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Maintenance of genetic homogeneity in systems with multiple genomes

Published online by Cambridge University Press:  14 April 2009

C. William Birky Jr
Affiliation:
Department of Genetics, The Ohio State University, Columbus, Ohio 43210, U.S.A.
Russell V. Skavaril
Affiliation:
Department of Genetics, The Ohio State University, Columbus, Ohio 43210, U.S.A.
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Genes or sequences of DNA present in multiple copies per cell include entire genomes of mitochondria and chloroplasts, nuclear ribosomal RNA genes, and highly repetitive sequences in heterochromatin. All copies are nearly identical, in spite of mutational pressure and weak selection. A zygote containing mitochondrial or chloroplast genophores of two different genotypes quickly produces progeny pure for one genotype or another (vegetative segregation). Evidence from yeast and Chlamy-domonas suggests that organelle genophores undergo repeated rounds of random mating and recombination. When two molecules carrying different alleles at a locus recombine, gene conversion can result in the cell becoming pure for one allele. Stochastic matching and conversion (SMAC) has been studied by computer simulations which suggest that it will tend to eliminate new mutations in yeast mitochondrial DNA and speed up vegetative segregation. We have verified previous suggestions that gene conversion, occurring during unequal mitotic sister-strand crossing-over, provides an efficient mechanism for maintaining the homogeneity of repeated sequences in eukaryotic chromosomes.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1976

