Genetics, Vol 127, 335-343, Copyright © 1991


INVESTIGATIONS

Mitochondrial Genetics of Chlamydomonas reinhardtii: Resistance Mutations Marking the Cytochrome b Gene

P. Bennoun, M. Delosme and U. Kuck
Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France

We describe the genetic and molecular analysis of the first non-Mendelian mutants of Chlamydomonas reinhardtii resistant to myxothiazol, an inhibitor of the respiratory cytochrome bc1 complex. Using a set of seven oligonucleotide probes, restriction fragments containing the mitochondrial cytochrome b (cyt b) gene from C. reinhardtii were isolated from a mitochondrial DNA library. This gene is located adjacent to the gene for subunit 4 of the mitochondrial NADH-dehydrogenase (ND4), near one end of the 15.8-kb linear mitochondrial genome of C. reinhardtii. The algal cytochrome b apoprotein contains 381 amino-acid residues and exhibits a sequence similarity of about 59% with other plant cytochrome b proteins. The cyt b gene from four myxothiazol resistant mutants of C. reinhardtii was amplified for DNA sequence analysis. In comparison to the wild-type strain, all mutants contain an identical point mutation in the cyt b gene, leading to a change of a phenylalanine codon to a leucine codon at amino acid position 129 of the cytochrome b protein. Segregation analysis in tetrads from reciprocal crosses of mutants with wild type shows a strict uniparental inheritance of this mutation from the mating type minus parent (UP(-)). However, mitochondrial markers from both parents are recovered in vegetative diploids in variable proportions from one experiment to the next for a given cross. On the average, a strong bias is seen for markers inherited from the mating type minus parent.


This article has been cited by other articles:


Home page
Proc. Natl. Acad. Sci. USAHome page
C. Remacle, P. Cardol, N. Coosemans, M. Gaisne, and N. Bonnefoy
High-efficiency biolistic transformation of Chlamydomonas mitochondria can be used to insert mutations in complex I genes
PNAS, March 21, 2006; 103(12): 4771 - 4776.
[Abstract] [Full Text] [PDF]


Home page
Plant CellHome page
F. Duby and R. F. Matagne
Alteration of Dark Respiration and Reduction of Phototrophic Growth in a Mitochondrial DNA Deletion Mutant of Chlamydomonas Lacking cob, nd4, and the 3' End of nd5
PLANT CELL, January 1, 1999; 11(1): 115 - 126.
[Abstract] [Full Text]


Home page
J. Biol. Chem.Home page
L. Cournac, K. Redding, J. Ravenel, D. Rumeau, E.-M. Josse, M. Kuntz, and G. Peltier
Electron Flow between Photosystem II and Oxygen in Chloroplasts of Photosystem I-deficient Algae Is Mediated by a Quinol Oxidase Involved in Chlororespiration
J. Biol. Chem., June 2, 2000; 275(23): 17256 - 17262.
[Abstract] [Full Text] [PDF]