Jan Aerts

Publications

• 3.43

  Impact points

  Arena3D: visualizing time-driven phenotypic differences in biological systems.

  Maria Secrier, Georgios A Pavlopoulos, Jan Aerts, Reinhard Schneider

  BMC bioinformatics. 03/2012; 13(1):45.

  ABSTRACT: BACKGROUND: Elucidating the genotype-phenotype connection is one of the big challenges of modern molecular biology. To fully understand this connection, it is necessary to consider the underlying networks and the time factor. In this context of data deluge and heterogeneous information, vi... [more] ABSTRACT: BACKGROUND: Elucidating the genotype-phenotype connection is one of the big challenges of modern molecular biology. To fully understand this connection, it is necessary to consider the underlying networks and the time factor. In this context of data deluge and heterogeneous information, visualization plays an essential role in interpreting complex and dynamic topologies. Thus, software that is able to bring the network, phenotypic and temporal information together is needed. Arena3D has been previously introduced as a tool that facilitates link discovery between processes. It uses a layered display to separate different levels of information while emphasizing the connections between them. We present novel developments of the tool for the visualization and analysis of dynamic genotype-phenotype landscapes. RESULTS: Version 2.0 introduces novel features that allow handling time course data in a phenotypic context. Gene expression levels or other measures can be loaded and visualized at different time points and phenotypic comparison is facilitated through clustering and correlation display or highlighting of impacting changes through time. Similarity scoring allows the identification of global patterns in dynamic heterogeneous data. In this paper we demonstrate the utility of the tool on two distinct biological problems of different scales. First, we analyze a medium scale dataset that looks at perturbation effects of the pluripotency regulator Nanog in murine embryonic stem cells. Dynamic cluster analysis suggests alternative indirect links between Nanog and other proteins in the core stem cell network. Moreover, recurrent correlations from the epigenetic to the translational level are identified. Second, we investigate a large scale dataset consisting of genome-wide knockdown screens for human genes essential in the mitotic process. Here, a potential new role for the gene lsm14a in cytokinesis is suggested. We also show how phenotypic patterning allows for extensive comparison and identification of high impact knockdown targets. CONCLUSIONS: We present a new visualization approach for perturbation screens with multiple phenotypic outcomes. The novel functionality implemented in Arena3D enables effective understanding and comparison of temporal patterns within morphological layers, to help with the system-wide analysis of dynamic processes. Arena3D is available free of charge for academics as a downloadable standalone application from: http://arena3d.org/.
• 4.93

  Impact points

  Biogem: an effective tool-based approach for scaling up open source software development in bioinformatics.

  Raoul J P Bonnal, Jan Aerts, George Githinji, Naohisa Goto, Dan Maclean, Chase A Miller, Hiroyuki Mishima, Massimiliano Pagani, Ricardo Ramirez-Gonzalez, Geert Smant, Francesco Strozzi, Rob Syme, Rutger Vos, Trevor J Wennblom, Ben J Woodcroft, Toshiaki Katayama, Pjotr Prins

  Bioinformatics (Oxford, England). 02/2012; 28(7):1035-1037.

  SUMMARY: Biogem provides a software development environment for the Ruby programming language, which encourages community-based software development for bioinformatics while lowering the barrier to entry and encouraging best practices. Biogem, with its targeted modular and decentralized approach, so... [more] SUMMARY: Biogem provides a software development environment for the Ruby programming language, which encourages community-based software development for bioinformatics while lowering the barrier to entry and encouraging best practices. Biogem, with its targeted modular and decentralized approach, software generator, tools and tight web integration, is an improved general model for scaling up collaborative open source software development in bioinformatics. AVAILABILITY: Biogem and modules are free and are OSS. Biogem runs on all systems that support recent versions of Ruby, including Linux, Mac OS X and Windows. Further information at http://www.biogems.info. A tutorial is available at http://www.biogems.info/howto.html CONTACT: bonnal@ingm.org.

• Which clustering algorithm is better for predicting protein complexes?

