Molecular evolution analysis of WUSCHEL-related homeobox transcription factor family reveals functional divergence among clades in the homeobox region

• Published in: Development genes and evolution Vol. 226; no. 4; pp. 259 - 268
• Main Authors: Segatto, Ana Lúcia A., Thompson, Claudia E., Freitas, Loreta B.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.07.2016; Springer Nature B.V
• Subjects: Animal Genetics and Genomics; Biomedical and Life Sciences; Cell Biology; Developmental Biology; Evolution, Molecular; Evolutionary Biology; Gene Duplication; Genome, Plant; Homeodomain Proteins - genetics; Life Sciences; Original Article; Phylogeny; Plant Genetics and Genomics; Plants - classification; Plants - genetics; Selaginella; Selection, Genetic; Zoology; Phylogenetic analysis; Whole-genome duplication; Functional divergence; Intron-exon structure; genes; Selection; WOX genes
• ISSN: 0949-944X; 1432-041X
• DOI: 10.1007/s00427-016-0545-4

Gene families have been shown to play important roles in plant evolution and are associated with diversification and speciation. Genes of WUSCHEL - related homeobox family of transcription factors have important functions in plant development and are correlated with the appearance of evolutionary novelties. There are several published studies related to this family, but little is known about the relationships among the main clades in the phylogeny and the molecular evolution of the family. In this study, we obtained a well-resolved Bayesian phylogenetic tree establishing the relationships among the main clades and determining the position of Selaginella moellendorffii WOX genes. Moreover, a correlation was identified between the number of genes in the genomes and the events of whole-genome duplications. The intron-exon structure is more consistent across the modern clade, which appeared more recently in the WOX evolutionary history, and coincides with the development of higher complexity in plant species. No positive selection was detected among sites through the branches in the tree. However, with regard to the main clades, functional divergence among certain amino acids in the homeodomain region was found. Relaxed purifying selection could be the main driving force in the evolution of these genes and in agreement with some genes have been demonstrated to be functionally redundant.