A Duplication of gcyc Predates Divergence Within Tribe Coronanthereae (Gesneriaceae): Phylogenetic Analysis and Evolution
Recent investigations in Gesneriaceae have indicated that the cycloidea homolog, gcyc, remains functional at the DNA level and rates of sequence divergence in this gene are not statistically different across all taxa regardless of floral symmetry. A duplication of gcyc has been detected within Coronanthereae, a tribe that has phylogenetic affinities to subfamily Gesnerioideae and includes two genera with radially symmetrical corollas. Duplication of gcyc has been detected in all Coronanthereae except Sarmienta. All paralogs appear functional at the DNA level. Likewise, there is no increased sequence divergence between the two copies, nor between species with radially symmetrical flowers to those with bilateral symmetry. The duplication of gcyc in Coronanthereae is most likely a result of polyploidy since Coronanthereae have the highest chromosome counts of all Gesneriaceae.
Smith, James F.; Funke, Minde M.; and Woo, V. L.. (2006). "A Duplication of gcyc Predates Divergence Within Tribe Coronanthereae (Gesneriaceae): Phylogenetic Analysis and Evolution". Plant Systematics and Evolution, 261(1-4), 245-256.