References

REFERENCES

Adoutte, A. (1974). Mitochondrial mutations in Paramecium: phenotypical characterization and recombination. The Biogenesis of Mitochondria (ed. Kroon, A. M. and Saccone, C.), pp. 263271. New York: Academic Press, Inc.CrossRefGoogle Scholar
Birky, C. W. Jr (1973). On the origin of mitochondrial mutants: evidence for intracellular selection of mitochondria in the origin of antibiotic-resistant cells in yeast. Genetics 74, 421432.CrossRefGoogle ScholarPubMed
Birky, C. W. Jr (1975). Mitochondrial genetics in fungi and ciliates. Genetics and Biogenesis of Mitochondria and Chloroplasts (ed. Birky, C. W. Jr, Perlman, P. S., and Byers, T. J.), pp. 182224. Columbus: Ohio State University Press.Google Scholar
Birky, C. W. Jr, & Skavaril, R. V. (1975). A possible role for gene conversion in achieving and maintaining genetic homogeneity among organelle genophores and repeated DNA sequences in general. Genetics 80, s 14.Google Scholar
Brown, D. B. & Sugimoto, K. (1974). The structure and evolution of ribosomal and 5S DNAs in Xenopus laevis and Xenopus Mulleri. Cold Spring Harbor Symposia on Quantitative Biology 38, 501505.CrossRefGoogle ScholarPubMed
Buongiorno-Nardelli, M., Amaldi, F. & Lavasanchez, P. (1972). Amplification as a rectification mechanism for the redundant rRNA genes. Nature New Biology 238, 134137.CrossRefGoogle ScholarPubMed
Callan, H. G. (1967). The organization of genetic units in chromosomes. Journal of Cell Science 2, 17.CrossRefGoogle ScholarPubMed
Callen, D. F. (1974). Segregation of mitochondrially inherited antibiotic resistance genes in zygote cell lineages of Saccharomyces cerevisiae. Molecular and General Genetics 104, 6576.CrossRefGoogle Scholar
Catcheside, D. G. (1974). Fungal genetics. Annual Review of Genetics 8, 279300.CrossRefGoogle ScholarPubMed
Drake, J. W. (1970). The Molecular Basis of Mutation. San Francisco: Holden-Day.Google Scholar
Dujon, B., Slonimski, P. P. & Weill, L. (1974). Mitochondrial genetics. IX. A model for recombination and segregation of mitochondrial genomes in Saccharomyces cerevisiae. Genetics 78, 415437.CrossRefGoogle Scholar
Dujon, B., Kruszewska, A., Slonimski, P. P., Bolotin-Fukuhara, M., Coen, D., Deutsch, J., Netter, P. & Weill, L. (1975). Mitochondrial genetics. X. Effects of UV irradiation on transmission and recombination of mitochondrial genes in Saccharomyces cerevisiae. Molecular and General Genetics 137, 2972.CrossRefGoogle Scholar
Edelman, G. M. & Gally, J. A. (1970). Arrangement and evolution of eukaryotic genes. The Neurosciences: Second Study Program (ed. Schmitt, F. O.), pp. 962972. New York: Rockefeller University Press.Google Scholar
Gall, J. G., Cohen, E. H. & Atherton, D. D. (1974). The satellite DNAs of Drosophila virilis. Cold Spring Harbor Symposia on Quantitative Biology 38, 417427.CrossRefGoogle ScholarPubMed
Gillham, N. W., Boynton, J. E. & Lee, R. W. (1974). Segregation and recombination of non-Mendelian genes in Chlamydomonas. Genetics 78, 439457.CrossRefGoogle ScholarPubMed
Grimes, G. W., Mahler, H. R. & Perlman, P. S. (1974). Nuclear gene dosage effects on mitochondrial mass and DNA. Journal of Cell Biology 61, 565574.CrossRefGoogle ScholarPubMed
Ikushima, T. & Wolff, S. (1974). Sister chromatid exchanges induced by light flashes to 5-bromodeoxyuridine- and 5-iododeoxyuridine substituted Chinese hamster chromosomes. Experimental Cell Research 87, 1519.CrossRefGoogle ScholarPubMed
Meselson, M. S. & Radding, C. M. (1975). A general model for genetic recombination. Proceedings of the National Academy of Sciences, U.S.A. 72, 358361.CrossRefGoogle ScholarPubMed
Michaelis, P. (1955). Über Gesetzmässigkeiten der Plasmon-Umkonbination und über eine Methode zur Trennung einer Plastiden-, Chondriosomen-, resp. Sphaerosomen-, (Mikrosomen)- und einer Zytoplasmavererbung. Cytologia 20, 315338.CrossRefGoogle Scholar
Orias, E. & Flacks, M. (1975). Macronuclear genetics of Tetrahymena. I. Random distribution of macronuclear gene copies in T. pyriformis, syngen 1. Genetics 79, 187206.CrossRefGoogle Scholar
Perlman, P. S. & Birky, C. W. Jr (1974). Mitochondrial genetics in bakers’ yeast: a molecular mechanism for recombinational polarity and suppressiveness. Proceedings of the National Academy of Sciences, U.S.A. 71, 46124616.CrossRefGoogle ScholarPubMed
Radding, C. (1973). Molecular mechanisms in genetic recombination. Annual Review of Genetics 7, 87111.CrossRefGoogle ScholarPubMed
Rowlands, R. T. & Turner, G. (1974). Recombination between the extranuclear genes conferring oligomycin resistance and cold sensitivity in Aspergillus nidulans. Molecular and General Genetics 133, 151161.CrossRefGoogle ScholarPubMed
Smith, G. P. (1974). Unequal crossover and the evolution of multigene families. Cold Spring Harbor Symposia on Quantitative Biology 38, 507513.CrossRefGoogle ScholarPubMed
Sparrow, A. H., Price, H. J. & Underbrink, A. G. (1972). A survey of DNA content per cell and per chromosome of prokaryotic and eukaryotic organisms: some evolutionary considerations. Evolution of Genetic Systems (ed. Smith, H. H.), pp. 451493. New York: Gordon and Breach.Google Scholar
Tartof, K. D. (1974). Unequal mitotic sister chromatid exchange and disproportionate replication as mechanisms regulating ribosomal RNA gene redundancy. Cold Spring Harbor Symposia on Quantitative Biology 38, 491500.CrossRefGoogle ScholarPubMed
Tartof, K. D. (1975). Redundant genes. Ann. Rev. Genet. 9 (in the Press).CrossRefGoogle ScholarPubMed
Taylor, J. H., Woods, P. S. & Hughes, W. L. (1957). The organization and duplication of chromosomes as revealed by autoradiographic studies using tritium labeled thymidine. Proceedings of the National Academy of Sciences, U.S.A. 43, 122128.CrossRefGoogle Scholar
Thomas, C. A. Jr (1970). The theory of the master gene. The Neurosciences: Second Study Program (ed. Schmitt, F. O.), pp. 973978. New York: Rockefeller University Press.Google Scholar
Thomas, C. A. Jr (1974). The rolling helix: a model for the eukaryotic gene? Cold Spring Harbor Symposia on Quantitative Biology 38, 347352.CrossRefGoogle Scholar
Visconti, N. & Delbrück, M. (1953). The mechanism of genetic recombination in phage. Genetics 38, 533.CrossRefGoogle ScholarPubMed
Williamson, D. H. & Fennell, D. J. (1974). Apparent dispersive replication of yeast mitochondrial DNA as revealed by density labelling experiments. Molecular and General Genetics 131, 193207.CrossRefGoogle ScholarPubMed