  Charalampos N Moschopoulos, Georgios A Pavlopoulos, Ernesto Iacucci, Jan Aerts, Spiridon Likothanassis, Reinhard Schneider, Sophia Kossida

  BMC research notes. 12/2011; 4:549.

  ABSTRACT: Protein-Protein interactions (PPI) play a key role in determining the outcome of most cellular processes. The correct identification and characterization of protein interactions and the networks, which they comprise, is critical for understanding the molecular mechanisms within the cell. L... [more] ABSTRACT: Protein-Protein interactions (PPI) play a key role in determining the outcome of most cellular processes. The correct identification and characterization of protein interactions and the networks, which they comprise, is critical for understanding the molecular mechanisms within the cell. Large-scale techniques such as pull down assays and tandem affinity purification are used in order to detect protein interactions in an organism. Today, relatively new high-throughput methods like yeast two hybrid, mass spectrometry, microarrays, and phage display are also used to reveal protein interaction networks. In this paper we evaluated four different clustering algorithms using six different interaction datasets. We parameterized the MCL, Spectral, RNSC and Affinity Propagation algorithms and applied them to six PPI datasets produced experimentally by Yeast 2 Hybrid (Y2H) and Tandem Affinity Purification (TAP) methods. The predicted clusters, so called protein complexes, were then compared and benchmarked with already known complexes stored in published databases. While results may differ upon parameterization, the MCL and RNSC algorithms seem to be more promising and more accurate at predicting PPI complexes. Moreover, they predict more complexes than other reviewed algorithms in absolute numbers. On the other hand the spectral clustering algorithm achieves the highest valid prediction rate in our experiments. However, it is nearly always outperformed by both RNSC and MCL in terms of the geometrical accuracy while it generates the fewest valid clusters than any other reviewed algorithm. This article demonstrates various metrics to evaluate the accuracy of such predictions as they are presented in the text below. Supplementary material can be found at: http://www.bioacademy.gr/bioinformatics/projects/ppireview.htm.

• The 2nd DBCLS BioHackathon: interoperable bioinformatics Web services for integrated applications.

  Toshiaki Katayama, Mark D Wilkinson, Rutger Vos, Takeshi Kawashima, Shuichi Kawashima, Mitsuteru Nakao, Yasunori Yamamoto, Hong-Woo Chun, Atsuko Yamaguchi, Shin Kawano, [......], Martin Senger, Jessica Severin, Yasumasa Shigemoto, Hideaki Sugawara, James Taylor, Oswaldo Trelles, Chisato Yamasaki, Riu Yamashita, Noriyuki Satoh, Toshihisa Takagi

  Journal of biomedical semantics. 08/2011; 2:4.

  ABSTRACT: The interaction between biological researchers and the bioinformatics tools they use is still hampered by incomplete interoperability between such tools. To ensure interoperability initiatives are effectively deployed, end-user applications need to be aware of, and support, best practices ... [more] ABSTRACT: The interaction between biological researchers and the bioinformatics tools they use is still hampered by incomplete interoperability between such tools. To ensure interoperability initiatives are effectively deployed, end-user applications need to be aware of, and support, best practices and standards. Here, we report on an initiative in which software developers and genome biologists came together to explore and raise awareness of these issues: BioHackathon 2009. Developers in attendance came from diverse backgrounds, with experts in Web services, workflow tools, text mining and visualization. Genome biologists provided expertise and exemplar data from the domains of sequence and pathway analysis and glyco-informatics. One goal of the meeting was to evaluate the ability to address real world use cases in these domains using the tools that the developers represented. This resulted in i) a workflow to annotate 100,000 sequences from an invertebrate species; ii) an integrated system for analysis of the transcription factor binding sites (TFBSs) enriched based on differential gene expression data obtained from a microarray experiment; iii) a workflow to enumerate putative physical protein interactions among enzymes in a metabolic pathway using protein structure data; iv) a workflow to analyze glyco-gene-related diseases by searching for human homologs of glyco-genes in other species, such as fruit flies, and retrieving their phenotype-annotated SNPs. Beyond deriving prototype solutions for each use-case, a second major purpose of the BioHackathon was to highlight areas of insufficiency. We discuss the issues raised by our exploration of the problem/solution space, concluding that there are still problems with the way Web services are modeled and annotated, including: i) the absence of several useful data or analysis functions in the Web service "space"; ii) the lack of documentation of methods; iii) lack of compliance with the SOAP/WSDL specification among and between various programming-language libraries; and iv) incompatibility between various bioinformatics data formats. Although it was still difficult to solve real world problems posed to the developers by the biological researchers in attendance because of these problems, we note the promise of addressing these issues within a semantic framework.
• 4.93

