Molecular Biology and Evolution 19:1752-1759 (2002)
© 2002 Society for Molecular Biology and Evolution
Duplication and Adaptive Evolution of the Chalcone Synthase Genes of Dendranthema (Asteraceae)
*College of Life Sciences, Peking University, Beijing;
College of Life Sciences, Fudan University, Shanghai;
Department of Biology, University College London
Chalcone synthase (CHS) is a key enzyme in the biosynthesis of flavonoids, which are important for the pigmentation of flowers and act as attractants to the pollinators. Genes encoding CHS constitute a multigene family in which the copy number varies among plant species and functional divergence appears to have occurred repeatedly. Plants of the Dendranthema genus have white, yellow, and pink flowers, exhibiting considerable variation in flower color. In this article, 18 CHS genes from six Dendranthema species were sequenced. Two of them were found to be pseudogenes. The functional Dendranthema CHS genes formed three well-supported subfamilies: SF1, SF2, and SF3. The inferred phylogeny of the CHS genes of Dendranthema and Gerbera suggests that those genes originated as a result of duplications before divergence of these two genera, and the function of Dendranthema CHS genes have diverged in a similar fashion to the Gerbera CHS genes; i.e., the genes of SF1 and SF3 code for typical CHS enzymes expressed during different stages of development, whereas the genes of SF2 code for another enzyme that is different from CHS in substrate specificity and reaction. Relative rate tests revealed that the Dendranthema CHS genes significantly deviated from clocklike evolution at nonsynonymous sites. Maximum likelihood analysis showed that the nonsynonymous-synonymous (
= dN/dS) rate ratio for the lineage ancestral to SF2 was much higher than for other lineages, with some sites having a ratio well above one. Positive selective pressure appears to have driven the divergence of SF2 from SF1 and SF3.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  P.-C. Liao, T.-P. Lin, W.-C. Lan, J.-D. Chung, and S.-Y. Hwang Duplication of the class I cytosolic small heat shock protein gene and potential functional divergence revealed by sequence variations flanking the {alpha}-crystallin domain in the genus Rhododendron (Ericaceae) Ann. Bot., November 3, 2009; (2009) mcp272v1. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y.-p. Zhang and S. Ge Molecular evolution study in China: progress and future promise Phil Trans R Soc B, June 29, 2007; 362(1482): 973 - 986. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. C. Opazo, R. E. Palma, F. Melo, and E. P. Lessa Adaptive Evolution of the Insulin Gene in Caviomorph Rodents Mol. Biol. Evol., May 1, 2005; 22(5): 1290 - 1298. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Zhang Frequent False Detection of Positive Selection by the Likelihood Method with Branch-Site Models Mol. Biol. Evol., July 1, 2004; 21(7): 1332 - 1339. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. S. Choi and B. T. Lahn Adaptive Evolution of MRG, a Neuron-Specific Gene Family Implicated in Nociception Genome Res., October 1, 2003; 13(10): 2252 - 2259. [Abstract] [Full Text] [PDF]
|
|