantial barriers to genome analysis. Here we report the sequencing of its large, 17-gigabase-pair, hexaploid genome using 454 pyrosequencing, and comparison of this with the sequences of diploid ancestral and progenitor genomes. We identified between 94,000 and 96,000 genes, and assigned two-thirds to the three component genomes (A, B and D) of hexaploid wheat. High-resolution synteny maps identified many small disruptions to conserved gene order. We show that the hexaploid genome is highly dynamic, with significant loss of gene family members on polyploidization and domestication, and an abundance of gene fragments. Several classes of genes involved in energy harvesting, metabolism and growth are among expanded gene families that could be associated with crop productivity. Our analyses, coupled with the identification of extensive genetic variation, provide a resource for accelerating gene discovery and improving this major crop.
Sequencing of the hexaploid bread wheat genome shows that it is highly dynamic, with significant loss of gene family members on polyploidization and domestication, and an abundance of gene fragments.
The bread — and barley — of life
Two groups in this issue report the compilation and analysis of the genome sequences of major cereal crops — bread wheat and barley — providing important resources for future crop improvement. Bread wheat accounts for one-fifth of the calories consumed by humankind. It has a very large and complex hexaploid genome of 17 Gigabases. Michael Bevan and colleagues have analysed the genome using 454 pyrosequencing and compared it with diploid ancestral and progenitor genomes. The authors discovered significant loss of gene family members upon polyploidization and domestication, and expansion of gene classes that may be associated with crop productivity.
Barley is one of the earliest domesticated plant crops. Although diploid, it has a very large genome of 5.1 Gigabases. Nils Stein and colleagues describe a physical map anchored to a high-resolution genetic map, on top of which they have overlaid a deep whole-genome shotgun assembly, cDNA and RNA-seq data to provide the first in-depth genome-wide survey of the barley genome.
Journal Article
Characterization of a Wheat Breeders’ Array suitable for high‐throughput SNP genotyping of global accessions of hexaploid bread wheat (Triticum aestivum)
2017
Summary Targeted selection and inbreeding have resulted in a lack of genetic diversity in elite hexaploid bread wheat accessions. Reduced diversity can be a limiting factor in the breeding of high yielding varieties and crucially can mean reduced resilience in the face of changing climate and resource pressures. Recent technological advances have enabled the development of molecular markers for use in the assessment and utilization of genetic diversity in hexaploid wheat. Starting with a large collection of 819 571 previously characterized wheat markers, here we describe the identification of 35 143 single nucleotide polymorphism‐based markers, which are highly suited to the genotyping of elite hexaploid wheat accessions. To assess their suitability, the markers have been validated using a commercial high‐density Affymetrix Axiom® genotyping array (the Wheat Breeders’ Array), in a high‐throughput 384 microplate configuration, to characterize a diverse global collection of wheat accessions including landraces and elite lines derived from commercial breeding communities. We demonstrate that the Wheat Breeders’ Array is also suitable for generating high‐density genetic maps of previously uncharacterized populations and for characterizing novel genetic diversity produced by mutagenesis. To facilitate the use of the array by the wheat community, the markers, the associated sequence and the genotype information have been made available through the interactive web site ‘CerealsDB’.
Journal Article
Dying to be Men
2005
One of the first comparative reflections of its kind, this book examines the challenges that young men face when trying to grow up in societies where violence is the norm. Barker, who has worked directly with low-income youth and witnessed first hand the violence he describes, provides a compelling account of the young men's struggles. He discusses the problems these men face in other areas of their lives, including the difficulty of staying in school, the multiple challenges of coming of age as men in the face of social exclusion, including finding meaningful employment, and their interactions with young women, including sexual behaviour and the implications of this for HIV/AIDS prevention.
The book presents examples of evaluated programs that have been able to aid young men in rethinking what it means to be a man and ultimately focuses on 'voices of resistance' – young men who find ways to stay out of violence and to show respect and equality in their relationships, even in settings where male violence and rigid attitudes about manhood are prevalent.
