The family of DOF transcription factors: from green unicellular algae to vascular plants

Abstract

This article deals with the origin and evolu-tion of the DOF transcription factor family through a phylogenetic analysis of those DOF sequences identi-Wed from a variety of representative organisms from diVerent taxonomic groups: the green unicellular alga Chlamydomonas reinhardtii, the moss Physcomitrella patens, the fern Selaginella moellendorYi, the gymno-sperm Pinus taeda, the dicotyledoneous Arabidopsis thaliana and the monocotyledoneous angiosperms Oryza sativa and Hordeum vulgare. In barley, we have identiWed 26 diVerent DOF genes by sequence analy-ses of clones isolated from the screening of genomic libraries and of ESTs, whereas a single DOF gene was identiWed by bioinformatics searches in the Chlamydo-monas genome. The phylogenetic analysis groups all these genes into six major clusters of orthologs origi-nated from a primary basal grade. Our results suggest that duplications of an ancestral DOF, probably formed in the photosynthetic eukaryotic ancestor, fol-lowed by subsequent neo-, sub-functionalization and pseudogenization processes would have triggered the expansion of the DOF family. Loss, acquisition and shuZing of conserved motifs among the new DOFs