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. 1983 Apr;3(4):635–642. doi: 10.1128/mcb.3.4.635

Inheritance of extrachromosomal rDNA in Physarum polycephalum.

P J Ferris, V M Vogt, C L Truitt
PMCID: PMC368579  PMID: 6855770

Abstract

In the acellular slime mold Physarum polycephalum, the several hundred genes coding for rRNA are located on linear extrachromosomal DNA molecules of a discrete size, 60 kilobases. Each molecule contains two genes that are arranged in a palindromic fashion and separated by a central spacer region. We investigated how rDNA is inherited after meiosis. Two Physarum amoebal strains, each with an rDNA recognizable by its restriction endonuclease cleavage pattern, were mated, the resulting diploid plasmodium was induced to sporulate, and haploid progeny clones were isolated from the germinated spores. The type of rDNA in each was analyzed by blotting hybridization, with cloned rDNA sequences used as probes. This analysis showed that rDNA was inherited in an all-or-nothing fashion; that is, progeny clones contained one or the other parental rDNA type, but not both. However, the rDNA did not segregate in a simple Mendelian way; one rDNA type was inherited more frequently than the other. The same rDNA type was also in excess in the diploid plasmodium before meiosis, and the relative proportions of the two rDNAs changed after continued plasmodial growth. The proportion of the two rDNA types in the population of progeny clones reflected the proportion in the parent plasmodium before meoisis. The rDNAs in many of the progeny clones contained specific deletions of some of the inverted repeat sequences at the central palindromic symmetry axis. To explain the pattern of inheritance of Physarum rDNA, we postulate that a single copy of rDNA is inserted into each spore or is selectively replicated after meiosis.

