107 research outputs found
WORKSPACE-BASED ARCHITECTURE SELECTION OF A 3-DEGREE- OF-FREEDOM PLANAR PARALLEL MANIPULATOR
ABSTRACT This paper presents the workspace-based architecture selection process and singularity analysis of a high-speed, high-precision three degree-of-freedom (3-DOF) planar parallel manipulator for wirebonding and electronic-component placement applications. A novel concept of manipulator "effective base area" is utilized for selecting the optimal architecture amongst the possible six well-known configurations. Dexterity regions, based on the manipulator requirements, within the reachable workspace have been identified for the selected architecture. Singular configurations of the optimal 3-PRR architecture have also been examined within the reachable workspace. Simulation results for both workspace and singularity analyses are also presented
Fungal cytochrome P450 database
<p>Abstract</p> <p>Background</p> <p>Cytochrome P450 enzymes play critical roles in fungal biology and ecology. To support studies on the roles and evolution of cytochrome P450 enzymes in fungi based on rapidly accumulating genome sequences from diverse fungal species, an efficient bioinformatics platform specialized for this super family of proteins is highly desirable.</p> <p>Results</p> <p>The Fungal Cytochrome P450 Database (FCPD) archives genes encoding P450s in the genomes of 66 fungal and 4 oomycete species (4,538 in total) and supports analyses of their sequences, chromosomal distribution pattern, and evolutionary histories and relationships. The archived P450s were classified into 16 classes based on InterPro terms and clustered into 141 groups using tribe-MCL. The proportion of P450s in the total proteome and class distribution in individual species exhibited certain taxon-specific characteristics.</p> <p>Conclusion</p> <p>The FCPD will facilitate systematic identification and multifaceted analyses of P450s at multiple taxon levels via the web. All data and functions are available at the web site <url>http://p450.riceblast.snu.ac.kr/</url>.</p
SNUGB: a versatile genome browser supporting comparative and functional fungal genomics
<p>Abstract</p> <p>Background</p> <p>Since the full genome sequences of <it>Saccharomyces cerevisiae</it> were released in 1996, genome sequences of over 90 fungal species have become publicly available. The heterogeneous formats of genome sequences archived in different sequencing centers hampered the integration of the data for efficient and comprehensive comparative analyses. The Comparative Fungal Genomics Platform (CFGP) was developed to archive these data via a single standardized format that can support multifaceted and integrated analyses of the data. To facilitate efficient data visualization and utilization within and across species based on the architecture of CFGP and associated databases, a new genome browser was needed.</p> <p>Results</p> <p>The Seoul National University Genome Browser (SNUGB) integrates various types of genomic information derived from 98 fungal/oomycete (137 datasets) and 34 plant and animal (38 datasets) species, graphically presents germane features and properties of each genome, and supports comparison between genomes. The SNUGB provides three different forms of the data presentation interface, including diagram, table, and text, and six different display options to support visualization and utilization of the stored information. Information for individual species can be quickly accessed via a new tool named the taxonomy browser. In addition, SNUGB offers four useful data annotation/analysis functions, including 'BLAST annotation.' The modular design of SNUGB makes its adoption to support other comparative genomic platforms easy and facilitates continuous expansion.</p> <p>Conclusion</p> <p>The SNUGB serves as a powerful platform supporting comparative and functional genomics within the fungal kingdom and also across other kingdoms. All data and functions are available at the web site <url>http://genomebrowser.snu.ac.kr/</url>.</p
IMGD: an integrated platform supporting comparative genomics and phylogenetics of insect mitochondrial genomes
<p>Abstract</p> <p>Background</p> <p>Sequences and organization of the mitochondrial genome have been used as markers to investigate evolutionary history and relationships in many taxonomic groups. The rapidly increasing mitochondrial genome sequences from diverse insects provide ample opportunities to explore various global evolutionary questions in the superclass Hexapoda. To adequately support such questions, it is imperative to establish an informatics platform that facilitates the retrieval and utilization of available mitochondrial genome sequence data.</p> <p>Results</p> <p>The Insect Mitochondrial Genome Database (IMGD) is a new integrated platform that archives the mitochondrial genome sequences from 25,747 hexapod species, including 112 completely sequenced and 20 nearly completed genomes and 113,985 partially sequenced mitochondrial genomes. The Species-driven User Interface (SUI) of IMGD supports data retrieval and diverse analyses at multi-taxon levels. The Phyloviewer implemented in IMGD provides three methods for drawing phylogenetic trees and displays the resulting trees on the web. The SNP database incorporated to IMGD presents the distribution of SNPs and INDELs in the mitochondrial genomes of multiple isolates within eight species. A newly developed comparative SNU Genome Browser supports the graphical presentation and interactive interface for the identified SNPs/INDELs.</p> <p>Conclusion</p> <p>The IMGD provides a solid foundation for the comparative mitochondrial genomics and phylogenetics of insects. All data and functions described here are available at the web site <url>http://www.imgd.org/</url>.</p