1. Why the Worry about Young Men? 2. Are You a Hippy or a Kicker?: A Personal Story and a Way of Understanding Manhood 3. Don’t Worry, I’m not a Thief: The Story of Joao 4. The Trouble with Young Men: Coming of Age in Social Exclusion 5. In the Headlines: Interpersonal Violence and Gang Involvement 6. No Place at School: Low-Income Young Men and Educational Attainment 7. If You Don’t Work, You Have to Steal: Low Income Young Men and Employment 8. In the Heat of the Moment: Relating to Women, Having Sex 9. Learning to Live with Women, Becoming Fathers 10. Dying to be Men, Living as Men: Conclusions and Final Reflections
Gary Barker is Chief Executive of Instituto Promundo - an NGO based in Rio de Janeiro, Brazil, working in gender equality, violence prevention, HIV/AIDS and youth development. He has coordinated research and program development on the socialization of young men in Latin America, the Caribbean, Africa, Asia and North America, in collaboration with international and national organisations. This book is based on nearly 10 years of field work with young men in Brazil, the Caribbean, and the USA and parts of Sub-Sahara Africa, including the author's direct work with young men in these settings in collaboration with governments and NGOs.
CerealsDB 2.0: an integrated resource for plant breeders and scientists
by
Allen, Alexandra M
,
Coghill, Jane A
,
Barker, Gary LA
in
Algorithms
,
Bioinformatics
,
Biomedical and Life Sciences
2012
Background
Food security is an issue that has come under renewed scrutiny amidst concerns that substantial yield increases in cereal crops are required to feed the world’s booming population. Wheat is of fundamental importance in this regard being one of the three most important crops for both human consumption and livestock feed; however, increase in crop yields have not kept pace with the demands of a growing world population. In order to address this issue, plant breeders require new molecular tools to help them identify genes for important agronomic traits that can be introduced into elite varieties. Studies of the genome using next-generation sequencing enable the identification of molecular markers such as single nucleotide polymorphisms that may be used by breeders to identify and follow genes when breeding new varieties. The development and application of next-generation sequencing technologies has made the characterisation of SNP markers in wheat relatively cheap and straightforward. There is a growing need for the widespread dissemination of this information to plant breeders.
Description
CerealsDB is an online resource containing a range of genomic datasets for wheat (
Triticum aestivum)
that will assist plant breeders and scientists to select the most appropriate markers for marker assisted selection. CerealsDB includes a database which currently contains in excess of 100,000 putative varietal SNPs, of which several thousand have been experimentally validated. In addition, CerealsDB contains databases for DArT markers and EST sequences, and links to a draft genome sequence for the wheat variety Chinese Spring.
Conclusion
CerealsDB is an open access website that is rapidly becoming an invaluable resource within the wheat research and plant breeding communities.
Journal Article
Segregation distortion: Utilizing simulated genotyping data to evaluate statistical methods
by
Burridge, Amanda J.
,
Edwards, Keith J.
,
Barker, Gary L. A.
in
Analysis
,
Biology and Life Sciences
,
Chi-square test
2020
Segregation distortion is the phenomenon in which genotypes deviate from expected Mendelian ratios in the progeny of a cross between two varieties or species. There is not currently a widely used consensus for the appropriate statistical test, or more specifically the multiple testing correction procedure, used to detect segregation distortion for high-density single-nucleotide polymorphism (SNP) data. Here we examine the efficacy of various multiple testing procedures, including chi-square test with no correction for multiple testing, false-discovery rate correction and Bonferroni correction using an in-silico simulation of a biparental mapping population. We find that the false discovery rate correction best approximates the traditional p-value threshold of 0.05 for high-density marker data. We also utilize this simulation to test the effect of segregation distortion on the genetic mapping process, specifically on the formation of linkage groups during marker clustering. Only extreme segregation distortion was found to effect genetic mapping. In addition, we utilize replicate empirical mapping populations of wheat varieties Avalon and Cadenza to assess how often segregation distortion conforms to the same pattern between closely related wheat varieties.
Journal Article
High‐density genotyping of the A.E. Watkins Collection of hexaploid landraces identifies a large molecular diversity compared to elite bread wheat
by
Burridge, Amanda J.
,
Allen, Alexandra M.
