Autonomous replication and addition of telomerelike sequences to DNA microinjected into Paramecium tetraurelia macronuclei (original) (raw)

Abstract

Paramecium tetraurelia can be transformed by microinjection of cloned serotype A gene sequences into the macronucleus. Transformants are detected by their ability to express serotype A surface antigen from the injected templates. After injection, the DNA is converted from a supercoiled form to a linear form by cleavage at nonrandom sites. The linear form appears to replicate autonomously as a unit-length molecule and is present in transformants at high copy number. The injected DNA is further processed by the addition of paramecium-type telomeric sequences to the termini of the linear DNA. To examine the fate of injected linear DNA molecules, plasmid pSA14SB DNA containing the A gene was cleaved into two linear pieces, a 14-kilobase (kb) piece containing the A gene and flanking sequences and a 2.2-kb piece consisting of the procaryotic vector. In transformants expressing the A gene, we observed that two linear DNA species were present which correspond to the two species injected. Both species had Paramecium telomerelike sequences added to their termini. For the 2.2-kb DNA, we show that the site of addition of the telomerelike sequences is directly at one terminus and within one nucleotide of the other terminus. These results indicate that injected procaryotic DNA is capable of autonomous replication in Paramecium macronuclei and that telomeric addition in the macronucleus does not require specific recognition sequences.

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Selected References

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  1. Blackburn E. H., Karrer K. M. Genomic reorganization in ciliated protozoans. Annu Rev Genet. 1986;20:501–521. doi: 10.1146/annurev.ge.20.120186.002441. [DOI] [PubMed] [Google Scholar]
  2. Capecchi M. R. High efficiency transformation by direct microinjection of DNA into cultured mammalian cells. Cell. 1980 Nov;22(2 Pt 2):479–488. doi: 10.1016/0092-8674(80)90358-x. [DOI] [PubMed] [Google Scholar]
  3. Dawson D., Herrick G. Rare internal C4A4 repeats in the micronuclear genome of Oxytricha fallax. Mol Cell Biol. 1984 Dec;4(12):2661–2667. doi: 10.1128/mcb.4.12.2661. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Epstein L. M., Forney J. D. Mendelian and non-mendelian mutations affecting surface antigen expression in Paramecium tetraurelia. Mol Cell Biol. 1984 Aug;4(8):1583–1590. doi: 10.1128/mcb.4.8.1583. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Findly R. C., Gall J. G. Free ribosomal RNA genes in Paramecium are tandemly repeated. Proc Natl Acad Sci U S A. 1978 Jul;75(7):3312–3316. doi: 10.1073/pnas.75.7.3312. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Folger K. R., Wong E. A., Wahl G., Capecchi M. R. Patterns of integration of DNA microinjected into cultured mammalian cells: evidence for homologous recombination between injected plasmid DNA molecules. Mol Cell Biol. 1982 Nov;2(11):1372–1387. doi: 10.1128/mcb.2.11.1372. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Forney J. D., Blackburn E. H. Developmentally controlled telomere addition in wild-type and mutant paramecia. Mol Cell Biol. 1988 Jan;8(1):251–258. doi: 10.1128/mcb.8.1.251. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Forney J. D., Epstein L. M., Preer L. B., Rudman B. M., Widmayer D. J., Klein W. H., Preer J. R., Jr Structure and expression of genes for surface proteins in Paramecium. Mol Cell Biol. 1983 Mar;3(3):466–474. doi: 10.1128/mcb.3.3.466. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Godiska R., Aufderheide K. J., Gilley D., Hendrie P., Fitzwater T., Preer L. B., Polisky B., Preer J. R., Jr Transformation of Paramecium by microinjection of a cloned serotype gene. Proc Natl Acad Sci U S A. 1987 Nov;84(21):7590–7594. doi: 10.1073/pnas.84.21.7590. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Graham F. L., van der Eb A. J. A new technique for the assay of infectivity of human adenovirus 5 DNA. Virology. 1973 Apr;52(2):456–467. doi: 10.1016/0042-6822(73)90341-3. [DOI] [PubMed] [Google Scholar]
  11. Greider C. W., Blackburn E. H. Identification of a specific telomere terminal transferase activity in Tetrahymena extracts. Cell. 1985 Dec;43(2 Pt 1):405–413. doi: 10.1016/0092-8674(85)90170-9. [DOI] [PubMed] [Google Scholar]
  12. Harland R. M., Laskey R. A. Regulated replication of DNA microinjected into eggs of Xenopus laevis. Cell. 1980 Oct;21(3):761–771. doi: 10.1016/0092-8674(80)90439-0. [DOI] [PubMed] [Google Scholar]
  13. Orr-Weaver T. L., Szostak J. W., Rothstein R. J. Yeast transformation: a model system for the study of recombination. Proc Natl Acad Sci U S A. 1981 Oct;78(10):6354–6358. doi: 10.1073/pnas.78.10.6354. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Perucho M., Hanahan D., Wigler M. Genetic and physical linkage of exogenous sequences in transformed cells. Cell. 1980 Nov;22(1 Pt 1):309–317. doi: 10.1016/0092-8674(80)90178-6. [DOI] [PubMed] [Google Scholar]
  15. Struhl K., Stinchcomb D. T., Scherer S., Davis R. W. High-frequency transformation of yeast: autonomous replication of hybrid DNA molecules. Proc Natl Acad Sci U S A. 1979 Mar;76(3):1035–1039. doi: 10.1073/pnas.76.3.1035. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Szostak J. W., Blackburn E. H. Cloning yeast telomeres on linear plasmid vectors. Cell. 1982 May;29(1):245–255. doi: 10.1016/0092-8674(82)90109-x. [DOI] [PubMed] [Google Scholar]