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Plasmodium formation without change in nuclear DNA content in Physarum polycephalum

Published online by Cambridge University Press:  14 April 2009

D. J. Cooke  and
Jennifer Dee
D. J. Cooke
Affiliation:
Department of Genetics, University of Leicester, Leicester LE1 7RH, England
Jennifer Dee
Affiliation:
Department of Genetics, University of Leicester, Leicester LE1 7RH, England
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The Colonia isolate of Physarum polycephalum produces plasmodia within amoebal clones. Wheals demonstrated genetically that amoebae of the C50 strain of this isolate, when crossed with heterothallic amoebae, yielded recombinant progeny. He concluded that nuclear fusion and meiosis occurred in these crosses and suggested that nuclear fusion was also involved in plasmodia formation in clones. He thus designated the strain ‘homothallic’.

In the present work genetic evidence is presented which indicates that the Colonia strain CL, when crossed with heterothallic strains, also yields recombinant progeny and thus undergoes nuclear fusion and meiosis. Microdensitometric measurements of nuclear DNA content are reported which indicate that CL amoebae are haploid like heterothallic amoebae, and crossed plasmodia are diploid. However, clonally formed CL plasmodia were found to have the same G2 nuclear DNA content as CL amoebae. This observation excludes the possibility of nuclear fusion when plasmodia form within clones of CL amoebae and therefore the strain cannot be homothallic. Two alternatives, apogamy and coalescence, are proposed as the most likely mechanisms for clonal plasmodium formation in strain CL.

Type
Research Article
Information
Genetics Research , Volume 23 , Issue 3 , June 1974 , pp. 307 - 317
Copyright
Copyright © Cambridge University Press 1974

References

REFERENCES

Aldrich, H. C. (1967). The ultrastructure of meiosis in three species of Physarum. Mycologia 59, 127–148.CrossRefGoogle ScholarPubMed
Bradbury, E. M., Matthews, H. R., McNaughton, J. & Molgaard, H. V. (1973). Sub-nuclear components of Physarum polycephalum. Biochemica et Biophysica Acta 335, 19–29.CrossRefGoogle Scholar
Darlington, C. D. & Cour, L. F. La (1962). The Handling of Chromosomes, 4th ed.London: Allen and Unwin.Google Scholar
Dee, J. (1966). Multiple alleles and other factors affecting plasmodium formation in the true slime mould Physarum polycephalum Schw. Journal of Protozoology 13, 610–616.CrossRefGoogle Scholar
Dee, J. (1973). Aims and techniques of genetic analysis in Physarum polycephalum. Berichte der Deutschen Botanischen Gesellschaft 86, 93–121.CrossRefGoogle Scholar
Dee, J. & Poulter, R. T. M. (1970). A gene conferring actidione resistance and abnormal morphology on Physarum polycephalum plasmodia. Genetical Research 15, 33–41.CrossRefGoogle Scholar
Dee, J., Wheals, A. E. & Holt, C. E. (1973). Inheritance of plasmodial valine requirement in Physarum polycephalum. Genetical Research 21, 87–101.CrossRefGoogle Scholar
Grant, W. D. & Poulter, R. T. M. (1973). Rifampicin-sensitive RNA and protein synthesis by isolated mitochondria of Physarum polycephalum. Journal of Molecular Biology 73, 439–455.CrossRefGoogle ScholarPubMed
Itakawa, O. & Ogura, Y. (1954). The Feulgen reaction after hydrolysis at room temperature. Stain Technology 29, 13–15.CrossRefGoogle Scholar
Kerr, N. S. (1967). Plasmodium formation by a minute mutant of the true slime mould, Didymium nigripes. Experimental Cell Research 45, 646–655.CrossRefGoogle Scholar
Kerr, S. (1968). Ploidy level in the true slime mould Didymium nigripes. Journal of General Microbiology 53, 9–15.CrossRefGoogle ScholarPubMed
Mittermayer, C., Braun, R. & Rusch, H. P. (1965). The effect of actinomycin D on the timing of mitosis in Physarum polycephalum. Experimental Cell Research 38, 33–41.CrossRefGoogle ScholarPubMed
Mohberg, J., Babcock, K. L., Haugli, F. B. & Rusch, H. P. (1973). Nuclear DNA content and chromosome numbers in the Myxomycete Physarum polycephalum. Developmental Biology 34, 228–245.CrossRefGoogle ScholarPubMed
Mohberg, J. & Rusch, H. P. (1971). Isolation and DNA content of nuclei of Physarum polycephalum. Experimental Cell Research 66, 305–316.CrossRefGoogle ScholarPubMed
Poulter, R. T. M. (1969). Senescence in the Myxomycete Physarum polycephalum. Ph.D. Thesis, University of Leicester.Google Scholar
Poulter, R. T. M. & Dee, J. (1968). Segregation of factors controlling fusion between plasmodia of the true slime mould Physarum polycephalum. Genetical Research 12, 71–79.CrossRefGoogle ScholarPubMed
Therrien, C. D. (1966). Microspectrophotometric measurements of nuclear deoxyribo-nucleic acid content in two Myxomycetes. Canadian Journal of Botany 44, 1667–1675.CrossRefGoogle Scholar
Von-Stosch, H. A., Van Zul-Pischinger, M. & Dersch, G. (1964). Nuclear phase alternance in the Myxomycete Physarum polycephalum, pp. 481–482. In Abstracts 10th International Botanical Congress, Edinburgh, 1964.Google Scholar
Wheals, A. E. (1970). A homothallic strain of the Myxomycete Physarum polycephalum. Genetics 66, 623–633.CrossRefGoogle ScholarPubMed
Wheals, A. E. (1973). Developmental mutants in a homothallic strain of Physarum polycephalum. Genetical Research 21, 79–86.CrossRefGoogle Scholar
Yemma, J. J. & Therrien, C. D. (1972). Quantitative microspectrophotometry of nuclear DNA in selfing strains of the Myxomycete Didymium iridis. American Journal of Botany 59, 828–835.CrossRefGoogle Scholar