Original "phylogenomics" figure from Eisen et al. 1997
Original submitted figure from Eisen, Kaiser, Myers 1997 "Gastrogenomic delights" article in Nature Medicine. See http://www.ncbi.nlm.nih.gov/pubmed/9334711 for article.
Original Figure legend:
Evolution and functional divergence of duplicated genes and the prediction of function of uncharacterized genes by "phylogenomics". Panels A-C are hypothetical scenarios and panel D is a reconstruction of the evolution of the MutS gene family in bacteria using molecular phylogenetic techniques. The thick blue trees represent the evolutionary history of the species, and thin trees represent the history of the genes. In each tree, genes diverge (become less similar to each other) as they evolve along the X axis from the past, on the left, to the present, on the right. In the first column, the gene trees are shown embedded within the species tree. Gene duplication events are labeled with an asterisk. Because orthologs (genes that diverged along with the species) frequently have distinct functions from paralogs (genes that diverged after gene duplication events), different colors and gene subscripts (a or b) are used to distinguish the separate paralogous gene groups. In the second row, the gene trees have been extracted from the species tree and untwisted to show better the relationships among the different gene forms. Molecular phylogenetic techniques can assist in the determination of orthologous groups by recreating the evolutionary history of the genes. In panel D, the phylogenetic tree of MutS proteins was determined by molecular phylogenetic techniques (column 2) and then used to generate the proposed evolutionary scenario for gene duplication and loss (column 1). Of the two mutS paralogous gene families, only one lineage (labeled in green) includes genes with established roles in mismatch repair (underlined). The genes in the second lineage (in red) have no known function. Since the H. pylori gene is a member of this second lineage, it should not be assigned the MutS function. Details of the methods and sequences used to generate the MutS tree are available from the authors on request.
