Received 2 December 1991. Accepted 21 February 1992.
DNA NUCLEOSIDE COMPOSITION AND METHYLATION IN SEVERAL SPECIES OF MICROALGAE1
Article first published online: 26 OCT 2004
Journal of Phycology
Volume 28, Issue 3, pages 356–362, June 1992
How to Cite
Jarvis, E. E., Dunahay, T. G. and Brown, L. M. (1992), DNA NUCLEOSIDE COMPOSITION AND METHYLATION IN SEVERAL SPECIES OF MICROALGAE. Journal of Phycology, 28: 356–362. doi: 10.1111/j.0022-3646.1992.00356.x
Previously Solar Energy Research Institute (SERI).
HPLC analysis of DNA samples was performed by Charles Gehrke and Ken Kuo at the Cancer Research Center, Columbia, Missouri. We are grateful to Kathryn Zeiler and Robert Laymon for critical reading of the manuscript. The technical assistance of Nicholas Nagle and Gordon Hahn in DNA extractions is appreciated. Financial support through the Aquatic Species Project of the Bio-fuels Systems Division, U.S. Department of Energy, is gratefully acknowledged.
- Issue published online: 26 OCT 2004
- Article first published online: 26 OCT 2004
- Crypthecodinium cohnii;
- Cyclotella cryptica;
- DNA composition;
- DNA methylation;
- GC content;
- Monoraphidium minutum;
- Nitzschia pusilla;
- Phaeodactylum tricornutum;
- Tetraselmis suecica
Total DNA was isolated from 10 species of microalgae, including representatives of the Chlorophyceae (Chlorella ellipsoidea, Chlamydomonas reinhardtii, and Monoraphidium minutum), Bacillariophyceae (Cyclotella cryptica, Navicula saprophila, Nitzschia pusilla, and Phaeodactylum tricornutum), Charophyceae (Stichococcus sp.), Dinophyceae (Crypthecodinium cohnii), and Prasinophyceae (Tetraselmis suecica). Control samples of Escherichia coli and calf thymus DNA were also analyzed. The nucleoside base composition of each DNA sample was determined by reversed-phase high performance liquid chromatography. All samples contained 5-methyldeoxycytidine, although at widely varying levels. In M. minutum, about one-third of the cytidine residues were methylated. Restriction analysis supported this high degree of methylation in M. minutum and suggested that methylation is biased toward 5′-CG dinucleotides. The guanosine + cytosine (GC) contents of the green algae were, with the exception of Stichococcus sp., consistently higher than those of the diatoms. Monoraphidium minutum exhibited an extremely high GC content of 71%. Such a value is rare among eukaryotic organisms and might indicate an unusual codon usage. This work is important for developing strategies for transformation and gene cloning in these algae.