Skip to main content
Genetics logoLink to Genetics
. 1998 Sep;150(1):21–30. doi: 10.1093/genetics/150.1.21

The [KIL-d] cytoplasmic genetic element of yeast results in epigenetic regulation of viral M double-stranded RNA gene expression.

Z Tallóczy 1, S Menon 1, L Neigeborn 1, M J Leibowitz 1
PMCID: PMC1460321  PMID: 9725827

Abstract

[KIL-d] is a cytoplasmically inherited genetic trait that causes killer virus-infected cells of Saccharomyces cerevisiae to express the normal killer phenotypes in a/alpha cells, but to show variegated defective killer phenotypes in a or alpha type cells. Mating of [KIL-d] haploids results in "healing" of their phenotypic defects, while meiosis of the resulting diploids results in "resetting" of the variegated, but mitotically stable, defects. We show that [KIL-d] does not reside on the double-stranded RNA genome of killer virus. Thus, the [KIL-d] effect on viral gene expression is epigenetic in nature. Resetting requires nuclear events of meiosis, since [KIL-d] can be cytoplasmically transmitted during cytoduction without causing defects in killer virus expression. Subsequently, mating of these cytoductants followed by meiosis generates spore clones expressing variegated defective phenotypes. Cytoduction of wild-type cytoplasm into a phenotypically defective [KIL-d] haploid fails to heal, nor does simultaneous or sequential expression of both MAT alleles cause healing. Thus, healing is not triggered by the appearance of heterozygosity at the MAT locus, but rather requires the nuclear fusion events which occur during mating. Therefore, [KIL-d] appears to interact with the nucleus in order to exert its effects on gene expression by the killer virus RNA genome.

