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. 1996 Nov;144(3):871–881. doi: 10.1093/genetics/144.3.871

Noncomplementing Diploids from Bacillus Subtilis Protoplast Fusion: Relationship between Maintenance of Chromosomal Inactivation and Segregation Capacity

V Grandjean 1, Y Hauck 1, J Le-Derout 1, L Hirschbein 1
PMCID: PMC1207628  PMID: 8913734

Abstract

Fusions of Bacillus subtilis protoplasts from two genetically marked strains produce noncomplementing heterodiploid bacteria. These noncomplementing diploids (Ncds) carry both parental chromosomes, but only one is expressed. Fusion products of strains polymorphic for NotI restriction sites provide new physical evidence to support the conclusion that Ncds are not an artifact of cross feeding or cell adhesion. We show that reversible chromosomal inactivation can only account for the biparental trait of unstable Ncds. Two types of cells were recovered from the late progeny of unstable Ncds: Ncds with irreversible chromosome silencing (stable Ncds) and secondary recombinants that displayed a genomic mosaic NotI profile. Segregants from an unstable Ncd population gave rise to two viable haploid cell types. By contrast, stable Ncds segregated into a population of viable and inviable haploid cells. We propose that the latter are derived from irreversible chromosome silencing. Our results indicate that clonal populations of stable Ncds are heterogenous and suggest that segregation and inactivation are independent parameters.