  Impact points

  A Ruby API to query the Ensembl database for genomic features.

  Francesco Strozzi, Jan Aerts

  Bioinformatics (Oxford, England). 01/2011; 27(7):1013-4.

  The Ensembl database makes genomic features available via its Genome Browser. It is also possible to access the underlying data through a Perl API for advanced querying. We have developed a full-featured Ruby API to the Ensembl databases, providing the same functionality as the Perl interface with a... [more] The Ensembl database makes genomic features available via its Genome Browser. It is also possible to access the underlying data through a Perl API for advanced querying. We have developed a full-featured Ruby API to the Ensembl databases, providing the same functionality as the Perl interface with additional features. A single Ruby API is used to access different releases of the Ensembl databases and is also able to query multi-species databases. Availability and Implementation: Most functionality of the API is provided using the ActiveRecord pattern. The library depends on introspection to make it release independent. The API is available through the Rubygem system and can be installed with the command gem install ruby-ensembl-api.

• Using graph theory to analyze biological networks.

  Georgios A Pavlopoulos, Maria Secrier, Charalampos N Moschopoulos, Theodoros G Soldatos, Sophia Kossida, Jan Aerts, Reinhard Schneider, Pantelis G Bagos

  BioData mining. 01/2011; 4:10.

  Understanding complex systems often requires a bottom-up analysis towards a systems biology approach. The need to investigate a system, not only as individual components but as a whole, emerges. This can be done by examining the elementary constituents individually and then how these are connected. ... [more] Understanding complex systems often requires a bottom-up analysis towards a systems biology approach. The need to investigate a system, not only as individual components but as a whole, emerges. This can be done by examining the elementary constituents individually and then how these are connected. The myriad components of a system and their interactions are best characterized as networks and they are mainly represented as graphs where thousands of nodes are connected with thousands of vertices. In this article we demonstrate approaches, models and methods from the graph theory universe and we discuss ways in which they can be used to reveal hidden properties and features of a network. This network profiling combined with knowledge extraction will help us to better understand the biological significance of the system.
• 34.28

  Impact points

  CEP152 is a genome maintenance protein disrupted in Seckel syndrome.

  Ersan Kalay, Gökhan Yigit, Yakup Aslan, Karen E Brown, Esther Pohl, Louise S Bicknell, Hülya Kayserili, Yun Li, Beyhan Tüysüz, Gudrun Nürnberg, [......], Karen Milstein, Helene Dollfus, Dagmar Wieczorek, Han G Brunner, Matthew Hurles, Andrew P Jackson, Anita Rauch, Peter Nürnberg, Ahmet Karagüzel, Bernd Wollnik

  Nature genetics. 01/2011; 43(1):23-6.

  Functional impairment of DNA damage response pathways leads to increased genomic instability. Here we describe the centrosomal protein CEP152 as a new regulator of genomic integrity and cellular response to DNA damage. Using homozygosity mapping and exome sequencing, we identified CEP152 mutations i... [more] Functional impairment of DNA damage response pathways leads to increased genomic instability. Here we describe the centrosomal protein CEP152 as a new regulator of genomic integrity and cellular response to DNA damage. Using homozygosity mapping and exome sequencing, we identified CEP152 mutations in Seckel syndrome and showed that impaired CEP152 function leads to accumulation of genomic defects resulting from replicative stress through enhanced activation of ATM signaling and increased H2AX phosphorylation.

