PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-9 (9)
 

Clipboard (0)
None

Select a Filter Below

Journals
Year of Publication
Document Types
author:("Gu, liaocheng")
1.  ABrowse - a customizable next-generation genome browser framework 
BMC Bioinformatics  2012;13:2.
Background
With the rapid growth of genome sequencing projects, genome browser is becoming indispensable, not only as a visualization system but also as an interactive platform to support open data access and collaborative work. Thus a customizable genome browser framework with rich functions and flexible configuration is needed to facilitate various genome research projects.
Results
Based on next-generation web technologies, we have developed a general-purpose genome browser framework ABrowse which provides interactive browsing experience, open data access and collaborative work support. By supporting Google-map-like smooth navigation, ABrowse offers end users highly interactive browsing experience. To facilitate further data analysis, multiple data access approaches are supported for external platforms to retrieve data from ABrowse. To promote collaborative work, an online user-space is provided for end users to create, store and share comments, annotations and landmarks. For data providers, ABrowse is highly customizable and configurable. The framework provides a set of utilities to import annotation data conveniently. To build ABrowse on existing annotation databases, data providers could specify SQL statements according to database schema. And customized pages for detailed information display of annotation entries could be easily plugged in. For developers, new drawing strategies could be integrated into ABrowse for new types of annotation data. In addition, standard web service is provided for data retrieval remotely, providing underlying machine-oriented programming interface for open data access.
Conclusions
ABrowse framework is valuable for end users, data providers and developers by providing rich user functions and flexible customization approaches. The source code is published under GNU Lesser General Public License v3.0 and is accessible at http://www.abrowse.org/. To demonstrate all the features of ABrowse, a live demo for Arabidopsis thaliana genome has been built at http://arabidopsis.cbi.edu.cn/.
doi:10.1186/1471-2105-13-2
PMCID: PMC3265404  PMID: 22222089
2.  Rice-Map: a new-generation rice genome browser 
BMC Genomics  2011;12:165.
Background
The concurrent release of rice genome sequences for two subspecies (Oryza sativa L. ssp. japonica and Oryza sativa L. ssp. indica) facilitates rice studies at the whole genome level. Since the advent of high-throughput analysis, huge amounts of functional genomics data have been delivered rapidly, making an integrated online genome browser indispensable for scientists to visualize and analyze these data. Based on next-generation web technologies and high-throughput experimental data, we have developed Rice-Map, a novel genome browser for researchers to navigate, analyze and annotate rice genome interactively.
Description
More than one hundred annotation tracks (81 for japonica and 82 for indica) have been compiled and loaded into Rice-Map. These pre-computed annotations cover gene models, transcript evidences, expression profiling, epigenetic modifications, inter-species and intra-species homologies, genetic markers and other genomic features. In addition to these pre-computed tracks, registered users can interactively add comments and research notes to Rice-Map as User-Defined Annotation entries. By smoothly scrolling, dragging and zooming, users can browse various genomic features simultaneously at multiple scales. On-the-fly analysis for selected entries could be performed through dedicated bioinformatic analysis platforms such as WebLab and Galaxy. Furthermore, a BioMart-powered data warehouse "Rice Mart" is offered for advanced users to fetch bulk datasets based on complex criteria.
Conclusions
Rice-Map delivers abundant up-to-date japonica and indica annotations, providing a valuable resource for both computational and bench biologists. Rice-Map is publicly accessible at http://www.ricemap.org/, with all data available for free downloading.
doi:10.1186/1471-2164-12-165
PMCID: PMC3072960  PMID: 21450055
3.  PlantTFDB 2.0: update and improvement of the comprehensive plant transcription factor database 
Nucleic Acids Research  2010;39(Database issue):D1114-D1117.
We updated the plant transcription factor (TF) database to version 2.0 (PlantTFDB 2.0, http://planttfdb.cbi.pku.edu.cn) which contains 53 319 putative TFs predicted from 49 species. We made detailed annotation including general information, domain feature, gene ontology, expression pattern and ortholog groups, as well as cross references to various databases and literature citations for these TFs classified into 58 newly defined families with computational approach and manual inspection. Multiple sequence alignments and phylogenetic trees for each family can be shown as Weblogo pictures or downloaded as text files. We have redesigned the user interface in the new version. Users can search TFs with much more flexibility through the improved advanced search page, and the search results can be exported into various formats for further analysis. In addition, we now provide web service for advanced users to access PlantTFDB 2.0 more efficiently.
doi:10.1093/nar/gkq1141
PMCID: PMC3013715  PMID: 21097470
4.  BOAT: Basic Oligonucleotide Alignment Tool 
BMC Genomics  2009;10(Suppl 3):S2.
