Hostname: page-component-5c6d5d7d68-txr5j Total loading time: 0 Render date: 2024-08-19T03:03:00.219Z Has data issue: false hasContentIssue false

Isolation and Analysis of Amoebal–Plasmodial Transition Mutants in the Myxomycete Physarum polycephalum

Published online by Cambridge University Press:  14 April 2009

R. W. Anderson
Affiliation:
Department of Genetics, University of Leicester, Leicester LE1 7RH, England
Jennifer Dee
Affiliation:
Department of Genetics, University of Leicester, Leicester LE1 7RH, England

Summary

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Plasmodium formation in the Myxomycete Physarum polycephalum normally involves fusion of haploid amoebae, carrying different alleles at the mating type (mt) locus, to give diploid plasmodia. Strains carrying the mth allele are capable of undergoing the amoebal–plasmodial transition with high efficiency within amoebal clones, resulting in the formation of haploid plasmodia. NMG mutagenesis of mth amoebae, followed by an enrichment procedure, was used to isolate mutants in which such clonal plasmodium formation was either delayed or absent. Thirteen mutants of the second type were analysed. Three of these were temperature-sensitive for plasmodium formation. All thirteen mutants were able to form diploid crossed plasmodia when mixed with a mt1 strain. Three new genes were identified and designated npfA, npfB and npfC. A mutant allele of npfA rendered clonal plasmodium formation temperature-sensitive, but did not prevent crossing at the non-permissive temperature with derived strains carrying the same mutant allele. No recombination was detected between npfB or npfC and mt, but npfA was unlinked to mt and a locus (apt-1) shown in a previous study to be involved in plasmodium formation. The genes npfB and npfC were distinguished by complementation analysis. Strains of the genotype npfB; npfC+ behaved in the same way as strains carrying the mt2 allele. The nature of the mutants and the role of the mating-type locus in the initiation of plasmodium formation are discussed.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1977

References

REFERENCES

Adler, P. N. & Holt, C. E. (1975). Mating type and the differentiated state in Physarum polycephalum. Developmental Biology 43, 240253.CrossRefGoogle Scholar
Anderson, R. W., Cooke, D. J. & Dee, J. (1976). Apogamic development of plasmodia in the Myxomycete Physarum polycephalum: A cinematographic analysis. Protoplasma 89, 2940.Google Scholar
Carlile, M. J. & Dee, J. (1967). Plasmodial fusion and lethal interaction between strains in a Myxomycete. Nature 215, 832834.Google Scholar
Cooke, D. J. (1974). Studies on the Colonia isolate of Physarum polycephalum. Ph.D. thesis, University of Leicester.Google Scholar
Cooke, D. J. & Dee, J. (1974). Plasmodium formation without change in nuclear DNA content in Physarum polycephalum. Genetical Research 23, 307317.Google Scholar
Cooke, D. J. & Dee, J. (1975). Methods for the isolation and analysis of plasmodial mutants in Physarum polycephalum. Genetical Research 24, 175187.CrossRefGoogle Scholar
Dee, J. (1960). A mating type system in an acellular slime mould. Nature 185, 780781.CrossRefGoogle Scholar
Dee, J. (1966). Multiple alleles and other factors affecting plasmodium formation in the true slime mould Physarum polycephalum Schw. Journal of Protozoology 13, 610616.CrossRefGoogle Scholar
Dee, J. (1975). Slime moulds in biological research. Science Progress 62, 523542.Google Scholar
Dee, J. & Poulter, R. T. M. (1970). A gene conferring actidione resistance and abnormal morphology on Physarum polycephalum plasmodia. Genetical Research 15, 3541.CrossRefGoogle Scholar
Dee, J., Wheals, A. B. & Holt, C. E. (1973). Inheritance of plasmodial valine requirement in Physarum polycephalum. Genetical Research 21, 87101.CrossRefGoogle Scholar
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, 3341.Google Scholar
Mohberg, J. (1976). Nuclear DNA content and chromosome number throughout the life cycle of the Colonia strain of the Myxomycete Physarum polycephalum. (Submitted for publication.)Google Scholar
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, 228245.CrossRefGoogle ScholarPubMed
Mohberg, J. & Rusch, H. P. (1971). Isolation and DNA content of nuclei of Physarum polycephalum. Experimental Cell Research 66, 305316.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, 7179.CrossRefGoogle ScholarPubMed
Rasch, E. M., Barr, H. J. & Rasch, R. W. (1971). The DNA content of sperm of Drosophila melanogaster. Chromosoma 33, 118.Google Scholar
Ross, I. K. (1957). Syngamy and plasmodium formation in the Myxogastres. American Journal of Botany 44, 843850.Google Scholar
Wheals, A. E. (1970). A homothallic strain of the Myxomycete Physarum polycephalum. Genetics 66, 623633.Google Scholar
Wheals, A. E. (1973). Developmental mutants in a homothallic strain of Physarum polycephalum. Genetical Research 21, 7986.Google Scholar