• Medusa: A tool for exploring and clustering biological networks.

  Georgios A Pavlopoulos, Sean D Hooper, Alejandro Sifrim, Reinhard Schneider, Jan Aerts

  BMC research notes. 01/2011; 4(1):384.

  ABSTRACT: Biological processes such as metabolic pathways, gene regulation or protein-protein interactions are often represented as graphs in systems biology. The understanding of such networks, their analysis, and their visualization are today important challenges in life sciences. While a great va... [more] ABSTRACT: Biological processes such as metabolic pathways, gene regulation or protein-protein interactions are often represented as graphs in systems biology. The understanding of such networks, their analysis, and their visualization are today important challenges in life sciences. While a great variety of visualization tools that try to address most of these challenges already exists, only few of them succeed to bridge the gap between visualization and network analysis. Medusa is a powerful tool for visualization and clustering analysis of large-scale biological networks. It is highly interactive and it supports weighted and unweighted multi-edged directed and undirected graphs. It combines a variety of layouts and clustering methods for comprehensive views and advanced data analysis. Its main purpose is to integrate visualization and analysis of heterogeneous data from different sources into a single network. Medusa provides a concise visual tool, which is helpful for network analysis and interpretation. Medusa is offered both as a standalone application and as an applet written in Java. It can be found at: https://sites.google.com/site/medusa3visualization.
• 4.93

  Impact points

  BioRuby: bioinformatics software for the Ruby programming language.

  Naohisa Goto, Pjotr Prins, Mitsuteru Nakao, Raoul Bonnal, Jan Aerts, Toshiaki Katayama

  Bioinformatics (Oxford, England). 10/2010; 26(20):2617-9.

  The BioRuby software toolkit contains a comprehensive set of free development tools and libraries for bioinformatics and molecular biology, written in the Ruby programming language. BioRuby has components for sequence analysis, pathway analysis, protein modelling and phylogenetic analysis; it suppor... [more] The BioRuby software toolkit contains a comprehensive set of free development tools and libraries for bioinformatics and molecular biology, written in the Ruby programming language. BioRuby has components for sequence analysis, pathway analysis, protein modelling and phylogenetic analysis; it supports many widely used data formats and provides easy access to databases, external programs and public web services, including BLAST, KEGG, GenBank, MEDLINE and GO. BioRuby comes with a tutorial, documentation and an interactive environment, which can be used in the shell, and in the web browser. BioRuby is free and open source software, made available under the Ruby license. BioRuby runs on all platforms that support Ruby, including Linux, Mac OS X and Windows. And, with JRuby, BioRuby runs on the Java Virtual Machine. The source code is available from http://www.bioruby.org/. katayama@bioruby.org

• Meeting Report from the Second "Minimum Information for Biological and Biomedical Investigations" (MIBBI) workshop.

  Carsten Kettner, Dawn Field, Susanna-Assunta Sansone, Chris Taylor, Jan Aerts, Nigel Binns, Andrew Blake, Cedrik M Britten, Ario de Marco, Jennifer Fostel, [......], Sandra Orchard, Helen Parkinson, William Piel, Shoba Ranganathan, Philippe Rocca-Serra, Annapaola Santarsiero, David Shotton, Peter Sterk, Andreas Untergasser, Patricia L Whetzel

  Standards in genomic sciences. 01/2010; 3(3):259-66.

