Resource Consumption of Additive Manufacturing

Abstract Since the 1980's, additive manufacturing (AM) has gradually advanced from rapid prototyping applications towards fabricating endconsumer products. Many small companies may prefer accessing AM technologies through service providers offering production services as result-oriented Industrial Product-Service System (IPSS) rather than investing in their own production line. This study investigated potential benefits of IPSS using system dynamics modeling to study resource demands between two situations: one where an IPSS approach is used and one that is the traditional ownership of production equipment. This study concluded that AM service providers with demand-varying customers could increase service performance and maximize use of production equipment

Genetic and molecular analysis of wheat tan spot resistance effective against Pyrenophora tritici-repentis races 2 and 5

Tan spot, a major foliar disease of wheat (Triticum aestivum L.), is caused by an ascomycete Pyrenophora tritici-repentis. Both culture filtrates and conidiospore inocula induce disease symptoms in susceptible wheat genotypes. The objectives of this study were to determine and map the genetic control of resistance to spore inocula and culture filtrates of P. tritici-repentis races 2 and 5. The F1 and F2 generations and an F2:6 recombinant inbred lines (RIL) population were developed from a cross between the resistant ND 735 and the susceptible Steele-ND. Disease assessments of the segregating generations were done at the seedling stage using culture filtrates and spore inocula under controlled environmental conditions. Genetic and mapping analyses of the F1 and F2 generations and the RIL by both methods indicated that the same single recessive gene, Tsr1, located on chromosome 5BL, controlled resistance and insensitivity to necrosis induced by race 2. A second recessive gene, designated Tsr6, located on chromosome 2BS, conferred resistance/insensitivity to chlorosis induced by spore inocula or culture filtrates of race 5. Diversity Arrays Technology markers wPt-3049 (2.9 cM) and wPt-0289 (4.6 cM) were closely linked to Tsr1 and Tsr6, respectively. The results further indicated that culture filtrates can be used as surrogates for spore inoculation. Tsr1 and Tsr6 can be selected by marker-assisted selection in breeding for resistance to tan spot

Development of a D genome specific marker resource for diploid and hexaploid wheat

Citation: Wang, Y., Drader, T., Tiwari, V. K., Dong, L. L., Kumar, A., Huo, N. X., . . . Gu, Y. Q. (2015). Development of a D genome specific marker resource for diploid and hexaploid wheat. Bmc Genomics, 16, 12. https://doi.org/10.1186/s12864-015-1852-2Background: Mapping and map-based cloning of genes that control agriculturally and economically important traits remain great challenges for plants with complex highly repetitive genomes such as those within the grass tribe, Triticeae. Mapping limitations in the Triticeae are primarily due to low frequencies of polymorphic gene markers and poor genetic recombination in certain genetic regions. Although the abundance of repetitive sequence may pose common problems in genome analysis and sequence assembly of large and complex genomes, they provide repeat junction markers with random and unbiased distribution throughout chromosomes. Hence, development of a high-throughput mapping technology that combine both gene-based and repeat junction-based markers is needed to generate maps that have better coverage of the entire genome. Results: In this study, the available genomics resource of the diploid Aegilop tauschii, the D genome donor of bread wheat, were used to develop genome specific markers that can be applied for mapping in modern hexaploid wheat. A NimbleGen array containing both gene-based and repeat junction probe sequences derived from Ae. tauschii was developed and used to map the Chinese Spring nullisomic-tetrasomic lines and deletion bin lines of the D genome chromosomes. Based on these mapping data, we have now anchored 5,171 repeat junction probes and 10,892 gene probes, corresponding to 5,070 gene markers, to the delineated deletion bins of the D genome. The order of the gene-based markers within the deletion bins of the Chinese Spring can be inferred based on their positions on the Ae. tauschii genetic map. Analysis of the probe sequences against the Chinese Spring chromosome sequence assembly database facilitated mapping of the NimbleGen probes to the sequence contigs and allowed assignment or ordering of these sequence contigs within the deletion bins. The accumulated length of anchored sequence contigs is about 155 Mb, representing similar to 3.2 % of the D genome. A specific database was developed to allow user to search or BLAST against the probe sequence information and to directly download PCR primers for mapping specific genetic loci. Conclusions: In bread wheat, aneuploid stocks have been extensively used to assign markers linked with genes/traits to chromosomes, chromosome arms, and their specific bins. Through this study, we added thousands of markers to the existing wheat chromosome bin map, representing a significant step forward in providing a resource to navigate the wheat genome. The database website (http://probes.pw.usda.gov/ATRJM/) provides easy access and efficient utilization of the data. The resources developed herein can aid map-based cloning of traits of interest and the sequencing of the D genome of hexaploid wheat

Chromosome Bin Map of Expressed Sequence Tags in Homoeologous Group 1 of Hexaploid Wheat and Homoeology With Rice and Arabidopsis

A total of 944 expressed sequence tags (ESTs) generated 2212 EST loci mapped to homoeologous group 1 chromosomes in hexaploid wheat (Triticum aestivum L.). EST deletion maps and the consensus map of group 1 chromosomes were constructed to show EST distribution. EST loci were unevenly distributed among chromosomes 1A, 1B, and 1D with 660, 826, and 726, respectively. The number of EST loci was greater on the long arms than on the short arms for all three chromosomes. The distribution of ESTs along chromosome arms was nonrandom with EST clusters occurring in the distal regions of short arms and middle regions of long arms. Duplications of group 1 ESTs in other homoeologous groups occurred at a rate of 35.5%. Seventy-five percent of wheat chromosome 1 ESTs had significant matches with rice sequences (E ≤ e(−10)), where large regions of conservation occurred between wheat consensus chromosome 1 and rice chromosome 5 and between the proximal portion of the long arm of wheat consensus chromosome 1 and rice chromosome 10. Only 9.5% of group 1 ESTs showed significant matches to Arabidopsis genome sequences. The results presented are useful for gene mapping and evolutionary and comparative genomics of grasses

