Analyses of physicochemical properties revealed drastic differences indicating functional diversification in MYBs. Conserved as well as novel and lineage-specific intron phases were identified. Distinct differences in gene structure between 1R-MYB and 2R-MYBs were observed regarding intron number, the ratio of gene length to coding DNA sequence (CDS) length and the length of exons encoding the MYB domain.

Phylogenetic reconstruction and analysis of selection pressure suggested ancestral nature of R1-type repeat containing 1R-MYBs that might have undergone intragenic duplication to form multi-repeat MYBs. Comparative analysis revealed predominance of 1R-MYBs in protists, fungi, animals and lower plants. We identified and analysed 1129 MYBs that included 1R-, 2R-, 3R- and atypical-MYBs across sixteen species representing protists, fungi, animals and plants and exclude MYB identified from Brassicaceae except Arabidopsis thaliana in addition, a total of 1137 2R-MYB genes from six Brassicaceae species were also analysed. The present study is an attempt to gain insights into the complexities of MYB family diversity, understand impacts of genome evolution on gene families and develop an evolutionary framework to understand the origin of various subcategories of MYB gene family.

Brassicaceae members are endowed with complex genomes, including dysploidy because of its unique history with multiple rounds of polyploidisation, genomic fractionations and rearrangements. In spite of several reports, evolution of MYB genes and repeats remains enigmatic. Myeloblastosis (MYB) family, the largest plant transcription factor family, has been subcategorised based on the number and type of repeats in the MYB domain.

Amadine jahad