I was trying to map a mouse gene: Arfgap1 to it's human ortholog. Uniprot shows there are two human orthologs of this gene:
The two human genes are: ARFGAP1 and ARFGAP3 (it says ARFGAP3 is a synonym of ARFGAP1)
When I tried to find the human homolog in the Mouse Genome Informatics (MGI) database: http://www.informatics.jax.org/downloads/reports/index.html#homology
I found that mouse gene, Arfgap1 only maps to human gene ARFGAP1. What could be a possible explanation for this? Is it possible for a mouse gene to have multiple human orthologs?
Edit: This is just one example. I have encountered mouse genes that have four human orthologs.