[BioC] Help using ENSMUSG ids in GOstats

[John Reid]

Hi,

I have some sets of genes I wish to test for enrichment against a 
background set of genes. These genes are identified by Ensembl 
identifiers. I have found it quite straightforward to use the topGO 
package to do this.

I would also like to use the GOstats package and test for enrichment 
against KEGG pathways. It looks as if I need to create an annotation 
package to do this. Is this straightforward? I didn't find out how to do 
it from the documentation. My guess is that someone has been in this 
situation before. I should say the genes come from a computational 
analysis and not from a microarray.

Any help appreciated,
John.