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Genetic analysis of a cross between two homothallic strains of Physarum polycephalum

Published online by Cambridge University Press:  14 April 2009

R. T. M. Poulter
Affiliation:
Department of Biochemistry, University of Otago, Dunedin, New Zealand
N. K. Honey
Affiliation:
Department of Biochemistry, University of Otago, Dunedin, New Zealand
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Summary

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The homothallic amoebal clones of Physarum polycephalum are of potential use in understanding the developmental genetics of this organism. Such an application requires that complementation and recombination analysis be possible between pairs of homothallic clones. This paper is a report of the formation of mixed plasmodia by pairs of homothallic amoebal clones. In order to detect such mixed plasmodia use was made of two marker genes involved in plasmodial fusion, fusA and fusB. Sporulation of a mixed plasmodium formed from two homothallic (delayed) amoebal clones yielded progeny amoebae which were genetically recombinant. It is deduced from the ratios of various genotypes in these progeny clones that the mixed plasmodium was diploid and that meiosis was associated with sporulation. There is therefore no impediment to the use of the homothallic strains for genetical analysis. The progeny amoebal clones were observed to be showing segregation for the characters homothallic (rapid) and homothallic (delayed). This observation, taken together with other related observations, suggests that the homothallic (delayed) character is produced by mutation of the homothallic (rapid) character. The rare plasmodia formed by a homothallic (delayed) amoebal clone are the result of reversion of this mutation. Amoebal clones of the homothallic (delayed) type are therefore developmental mutants unable to perform the differentiation from amoeba to plasmodium.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1977

References

REFERENCES

Carlile, M. J. (1976). The genetic basis of the incompatibility reaction following plasmodial fusion between different strains of the Myxomycete Physarum polycephalum. Journal of General Microbiology 93, 371376.CrossRefGoogle Scholar
Collins, O. R. (1972). Plasmodial fusion in Physarum polycephalum: Genetic analysis of a Turtox strain. Mycologia 64, 11301137.CrossRefGoogle Scholar
Cooke, D. J. & Dee, J. (1974). Plasmodium formation without change in nuclear DNA content in Physarum polycephalum. Genetical Research 23, 307317.CrossRefGoogle ScholarPubMed
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. (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 ScholarPubMed
Dee, J. & Poulter, R. T. M. (1970). A gene conferring actidione resistance and abnormal morphology on Physarum polycephalum plasmodia. Genetical Research 15, 3341.CrossRefGoogle Scholar
Olive, L. S. (1975). The Mycetozoans. London: Academic Press.Google Scholar
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
Wheals, A. E. (1970). A homothallic strain of the Myxomycete Physarum polycephalum. Genetics 66, 623633.CrossRefGoogle ScholarPubMed