Systematic and searchable classification of cytochrome P450 proteins encoded by fungal and oomycete genomes
Background: Cytochrome P450 proteins (CYPs) play diverse and pivotal roles in fungal metabolism and adaptation to specific ecological niches. Fungal genomes encode extremely variableThis research has been supported by the USDA Agriculture and Food Research Initiative Competitive Grants Program (Grant no. 2010-65110-20488). The work in Lees lab has been supported by the National Research Foundation of Korea (2012–0001149 and 2012–0000141) and the NextGeneration Bio-Green 21 Program of Rural Development Administration in
Korea (PJ00821201).OAIID:oai:osos.snu.ac.kr:snu2012-01/102/0000003441/6SEQ:6PERF_CD:SNU2012-01EVAL_ITEM_CD:102USER_ID:0000003441ADJUST_YN:YEMP_ID:A003535DEPT_CD:5321CITE_RATE:4.073FILENAME:첨부된 내역이 없습니다.DEPT_NM:농생명공학부EMAIL:[email protected]_YN:YCONFIRM:
A comprehensive and high-resolution genome-wide response of p53 to stress
Tumor suppressor p53 regulates transcription of stress-response genes. Many p53 targets remain undiscovered because of uncertainty as to where p53 binds in the genome and the fact that few genes reside near p53-bound recognition elements (REs). Using chromatin immunoprecipitation followed by exonuclease treatment (ChIP-exo), we associated p53 with 2,183 unsplit REs. REs were positionally constrained with other REs and other regulatory elements, which may reflect structurally organized p53 interactions. Surprisingly, stress resulted in increased occupancy of transcription factor IIB (TFIIB) and RNA polymerase (Pol) II near REs, which was reduced when p53 was present. A subset associated with antisense RNA near stress-response genes. The combination of high-confidence locations for p53/REs, TFIIB/Pol II, and their changes in response to stress allowed us to identify 151 high-confidence p53-regulated genes, substantially increasing the number of p53 targets. These genes composed a large portion of a predefined DNA-damage stress-response network. Thus, p53 plays a comprehensive role in regulating the stress-response network, including regulating noncoding transcription
CRISPR/Cas9-induced knockout and knock-in mutations in Chlamydomonas reinhardtii
Genome editing is crucial for genetic engineering of organisms for improved traits, particularly in microalgae due to the urgent necessity for the next generation biofuel production. The most advanced CRISPR/Cas9 system is simple, efficient and accurate in some organisms; however, it has proven extremely difficult in microalgae including the model alga Chlamydomonas. We solved this problem by delivering Cas9 ribonucleoproteins (RNPs) comprising the Cas9 protein and sgRNAs to avoid cytotoxicity and off-targeting associated with vector-driven expression of Cas9. We obtained CRISPR/Cas9-induced mutations at three loci including MAA7, CpSRP43 and ChlM, and targeted mutagenic efficiency was improved up to 100 fold compared to the first report of transgenic Cas9-induced mutagenesis. Interestingly, we found that unrelated vectors used for the selection purpose were predominantly integrated at the Cas9 cut site, indicative of NHEJ-mediated knock-in events. As expected with Cas9 RNPs, no off-targeting was found in one of the mutagenic screens. In conclusion, we improved the knockout efficiency by using Cas9 RNPs, which opens great opportunities not only for biological research but also industrial applications in Chlamydomonas and other microalgae. Findings of the NHEJ-mediated knock-in events will allow applications of the CRISPR/Cas9 system in microalgae, including safe harboring techniques shown in other organisms.
CRISPR/Cas9-induced knockout and knock-in mutations in Chlamydomonas reinhardtii
Genome editing is crucial for genetic engineering of organisms for improved traits, particularly in microalgae due to the urgent necessity for the next generation biofuel production. The most advanced CRISPR/Cas9 system is simple, efficient and accurate in some organisms; however, it has proven extremely difficult in microalgae including the model alga Chlamydomonas. We solved this problem by delivering Cas9 ribonucleoproteins (RNPs) comprising the Cas9 protein and sgRNAs to avoid cytotoxicity and off-targeting associated with vector-driven expression of Cas9. We obtained CRISPR/Cas9-induced mutations at three loci including MAA7, CpSRP43 and ChlM, and targeted mutagenic efficiency was improved up to 100 fold compared to the first report of transgenic Cas9-induced mutagenesis. Interestingly, we found that unrelated vectors used for the selection purpose were predominantly integrated at the Cas9 cut site, indicative of NHEJ-mediated knock-in events. As expected with Cas9 RNPs, no off-targeting was found in one of the mutagenic screens. In conclusion, we improved the knockout efficiency by using Cas9 RNPs, which opens great opportunities not only for biological research but also industrial applications in Chlamydomonas and other microalgae. Findings of the NHEJ-mediated knock-in events will allow applications of the CRISPR/Cas9 system in microalgae, including "safe harboring" techniques shown in other organisms142561sciescopu
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