Heterogeneity, Complexity, and Repetition of the Chloroplast DNA of Chlamydomonas reinhardtii
Abstract
The chloroplast DNA of wild-type Chlamydomonas reinhardtii was isolated in a CsCl density gradient as a single, homogeneous density class with a mean density of 1.695 g/cm3. Irrespective of sheared size, denatured chloroplast DNA renatured as a single homogeneous species. Compositional heterogeneity, presumably intramolecular, was revealed by the absorbance-temperature profile. The complement of unique nucleotide sequences of the chloroplast DNA, as determined by the rate of renaturation, was 1.94 × 108 daltons. This kinetic complexity is 26-fold less than the DNA content of a single gamete chloroplast, and 52-fold less than the chloroplast of a vegetative cell, which indicates that the chloroplast of C. reinhardtii possesses at least 26 copies of a unique nucleotide sequence.
- Publication:
-
Proceedings of the National Academy of Science
- Pub Date:
- June 1971
- DOI:
- 10.1073/pnas.68.6.1157
- Bibcode:
- 1971PNAS...68.1157B