93 research outputs found
Visit to Papermaking Studio; Letterpress Studio; Media Archaeology Collection
Aimee Lee: Papermaking StudioLocation: Hales Gym
Ed Vermue: Letterpress Studio Demo and Open HouseLocation: Mary Church Terrell Main Library
Rian Brown-Orso and Heath Patten: Media Archaeology Collection of Objects and Screening of Rian Brown-Orso\u27s animated shortsLocation: Goodrich Room, Mary Church Terrell Main Librar
Synteny mapping between common bean and soybean reveals extensive blocks of shared loci
<p>Abstract</p> <p>Background</p> <p>Understanding syntentic relationship between two species is critical to assessing the potential for comparative genomic analysis. Common bean (<it>Phaseolus vulgaris </it>L.) and soybean (<it>Glycine max </it>L.), the two most important members of the Phaseoleae legumes, appear to have a diploid and polyploidy recent past, respectively. Determining the syntentic relationship between these two species will allow researchers to leverage not only genomic resources but also genetic data for important agronomic traits to improve both of these species.</p> <p>Results</p> <p>Genetically-positioned transcript loci of common bean were mapped relative to the recent soybean 1.01 pseudochromosome assembly. In nearly every case, each common bean locus mapped to two loci in soybean, a result consistent with the duplicate polyploidy history of soybean. Blocks of synteny averaging 32 cM in common bean and 4.9 Mb in soybean were observed for all 11 common bean linkage groups, and these blocks mapped to all 20 soybean pseudochromosomes. The median physical-to-genetic distance ratio in common bean (based on soybean physical distances) was ~120 kb/cM. ~15,000 common bean sequences (primarily EST contigs and EST singletons) were electronically positioned onto the common bean map using the shared syntentic blocks as references points.</p> <p>Conclusion</p> <p>The collected evidence from this mapping strongly supports the duplicate history of soybean. It further provides evidence that the soybean genome was fractionated and reassembled at some point following the duplication event. These well mapped syntentic relationships between common bean and soybean will enable researchers to target specific genomic regions to discover genes or loci that affect phenotypic expression in both species.</p
Genetic Associations in Four Decades of Multienvironment Trials Reveal Agronomic Trait Evolution in Common Bean
Multienvironment trials (METs) are widely used to assess the performance of promising crop germplasm. Though seldom designed to elucidate genetic mechanisms, MET data sets are often much larger than could be duplicated for genetic research and, given proper interpretation, may offer valuable insights into the genetics of adaptation across time and space. The Cooperative Dry Bean Nursery (CDBN) is a MET for common bean (Phaseolus vulgaris) grown for . 70 years in the United States and Canada, consisting of 20–50 entries each year at 10–20 locations. The CDBN provides a rich source of phenotypic data across entries, years, and locations that is amenable to genetic analysis. To study stable genetic effects segregating in this MET, we conducted genome-wide association studies (GWAS) using best linear unbiased predictions derived across years and locations for 21 CDBN phenotypes and genotypic data (1.2 million SNPs) for 327 CDBN genotypes. The value of this approach was confirmed by the discovery of three candidate genes and genomic regions previously identified in balanced GWAS. Multivariate adaptive shrinkage (mash) analysis, which increased our power to detect significant correlated effects, found significant effects for all phenotypes. Mash found two large genomic regions with effects on multiple phenotypes, supporting a hypothesis of pleiotropic or linked effects that were likely selected on in pursuit of a crop ideotype. Overall, our results demonstrate that statistical genomics approaches can be used on MET phenotypic data to discover significant genetic effects and to define genomic regions associated with crop improvement
Improving the Health Benefits of Snap Bean: Genome-Wide Association Studies of Total Phenolic Content
Snap beans are a significant source of micronutrients in the human diet. Among the micronutrients present in snap beans are phenolic compounds with known beneficial effects on human health, potentially via their metabolism by the gut-associated microbiome. The genetic pathways leading to the production of phenolics in snap bean pods remain uncertain. In this study, we quantified the level of total phenolic content (TPC) in the Bean Coordinated Agriculture Program (CAP) snap bean diversity panel of 149 accessions. The panel was characterized spectrophotometrically for phenolic content with a Folin-Ciocalteu colorimetric assay. Flower, seed and pod color were also quantified, as red, purple, yellow and brown colors are associated with anthocyanins and flavonols in common bean. Genotyping was performed through an Illumina Infinium Genechip BARCBEAN6K_3 single nucleotide polymorphism (SNP) array. Genome-Wide Association Studies (GWAS) analysis identified 11 quantitative trait nucleotides (QTN) associated with TPC. An SNP was identified for TPC on Pv07 located near the P gene, which is a major switch in the flavonoid biosynthetic pathway. Candidate genes were identified for seven of the 11 TPC QTN. Five regulatory genes were identified and represent novel sources of variation for exploitation in developing snap beans with higher phenolic levels for greater health benefits to the consumer
