Nuclear and mitochondrial DNA have sequence homology with a chloroplast gene
- 75 Downloads
A PstI 7.7 kbp fragment from chloroplast (ct) DNA of spinach shows homology to an EcoRI 8.3 kbp fragment of mitochondrial (mt) DNA and in turn, both are homologous to a number of common regions of nuclear (n) DNA. The common area of homology between the chloroplast and mitochondrial fragments is between a KpnI 1.8 segment internal to the PstI sites in the ctDNA and an EcoRI/BamHI 2.9 kbp fragment at one end of the mitochondrial 8.3 kbp fragment. The KpnI 1.8 kbp ctDNA fragment is within a structural gene for the P700 chlorophyll a apoprotein. Further analysis of this KpnI 1.8 kbp fragment confined the homologous region in mtDNA to a ct 0.8 kbp HpaII fragment. These smaller pieces of the organellar genomes share homologies with nuclear DNA as well as displaying unique hybridization sites. The observations reported here demonstrate that there is a common or closely related sequence in all three genetic compartments of the cell.
Keywordschloroplast DNA DNA homologies mitochondrial DNA nuclear DNA photosystem I spinach
Unable to display preview. Download preview PDF.
- 17.Possingham JV, Smith JW: Factors affecting chloroplast replication in spinach. J Exp Bot 23:1050–1059, 1972.Google Scholar
- 18.Scott NS, Possingham JV: Chloroplast DNA in expanding spinach leaves. J Exp Bot 123:1081–1092, 1980.Google Scholar
- 21.Stern DB, Palmer JD: Extensive and widespread homologies between mitochondrial DNA and chloroplast DNA in plants. Proc Natl Acad Sci USA, in press (1984).Google Scholar
- 23.Timmis JN, Scott NS: Promiscuous DNA: Sequence homologies between DNA of separate organelles. TIBS 9(6):271–273, 1984.Google Scholar
- 27.Whitfeld PR, Bottomley W: Mapping of the gene for the large subunit of ribulose bisphosphate carboxylase on spinach chloroplast DNA. Biochem Int 1:172–178, 1980.Google Scholar