Skip to main content
NCBI home page
The Journal of Cell Biology logoLink to The Journal of Cell Biology
. 1976 May 1;69(2):352–370. doi: 10.1083/jcb.69.2.352

Characterization of cytoplasmic and nuclear genomes in the colorless alga Polytoma. I. Ultrastructural analysis of organelles

PMCID: PMC2109689  PMID: 177431

Abstract

Electron microscope studies have been made on the fine structure of the colorless biflagellate, Polytoma obtusum, with main emphasis on the structural organization of the mitochondria and the leucoplast. Both organelles have been demonstrated to contain DNA aggregates as well as ribosomal particles within their matrix material. Reconstructions from serial showed that (a) the mitochondria were highly convoluted and irregular in shape and size, and (b) the leucoplast was a single cup- shaped entity, with large starch grains, localized at the posterior end, and multiple sites of DNA aggregates. The starch-containing compartments appeared to be interconnected by narrow tubular or sheetlike bridges. Cytoplasmic invaginations into the plastid, often containing mitochondria, were of frequent occurrence, and membranes of mitochondria and the leucoplast appeared to be closely apposed. Membranes elements, both sheetlike and vesicular, were also present in the matrix. The Polytoma leucoplast was, in certain respects, morphologically similar to the plastids of various photosynthetic mutants of Chlamydomonas, most of which show Menedelian segregation. It is suggested that Polytoma arose from a Chlamydomonas-like ancestor, possibly through combined mutational processess of both chloroplast and nuclear genomes. Since Polytoma leucoplasts contain both DNA and ribosomal particles, it is probable that these organelles still possess semiautonomy and limited ability for protein synthesis.

Full Text

The Full Text of this article is available as a PDF (8.9 MB).

