MBE Advance Access published online on July 28, 2003
Molecular Biology and Evolution, doi:10.1093/molbev/msg211
Molecular Biology and Evolution © Society for Molecular Biology and Evolution 2003; all rights reserved
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Botany, University of Washington, Seattle, Washington, 98195
* To whom correspondence should be addressed. E-mail: reevesp{at}lamar.colostate.edu.
In the plant subclass Asteridae, bilaterally symmetrical flowers have evolved from a radially symmetrical ancestral phenotype on at least three independent occasions: in the Boraginaceae, Solanaceae, and Lamiales. Development of bilateral flower symmetry has been shown to be determined by the early-acting cycloidea (cyc) and dichotoma (dich) genes in Antirrhinum, a member of the Lamiales. Cyc and dich belong to the TCP gene family of putative transcription factors. TCP gene sequences were isolated from 11 Asteridae taxa using an array of degenerate PCR primers. Closely related species exhibiting either ancestral actinomorphic or derived zygomorphic flowers were sampled for each independent origin of bilateral flower symmetry. Cladistic and network-based analyses were performed to establish viable hypotheses regarding the evolution of bilateral symmetry in Asteridae. For the TCP gene family, the use of cladistic phylogenetic analysis to identify orthologous genes is complicated by a paucity of alignable data, frequent gene duplication and extinction, and the possibility of reticulate evolution via intergenic recombination. These complicating factors can be generalized to many regulatory gene families. As an alternative to cladistic analysis, we propose the use of network analysis for the reconstruction of regulatory gene family phylogenetic and functional relationships. Results of analyses support the hypothesis that the origin of bilaterally symmetrical flowers in the Boraginaceae and Solanaceae did not require orthologs or functional analogs of cyc or dich. This suggests that the genetic mechanism that determines bilateral flower symmetry in these taxa is not homologous to that of the Lamiales. Results of analyses are consistent with the hypothesis that the evolution of bilateral floral symmetry in the Lamiales required the origin of a novel gene function subsequent to gene duplication. Key Words:
Development, evolution, gene family, flower symmetry, cycloidea, phylogenetics, network
© 2003 Society for Molecular Biology and Evolution
Original Articles
Evolution of the TCP Gene Family in Asteridae: Cladistic and Network Approaches to Understanding Regulatory Gene Family Diversification and Its Impact on Morphological Evolution
![]()
Abstract ![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
F. Jabbour, C. Damerval, and S. Nadot Evolutionary Trends in the Flowers of Asteridae: Is Polyandry an Alternative to Zygomorphy? Ann. Bot., August 1, 2008; 102(2): 153 - 165. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. A. Chapman, J. H. Leebens-Mack, and J. M. Burke Positive Selection and Expression Divergence Following Gene Duplication in the Sunflower CYCLOIDEA Gene Family Mol. Biol. Evol., July 1, 2008; 25(7): 1260 - 1273. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Damerval and S. Nadot Evolution of Perianth and Stamen Characteristics with Respect to Floral Symmetry in Ranunculales Ann. Bot., September 1, 2007; 100(3): 631 - 640. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Damerval, M. L. Guilloux, M. Jager, and C. Charon Diversity and Evolution of CYCLOIDEA-Like TCP Genes in Relation to Flower Development in Papaveraceae Plant Physiology, February 1, 2007; 143(2): 759 - 772. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. G. Howarth and M. J. Donoghue Phylogenetic analysis of the "ECE" (CYC/TB1) clade reveals duplications predating the core eudicots PNAS, June 13, 2006; 103(24): 9101 - 9106. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Feng, Z. Zhao, Z. Tian, S. Xu, Y. Luo, Z. Cai, Y. Wang, J. Yang, Z. Wang, L. Weng, et al. From the Cover: Control of petal shape and floral zygomorphy in Lotus japonicus PNAS, March 28, 2006; 103(13): 4970 - 4975. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. A. Kellogg and J. L. Bennetzen The evolution of nuclear genome structure in seed plants Am. J. Botany, October 1, 2004; 91(10): 1709 - 1725. [Abstract] [Full Text] [PDF] |
||||




