Abstract
The focus of this review is on the micronucleus and macronucleus in the ciliated protozoa and the organization and function of the DNA molecules within them. We present (1) some of the structural and functional differences which are known, (2) the genetic evidence for macronuclear units, (3) two hypotheses for the organization of the DNA molecules in the macronucleus to explain these units, and (4) experiments designed to discriminate between these hypotheses. We conclude that the size of the genome is not reduced in the macronucleus and that there are 45 copies of the haploid genome present in the macronucleus of normal strains of Tetrahymena pyriformis and 800 copies in the macronucleus of Paramecium aurelia. The ciliate genome is relatively simple in terms of repeated sequences. However, not all copies of the genes present in the macronucleus may be identical since fractions of differing thermal stability appear after renaturation.
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References
Allen, S. L. (1964). Linkage studies in variety 1 of Tetrayhmena pyriformis: A first case of linkage in the ciliated protozoa. Genetics 49617.
Allen, S. L. (1967). Genomic exclusion: A rapid means for inducing homozygous diploid lines in Tetrahymena pyriformis, syngen 1. Science 155575.
Allen, S. L. (1971). A late-determined gene in Tetrahymena heterozygotes. Genetics 68415.
Allen, S. L., and Gibson, I. (1967). Genetic homologies and drift within populations of DNA molecules. Science 158523.
Allen, S. L., and Gibson, I. (1971). The purification of DNA from the genomes of Paramecium aurelia and Tetrahymena pyriformis. J. Protozool. 18518.
Allen, S. L., and Gibson, I. (1972). Genetics of Tetrahymena. In Elliott, A. M. (ed.), Biology of Tetrahymena, Dowden, Hutchinson & Ross, Stroudsburg. (in press).
Allen, S. L., and Lee, P. H. T. (1971). The preparation of congenic strains of Tetrahymena. J. Protozool. 18214.
Allen, S. L., File, S. K., and Koch, S. L. (1967). Genomic exclusion in Tetrahymena. Genetics 55823. (in press).
Ammerman, D. (1970). The micronucleus of the ciliate Stylonychia mytilus: its nucleic acid synthesis and its function. Exptl. Cell Res. 616.
Ammermann, D. (1971). Morphology and development of the macronuclei of the ciliates Stylonychia mytilus and Euplotes aediculatus. Chromosoma 33209.
Behme, R. J., and Berger, J. D. (1970). The DNA content of Paramecium aurelia, stock 51. J. Protozool. (Suppl. 1720.
Beisson, J., and Rossignol, M. (1969). The first case of linkage in Paramecium aurelia. Genet. Res. Camb. 1385.
Britten, R. J., and Kohne, D. E. (1966). Nucleotide sequence repetition in DNA. Carnegie Inst. Wash. Year Book 6578.
Britten, R. J., and Kohne, D. E. (1968). Repeated sequences in DNA. Science 161529.
Britten, R. J., and Smith, J. (1969). A bovine genome. Carnegie Inst. Wash. Year Book 68378.
Cairns, J. (1963). The chromosome of Escherichia coli. Cold Spring Harbor Symp. Quant. Biol. 2843.
Cleffmann, G. (1967). Regulierung der DNA-Menge im Makronucleus von Tetrahymena. Exptl. Cell Res. 50193.
Dippell, R. V. (1954). A preliminary report on the chromosomal constitution of certain variety 4 races of Paramecium aurelia. Caryologia (Suppl. 51109.
Flavell, R. A., and Jones, I. G. (1970). Kinetic complexity of Tetrahymena pyriformis nuclear deoxyribonucleic acid. Biochem. J. 116155.
Gibson, I., and Hewitt, G. (1972). DNA sequences in the B chromosomes of grasshoppers. Nature New Biol.
Grell, K. G. (1964). The protozoan nucleus. In Brachet, J., and Mirsky, A. (eds.), The Cell, Vol. 6, Academic Press, New York, pp. 1–79.
Jones, K. W. (1956). Nuclear differentiation in Paramecium aurelia. Ph. D. thesis, Aberystwyth University, Wales.
Kimball, R. F. (1964). Physiological genetics of the ciliates. In Hutner, S. H. (ed.), Biochemistry and Physiology of Protozoa, Vol. III, Academic Press, New York, pp. 243–275.
Kimball, R. F. (1967). Persistent intraclonal variations in cell dry mass and DNA content in Paramecium aurelia. Exptl. Cell Res. 48378.
Kloetzel, J. A. (1970). Compartmentalization of the developing macronucleus following conjugation in Stylonychia and Euplotes. J. Cell Biol. 47395.
Kohne, D. E. (1970). Evolution of higher organism DNA. Quart. Rev. Biophys. 3327.
Košciuszko, H. (1965). Karyologic and genetic investigations of syngen 1 of Paramecium aurelia. Folia Biol. 13339.
Laird, C. D., and McCarthy (1969). Molecular characterization of the Drosophila genome. Genetics 63865.
McDonald, B. B. (1972). Nucleic acids during vegetative growth and conjugation in Tetrahymena. In Elliott, A. M. (ed.), Biology of Tetrahymena, Dowden, Hutchinson & Ross, Stroudsburg. (in press).
Murti, K. G., and Prescott, D. M. (1970). Micronuclear ribonucleic acid in Tetrahymena pyriformis. J. Cell Biol. 47460.