  This report summarizes the proceedings of the second workshop of the 'Minimum Information for Biological and Biomedical Investigations' (MIBBI) consortium held on Dec 1-2, 2010 in Rüdesheim, Germany through the sponsorship of the Beilstein-Institute. MIBBI is an umbrella organization uniting... [more] This report summarizes the proceedings of the second workshop of the 'Minimum Information for Biological and Biomedical Investigations' (MIBBI) consortium held on Dec 1-2, 2010 in Rüdesheim, Germany through the sponsorship of the Beilstein-Institute. MIBBI is an umbrella organization uniting communities developing Minimum Information (MI) checklists to standardize the description of data sets, the workflows by which they were generated and the scientific context for the work. This workshop brought together representatives of more than twenty communities to present the status of their MI checklists and plans for future development. Shared challenges and solutions were identified and the role of MIBBI in MI checklist development was discussed. The meeting featured some thirty presentations, wide-ranging discussions and breakout groups. The top outcomes of the two-day workshop as defined by the participants were: 1) the chance to share best practices and to identify areas of synergy; 2) defining a series of tasks for updating the MIBBI Portal; 3) reemphasizing the need to maintain independent MI checklists for various communities while leveraging common terms and workflow elements contained in multiple checklists; and 4) revision of the concept of the MIBBI Foundry to focus on the creation of a core set of MIBBI modules intended for reuse by individual MI checklist projects while maintaining the integrity of each MI project. Further information about MIBBI and its range of activities can be found at http://mibbi.org/.

• The DBCLS BioHackathon: standardization and interoperability for bioinformatics web services and workflows. The DBCLS BioHackathon Consortium*.

  Toshiaki Katayama, Kazuharu Arakawa, Mitsuteru Nakao, Keiichiro Ono, Kiyoko F Aoki-Kinoshita, Yasunori Yamamoto, Atsuko Yamaguchi, Shuichi Kawashima, Hong-Woo Chun, Jan Aerts, [......], Daron M Standley, Hideaki Sugawara, Toshiyuki Tashiro, Oswaldo Trelles, Rutger A Vos, Mark D Wilkinson, William York, Christian M Zmasek, Kiyoshi Asai, Toshihisa Takagi

  Journal of biomedical semantics. 01/2010; 1(1):8.

  Web services have become a key technology for bioinformatics, since life science databases are globally decentralized and the exponential increase in the amount of available data demands for efficient systems without the need to transfer entire databases for every step of an analysis. However, vario... [more] Web services have become a key technology for bioinformatics, since life science databases are globally decentralized and the exponential increase in the amount of available data demands for efficient systems without the need to transfer entire databases for every step of an analysis. However, various incompatibilities among database resources and analysis services make it difficult to connect and integrate these into interoperable workflows. To resolve this situation, we invited domain specialists from web service providers, client software developers, Open Bio* projects, the BioMoby project and researchers of emerging areas where a standard exchange data format is not well established, for an intensive collaboration entitled the BioHackathon 2008. The meeting was hosted by the Database Center for Life Science (DBCLS) and Computational Biology Research Center (CBRC) and was held in Tokyo from February 11th to 15th, 2008. In this report we highlight the work accomplished and the common issues arisen from this event, including the standardization of data exchange formats and services in the emerging fields of glycoinformatics, biological interaction networks, text mining, and phyloinformatics. In addition, common shared object development based on BioSQL, as well as technical challenges in large data management, asynchronous services, and security are discussed. Consequently, we improved interoperability of web services in several fields, however, further cooperation among major database centers and continued collaborative efforts between service providers and software developers are still necessary for an effective advance in bioinformatics web service technologies.
• 34.48

  Impact points

  Origins and functional impact of copy number variation in the human genome.

  Donald F Conrad, Dalila Pinto, Richard Redon, Lars Feuk, Omer Gokcumen, Yujun Zhang, Jan Aerts, T Daniel Andrews, Chris Barnes, Peter Campbell, [......], Sam Robson, Kathy Stirrups, Armand Valsesia, Klaudia Walter, John Wei, Chris Tyler-Smith, Nigel P Carter, Charles Lee, Stephen W Scherer, Matthew E Hurles

  Nature. 10/2009;