Linked candidate genes of different functions for white mold resistance in common bean (Phaseolus vulgaris L) are identified by multiple QTL mapping approaches
White mold (WM) is a major disease in common bean (Phaseolus vulgaris L.), and its complex quantitative genetic control limits the development of WM resistant cultivars. WM2.2, one of the nine meta-QTL with a major effect on WM tolerance, explains up to 35% of the phenotypic variation and was previously mapped to a large genomic interval on Pv02. Our objective was to narrow the interval of this QTL using combined approach of classic QTL mapping and QTL-based bulk segregant analysis (BSA), and confirming those results with Khufu de novo QTL-seq. The phenotypic and genotypic data from two RIL populations, ‘Raven’/I9365-31 (R31) and ‘AN–37’/PS02–029C–20 (Z0726-9), were used to select resistant and susceptible lines to generate subpopulations for bulk DNA sequencing. The QTL physical interval was determined by considering overlapping interval of the identified QTL or peak region in both populations by three independent QTL mapping analyses. Our findings revealed that meta-QTL WM2.2 consists of three regions, WM2.2a (4.27-5.76 Mb; euchromatic), WM 2.2b (12.19 to 17.61 Mb; heterochromatic), and WM2.2c (23.01-25.74 Mb; heterochromatic) found in both populations. Gene models encoding for gibberellin 2-oxidase 8, pentatricopeptide repeat, and heat-shock proteins are the likely candidate genes associated with WM2.2a resistance. A TIR-NBS-LRR class of disease resistance protein (Phvul.002G09200) and LRR domain containing family proteins are potential candidate genes associated with WM2.2b resistance. Nine gene models encoding disease resistance protein [pathogenesis-related thaumatin superfamily protein and disease resistance-responsive (dirigent-like protein) family protein etc] found within the WM2.2c QTL interval are putative candidate genes. WM2.2a region is most likely associated with avoidance mechanisms while WM2.2b and WM2.2c regions trigger physiological resistance based on putative candidate genes
Towards the Human Colorectal Cancer Microbiome
Multiple factors drive the progression from healthy mucosa towards sporadic
colorectal carcinomas and accumulating evidence associates intestinal bacteria
with disease initiation and progression. Therefore, the aim of this study was to
provide a first high-resolution map of colonic dysbiosis that is associated with
human colorectal cancer (CRC). To this purpose, the microbiomes colonizing colon
tumor tissue and adjacent non-malignant mucosa were compared by deep rRNA
sequencing. The results revealed striking differences in microbial colonization
patterns between these two sites. Although inter-individual colonization in CRC
patients was variable, tumors consistently formed a niche for
Coriobacteria and other proposed probiotic bacterial
species, while potentially pathogenic Enterobacteria were
underrepresented in tumor tissue. As the intestinal microbiota is generally
stable during adult life, these findings suggest that CRC-associated
physiological and metabolic changes recruit tumor-foraging commensal-like
bacteria. These microbes thus have an apparent competitive advantage in the
tumor microenvironment and thereby seem to replace pathogenic bacteria that may
be implicated in CRC etiology. This first glimpse of the CRC microbiome provides
an important step towards full understanding of the dynamic interplay between
intestinal microbial ecology and sporadic CRC, which may provide important leads
towards novel microbiome-related diagnostic tools and therapeutic
interventions
Genome‐Wide Association Study Identifies Candidate Loci Underlying Agronomic Traits in a Middle American Diversity Panel of Common Bean
Genome-Wide Association Analysis Identifies Candidate Genes Associated with Iron Deficiency Chlorosis in Soybean
Ex-post Performance Implications of Divergence of Managers’ Perceptions of ‘Distance’ From ‘Reality’ in International Business
Despite much research on “distance”, little attention has been paid to the effect of divergence of managers’ perceptions of distance from reality (i.e. distance divergence) and its implications for firm performance. This knowledge is highly important since managerial perceptions of the firm’s environment do not always coincide with the actual environmental characteristics. Consequently, strategies based on inaccurate data may result in erroneous forecasts, missed opportunities and business failure. Using survey data from senior managers of Swedish exporters and corresponding objective data, this study is a first attempt to explore the ex-post performance implications of “distance divergence” when expanding into foreign markets. Our results demonstrate that the larger the divergence between managers’ perceptions of cultural distance and corresponding “objective” distance, the lower the performance expressed in companies’ sales. However, over/underestimation of cultural distance does not have differential effects on firm performance.“Stiftelsen Olle Hakelius Stipendiefond”, Grant no: 1165001
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