Nanney, D. L. (1957). Inbreeding degeneration in Tetrahymena. Genetics 42137.
Nanney, D. L. (1964). Macronuclear differentiation and subnuclear assortment in ciliates. In Locke, M. (eds.), The Role of Chromosomes in Development, Academic Press, New York, pp. 253–273.
Nanney, D. L. (1968). Ciliate genetics: Patterns and programs of gene action. Ann. Rev. Genet. 2121.
Nanney, D. L., Nagel, M. J., and Touchberry, R. W. (1964). The timing of H antigenic differentiation in Tetrahymena. J. Exptl. Zool. 15525.
Nilsson, J. R. (1970). Suggestive structural evidence for macronuclear “subnuclei” in Tetrahymena pyriformis GL. J. Protozool. 17539.
Pasternak, J. (1967). Differential genic activity in Paramecium aurelia. J. Exptl. Zool. 165395.
Prescott, D. M., and Stone, G. E. (1967). Replication and function of the protozoan nucleus. In Chen, T.-T. (ed.), Research in Protozoology, Vol. 2, Pergamon Press, New York, pp. 118–146.
Raikov, I. B. (1962). Der Kernapparat von Nassula ornata Ehrb. (Ciliata, Holotricha). Zur Frage über den Chromosomenaufbau des Makronucleus. Arch. Protistenk. 105463.
Raikov, I. B. (1969). Macronucleus of ciliates. In Chen. T.-T. (ed.), Research in Protozoology, Vol. 3, Pergamon Press, New York, pp. 1–128.
Rao, M. V. N., and Ammermann, D. (1970). Polytene chromosomes and nucleic acid metabolism during macronuclear development in Euplotes. Chromosoma 29246.
Rao, M. V. N., and Prescott, D. M. (1967). Micronuclear RNA synthesis in Paramecium caudatum. J. Cell. Biol. 33281.
Rasch, E. M., Barr, H. J., and Rasch, R. W. (1971). The DNA content of sperm of Drosophila melanogaster. Chromosoma 331.
Ray, C., Jr. (1956). Meiosis and nuclear behavior in Tetrahymena pyriformis. J. Protozool. 388.
Schensted, I. V. (1958). Model of subnuclear segregation in the macronucleus of ciliates. Am. Naturalist. 92161.
Scherbaum, O. H., Louderback, A. L., and Jahn, T. L. (1958). The formation of subnuclear aggregates in normal and synchronized protozoan cells. Biol. Bull. 115269.
Scherbaum, O. H., Louderback, A. L., and Jahn, T. L. (1959). DNA synthesis, phosphate content and growth in mass and volume in synchronously dividing cells. Exptl. Cell Res. 18150.
Soldo, A. T., van Wagtendonk, W. J., and Godoy, G. A. (1970). Nucleic acid and protein content of purified endosymbiote particles of Paramecium aurelia. Biochim. Biophys. Acta 204325.
Sonneborn, T. M. (1937). Sex, sex inheritance and sex determination in P. aurelia. Proc. Natl. Acad. Sci. 23378.
Sonneborn, T. M. (1947). Recent advances in the genetics of Paramecium and Euplotes. Adv. Genet. 1263.
Sonneborn, T. M. (1954). Is gene K active in the micronucleus of Paramecium aurelia? Microbiol. Genet. Bull. 1125.
Southern, E. M. (1971). Effects of sequence divergence on reassociation properties of repetitive DNA's. Nature New Biol. 23282.
Suyama, Y. (1966). Mitochondrial deoxyribonucleic acid of Tetrahymena. Its partial physical characterization. Biochemistry 52214.
Suyama, Y., and Miura, K. (1968). Size and structural variations of mitochondrial DNA. Proc. Natl. Acad. Sci. 60235.
Wells, C. (1961). Evidence for micronuclear function during vegetative growth and reproduction of the ciliate. Tetrahymena pyriformis. J. Protozool. 8284.
Wetmur, J. G., and Davidson, N. (1968). Kinetics of renaturation of DNA. J. Mol. Biol. 31349.
Wolfe, J. (1967). Structural aspects of amitosis: A light and electron microscope study of the isolated macronuclei of Paramecium aurelia and Tetrahymena pyriformis. Chromosoma 2359.
Woodard, J., Woodard, M., Gelber, B., and Swift, H. (1966). Cytochemical studies of conjugation in Paramecium aurelia. Exptl. Cell. Res. 4155.
Woodard, J., Gorovsky, M., and Kaneshiro, E. (1968). Macronuclear subnuclei of Tetrahymena. J. Cell Biol. 39:182a.
Wyatt, G. R. (1951). The purine and pyrimidine content of deoxypentose nucleic acids. Biochem. J. 48584
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The work reported in this paper has been supported by a research grant, GM 15879, from the National Institute of General Medical Sciences, U.S. Public Health Service, and by grants from the Science and Medical Research Councils of Great Britain. We are also grateful to the Center for Human Growth and Development, University of Michigan, for a summer fellowship facilitating collaboration.
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Allen, S., Gibson, I. Genome amplification and gene expression in the ciliate macronucleus. Biochem Genet 6, 293–313 (1972). https://doi.org/10.1007/BF00486122
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DOI: https://doi.org/10.1007/BF00486122