Evolutionary variations in DNA sequences transferred from chloroplast genomes to mitochondrial genomes in the Gramineae.
The transfer of fragments of DNA from chloroplast genomes to mitochondrial genomes is considered to be a general phenomenon in higher plants. In the present study, Southern hybridization, together with amplification by PCR and DNA sequencing techniques, was used to examine the regions homologous to chloroplast rps19 in the mitochondrial genomes of several gramineous plants. In all the mitochondrial DNAs from the gramineous plants examined, except for that from wheat, the transferred fragments of chloroplast DNA were found to be maintained and the same junctions of mitochondrion-specific and chloroplast-like sequences were found at one terminus. This finding indicates that the transfer of the chloroplast sequence occurred in the distant past during the evolution of gramineous plants. Subsequent analysis revealed that the fragments had been variously rearranged among species with respect to the other terminus. Considering the current diversity of this one particular transferred fragment of chloroplast DNA, we propose that chloroplast-derived DNA sequences that have lost their original functions tend to be rearranged during evolution in mitochondrial genomes.
Watanabe
N
N
Laboratory of Radiation Genetics, Faculty of Agriculture, University of Tokyo, Japan.
Nakazono
M
M
Kanno
A
A
Tsutsumi
N
N
Hirai
A
A
D001483:Base Sequence; D005075:Biological Evolution; D002736:Chloroplasts / Q000378:metabolism*; D017931:DNA Primers; D004272:DNA, Mitochondrial / Q000235:genetics / Q000378:metabolism; D018744:DNA, Plant / Q000235:genetics / Q000378:metabolism*; D014644:Genetic Variation; D015698:Genomic Library; D008928:Mitochondria / Q000378:metabolism*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D012275:Oryza / Q000235:genetics; D010944:Plants / Q000235:genetics* / Q000378:metabolism; D006109:Poaceae / Q000235:genetics; D016133:Polymerase Chain Reaction; D011995:Recombination, Genetic; D012434:Secale / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D003313:Zea mays / Q000235:genetics
D017931:DNA Primers; D004272:DNA, Mitochondrial; D018744:DNA, Plant