Genes encoding actin in higher plants: intron positions are highly conserved but the coding sequences are not.

摘要: We have isolated actin genes from genomic libraries of two highly diverged plants, maize and soybean. The complete nucleotide sequences a gene, MAc1, soybean SAc1, were determined. these previously sequenced gene compared with the wide spectrum evolutionarily eukaryotes. Some striking features pertinent to evolution function plant families emerged. deduced amino acid sequence actins resembles both cytoplasmic- muscle-specific actins. DNA analysis as well blotting experiments using cloned probes show that large heterogeneity exists among members multigene between species. first nine acids at terminal end are far more conserved distant than corresponding in distantly related animal genes, suggesting unique for NH2 higher plants. examined each contain three introns precisely same positions, quite contrary divergent placement observed animal, protozoan, fungal position intron corresponds an found nematode gene. second coincides one rat chicken skeletal genes. These data suggest numerous all ancient origin. degree silent substitution replacement was those yeast It is clear sites saturated compared, whereas only 5-17% their possible positions. By criteria most 6% diverged. 8-10% other approximately 14% any examined. this manuscript may single common ancestral long before divergence monocots dicots.