Molecular evolution of anthocyanin pigmentation genes following losses of flower color

BMC Evolutionary Biology

Research Article

Stacey D. Smith¹  Winnie W. Ho¹ 

[1] Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, USA;

关键词: Molecular decay;    Reversibility;    Trait evolution;    Predictability;    Gene fate;    Evolutionary trajectory;   

DOI  :  10.1186/s12862-016-0675-3

 received in 2016-01-28, accepted in 2016-04-29,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundPhenotypic transitions, such as trait gain or loss, are predicted to carry evolutionary consequences for the genes that control their development. For example, trait losses can result in molecular decay of the pathways underlying the trait. Focusing on the Iochrominae clade (Solanaceae), we examine how repeated losses of floral anthocyanin pigmentation associated with flower color transitions have affected the molecular evolution of three anthocyanin pathway genes (Chi, F3h, and Dfr).ResultsWe recovered intact coding regions for the three genes in all of the lineages that have lost floral pigmentation, suggesting that molecular decay is not associated with these flower color transitions. However, two of the three genes (Chi, F3h) show significantly elevated dN/dS ratios in lineages without floral pigmentation. Maximum likelihood analyses suggest that this increase is due to relaxed constraint on anthocyanin genes in the unpigmented lineages as opposed to positive selection. Despite the increase, the values for dN/dS in both pigmented and unpigmented lineages were consistent overall with purifying selection acting on these loci.ConclusionsThe broad conservation of anthocyanin pathway genes across lineages with and without floral anthocyanins is consistent with the growing consensus that losses of pigmentation are largely achieved by changes in gene expression as opposed to structural mutations. Moreover, this conservation maintains the potential for regain of flower color, and indicates that evolutionary losses of floral pigmentation may be readily reversible.

【 授权许可】

CC BY   
© Ho and Smith. 2016