Nucleic Acids Research, 1989, Vol. 17, No. 6 2315-2332
© 1989
MOLECULAR BIOLOGY |
The effects of transcription on the nucleosome structure of four Dictyostelium genes
Institut für Immunologie und Virologie, Universitiät Zürich Switzerland 1Institut für Pflanzenbiologie, Universität Zürich Switzerland 2Botany Department and Centre for Protein and Enzyme Technology, La Trobe University Bundoora, Victoria 3083, Australia
Received September 14, 1988. Revised February 22, 1989. Accepted February 22, 1989.
Micrococcal nuclease digestion of Dictyostelium discoideum nuclei from various developmental stages was used to investigate transcription-related changes in the chromatin structure of the coding region of four genes. Gene activity was determined by Northern blotting and nuclear run on experiments. During strong transcription of the developmentally regulated cysteine proteinase I gene, a smear superimposed on a nucleosomal ladder was observed, indicating perturbation of nucleosomal structure was occurring. However, two other developmentally regulated genes, discoidin I and pSC253, showed only slight nucleosome disruption during high levels of transcription. The chromatin structure of a fourth gene (pCZ22) was disrupted throughout development, even at those stages where transcription was greatly reduced. We suggest that although nucleosome structure can be transiently perturbed by the passage of the transcription complex in vivo, the degree of perturbation and the speed with which nucleosomes reassemble is also influenced by the DNA sequence.