Skip to main content
NCBI home page
The Journal of Cell Biology logoLink to The Journal of Cell Biology
. 1976 May 1;69(2):371–382. doi: 10.1083/jcb.69.2.371

Characterization of cytoplasmic and nuclear genomes in the colorless alga Polytoma. II. General characterization of organelle nucleic acids

PMCID: PMC2109693  PMID: 1262395

Abstract

Polytoma obtusum has a main band DNA (alpha) with a buoyant density in CsC1 of rho = 1.711 g/ml and a light DNA satellite (beta) with rho = 1.682 g/ml. beta-DNA was substantially enriched in a fraction containing small leucoplast fragments and some mitochondria, which was obtained in a pellet sedimenting between 3,000 g and 5,000 g. A crude mitochondrial pellet was also obtained by sedimenting at 12,000 g to recover particulates remaining in the supernate after 10 min at 5,000 g. This fraction contained a third DNA component (gamma) with rho = 1.714 g/ml. We have concluded that the leucoplasts of P. obtusum contain the beta-DNA (1.6882) and the mitochondria possess the gamma- component (1.714). Two distinct classess of ribosomes were isolated and separated by sucrose density gradients, a major 79S species and a minor species at 75S. The major species possessed the 25S and 18S ribosomal RNA (rRNA), characteristic of cytoplasmic ribosomes, and these particles co-sedimented in sucrose gradients with the 79S cytoplasmic ribosomes of Chlamydomonas reinhardtii. The minor species was present in about 2% of the total ribosomal population but showed an eight-to- ninefold enrichment in the leucoplast pellet, suggesting that it was of organelle origin. These 73S particles had RNA components migrating very closely with the 18S and 25S species of the 79S ribosomes, but the base composition of the rRNA from these two classes of ribosomes was significantly different; the rRNA from the 79S ribosomes had a G+C mole ratio of 50.0%, while the rRNA from the 73S class had a ratio of 47.5%. By comparison, chloroplast ribosomes of C. reinhardtii were found to sediment at 70S and contain rRNA molecules of 23S and 16S, with a G + C content of 51.0%. These findings support the concept that the Polytoma leucoplast possesses characteristic genetic and protein-forming systems.

Full Text

The Full Text of this article is available as a PDF (1.6 MB).