Background
Next-generation DNA sequencing technologies generate tens of millions of sequencing reads in one run. These technologies are now widely used in biology research such as in genome-wide identification of polymorphisms, transcription factor binding sites, methylation states, and transcript expression profiles. Mapping the sequencing reads to reference genomes efficiently and effectively is one of the most critical analysis tasks. Although several tools have been developed, their performance suffers when both multiple substitutions and insertions/deletions (indels) occur together.
Results
We report a new algorithm, Basic Oligonucleotide Alignment Tool (BOAT) that can accurately and efficiently map sequencing reads back to the reference genome. BOAT can handle several substitutions and indels simultaneously, a useful feature for identifying SNPs and other genomic structural variations in functional genomic studies. For better handling of low-quality reads, BOAT supports a "3'-end Trimming Mode" to build local optimized alignment for sequencing reads, further improving sensitivity. BOAT calculates an E-value for each hit as a quality assessment and provides customizable post-mapping filters for further mapping quality control.
Conclusion
Evaluations on both real and simulation datasets suggest that BOAT is capable of mapping large volumes of short reads to reference sequences with better sensitivity and lower memory requirement than other currently existing algorithms. The source code and pre-compiled binary packages of BOAT are publicly available for download at http://boat.cbi.pku.edu.cn under GNU Public License (GPL). BOAT can be a useful new tool for functional genomics studies.
doi:10.1186/1471-2164-10-S3-S2
PMCID: PMC2788372  PMID: 19958483
5.  Expression pattern divergence of duplicated genes in rice 
BMC Bioinformatics  2009;10(Suppl 6):S8.
Background
Genome-wide duplication is ubiquitous during diversification of the angiosperms, and gene duplication is one of the most important mechanisms for evolutionary novelties. As an indicator of functional evolution, the divergence of expression patterns following duplication events has drawn great attention in recent years. Using large-scale whole-genome microarray data, we systematically analyzed expression divergence patterns of rice genes from block, tandem and dispersed duplications.
Results
We found a significant difference in expression divergence patterns for the three types of duplicated gene pairs. Expression correlation is significantly higher for gene pairs from block and tandem duplications than those from dispersed duplications. Furthermore, a significant correlation was observed between the expression divergence and the synonymous substitution rate which is an approximate proxy of divergence time. Thus, both duplication types and divergence time influence the difference in expression divergence. Using a linear model, we investigated the influence of these two variables and found that the difference in expression divergence between block and dispersed duplicates is attributed largely to their different divergence time. In addition, the difference in expression divergence between tandem and the other two types of duplicates is attributed to both divergence time and duplication type.
Conclusion
Consistent with previous studies on Arabidopsis, our results revealed a significant difference in expression divergence between the types of duplicated genes and a significant correlation between expression divergence and synonymous substitution rate. We found that the attribution of duplication mode to the expression divergence implies a different evolutionary course of duplicated genes.
doi:10.1186/1471-2105-10-S6-S8
PMCID: PMC2697655  PMID: 19534757
6.  WebLab: a data-centric, knowledge-sharing bioinformatic platform 
Nucleic Acids Research  2009;37(Web Server issue):W33-W39.
With the rapid progress of biological research, great demands are proposed for integrative knowledge-sharing systems to efficiently support collaboration of biological researchers from various fields. To fulfill such requirements, we have developed a data-centric knowledge-sharing platform WebLab for biologists to fetch, analyze, manipulate and share data under an intuitive web interface. Dedicated space is provided for users to store their input data and analysis results. Users can upload local data or fetch public data from remote databases, and then perform analysis using more than 260 integrated bioinformatic tools. These tools can be further organized as customized analysis workflows to accomplish complex tasks automatically. In addition to conventional biological data, WebLab also provides rich supports for scientific literatures, such as searching against full text of uploaded literatures and exporting citations into various well-known citation managers such as EndNote and BibTex. To facilitate team work among colleagues, WebLab provides a powerful and flexible sharing mechanism, which allows users to share input data, analysis results, scientific literatures and customized workflows to specified users or groups with sophisticated privilege settings. WebLab is publicly available at http://weblab.cbi.pku.edu.cn, with all source code released as Free Software.
doi:10.1093/nar/gkp428
PMCID: PMC2703900  PMID: 19465388
7.  PlantTFDB: a comprehensive plant transcription factor database 
Nucleic Acids Research  2007;36(Database issue):D966-D969.