  Structural variations of DNA greater than 1 kilobase in size account for most bases that vary among human genomes, but are still relatively under-ascertained. Here we use tiling oligonucleotide microarrays, comprising 42 million probes, to generate a comprehensive map of 11,700 copy number variation... [more] Structural variations of DNA greater than 1 kilobase in size account for most bases that vary among human genomes, but are still relatively under-ascertained. Here we use tiling oligonucleotide microarrays, comprising 42 million probes, to generate a comprehensive map of 11,700 copy number variations (CNVs) greater than 443 base pairs, of which most (8,599) have been validated independently. For 4,978 of these CNVs, we generated reference genotypes from 450 individuals of European, African or East Asian ancestry. The predominant mutational mechanisms differ among CNV size classes. Retrotransposition has duplicated and inserted some coding and non-coding DNA segments randomly around the genome. Furthermore, by correlation with known trait-associated single nucleotide polymorphisms (SNPs), we identified 30 loci with CNVs that are candidates for influencing disease susceptibility. Despite this, having assessed the completeness of our map and the patterns of linkage disequilibrium between CNVs and SNPs, we conclude that, for complex traits, the heritability void left by genome-wide association studies will not be accounted for by common CNVs.
• 3.76

  Impact points

  Genomic analysis reveals extensive gene duplication within the bovine TRB locus.

  Timothy Connelley, Jan Aerts, Andy Law, W Ivan Morrison

  BMC genomics. 05/2009; 10(1):192.

  ABSTRACT: BACKGROUND: Diverse TCR and Ig repertoires are generated by V(D)J somatic recombination. Genomic studies have been pivotal in cataloguing the V, D, J and C gene segments present in the various TCR/Ig loci and describing how duplication events have expanded the number of these gene segments... [more] ABSTRACT: BACKGROUND: Diverse TCR and Ig repertoires are generated by V(D)J somatic recombination. Genomic studies have been pivotal in cataloguing the V, D, J and C gene segments present in the various TCR/Ig loci and describing how duplication events have expanded the number of these gene segments. Such studies have also provided insights into the evolution of these loci and the complex mechanisms that regulate TCR/Ig expression. In this study we analyze the sequence of the third bovine genome assembly to characterize the germline repertoire of bovine TCRbeta genes and compare the organization, evolution and regulatory structure of the bovine TRB locus with that of humans and mice. RESULTS: The TRB locus in the third bovine genome assembly is distributed over 5 scaffolds, extending to ~730Kb. The available sequence contains a total of 134 Vbeta genes, assigned to 24 Vbeta subgroups, and 3 clusters of DJC genes, each comprising a single Dbeta gene, 5-7 Jbeta genes and a single Cbeta gene. Seventy-nine of the Vbeta genes are predicted to be functional. Comparison with the human and murine TRB loci shows that the gene order, as well as the sequences of non-coding elements that regulate TCRbeta expression, are highly conserved in the bovine. Dot-plot analyses demonstrated that expansion of the genomic Vbeta repertoire has occurred via a complex and extensive series of duplications, predominantly involving DNA blocks containing multiple genes. These duplication events have resulted in massive expansion of several Vbeta subgroups, most notably Vbeta6, 9 and 21 which contain 40, 35 and 16 members respectively. Similarly, duplication has lead to the generation of a third DJC cluster. Analyses of cDNA data confirms the diversity of the Vbeta genes and, in addition, identifies a substantial number of Vbeta genes, predominantly from the larger subgroups, which are still absent from the genome assembly. The observed gene duplication within the bovine TCRbeta locus has created a repertoire of phylogenetically diverse functional Vbeta genes, which is substantially larger than that described for humans and mice. CONCLUSION: The analyses completed in this study reveal that, although the gene content and organization of the bovine TRB locus are broadly similar to that of humans and mice, multiple duplication events have led to a marked expansion in the number of Vbeta genes. Similar expansions in other ruminant TCR loci suggest strong evolutionary pressures in this lineage have selected for the development of enlarged sets of TCR gene segments that can contribute to diverse TCR repertoires.
• 29.75

  Impact points

  Genome-Wide Survey of SNP Variation Uncovers the Genetic Structure of Cattle Breeds.

