GO RDF-XML Format
The GO Consortium makes ontology and gene association data available as RDF-XML, which can be downloaded from the GO database archive. The document type definition (DTD) is available from GO CVS web or from the directory go/www/xml-dtd/ in the GO CVS repository.
Sample data
Here's a GO RDF-XML snapshot (with some lines wrapped for legibility):
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE go:go PUBLIC "-//Gene Ontology//Custom XML/RDF Version 2.0//EN" "http://www.geneontology.org/dtd/go.dtd"> <go:go xmlns:go="http://www.geneontology.org/dtd/go.dtd#" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"> <rdf:RDF> <go:term rdf:about="http://www.geneontology.org/go#GO:0000001"> <go:accession>GO:0000001</go:accession> <go:name>mitochondrion inheritance</go:name> <go:synonym>mitochondrial inheritance</go:synonym> <go:definition>The distribution of mitochondria, including the mitochondrial genome, into daughter cells after mitosis or meiosis, mediated by interactions between mitochondria and the cytoskeleton. </go:definition> <go:is_a rdf:resource="http://www.geneontology.org/go#GO:0048308" /> <go:part_of rdf:resource="http://www.geneontology.org/go#GO:0009530" /> <go:negatively_regulates rdf:resource="http://www.geneontology.org/go#GO:0006312" /> </go:term> <go:term rdf:about="http://www.geneontology.org/go#GO:0000002"> <go:accession>GO:0000002</go:accession> <go:name>mitochondrial genome maintenance</go:name> <go:definition>The maintenance of the structure and integrity of the mitochondrial genome; includes replication and segregation of the mitochondrial chromosome.</go:definition> <go:is_a rdf:resource="http://www.geneontology.org/go#GO:0007005" /> <go:dbxref rdf:parseType="Resource"> <go:database_symbol>InterPro</go:database_symbol> <go:reference>IPR009446</go:reference> </go:dbxref> <go:dbxref rdf:parseType="Resource"> <go:database_symbol>Pfam</go:database_symbol> <go:reference>PF06420</go:reference> </go:dbxref> </go:term> <go:term rdf:about="http://www.geneontology.org/go#GO:0000003"> <go:accession>GO:0000003</go:accession> <go:name>reproduction</go:name> <go:synonym>GO:0019952</go:synonym> <go:synonym>GO:0050876</go:synonym> <go:synonym>reproductive physiological process</go:synonym> <go:definition>The production by an organism of new individuals that contain some portion of their genetic material inherited from that organism.</go:definition> <go:is_a rdf:resource="http://www.geneontology.org/go#GO:0008150" /> <go:dbxref rdf:parseType="Resource"> <go:database_symbol>Wikipedia</go:database_symbol> <go:reference>Reproduction</go:reference> </go:dbxref> </go:term>
RDF-XML Format Guide
The basic unit of the GO RDF-XML database is GO:termid
. Owing to limitations of the XML id and idref attributes (for instance, multiple parentage cannot be represented), the linking mechanism is RDF. RDF provides a much more flexible system for representing trees. To follow the links, note that term mitochondrion inheritance ; GO:0000001 has the attribute
<go:term rdf:about="http://www.geneontology.org/go#GO:0000001">
This is roughly equivalent to
<go:term id="go#GO:0000001">
In rdf, URLs are used as IDs to make them universally unique. Now, note that term mitochondrion inheritance ; GO:0000001 has the tag
<go:is_a rdf:resource="http://www.geneontology.org/go#GO:0048308" />
This tag represents the relationship "GO:0000001 isa GO:0048308", i.e. GO:0000001 is a subtype of GO:0048308. Other types of relationship are also possible; in these cases, isa is substituted with the appropriate string; for example:
<go:part_of rdf:resource="http://www.geneontology.org/go#GO:0009530" />
<go:negatively_regulates rdf:resource="http://www.geneontology.org/go#GO:0006312" />
These lines show the relationships GO:0000001 part of GO:0009530 and GO:0000001 negatively regulates GO:0006312 respectively. See the GO relations documentation for the different relations used in GO.
In addition, each term can have one go:name
, go:accession
, go:definition
, or multiple go:dbxref
s or go:association
s. go:name
, go:accession
and go:definition
are self-explanatory. go:dbxref
represents the term in an external database, and go:association
represents the gene associations of each term. go:association
can have both go:evidence
, which holds a go:dbxref
to the evidence supporting the association, and a go:gene_product
, which has the gene symbol and go:dbxref
.
DTD Download
The RDF-XML DTD is available to download.