Molecular evolutionary analysis of the Arabidopsis L7 ribosomal protein gene family

Barakat A, Müller KF, Sáenz de Miera

Research article (journal)


Cytoplasmic ribosomal protein (r-protein) genes in Arabidopsis thaliana are encoded by 80 multigene families that contain between two and seven members. Gene family members are typically similar at the protein sequence level, with the most divergent members of any gene family retaining 94\% identity, on average. However, three Arabidopsis r-protein families -S15a, L7 and P2 - contain highly divergent family members. Here, we investigated the organization, structure, expression and molecular evolution of the L7 r-protein family. Phylogenetic analyses showed that L7 r-protein gene family members constitute two distinct phylogenetic groups. The first group including RPL713, RPL7C and {RPL7D} has hornologs in plants, animals and fungi. The second group represented by {RPL7A} is found in plants but has no orthologs from other fully-sequenced eukaryotic genomes. These two groups may have derived from a duplication event prior to the divergence of animals and plants. All four L7 r-protem genes are expressed and all exhibit a differential expression in inflorescence and flowers. RPL7A and RPL7B are less expressed than the other genes in all tissues analyzed. Molecular characterization of nucleic and protein sequences of L7 r-protein genes and analysis of their codon usage did not indicate any functional divergence. The probable evolution of an extra-ribosomal function of group 2 genes is discussed.

Details zur Publikation

Pages: 8
Release year: 2007
Language in which the publication is writtenEnglish