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Selected References

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  1. Adler P. N., Holt C. E. Mating type and the differentiated state in Physarum polycephalum. Dev Biol. 1975 Apr;43(2):240–253. doi: 10.1016/0012-1606(75)90024-x. [DOI] [PubMed] [Google Scholar]
  2. Affolter H. U., Braun R. Ribosomal DNA in spores of Physarum polycephalum. Biochim Biophys Acta. 1978 Jun 22;519(1):118–124. doi: 10.1016/0005-2787(78)90066-7. [DOI] [PubMed] [Google Scholar]
  3. Blackburn E. H., Gall J. G. A tandemly repeated sequence at the termini of the extrachromosomal ribosomal RNA genes in Tetrahymena. J Mol Biol. 1978 Mar 25;120(1):33–53. doi: 10.1016/0022-2836(78)90294-2. [DOI] [PubMed] [Google Scholar]
  4. Cheung M. K., Drivas D. T., Littau V. C., Johnson E. M. Protein tightly bound near the termini of the Physarum extrachromosomal rDNA palindrome. J Cell Biol. 1981 Oct;91(1):309–314. doi: 10.1083/jcb.91.1.309. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Ferris P. J., Vogt V. M. Structure of the central spacer region of extrachromosomal ribosomal DNA in Physarum polycephalum. J Mol Biol. 1982 Aug 15;159(3):359–381. doi: 10.1016/0022-2836(82)90289-3. [DOI] [PubMed] [Google Scholar]
  6. Hall L., Braun R. The organisation of genes for transfer RNA and ribosomal RNA in amoebae and plasmodia of Physarum polycephalum. Eur J Biochem. 1977 Jun 1;76(1):165–174. doi: 10.1111/j.1432-1033.1977.tb11582.x. [DOI] [PubMed] [Google Scholar]
  7. Johnson E. M. A family of inverted repeat sequences and specific single-strand gaps at the termini of the Physarum rDNA palindrome. Cell. 1980 Dec;22(3):875–886. doi: 10.1016/0092-8674(80)90564-4. [DOI] [PubMed] [Google Scholar]
  8. Kan N. C., Gall J. G. Sequence homology near the center of the extrachromosomal rDNA palindrome in Tetrahymena. J Mol Biol. 1981 Dec 25;153(4):1151–1155. doi: 10.1016/0022-2836(81)90472-1. [DOI] [PubMed] [Google Scholar]
  9. Karrer K. M., Gall J. G. The macronuclear ribosomal DNA of Tetrahymena pyriformis is a palindrome. J Mol Biol. 1976 Jun 25;104(2):421–453. doi: 10.1016/0022-2836(76)90280-1. [DOI] [PubMed] [Google Scholar]
  10. Laffler T. G., Dove W. F. Viability of Physarum polycephalum spores and ploidy of plasmodial nuclei. J Bacteriol. 1977 Aug;131(2):473–476. doi: 10.1128/jb.131.2.473-476.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Novick R. P., Hoppensteadt F. C. On plasmid incompatibility. Plasmid. 1978 Sep;1(4):421–434. doi: 10.1016/0147-619x(78)90001-x. [DOI] [PubMed] [Google Scholar]
  12. Pan W. C., Blackburn E. H. Single extrachromosomal ribosomal RNA gene copies are synthesized during amplification of the rDNA in Tetrahymena. Cell. 1981 Feb;23(2):459–466. doi: 10.1016/0092-8674(81)90141-0. [DOI] [PubMed] [Google Scholar]
  13. Pan W. C., Orias E., Flacks M., Blackburn E. H. Allele-specific, selective amplification of a ribosomal RNA gene in Tetrahymena thermophila. Cell. 1982 Mar;28(3):595–604. doi: 10.1016/0092-8674(82)90214-8. [DOI] [PubMed] [Google Scholar]
  14. Rigby P. W., Dieckmann M., Rhodes C., Berg P. Labeling deoxyribonucleic acid to high specific activity in vitro by nick translation with DNA polymerase I. J Mol Biol. 1977 Jun 15;113(1):237–251. doi: 10.1016/0022-2836(77)90052-3. [DOI] [PubMed] [Google Scholar]
  15. Truitt C. L., Hoffman C. S., Holt C. E. A Gene, ALCA, Affecting the Life Cycle Form Expressed in PHYSARUM POLYCEPHALUM. Genetics. 1982 May;101(1):35–55. doi: 10.1093/genetics/101.1.35. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Vogt V. M., Braun R. Structure of ribosomal DNA in Physarum polycephalum. J Mol Biol. 1976 Sep 25;106(3):567–587. doi: 10.1016/0022-2836(76)90252-7. [DOI] [PubMed] [Google Scholar]
  17. Vogt V. M., Braun R. The replication of ribosomal DNA in Physarum polycephalum. Eur J Biochem. 1977 Nov 1;80(2):557–566. doi: 10.1111/j.1432-1033.1977.tb11912.x. [DOI] [PubMed] [Google Scholar]
  18. Wahl G. M., Stern M., Stark G. R. Efficient transfer of large DNA fragments from agarose gels to diazobenzyloxymethyl-paper and rapid hybridization by using dextran sulfate. Proc Natl Acad Sci U S A. 1979 Aug;76(8):3683–3687. doi: 10.1073/pnas.76.8.3683. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Yang R., Lis J., Wu R. Elution of DNA from agarose gels after electrophoresis. Methods Enzymol. 1979;68:176–182. doi: 10.1016/0076-6879(79)68012-6. [DOI] [PubMed] [Google Scholar]
  20. Yao M. C., Gall J. G. A single integrated gene for ribosomal RNA in a eucaryote, Tetrahymena pyriformis. Cell. 1977 Sep;12(1):121–132. doi: 10.1016/0092-8674(77)90190-8. [DOI] [PubMed] [Google Scholar]
  21. Yao M. C. Ribosomal RNA gene amplification in Tetrahymena may be associated with chromosome breakage and DNA elimination. Cell. 1981 Jun;24(3):765–774. doi: 10.1016/0092-8674(81)90102-1. [DOI] [PubMed] [Google Scholar]
  22. Youngman P. J., Anderson R. W., Holt C. E. Two Multiallelic Mating Compatibility Loci Separately Regulate Zygote Formation and Zygote Differentiation in the Myxomycete PHYSARUM POLYCEPHALUM. Genetics. 1981 Mar;97(3-4):513–530. doi: 10.1093/genetics/97.3-4.513. [DOI] [PMC free article] [PubMed] [Google Scholar]

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