Abstract
Evola is a sub-database of H-InvDB, an integrated database of human transcriptome (http：//h-invitational.jp/), and contains human orthologs for 11 model vertebrates including chimpanzee, mouse, cow, chicken, fugu, etc.. Orthologs are a pair of genes in different species that evolved from a common ancestral gene by speciation. Orthologous relationships are not only one-to-one but also many-to-one, one-to-many and many-to-many between two species. Most of these multi-gene relationships are thought to be results of gene duplication after speciation. How duplications have occurred is one of the most actively pursued issues in current genomics. By investigating original pipelines, we detected 29.8% of human genes have multi-gene orthologous relationships to mouse, and 23.0% to chimpanzee. Gene structure and evolutionary conservation among these duplicate genes will be discussed.