  Richard A Gibbs, Jeremy F Taylor, Curtis P Van Tassell, William Barendse, Kellye A Eversole, Clare A Gill, Ronnie D Green, Debora L Hamernik, Steven M Kappes, Sigbjørn Lien, [......], Riccardo Negrini, Mike E Goddard, Ben J Hayes, Daniel G Bradley, Marcos Barbosa da Silva, Lilian P L Lau, George E Liu, David J Lynn, Francesca Panzitta, Ken G Dodds

  Science (New York, N.Y.). 05/2009; 324(5926):528-532.

  The imprints of domestication and breed development on the genomes of livestock likely differ from those of companion animals. A deep draft sequence assembly of shotgun reads from a single Hereford female and comparative sequences sampled from six additional breeds were used to develop probes to int... [more] The imprints of domestication and breed development on the genomes of livestock likely differ from those of companion animals. A deep draft sequence assembly of shotgun reads from a single Hereford female and comparative sequences sampled from six additional breeds were used to develop probes to interrogate 37,470 single-nucleotide polymorphisms (SNPs) in 497 cattle from 19 geographically and biologically diverse breeds. These data show that cattle have undergone a rapid recent decrease in effective population size from a very large ancestral population, possibly due to bottlenecks associated with domestication, selection, and breed formation. Domestication and artificial selection appear to have left detectable signatures of selection within the cattle genome, yet the current levels of diversity within breeds are at least as great as exists within humans.
• 29.75

  Impact points

  The Genome Sequence of Taurine Cattle: A Window to Ruminant Biology and Evolution.

  Christine G Elsik, Ross L Tellam, Kim C Worley, Richard A Gibbs, Donna M Muzny, George M Weinstock, David L Adelson, Evan E Eichler, Laura Elnitski, Roderic Guigó, [......], Ashley J Waardenberg, Zhiquan Wang, Robert Ward, Rosemarie Weikard, Thomas H Welsh, Stephen N White, Laurens G Wilming, Kris R Wunderlich, Jianqi Yang, Feng-Qi Zhao

  Science (New York, N.Y.). 05/2009; 324(5926):522-528.

  To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (ma... [more] To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (marsupial or monotreme) genomes. Cattle-specific evolutionary breakpoint regions in chromosomes have a higher density of segmental duplications, enrichment of repetitive elements, and species-specific variations in genes associated with lactation and immune responsiveness. Genes involved in metabolism are generally highly conserved, although five metabolic genes are deleted or extensively diverged from their human orthologs. The cattle genome sequence thus provides a resource for understanding mammalian evolution and accelerating livestock genetic improvement for milk and meat production.
• 3.43

  Impact points

  An introduction to scripting in Ruby for biologists.

  Jan Aerts, Andy Law

  BMC bioinformatics. 02/2009; 10:221.

  The Ruby programming language has a lot to offer to any scientist with electronic data to process. Not only is the initial learning curve very shallow, but its reflection and meta-programming capabilities allow for the rapid creation of relatively complex applications while still keeping the code sh... [more] The Ruby programming language has a lot to offer to any scientist with electronic data to process. Not only is the initial learning curve very shallow, but its reflection and meta-programming capabilities allow for the rapid creation of relatively complex applications while still keeping the code short and readable. This paper provides a gentle introduction to this scripting language for researchers without formal informatics training such as many wet-lab scientists. We hope this will provide such researchers an idea of how powerful a tool Ruby can be for their data management tasks and encourage them to learn more about it.

• Structural Variation in Great Ape Genomes

  Jan A. Aerts, Chris Tyler-Smith

  01/2009;
• 29.50

  Impact points

  Promoting coherent minimum reporting guidelines for biological and biomedical investigations: the MIBBI project.

  Chris F Taylor, Dawn Field, Susanna-Assunta Sansone, Jan Aerts, Rolf Apweiler, Michael Ashburner, Catherine A Ball, Pierre-Alain Binz, Molly Bogue, Tim Booth, [......], Richard H Scheuermann, Daniel Schober, Barry Smith, Jason Snape, Christian J Stoeckert, Keith Tipton, Peter Sterk, Andreas Untergasser, Jo Vandesompele, Stefan Wiemann

  Nature biotechnology. 09/2008; 26(8):889-96.
• 2.23

  Impact points

  An assessment of population structure in eight breeds of cattle using a whole genome SNP panel.

