LibSBGN: Electronic Processing of SBGN maps

Introduction

Graphical representations of participants and their relationships are essential for exchanging knowledge about complex biological processes. To convey this information clearly and unambiguously, it is necessary to assign standard meanings to symbols and their connectivity. For this purpose, the System Biology Graphical Notation (SBGN) has been developed.

As SBGN is becoming more widely adopted, and used in various software tools, there is an increasing need for a standard file format able to capture the SBGN maps. Exchange using graphics-only file formats (such as SVG) is insufficient, because the biological meaning of elements is lost. There is a need for a toolset that enables diagram exchange while preserving biological meaning and relations.

Results

To meet this need, we are developing an Extensible Markup Language (XML) schema definition. In addition we are developing a software library called LibSBGN. Besides reading and writing files, this library will also be used to validate SBGN maps against the specifications, and convert to and from related systems biology standards, such as SBML and BioPAX.

LibSBGN is still under development, but is already being adopted by several tools (See the LibSBGN project page for an up-to-date list of client software). The early adoption of LibSBGN by those tools helps to ensure that LibSBGN is independent of a specific software application, and does not contain artifacts for specific tools. LibSBGN is currently implemented in Java, a parallel C++ version is planned for the future.

A test-suite of dozens of LibSBGN documents, covering every possible feature of SBGN maps, was created. This test-suite can be used by developers to check for compliance with the standard, and compare rendering capabilities with other tools.

LibSBGN is a community effort, involving people from institutes all around the world, representing a wide selection of pathway tools. The community is organized around a sourceforge project site (http://libsbgn.sourceforge.net), a mailing list and monthly online meetings.

A first release of LibSBGN, covering only the Process Description (PD) language, is planned in October 2010. Support for all three languages of SBGN is planned for a later release