There is a small part of mouse genes that cannot be matched to homologous human genes. For example, the Apoc1 gene:
http://www.informatics.jax.org/marker/MGI:88053
Since there is a gene, APOC1, with exactly the same symbol in human, why is this mouse Apoc1 gene not homologous to human APOC1 gene?
2 answers
Homologene is a database of homologs only. As far as I know it's not building any tree so can't infer orthologs and paralogs properly. A tree built out of multiple alignments would be able to resolve more distant homology than pairwise alignment-based methods. For finding orthologs and/or paralogs, have a look at TreeFam or Ensembl. Human APOC1 is clearly orthologous to mouse Apoc1 in Treefam: http://www.treefam.org/family/TF330940#tabview=tab1
Log in to answer this question.