  Stephanie D McKay, Robert D Schnabel, Brenda M Murdoch, Lakshmi K Matukumalli, Jan Aerts, Wouter Coppieters, Denny Crews, Emmanuel Dias-Neto, Clare A Gill, Chuan Gao, Hideyuki Mannen, Zhiquan Wang, Curt P Van Tassell, John L Williams, Jeremy F Taylor, Stephen S Moore

  BMC genetics. 02/2008; 9:37.

  BACKGROUND: Analyses of population structure and breed diversity have provided insight into the origin and evolution of cattle. Previously, these studies have used a low density of microsatellite markers, however, with the large number of single nucleotide polymorphism markers that are now available... [more] BACKGROUND: Analyses of population structure and breed diversity have provided insight into the origin and evolution of cattle. Previously, these studies have used a low density of microsatellite markers, however, with the large number of single nucleotide polymorphism markers that are now available, it is possible to perform genome wide population genetic analyses in cattle. In this study, we used a high-density panel of SNP markers to examine population structure and diversity among eight cattle breeds sampled from Bos indicus and Bos taurus. RESULTS: Two thousand six hundred and forty one single nucleotide polymorphisms (SNPs) spanning all of the bovine autosomal genome were genotyped in Angus, Brahman, Charolais, Dutch Black and White Dairy, Holstein, Japanese Black, Limousin and Nelore cattle. Population structure was examined using the linkage model in the program STRUCTURE and Fst estimates were used to construct a neighbor-joining tree to represent the phylogenetic relationship among these breeds. CONCLUSION: The whole-genome SNP panel identified several levels of population substructure in the set of examined cattle breeds. The greatest level of genetic differentiation was detected between the Bos taurus and Bos indicus breeds. When the Bos indicus breeds were excluded from the analysis, genetic differences among beef versus dairy and European versus Asian breeds were detected among the Bos taurus breeds. Exploration of the number of SNP loci required to differentiate between breeds showed that for 100 SNP loci, individuals could only be correctly clustered into breeds 50% of the time, thus a large number of SNP markers are required to replace the 30 microsatellite markers that are currently commonly used in genetic diversity studies.
• 2.29

  Impact points

  Construction of bovine whole-genome radiation hybrid and linkage maps using high-throughput genotyping.

  S D McKay, R D Schnabel, B M Murdoch, J. Aerts, C A Gill, C Gao, C Li, L K Matukumalli, P Stothard, Z Wang, C P Van Tassell, J L Williams, J F Taylor, S S Moore

  Animal genetics. 05/2007; 38(2):120-5.

  High-density whole-genome maps are essential for ordering genes or markers and aid in the assembly of genome sequence. To increase the density of markers on the bovine radiation hybrid map, and hence contribute to the assembly of the bovine genome sequence, an Illumina BeadStation was used to simult... [more] High-density whole-genome maps are essential for ordering genes or markers and aid in the assembly of genome sequence. To increase the density of markers on the bovine radiation hybrid map, and hence contribute to the assembly of the bovine genome sequence, an Illumina BeadStation was used to simultaneously type large numbers of markers on the Roslin-Cambridge 3000 rad bovine-hamster whole-genome radiation hybrid panel (WGRH3000). In five multiplex reactions, 6738 sequence tagged site (STS) markers were successfully typed on the WGRH3000 panel DNA. These STSs harboured SNPs that were developed as a result of the bovine genome sequencing initiative. Typically, the most time consuming and expensive part of creating high-density radiation hybrid (RH) maps is genotyping the markers on the RH panel with conventional approaches. Using the method described in this article, we have developed a high-density whole-genome RH map with 4690 loci and a linkage map with 2701 loci, with direct comparison to the bovine whole-genome sequence assembly (Btau_2.0) in a fraction of the time it would have taken with conventional typing and genotyping methods.