Selected References

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

  1. BRAWERMAN G., EISENSTADT J. M. DEOXYRIBONUCLEIC ACID FROM THE CHLOROPLASTS OF EUGLENA GRACILIS. Biochim Biophys Acta. 1964 Nov 15;91:477–485. doi: 10.1016/0926-6550(64)90077-5. [DOI] [PubMed] [Google Scholar]
  2. Bourque D. P., Boynton J. E., Gillham N. W. Studies on the structure and cellular location of various ribosome and ribosomal RNA species in the green alga Chlamydomonas reinhardi. J Cell Sci. 1971 Jan;8(1):153–183. doi: 10.1242/jcs.8.1.153. [DOI] [PubMed] [Google Scholar]
  3. CHUN E. H., VAUGHAN M. H., Jr, RICH A. THE ISOLATION AND CHARACTERIZATION OF DNA ASSOCIATED WITH CHLOROPLAST PREPARATIONS. J Mol Biol. 1963 Aug;7:130–141. doi: 10.1016/s0022-2836(63)80042-x. [DOI] [PubMed] [Google Scholar]
  4. Chiang K. S. Physical conservation of parental cytoplasmic DNA through meiosis in Chlamydomonas reinhardi. Proc Natl Acad Sci U S A. 1968 May;60(1):194–200. doi: 10.1073/pnas.60.1.194. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Chiang K. S., Sueoka N. Replication of chloroplast DNA in Chlamydomonas reinhardi during vegetative cell cycle: its mode and regulation. Proc Natl Acad Sci U S A. 1967 May;57(5):1506–1513. doi: 10.1073/pnas.57.5.1506. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. EDELMAN M., SCHIFF J. A., EPSTEIN H. T. STUDIES OF CHLOROPLAST DEVELOPMENT IN EUGLENA. XII. TWO TYPES OF SATELLITE DNA. J Mol Biol. 1965 Apr;11:769–774. doi: 10.1016/s0022-2836(65)80034-1. [DOI] [PubMed] [Google Scholar]
  7. Edelman M., Cowan C. A., Epstein H. T., Schiff J. A. STUDIES OF CHLOROPLAST DEVELOPMENT IN EUGLENA, VIII. CHLOROPLAST-ASSOCIATED DNA. Proc Natl Acad Sci U S A. 1964 Nov;52(5):1214–1219. doi: 10.1073/pnas.52.5.1214. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Fauman M., Rabiwitz M., Getz G. S. Base composition and sedimentation properties of mitochondrial RNA of Saccharomyces cerebisiae. Biochim Biophys Acta. 1969 Jun 17;182(2):355–360. doi: 10.1016/0005-2787(69)90186-5. [DOI] [PubMed] [Google Scholar]
  9. Faye G., Fukuhara H., Grandchamp C., Lazowska J., Michel F., Casey J., Getz G. S., Locker J., Rabinowitz M., Bolotin-Fukuhara M. Mitochondrial nucleic acids in the petite colonie mutants: deletions and repetition of genes. Biochimie. 1973;55(6):779–792. doi: 10.1016/s0300-9084(73)80030-6. [DOI] [PubMed] [Google Scholar]
  10. Hoober J. K., Blobel G. Characterization of the chloroplastic and cytoplasmic ribosomes of Chlamydomonas reinhardi. J Mol Biol. 1969 Apr 14;41(1):121–138. doi: 10.1016/0022-2836(69)90130-2. [DOI] [PubMed] [Google Scholar]
  11. Kieras F. J., Chiang K. S. Characterization of DNA components from some colorless algae. Exp Cell Res. 1971 Jan;64(1):89–96. doi: 10.1016/0014-4827(71)90196-0. [DOI] [PubMed] [Google Scholar]
  12. Krawiec S., Eisenstadt J. M. Ribonucleic acids from the mitochondria of bleached Euglena gracilis Z. I. Isolation of mitochondria and extraction of nucleic acids. Biochim Biophys Acta. 1970 Sep 17;217(1):120–131. doi: 10.1016/0005-2787(70)90128-0. [DOI] [PubMed] [Google Scholar]
  13. Loening U. E. Molecular weights of ribosomal RNA in relation to evolution. J Mol Biol. 1968 Dec;38(3):355–365. doi: 10.1016/0022-2836(68)90391-4. [DOI] [PubMed] [Google Scholar]
  14. Loening U. E. The fractionation of high-molecular-weight ribonucleic acid by polyacrylamide-gel electrophoresis. Biochem J. 1967 Jan;102(1):251–257. doi: 10.1042/bj1020251. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Mets L., Bogorad L. Altered chlorplast ribosomal proteins associated with erythromycin-resistant mutants in two genetic systems of Chlamydomonas reinhardi. Proc Natl Acad Sci U S A. 1972 Dec;69(12):3779–3783. doi: 10.1073/pnas.69.12.3779. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Noll H. Characterization of macromolecules by constant velocity sedimentation. Nature. 1967 Jul 22;215(5099):360–363. doi: 10.1038/215360a0. [DOI] [PubMed] [Google Scholar]