Full Text

The Full Text of this article is available as a PDF (111.8 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Aigle M., Lacroute F. Genetical aspects of [URE3], a non-mitochondrial, cytoplasmically inherited mutation in yeast. Mol Gen Genet. 1975;136(4):327–335. doi: 10.1007/BF00341717. [DOI] [PubMed] [Google Scholar]
  2. Conde J., Fink G. R. A mutant of Saccharomyces cerevisiae defective for nuclear fusion. Proc Natl Acad Sci U S A. 1976 Oct;73(10):3651–3655. doi: 10.1073/pnas.73.10.3651. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Derkatch I. L., Bradley M. E., Zhou P., Chernoff Y. O., Liebman S. W. Genetic and environmental factors affecting the de novo appearance of the [PSI+] prion in Saccharomyces cerevisiae. Genetics. 1997 Oct;147(2):507–519. doi: 10.1093/genetics/147.2.507. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Derkatch I. L., Chernoff Y. O., Kushnirov V. V., Inge-Vechtomov S. G., Liebman S. W. Genesis and variability of [PSI] prion factors in Saccharomyces cerevisiae. Genetics. 1996 Dec;144(4):1375–1386. doi: 10.1093/genetics/144.4.1375. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Dinman J. D., Icho T., Wickner R. B. A -1 ribosomal frameshift in a double-stranded RNA virus of yeast forms a gag-pol fusion protein. Proc Natl Acad Sci U S A. 1991 Jan 1;88(1):174–178. doi: 10.1073/pnas.88.1.174. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Dinman J. D. Ribosomal frameshifting in yeast viruses. Yeast. 1995 Sep 30;11(12):1115–1127. doi: 10.1002/yea.320111202. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Fried H. M., Fink G. R. Electron microscopic heteroduplex analysis of "killer" double-stranded RNA species from yeast. Proc Natl Acad Sci U S A. 1978 Sep;75(9):4224–4228. doi: 10.1073/pnas.75.9.4224. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Goldring E. S., Grossman L. I., Krupnick D., Cryer D. R., Marmur J. The petite mutation in yeast. Loss of mitochondrial deoxyribonucleic acid during induction of petites with ethidium bromide. J Mol Biol. 1970 Sep 14;52(2):323–335. doi: 10.1016/0022-2836(70)90033-1. [DOI] [PubMed] [Google Scholar]
  9. Hannig E. M., Leibowitz M. J., Wickner R. B. On the mechanism of exclusion of M2 double-stranded RNA by L-A-E double-stranded RNA in Saccharomyces cerevisiae. Yeast. 1985 Sep;1(1):57–65. doi: 10.1002/yea.320010107. [DOI] [PubMed] [Google Scholar]
  10. Henikoff S., Matzke M. A. Exploring and explaining epigenetic effects. Trends Genet. 1997 Aug;13(8):293–295. doi: 10.1016/s0168-9525(97)01219-5. [DOI] [PubMed] [Google Scholar]
  11. Herskowitz I., Jensen R. E. Putting the HO gene to work: practical uses for mating-type switching. Methods Enzymol. 1991;194:132–146. doi: 10.1016/0076-6879(91)94011-z. [DOI] [PubMed] [Google Scholar]
  12. Icho T., Wickner R. B. The double-stranded RNA genome of yeast virus L-A encodes its own putative RNA polymerase by fusing two open reading frames. J Biol Chem. 1989 Apr 25;264(12):6716–6723. [PubMed] [Google Scholar]
  13. Leibowitz M. J., Wickner R. B. Pet18: a chromosomal gene required for cell growth and for the maintenance of mitochondrial DNA and the killer plasmid of yeast. Mol Gen Genet. 1978 Oct 4;165(2):115–121. doi: 10.1007/BF00269899. [DOI] [PubMed] [Google Scholar]
  14. Michaelis G., Douglass S., Tsai M. J., Criddle R. S. Mitochondrial DNA and suppressiveness of petite mutants in Saccharomyces cerevisiae. Biochem Genet. 1971 Oct;5(5):487–495. doi: 10.1007/BF00487138. [DOI] [PubMed] [Google Scholar]
  15. Mitchell A. P., Herskowitz I. Activation of meiosis and sporulation by repression of the RME1 product in yeast. 1986 Feb 27-Mar 5Nature. 319(6056):738–742. doi: 10.1038/319738a0. [DOI] [PubMed] [Google Scholar]
  16. Prusiner S. B. Prion diseases and the BSE crisis. Science. 1997 Oct 10;278(5336):245–251. doi: 10.1126/science.278.5336.245. [DOI] [PubMed] [Google Scholar]
  17. SHERMAN F. The effects of elevated temperatures on yeast. II. Induction of respiratory-deficient mutants. J Cell Comp Physiol. 1959 Aug;54:37–52. doi: 10.1002/jcp.1030540106. [DOI] [PubMed] [Google Scholar]
  18. Sommer S. S., Wickner R. B. Yeast L dsRNA consists of at least three distinct RNAs; evidence that the non-Mendelian genes [HOK], [NEX] and [EXL] are on one of these dsRNAs. Cell. 1982 Dec;31(2 Pt 1):429–441. doi: 10.1016/0092-8674(82)90136-2. [DOI] [PubMed] [Google Scholar]
  19. Thiele D. J., Hannig E. M., Leibowitz M. J. Multiple L double-stranded RNA species of Saccharomyces cerevisiae: evidence for separate encapsidation. Mol Cell Biol. 1984 Jan;4(1):92–100. doi: 10.1128/mcb.4.1.92. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Weinstein L. A., Capaldo-Kimball F., Leibowitz M. J. Genetics of heat-curability of killer virus of yeast. Yeast. 1993 Apr;9(4):411–418. doi: 10.1002/yea.320090411. [DOI] [PubMed] [Google Scholar]
  21. Welsh J. D., Leibowitz M. J., Wickner R. B. Virion DNA-independent RNA polymerase from Saccharomyces cerevisiae. Nucleic Acids Res. 1980 Jun 11;8(11):2349–2363. doi: 10.1093/nar/8.11.2349. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Wickner R. B. "Killer character" of Saccharomyces cerevisiae: curing by growth at elevated temperature. J Bacteriol. 1974 Mar;117(3):1356–1357. doi: 10.1128/jb.117.3.1356-1357.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Wickner R. B. Chromosomal and nonchromosomal mutations affecting the "killer character" of Saccharomyces cerevisiae. Genetics. 1974 Mar;76(3):423–432. doi: 10.1093/genetics/76.3.423. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Wickner R. B. Double-stranded RNA viruses of Saccharomyces cerevisiae. Microbiol Rev. 1996 Mar;60(1):250–265. doi: 10.1128/mr.60.1.250-265.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Wickner R. B. [URE3] as an altered URE2 protein: evidence for a prion analog in Saccharomyces cerevisiae. Science. 1994 Apr 22;264(5158):566–569. doi: 10.1126/science.7909170. [DOI] [PubMed] [Google Scholar]

Articles from Genetics are provided here courtesy of Oxford University Press

RESOURCES