,
Wingen, Luzie U.
in
alleles
,
Biological diversity
,
Bread
2018
Summary The importance of wheat as a food crop makes it a major target for agricultural improvements. As one of the most widely grown cereal grains, together with maize and rice, wheat is the leading provider of calories in the global diet, constituting 29% of global cereal production in 2015. In the last few decades, however, yields have plateaued, suggesting that the green revolution, at least for wheat, might have run its course and that new sources of genetic variation are urgently required. The overall aim of our work was to identify novel variation that may then be used to enable the breeding process. As landraces are a potential source of such diversity, here we have characterized the A.E. Watkins Collection alongside a collection of elite accessions using two complementary high‐density and high‐throughput genotyping platforms. While our results show the importance of using the appropriate SNP collection to compare diverse accessions, they also show that the Watkins Collection contains a substantial amount of novel genetic diversity which has either not been captured in current breeding programmes or which has been lost through previous selection pressures. As a consequence of our analysis, we have identified a number of accessions which carry an array of novel alleles along with a number of interesting chromosome rearrangements which confirm the variable nature of the wheat genome.
Journal Article
Gender-transformative Bandebereho couples’ intervention to promote male engagement in reproductive and maternal health and violence prevention in Rwanda: Findings from a randomized controlled trial
2018
Rigorous evidence of the effectiveness of male engagement interventions, particularly on how these interventions impact relationship power dynamics and women's decision-making, remains limited. This study assessed the impact of the Bandebereho gender-transformative couples' intervention on impact on multiple behavioral and health-related outcomes influenced by gender norms and power relations.
We conducted a multi-site randomised controlled trial in four Rwandan districts with expectant/current fathers and their partners, who were randomised to the intervention (n = 575 couples) or control group (n = 624 couples). Primary outcomes include women's experience of physical and sexual IPV, women's attendance and men's accompaniment at ANC, modern contraceptive use, and partner support during pregnancy. At 21-months post-baseline, 1123 men and 1162 partners were included in intention to treat analysis. Generalized estimating equations with robust standard errors were used to fit the models.
The Bandebereho intervention led to substantial improvements in multiple reported outcomes. Compared to the control group, women in the intervention group reported: less past-year physical (OR 0.37, p<0.001) and sexual IPV (OR 0.34, p<0.001); and greater attendance (IRR 1.09, p<0.001) and male accompaniment at antenatal care (IRR 1.50, p<0.001); and women and men in the intervention group reported: less child physical punishment (women: OR 0.56, p = 0.001; men: OR 0.66, p = 0.005); greater modern contraceptive use (women: OR 1.53, p = 0.004; men: OR 1.65, p = 0.001); higher levels of men's participation in childcare and household tasks (women: beta 0.39, p<0.001; men: beta 0.33, p<0.001); and less dominance of men in decision-making.
Our study strengthens the existing evidence on male engagement approaches; together with earlier studies our findings suggest that culturally adapted gender-transformative interventions with men and couples can be effective at changing deeply entrenched gender inequalities and a range of health-related behavioral outcomes.
ClinicalTrials.gov NCT02694627.
Journal Article
Risk Factors for Men’s Lifetime Perpetration of Physical Violence against Intimate Partners: Results from the International Men and Gender Equality Survey (IMAGES) in Eight Countries
by
Barker, Gary
,
McCleary-Sills, Jennifer
,
Fleming, Paul J.
in
Abused women
,
Acceptability
,
Acquired immune deficiency syndrome
2015
This paper examines men's lifetime physical intimate partner violence (IPV) perpetration across eight low- and middle-income countries to better understand key risk factors that interventions can target in order to promote gender equality and reduce IPV. We use data from men (n = 7806) that were collected as part of the International Men and Gender Equality Survey (IMAGES) in Bosnia and Herzegovina, Brazil, Chile, Croatia, Democratic Republic of Congo (DRC), India, Mexico, and Rwanda. Results show that there is wide variation across countries for lifetime self-reported physical violence perpetration (range: 17% in Mexico to 45% in DRC), men's support for equal roles for men and women, and acceptability of violence against women. Across the sample, 31% of men report having perpetrated physical violence against a partner in their lifetime. In multivariate analyses examining risk factors for men ever perpetrating physical violence against a partner, witnessing parental violence was the strongest risk factor, reinforcing previous research suggesting the inter-generational transmission of violence. Additionally, having been involved in fights not specifically with an intimate partner, permissive attitudes towards violence against women, having inequitable gender attitudes, and older age were associated with a higher likelihood of ever perpetrating physical IPV. In separate analyses for each country, we found different patterns of risk factors in countries with high perpetration compared to countries with low perpetration. Findings are interpreted to identify key knowledge gaps and directions for future research, public policies, evaluation, and programming.
Journal Article