1887

Abstract

The development of a protoplast fusion technique for oxytetracycline-producing strains, and its evaluation for the application for a breeding programme, has been described. Treatment of protoplasts with 40% (w/v) PEG 1550 for 30 min gave optimal numbers of recombinants ranging from 1 to 10% of the total progeny. Therefore, by comparison with conjugation, protoplast fusion increased the frequency of recombination by two to three orders of magnitude. The proportion of multiple crossover classes amongst recombinants was higher, by a factor of ten, after protoplast fusion (13·3%) than after conjugation (1·5%). Participation of less frequent complementary genotype doubled from 9·0% in conjugation to 17·9% in protoplast fusion. Overall, this suggested that the opportunities for crossing over in a fusion of protoplasts were spatially and/or temporally extended leading to a loosening of linkage with a near-random assortment of genotypes in a cross. However, by minimizing the multiple crossover classes and calculating allele frequency gradients, it was shown that the protoplast fusion technique allows arrangement of genetic markers on the chromosome. These are ideal characteristics for the recombination of divergent lines in a strain improvement programme.

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1983-05-01
2021-05-13
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References

  1. Alačević M. 1969; Recombination inStreptomycesproducing tetracycline. In Genetics and Breeding of Streptomyces pp. 137–145 Edited by Sermonti G., Alačević M. Zagreb: Yugoslav Academy of Sciences and Arts;
    [Google Scholar]
  2. Alačević M., Strašek-Vešligaj M., Sermonti G. 1973; The circular linkage map ofStreptomyces rimosus. Journal of General Microbiology 77:173–175
    [Google Scholar]
  3. Alačević M., Pigac J., Vešligaj M. 1978; Different approaches to the gene mapping inStreptomyces rimosus. In Genetics of the Actino- mycetales pp. 65–70 Edited by Freerksen E., Tarnok I., Thumim J. H. Stuttgart & New York: Gustav Fischer Verlag;
    [Google Scholar]
  4. Anderson R. P., Roth J. R. 1977; Tandem genetic duplications in phage and bacteria. Annual Review of Microbiology 31:473–505
    [Google Scholar]
  5. Baltz R. H. 1978; Genetic recombination inStreptomyces fradiae by protoplast fusion and cell regeneration. Journal of General Microbiology 107:93–102
    [Google Scholar]
  6. Baltz R. H. 1980; Genetic recombination by protoplast fusion inStreptomyces. Developments in Industrial Microbiology 21:43–54
    [Google Scholar]
  7. Baltz R. H., Matsushima P. 1981; Protoplast fusion inStreptomyces: conditions for efficient genetic recombination and cell regeneration. Journal of General Microbiology 127:137–146
    [Google Scholar]
  8. Fodor K., Alföldi L. 1976; Fusion of protoplast ofBacillus megaterium. Proceedings of the National Academy of Sciences of the United States of America 73:2147–2150
    [Google Scholar]
  9. Friend E. J., Hopwood D. A. 1971; The linkage map ofStreptomyces rimosus. Journal of General Microbiology 68:187–197
    [Google Scholar]
  10. Godfrey O., Ford L., Huber M. L. B. 1978; Interspecies matings ofStreptomyces fradiae withStreptomyces bikiniensis mediated by conventional and protoplast fusion techniques. Canadian Journal of Microbiology 24:994–997
    [Google Scholar]
  11. Hopwood D. A. 1981; Genetic studies with bacterial protoplasts. Annual Review of Microbiology 35:237–272
    [Google Scholar]
  12. Hopwood D. A., Chater K. F. 1980; New approaches to antibiotic production. Philosophical Transactions of the Royal Society of London Series B 290:313–328
    [Google Scholar]
  13. Hopwood D. A., Wright H. M. 1978; Bacterial protoplast fusion: recombination in fused protoplasts of Streptomyces coelicolor. Molecular and General Genetics 162:307–317
    [Google Scholar]
  14. Hopwood D. A., Wright H. M. 1979; Factors affecting recombinant frequency in protoplast fusions ofStreptomyces coelicolor. Journal of General Microbiology 111:137–143
    [Google Scholar]
  15. Hopwood D. A., Wright H. M., Bibb M. J., Cohen S. N. 1977; Genetic recombination through protoplast fusion inStreptomyces. Nature, London 268:171–174
    [Google Scholar]
  16. Ochi K. 1982; Protoplast fusion permits high- frequency transfer of aStreptomyces determinant which mediates actinomycin synthesis. Journal of Bacteriology 150:592–597
    [Google Scholar]
  17. Ochi K., Hitchcock M. J. M., Katz E. 1979; High-frequency fusion ofStreptomyces parvulus orStreptomyces antibioticus protoplasts induced by polyethylene glycol. Journal of Bacteriology 139:984–992
    [Google Scholar]
  18. Okanishi M., Suzuki K., Umezawa H. 1974; Formation and reversion of streptomycete protoplasts: cultural condition and morphological study. Journal of General Microbiology 80:389–400
    [Google Scholar]
  19. Pigac J., Hranueli D., Smokvina T., Alačević M. 1982; Optimal cultural and physiological conditions for handlingStreptomyces rimosus protoplasts. Applied and Environmental Microbiology 44:1178–1186
    [Google Scholar]
  20. Sermonti G., Mancinelli A., Spada-Sermonti I. 1960; Heterogeneous clones (“heteroclones”) inStreptomyces coelicolor A3(2). Genetics 45:669–672
    [Google Scholar]
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