Kramer, ElenaJaramillo, M. AlejandraDi Stilio, Veronica S.2009-03-042004Kramer, Elena M., M. Alejandra Jaramillo, and Veronica S. Di Stilio. 2004. Patterns of gene duplication and functional evolution during the diversification of the AGAMOUS subfamily of MADS box genes in angiosperms. Genetics 166(2): 1011-1023.0016-6731http://nrs.harvard.edu/urn-3:HUL.InstRepos:2641741Members of the <i>AGAMOUS</i> (<i>AG</i>) subfamily of MIKC-type MADS-box genes appear to control the development of reproductive organs in both gymnosperms and angiosperms. To understand the evolution of this subfamily in the flowering plants, we have identified 26 new <i>AG</i>-like genes from 15 diverse angiosperm species. Phylogenetic analyses of these genes within a large data set of <i>AG</i>-like sequences show that ancient gene duplications were critical in shaping the evolution of the subfamily. Before the radiation of extant angiosperms, one event produced the ovule-specific D lineage and the well-characterized C lineage, whose members typically promote stamen and carpel identity as well as floral meristem determinacy. Subsequent duplications in the C lineage resulted in independent instances of paralog subfunctionalization and maintained functional redundancy. Most notably, the functional homologs <i>AG</i> from Arabidopsis and <i>PLENA</i> (<i>PLE</i>) from Antirrhinum are shown to be representatives of separate paralogous lineages rather than simple genetic orthologs. The multiple subfunctionalization events that have occurred in this subfamily highlight the potential for gene duplication to lead to dissociation among genetic modules, thereby allowing an increase in morphological diversity.en-USJournal Article10.1534/genetics.166.2.1011