Selected References

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

  1. Armstrong J. J., Moll B., Surzycki S. J., Levine R. P. Genetic transcription and translation specifying chloroplast components in Chlamydomonas reinhardi. Biochemistry. 1971 Feb 16;10(4):692–701. doi: 10.1021/bi00780a022. [DOI] [PubMed] [Google Scholar]
  2. Arnold C. G., Schimmer O., Schötz F., Bathelt H. Die Mitochondrien von Chlamydomonas reinhardii. Arch Mikrobiol. 1972;81(1):50–67. [PubMed] [Google Scholar]
  3. Bastia D., Chiang K. S., Swift H., Siersma P. Heterogeneity, complexity, and repetition of the chloroplast DNA of Chlamydomonas reinhardtii. Proc Natl Acad Sci U S A. 1971 Jun;68(6):1157–1161. doi: 10.1073/pnas.68.6.1157. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. 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]
  5. 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]
  6. GIBOR A., GRANICK S. PLASTIDS AND MITOCHONDRIA: INHERITABLE SYSTEMS. Science. 1964 Aug 14;145(3633):890–897. doi: 10.1126/science.145.3635.890. [DOI] [PubMed] [Google Scholar]
  7. Goodenough U. W., Levine R. P. Chloroplast structure and function in ac-20, a mutant strain of Chlamydomonas reinhardi. 3. Chloroplast ribosomes and membrane organization. J Cell Biol. 1970 Mar;44(3):547–562. doi: 10.1083/jcb.44.3.547. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Gross R. E., Dugger W. M. Photoinhibition of growth of a yellow and colorless form of Chlamydomonas reinhardtii. Photochem Photobiol. 1969 Oct;10(4):243–250. doi: 10.1111/j.1751-1097.1969.tb05687.x. [DOI] [PubMed] [Google Scholar]
  9. 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]
  10. KISLEV N., SWIFT H., BOGORAD L. NUCLEIC ACIDS OF CHLOROPLASTS AND MITOCHONDRIA IN SWISS CHARD. J Cell Biol. 1965 May;25:327–344. doi: 10.1083/jcb.25.2.327. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. LANG N. J. AN ADDITIONAL ULTRASTRUCTURAL COMPONENT OF FLAGELLA. J Cell Biol. 1963 Dec;19:631–634. doi: 10.1083/jcb.19.3.631. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. LANG N. J. ELECTRON-MICROSCOPIC DEMONSTRATION OF PLASTIDS IN POLYTOMA. J Protozool. 1963 Aug;10:333–339. doi: 10.1111/j.1550-7408.1963.tb01685.x. [DOI] [PubMed] [Google Scholar]
  13. LUFT J. H. Improvements in epoxy resin embedding methods. J Biophys Biochem Cytol. 1961 Feb;9:409–414. doi: 10.1083/jcb.9.2.409. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Levine R. P., Goodenough U. W. The genetics of photosynthesis and of the chloroplast in Chlamydomonas reinhardi. Annu Rev Genet. 1970;4:397–408. doi: 10.1146/annurev.ge.04.120170.002145. [DOI] [PubMed] [Google Scholar]
  15. Michaels A., Gibor A. Ultrastructural changes in Euglena after ultraviolet irradiation. J Cell Sci. 1973 Nov;13(3):799–809. doi: 10.1242/jcs.13.3.799. [DOI] [PubMed] [Google Scholar]
  16. NASS M. M., NASS S., AFZELIUS B. A. THE GENERAL OCCURENCE OF MITOCHONDRIAL DNA. Exp Cell Res. 1965 Mar;37:516–539. doi: 10.1016/0014-4827(65)90204-1. [DOI] [PubMed] [Google Scholar]
  17. NASS M. M., NASS S. INTRAMITOCHONDRIAL FIBERS WITH DNA CHARACTERISTICS. I. FIXATION AND ELECTRON STAINING REACTIONS. J Cell Biol. 1963 Dec;19:593–611. doi: 10.1083/jcb.19.3.593. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Ohad I., Siekevitz P., Palade G. E. Biogenesis of chloroplast membranes. I. Plastid dedifferentiation in a dark-grown algal mutant (Chlamydomonas reinhardi). J Cell Biol. 1967 Dec;35(3):521–552. doi: 10.1083/jcb.35.3.521. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. 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]
  20. REYNOLDS E. S. The use of lead citrate at high pH as an electron-opaque stain in electron microscopy. J Cell Biol. 1963 Apr;17:208–212. doi: 10.1083/jcb.17.1.208. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. RIS H., PLAUT W. Ultrastructure of DNA-containing areas in the chloroplast of Chlamydomonas. J Cell Biol. 1962 Jun;13:383–391. doi: 10.1083/jcb.13.3.383. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. RIS H., SINGH R. N. Electron microscope studies on blue-green algae. J Biophys Biochem Cytol. 1961 Jan;9:63–80. doi: 10.1083/jcb.9.1.63. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. RIS H. Ultrastructure and molecular organization of genetic systems. Can J Genet Cytol. 1961 Jun;3:95–120. doi: 10.1139/g61-015. [DOI] [PubMed] [Google Scholar]
  24. Ringo D. L. Flagellar motion and fine structure of the flagellar apparatus in Chlamydomonas. J Cell Biol. 1967 Jun;33(3):543–571. doi: 10.1083/jcb.33.3.543. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. SAGER R., PALADE G. E. Structure and development of the chloroplast in Chlamydomonas. I. The normal green cell. J Biophys Biochem Cytol. 1957 May 25;3(3):463–488. doi: 10.1083/jcb.3.3.463. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Sepsenwol S. Leucoplast of the cryptomonad Chilomonas paramecium. Evidence for presence of a true plastid in a colorless flagellate. Exp Cell Res. 1973 Feb;76(2):395–409. doi: 10.1016/0014-4827(73)90392-3. [DOI] [PubMed] [Google Scholar]
  27. 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]
  28. Wells R., Sager R. Denaturation and the renaturation kinetics of chloroplast DNA from Chlamydomonas reinhardi. J Mol Biol. 1971 Jun 14;58(2):611–622. doi: 10.1016/0022-2836(71)90375-5. [DOI] [PubMed] [Google Scholar]

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

RESOURCES