  17. RAY D. S., HANAWALT P. C. PROPERTIES OF THE SATELLITE DNA ASSOCIATED WITH THE CHLOROPLASTS OF EUGLENA GRACILIS. J Mol Biol. 1964 Sep;9:812–824. doi: 10.1016/s0022-2836(64)80187-x. [DOI] [PubMed] [Google Scholar]
  18. RAY D. S., HANAWALT P. C. SATELLITE DNA COMPONENTS IN EUGLENA GRACILIS CELLS LACKING CHLOROPLASTS. J Mol Biol. 1965 Apr;11:760–768. doi: 10.1016/s0022-2836(65)80033-x. [DOI] [PubMed] [Google Scholar]
  19. Rawson J. R., Crouse E. J., Stutz E. The integrity of the 25-S ribosomal RNA from Euglena gracilis 87-S ribosomes. Biochim Biophys Acta. 1971 Sep 24;246(3):507–516. doi: 10.1016/0005-2787(71)90788-x. [DOI] [PubMed] [Google Scholar]
  20. Rifkin M. R., Wood D. D., Luck D. J. Ribosomal RNA and ribosomes from mitochondria of Neurospora crassa. Proc Natl Acad Sci U S A. 1967 Sep;58(3):1025–1032. doi: 10.1073/pnas.58.3.1025. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. SAGER R., ISHIDA M. R. CHLOROPLAST DNA IN CHLAMYDOMONAS. Proc Natl Acad Sci U S A. 1963 Oct;50:725–730. doi: 10.1073/pnas.50.4.725. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. SCHILDKRAUT C. L., MARMUR J., DOTY P. Determination of the base composition of deoxyribonucleic acid from its buoyant density in CsCl. J Mol Biol. 1962 Jun;4:430–443. doi: 10.1016/s0022-2836(62)80100-4. [DOI] [PubMed] [Google Scholar]
  23. Schlanger G., Sager R., Ramanis Z. Mutation of a cytoplasmic gene in Chlamydomonas alters chlorplast ribosome function. Proc Natl Acad Sci U S A. 1972 Dec;69(12):3551–3555. doi: 10.1073/pnas.69.12.3551. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Siersma P. W., Chiang K. S. Conservation and degradation of cytoplasmic and chloroplast ribosomes in Chlamydomonas reinhardtii. J Mol Biol. 1971 May 28;58(1):167–185. doi: 10.1016/0022-2836(71)90239-7. [DOI] [PubMed] [Google Scholar]
  25. Sinclair J. H., Brown D. D. Retention of common nucleotide sequences in the ribosomal deoxyribonucleic acid of eukaryotes and some of their physical characteristics. Biochemistry. 1971 Jul 6;10(14):2761–2769. doi: 10.1021/bi00790a017. [DOI] [PubMed] [Google Scholar]
  26. Siu C. H., Chiang K. S., Swift H. Characterization of cytoplasmic and nuclear genomes in the colorless alga Polytoma. IV. Heterogeneity and complexity of the nuclear genome. Chromosoma. 1974;48(1):19–40. doi: 10.1007/BF00284864. [DOI] [PubMed] [Google Scholar]
  27. Siu C. H., Chiang K. S., Swift H. Characterization of cytoplasmic and nuclear genomes in the colorless alga Polytoma. V. Molecular structure and heterogenity of leucoplast DNA. J Mol Biol. 1975 Oct 25;98(2):369–391. doi: 10.1016/s0022-2836(75)80125-2. [DOI] [PubMed] [Google Scholar]
  28. Siu C., Chiang K., Swift H. Characterization of cytoplasmic and nuclear genomes in the colorless alga Polytoma. III. Ribosomal RNA cistrons of the nucleus and leucoplast. J Cell Biol. 1976 May;69(2):383–392. doi: 10.1083/jcb.69.2.383. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Siu C., Swift H., Chiang K. Characterization of cytoplasmic and nuclear genomes in the colorless alga Polytoma. I. Ultrastructural analysis of organelles. J Cell Biol. 1976 May;69(2):352–370. doi: 10.1083/jcb.69.2.352. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Stutz E., Noll H. Characterization of cytoplasmic and chloroplast polysomes in plants: evidence for three classes of ribosomal RNA in nature. Proc Natl Acad Sci U S A. 1967 Mar;57(3):774–781. doi: 10.1073/pnas.57.3.774. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. Sueoka N., Chiang K. S., Kates J. R. Deoxyribonucleic acid replication in meiosis of Chlamydomonas reinhardi. I. Isotopic transfer experiments with a strain producing eight zoospores. J Mol Biol. 1967 Apr 14;25(1):47–66. doi: 10.1016/0022-2836(67)90278-1. [DOI] [PubMed] [Google Scholar]
  32. Surzycki S., Hastings P. J. Control of chloroplast RNA synthesis in Chlamydomonas rinhardi. Nature. 1968 Nov 23;220(5169):786–787. doi: 10.1038/220786a0. [DOI] [PubMed] [Google Scholar]

Articles from The Journal of Cell Biology are provided here courtesy of The Rockefeller University Press

RESOURCES