ABSTRACT
Homolog identification is becoming more and more important in modern biology. Traditional biology studies have been focused extensively on model systems, and these studies provide a tremendous resource to investigate other species. The most used model systems include E. coli, budding yeast (Saccharomyces cerevisiae), fission yeast (Schizosaccharomyces pombe), Caenorhabditis elegans, Drosophila melanogaster, zebrafish (Danio Rerio), Arabidopsis thaliana, and mouse (Mus musculus) [7]. Most of the biological knowledge that has been accumulated so far is related to these model organisms. A convenient way to study the functions and structures of a new gene is to identify homologs (evolutionary relationships) in model organisms, from which one can infer structure, function and mechanism of the new gene. Such an approach becomes very powerful nowadays, given the surge in biological sequence data resulting from large-scale sequencing technologies and various genome projects.