Genetic analysis and mapping of seedling resistance to Septoria tritici blotch in ‘Steele-ND’/‘ND 735’ bread wheat population

Septoria tritici blotch (STB) caused by Mycosphaerella graminicola, is one of the most destructive foliar diseases of wheat (Triticum aestivum L.) especially in temperate and humid regions across the world. The susceptibility of recently released varieties, evolution of resistance to fungicides and increasing incidence of STB disease emphasizes the need to understand the genetics of resistance to this disease and to incorporate host resistance into adapted cultivars. This study aimed to decipher the genetics and map the resistance to STB using a recombinant inbred line (RIL) mapping population derived from ‘Steele-ND’ (susceptible parent) and ‘ND 735’ (resistant parent). The RILs were evaluated in three greenhouse experiments, using a North Dakota (ND) isolate of STB pathogen. The mean disease severity of parental genotypes, ‘ND 735’ (11.96%) and ‘Steele-ND’ (66.67%) showed significant differences (p < 0.05). The population segregated for STB and the frequency distribution of RILs indicated quantitative inheritance for resistance. The mean disease severity in RILs ranged from 0 to 71.55% with a mean of 21.98%. The genome map of this population was developed using diversity array technology (DArT) and simple sequence repeat (SSR) markers. The framework linkage map of this population was developed using 469 molecular markers. This map spanned a total distance of 1,789.3 cM and consisted of 17 linkage groups. QTL mapping using phenotypic data and the framework linkage maps detected three QTL through composite interval mapping. One QTL was consistently detected in all experiments on the long arm of chromosome 5B, and explained up to 10.2% phenotypic variation. The other two QTLs, detected in single environments, were mapped to 1D and 7A and explain 13% and 5.5% of the phenotypic variation, respectively. The map position of the consistent QTL on 5BL coincides with the map position of durable resistance gene Stb1 suggesting the importance of this region of ‘ND 735’ as a source of durable STB resistance for the wheat germplasm

Listeria monocytogenes triggers noncanonical autophagy upon phagocytosis, but avoids subsequent growth-restricting xenophagy

Xenophagy is a selective macroautophagic process that protects the host cytosol by entrapping and delivering microbes to a degradative compartment. Both noncanonical autophagic pathways and xenophagy are activated by microbes during infection, but the relative importance and function of these distinct processes are not clear. In this study, we used bacterial and host mutants to dissect the contribution of autophagic processes responsible for bacterial growth restriction of Listeria monocytogenesL. monocytogenes is a facultative intracellular pathogen that escapes from phagosomes, grows in the host cytosol, and avoids autophagy by expressing three determinants of pathogenesis: two secreted phospholipases C (PLCs; PlcA and PlcB) and a surface protein (ActA). We found that shortly after phagocytosis, wild-type (WT) L. monocytogenes escaped from a noncanonical autophagic process that targets damaged vacuoles. During this process, the autophagy marker LC3 localized to single-membrane phagosomes independently of the ULK complex, which is required for initiation of macroautophagy. However, growth restriction of bacteria lacking PlcA, PlcB, and ActA required FIP200 and TBK1, both involved in the engulfment of microbes by xenophagy. Time-lapse video microscopy revealed that deposition of LC3 on L. monocytogenes-containing vacuoles via noncanonical autophagy had no apparent role in restricting bacterial growth and that, upon access to the host cytosol, WT L. monocytogenes utilized PLCs and ActA to avoid subsequent xenophagy. In conclusion, although noncanonical autophagy targets phagosomes, xenophagy was required to restrict the growth of L. monocytogenes, an intracellular pathogen that damages the entry vacuole

Development of an Expressed Sequence Tag (EST) Resource for Wheat (\u3ci\u3eTriticum aestivum\u3c/i\u3e L.): EST Generation, Unigene Analysis, Probe Selection and Bioinformatics for a 16,000-Locus Bin-Delineated Map

This report describes the rationale, approaches, organization, and resource development leading to a large-scale deletion bin map of the hexaploid (2n = 6x = 42) wheat genome (Triticum aestivum L.). Accompanying reports in this issue detail results from chromosome bin-mapping of expressed sequence tags (ESTs) representing genes onto the seven homoeologous chromosome groups and a global analysis of the entire mapped wheat EST data set. Among the resources developed were the first extensive public wheat EST collection (113,220 ESTs). Described are protocols for sequencing, sequence processing, EST nomenclature, and the assembly of ESTs into contigs. These contigs plus singletons (unassembled ESTs) were used for selection of distinct sequence motif unigenes. Selected ESTs were rearrayed, validated by 5’ and 3’ sequencing, and amplified for probing a series of wheat aneuploid and deletion stocks. Images and data for all Southern hybridizations were deposited in databases and were used by the coordinators for each of the seven homoeologous chromosome groups to validate the mapping results. Results from this project have established the foundation for future developments in wheat genomics