Transcription factors (TFs) play key roles in controlling gene expression. Systematic identification and annotation of TFs, followed by construction of TF databases may serve as useful resources for studying the function and evolution of transcription factors. We developed a comprehensive plant transcription factor database PlantTFDB (http://planttfdb.cbi.pku.edu.cn), which contains 26 402 TFs predicted from 22 species, including five model organisms with available whole genome sequence and 17 plants with available EST sequences. To provide comprehensive information for those putative TFs, we made extensive annotation at both family and gene levels. A brief introduction and key references were presented for each family. Functional domain information and cross-references to various well-known public databases were available for each identified TF. In addition, we predicted putative orthologs of those TFs among the 22 species. PlantTFDB has a simple interface to allow users to search the database by IDs or free texts, to make sequence similarity search against TFs of all or individual species, and to download TF sequences for local analysis.
doi:10.1093/nar/gkm841
PMCID: PMC2238823  PMID: 17933783
8.  Serum levels of preS antigen (HBpreSAg) in chronic hepatitis B virus infected patients 
Virology Journal  2007;4:93.
Background
Hepatitis B virus (HBV) infection is a serious health problem worldwide. Treatment recommendation and response are mainly indicated by viral load, e antigen (HBeAg) seroconversion, and ALT levels. The S antigen (HBsAg) seroconversion is much less frequent. Since HBeAg can be negative in the presence of high viral replication, preS antigen (HBpreSAg) might be a useful indicator in management of chronic HBV infection.
Results
A new assay of double antibody sandwich ELISA was established to detect preS antigens. Sera of 104 HBeAg-negative and 50 HBeAg-positive chronic hepatitis B patients have been studied and 23 HBeAg-positive patients were enrolled in a treatment follow-up study. 70% of the HBeAg-positive patients and 47% of the HBeAg-negative patients showed HBpreSAg positive. Particularly, in the HBeAg-negative patients, 30 out of 47 HBpreSAg positive patients showed no evidence of viral replication based on HBV DNA copies. A comparison with HBV DNA copies demonstrated that the overall accuracy of the HBpreSAg test could reach 72% for active HBV replication. HBpreSAg changes were well correlated with changes of HBsAg, HBV DNA and ALT levels during the course of IFN-α treatment and follow-up. HBeAg positive patients responded well to treatment when reduction of HBpreSAg levels was more pronounced.
Conclusion
Our results suggested that HBpreSAg could be detected effectively, and well correlated with HBsAg and HBV DNA copies. The reduction of HBpreSAg levels in conjunction with the HBV DNA copies appears to be an improved predictor of treatment outcome.
doi:10.1186/1743-422X-4-93
PMCID: PMC2082030  PMID: 17892580
9.  Structure of Double-Shelled Rice Dwarf Virus 
Journal of Virology  1998;72(11):8541-8549.
Rice dwarf virus (RDV), a member of the Reoviridae family, is a double-stranded RNA virus. Infection of rice plants with RDV reduces crop production significantly and can pose a major economic threat to Southeast Asia. A 25-Å three-dimensional structure of the 700-Å-diameter RDV capsid has been determined by 400-kV electron cryomicroscopy and computer reconstruction. The structure revealed two distinctive icosahedral shells: a T=13l outer icosahedral shell composed of 260 trimeric clusters of P8 (46 kDa) and an inner T=1 icosahedral shell of 60 dimers of P3 (114 kDa). Sequence and structural comparisons were made between the RDV outer shell trimer and the two crystal conformations (REF and HEX) of the VP7 trimer of bluetongue virus, an animal analog of RDV. The low-resolution structural match of the RDV outer shell trimer to the HEX conformation of VP7 trimer has led to the proposal that P8 consists of an upper domain of β-sandwich motif and a lower domain of α helices. The less well fit REF conformation of VP7 to the RDV trimer may be due to the differences between VP7 and P8 in the sequence of the hinge region that connects the two domains. The additional mass density and the absence of a known signaling peptide on the surface of the RDV outer shell trimer may be responsible for the different interactions between plants and animal reoviruses.
PMCID: PMC110264  PMID: 9765392

Results 1-9 (9)