NCBO-Galaxy: bridging the BioPortal web services and the Galaxy platform

Abstract

Ontology Annotator Recommender service service

INTRODUCTION

BioPortal (Noy et al. (2009)) is a web-based application for

searching, sharing, visualizing, and analyzing bio-ontologies. It has become one of the major, centralised bio-ontologies repositories. BioPortal not only hosts a considerable number of important biomedical ontologies (currently almost 300 ontologies covering various life science domains) but also provides access to its contents via RESTful web services, which are a flexible means for programmatically exploiting the stored ontologies. Consequently, its usage should be promoted in bioinformatics environments for facilitating the usage of bio-ontologies.

The lack of integration of bio-ontologies and semantic tools with

traditional bioinformatics suites is a major reason for the limited usage of bio-ontologies by bioinformaticians. Galaxy ( Goecks et al. (2010) ) is a web-based platform offering a one-stop-shop of common bioinformatics tools enabling biological data analyses.

The so-called Galaxy tools are executed within an environment that

keeps an execution history as well as the output of each executed tool, which can be easily shared and reproduced. Even though Galaxy offers a wide range of tools, and recently, some efforts have provided a few tools for ontology manipulation: ONTOtoolkit ( Antezana et al. (2010) ), OPPL-Galaxy ( Aranguren et al. (2012) ), and Blast2GO ( Conesa et al. (2005) ). Each of them offers a complementary functionality, but none of them provides a mechanism to exploit directly a repository of bio-ontologies, such as BioPortal, without having to upload them prior their exploitation.

Therefore, providing Galaxy users with direct access to the

BioPortal ontologies seems an interesting option. In this work,

we describe the development of a set of Galaxy tools, called

NCBO-Galaxy, which provide BioPortal functionalities via its set of RESTful web services (Whetzel et al. (2011)). Such a coupling enables the development of advanced analysis workflows, which eventually could improve data curation and management processes.

NCBO GALAXY

NCBO-Galaxy has the following components (depicted in Figure 1):

The Galaxy platform facilitates developing and sharing new

tool definitions through a common web interface.

The NCBO-Galaxy tools provide Galaxy users with the functionality of the BioPortal services.

The NCBO RESTful services, which belong to NCBO

BioPortal, allow to access BioPortal content.

m r o ltf a P XY OBO

LA tools

A G tlr a ooP Ontology iBManipulation

O services

B C N

Common Web Interface NGS tools

NCBO

Galaxy tools

FastaQ tools

Text

manipulation …. tools

BioPortal RESTful services

Search

services

Each NCBO-Galaxy tool provides the functionalities according to its RESTful service. All the tools have a web interface through which the user can provide the values and preferences for the execution of such service. For example, an excerpt of the interface of the NCBO Galaxy tool for annotating a text with bio-ontology terms is displayed in Figure 2 . The list of tools included in the current version of NCBO Galaxy are:

Get ontology by its identifier,

Extract a branch from an ontology,

Get a concrete view of an ontology,

Annotate a text with bio-ontology terms,

Recommend a bio-ontology depending on annotations of a text,

Search for terms in bio-ontologies depending on the text provided,

Search for resources matched up with terms in bio-ontologies.

All these tools can be combined in Galaxy workflows, as it will be illustrated in the next section.

Min˜ arro Gime´ nez, Egan˜ a Aranguren, Ferna´ ndez-Breis, and Antezana

EXAMPLE

Let us describe how we could retrieve the biological entities that

have been annotated as participating in both positive and negative regulation processes by combining NCBO Galaxy with other

Galaxy tools and, therefore, implemented as a Galaxy workflow.

Galaxy permits the graphical definition of the workflow. Our example workflow is shown in Figure 3.

This workflow consists of two executions of the NCBO

Galaxy tool ”Search for resources matched up with terms in

bio-ontologies”, whose input text will be, respectively, positive regulation and negative regulation. The results are two sets of annotations, and an extract of the results for ”negative regulation” are shown in Table 1.

Then, the cut operations allow us to select the first two columns in order to compare the datasets. The final result would contain the ones that appear in both datasets. Both the data used for this example and the workflow are available, respectively, at http://sele.inf.um.es:9080/u/jesualdo/h/history-demoicbo and http://sele.inf.um.es:9080/u/jesualdo/w/demo-ncbo-galaxy. 4

RESULTS AND FUTURE WORK

NCBO-Galaxy is a prototype aiming at serving ontologists and

bioinformaticians who are interested in exploiting controlled vocabularies as part of their data analysis procedures from within the same framework, namely Galaxy, without the hassle of changing tools or working-environments. Moreover, NCBO-Galaxy provides a unique solution to access a major ontology repository (BioPortal).

Finally, we plan to extend the tools to access other NCBO services (such as BioPortal SPARQL).

5

AVAILABILITY

NCBO-Galaxy is available at the following public instances:

http://sele.inf.um.es/galaxy and http://linkeddata2.dia.fi.upm.es:8080/ and it can be downloaded from the Galaxy Toolshed, available at http://toolshed.g2.bx.psu.edu/repos/mikel-egana-aranguren/ncbo services.

ACKNOWLEDGEMENTS

Mikel Egan˜a Aranguren is funded by the Marie Curie Cofund programme (FP7). This work has been possible thanks to the funding of the Spanish Ministry of Science and Innovation through grant TIN2010-21388-C02-02.

References

Antezana , E. , Venkatesan , A. , Mungall , C. , Mironov , V. , and Kuiper , M. ( 2010 ). ONTO-ToolKit: enabling bio-ontology engineering via galaxy . BMC bioinformatics , (Suppl 12) , S8 +.

Aranguren , M. E. n. , Ferna´ndez- Breis , J. T. , and Antezana , E. ( 2012 ). OPPL-Galaxy: enhancing ontology exploitation in galaxy with OPPL . In Proceedings of the 4th International Workshop on Semantic Web Applications and Tools for the Life Sciences, SWAT4LS '11 , pages 12 - 19 , New York, NY, USA. ACM.

Conesa , A. , Gtz , S. , Garcia-Gomez , J. M. , Terol , J. , Talon , M. , and Robles , M. ( 2005 ). Blast2go: a universal tool for annotation, visualization and analysis in functional genomics research . Bioinformatics, 21 , 3674 - 3676 .

Goecks , J. , Nekrutenko , A. , Taylor , J., and Galaxy Team ( 2010 ). Galaxy: a comprehensive approach for supporting accessible, reproducible, and transparent computational research in the life sciences . Genome biology , 11 ( 8 ), R86 +.

Noy , N. F. , Shah , N. H. , Whetzel , P. L. , Dai , B. , Dorf , M. , Griffith , N. , Jonquet , C. , Rubin , D. L. , Storey , M.- A. , Chute , C. G. , and Musen , M. A. ( 2009 ). Bioportal: ontologies and integrated data resources at the click of a mouse . Nucleic Acids Research , 37 ( suppl 2 ), W170 - W173 .

Whetzel , P. L. , Noy , N. F. , Shah , N. H. , Alexander , P. R. , Nyulas , C. , Tudorache , T. , and Musen , M. A. ( 2011 ). Bioportal: enhanced functionality via new web services from the national center for biomedical ontology to access and use ontologies in software applications . Nucleic Acids Research , 39 ( suppl 2 ), W541 - W545 .