Nucleic Acids Research, 1981, Vol. 9, No. 6 1451-1462
© 1981
MOLECULAR BIOLOGY |
Phylogenetic tree derived from bacterial, cytosol and organelle 5S rRNA sequences
Max-Planck-Institut für experimentelle Medizin, Abteilung Chemie Hermann-Rein-Str. 3, D-3400 Göttingen, GFR
Received January 19, 1981. A phylogenetic tree was constructed by computer analysis of 47 completely determined 5S rRNA sequences.
The wheat mitochondrial sequence is significantly more related to pro-karyotic than to eukaryotic sequences, and its affinity to that of the thermophilic Gram-negative bacterium Thermus aquaticus is comparable to the affinity between Anacystis nidulans and chloroplastic sequences. This strongly supports the idea of an endosymbiotic origin of plant mitochondria.
A comparison of the plant cytosol and chloroplast sub-trees suggests a similar rate of nucleotide substitution in nuclear genes and chloroplastic genes. Other features of the tree are a common precursor of protozoa and metazoa, which appears to be more related to the fungal than to the plant proto-sequence, and an early divergence of the archebacterial sequence (Halobacterium cutirubrum) from the prokaryotic branch.