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Selected References

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  1. Anagnostopoulos C., Spizizen J. REQUIREMENTS FOR TRANSFORMATION IN BACILLUS SUBTILIS. J Bacteriol. 1961 May;81(5):741–746. doi: 10.1128/jb.81.5.741-746.1961. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Assaad F. F., Tucker K. L., Signer E. R. Epigenetic repeat-induced gene silencing (RIGS) in Arabidopsis. Plant Mol Biol. 1993 Sep;22(6):1067–1085. doi: 10.1007/BF00028978. [DOI] [PubMed] [Google Scholar]
  3. Crouse H. V., Brown A., Mumford B. C. --chromosome inheritance and the porblem of chromosome "imprinting" in Sciara (Sciaridae, Diptera). Chromosoma. 1971;34(3):324–8. doi: 10.1007/BF00286156. [DOI] [PubMed] [Google Scholar]
  4. Dubnau D., Cirigliano C. Fate of transforming DNA following uptake by competent Bacillus subtilis. Formation and properties of products isolated from transformed cells which are derived entirely from donor DNA. J Mol Biol. 1972 Feb 28;64(1):9–29. doi: 10.1016/0022-2836(72)90318-x. [DOI] [PubMed] [Google Scholar]
  5. Gabor M. H., Hotchkiss R. D. Reciprocal and nonreciprocal recombination in diploid clones from Bacillus subtilis protoplast fusion: Association with the replication origin and terminus. Proc Natl Acad Sci U S A. 1983 Mar;80(5):1426–1430. doi: 10.1073/pnas.80.5.1426. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Goyon C., Faugeron G. Targeted transformation of Ascobolus immersus and de novo methylation of the resulting duplicated DNA sequences. Mol Cell Biol. 1989 Jul;9(7):2818–2827. doi: 10.1128/mcb.9.7.2818-2827.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Grandjean V., Nguyen J., Hauck Y., Hirschbein L. Establishment of a new replicon generated from an integrational plasmid and a cryptic pUB110 origin-like region in Bacillus subtilis. Plasmid. 1993 Jul;30(1):1–13. doi: 10.1006/plas.1993.1029. [DOI] [PubMed] [Google Scholar]
  8. Grant S. G., Chapman V. M. Mechanisms of X-chromosome regulation. Annu Rev Genet. 1988;22:199–233. doi: 10.1146/annurev.ge.22.120188.001215. [DOI] [PubMed] [Google Scholar]
  9. Guillen N., Gabor M. H., Hotchkiss R. D., Hirschbein L. Isolation and characterization of the nucleoid of non-complementing diploids from protoplast fusion in Bacillus subtilis. Mol Gen Genet. 1982;185(1):69–74. doi: 10.1007/BF00333792. [DOI] [PubMed] [Google Scholar]
  10. Guillén N., Amar M., Hirschbein L. Stabilized non-complementing diploids (Ncd) from fused protoplast products of B. subtilis. EMBO J. 1985 May;4(5):1333–1338. doi: 10.1002/j.1460-2075.1985.tb03781.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Hauser P. M., Karamata D. Ploidy of Bacillus subtilis exfusants: a controversy. II. No experimental support for diploidy and chromosomal silencing. Microbiology. 1994 Jan;140(Pt 1):2–3. doi: 10.1099/13500872-140-1-2. [DOI] [PubMed] [Google Scholar]
  12. Hauser P. M., Karamata D. Ploidy of Bacillus subtilis exfusants: the haploid nature of cells forming colonies with biparental or prototrophic phenotypes. J Gen Microbiol. 1992 Jun;138(6):1077–1088. doi: 10.1099/00221287-138-6-1077. [DOI] [PubMed] [Google Scholar]
  13. Horinouchi S., Weisblum B. Nucleotide sequence and functional map of pC194, a plasmid that specifies inducible chloramphenicol resistance. J Bacteriol. 1982 May;150(2):815–825. doi: 10.1128/jb.150.2.815-825.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Hotchkiss R. D., Gabor M. H. Biparental products of bacterial protoplast fusion showing unequal parental chromosome expression. Proc Natl Acad Sci U S A. 1980 Jun;77(6):3553–3557. doi: 10.1073/pnas.77.6.3553. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Itaya M., Tanaka T. Complete physical map of the Bacillus subtilis 168 chromosome constructed by a gene-directed mutagenesis method. J Mol Biol. 1991 Aug 5;220(3):631–648. doi: 10.1016/0022-2836(91)90106-g. [DOI] [PubMed] [Google Scholar]
  16. Le Dérout J., Thaler D. S., Guillén N., Hirschbein L. The spo0A gene is implicated in the maintenance of non-complementing diploids in Bacillus subtilis. Mol Microbiol. 1992 Jun;6(11):1495–1505. doi: 10.1111/j.1365-2958.1992.tb00870.x. [DOI] [PubMed] [Google Scholar]
  17. Lynch A. S., Wang J. C. SopB protein-mediated silencing of genes linked to the sopC locus of Escherichia coli F plasmid. Proc Natl Acad Sci U S A. 1995 Mar 14;92(6):1896–1900. doi: 10.1073/pnas.92.6.1896. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Lévi-Meyrueis C., Sanchez-Rivas C. Complementation and genetic inactivation: two alternative mechanisms leading to prototrophy in diploid bacterial clones. Mol Gen Genet. 1984;196(3):488–493. doi: 10.1007/BF00436197. [DOI] [PubMed] [Google Scholar]
  19. Lévi-Meyrueis C., Sanchez-Rivas C., Schaeffer P. Formation de bactéries diploïdes stables par fusion de protoplastes de Bacillus subtilis et effet de mutations rec- sur les produits de fusion formés. C R Seances Acad Sci D. 1980 Jul 7;291(1):67–70. [PubMed] [Google Scholar]
  20. Niaudet B., Ehrlich S. D. In vitro genetic labeling of Bacillus subtilis cryptic plasmid pHV400. Plasmid. 1979 Jan;2(1):48–58. doi: 10.1016/0147-619x(79)90005-2. [DOI] [PubMed] [Google Scholar]
  21. Sanchez-Rivas C., Levi-Meyrueis C. Ploidy of Bacillus subtilis exfusants: a controversy. I. The case for diploidy. Microbiology. 1994 Jan;140(Pt 1):1–2. doi: 10.1099/13500872-140-1-a. [DOI] [PubMed] [Google Scholar]
  22. Schaeffer P., Cami B., Hotchkiss R. D. Fusion of bacterial protoplasts. Proc Natl Acad Sci U S A. 1976 Jun;73(6):2151–2155. doi: 10.1073/pnas.73.6.2151. [DOI] [PMC free article] [PubMed] [Google Scholar]

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