Abstract
When the chromatin of Drosophila is examined by digestion with DNAase I or micrococcal nuclease, no general structural organization above the level of the nucleosome is revealed by the cleavage pattern. In contrast, the DNAase I cleavage pattern of specific regions of the Drosophila chromosome shows discrete bands with sizes ranging from a few kilobase pairs (kb) to more than 20 kb. Visualization of such higher order bands was achieved by the use of the Southern blotting technique. The DNAase I-cleaved fragments were transferred onto a nitrocellulose sheet after size fractionation by gel electrophoresis. Hybridization was then carried out with radioactively labeled cloned fragments of DNA from D. melanogaster. For the five different chromosomal regions examined, each gives a unique pattern of higher order bands on the autoradiogram; the patterns are different for different regions. Restriction enzyme cleavage of the fragments generated indicates that the preferential DNAase I cleavage sites in chromatin are position-specific. The chromosomal regions bounded by preferential DNAase I cleavage sites are referred to as supranucleosomal or higher order domains for purposes of discussion and analysis. The micrococcal nuclease cleavage pattern of chromatin at specific loci was also examined. In the one case studied in detail, this nuclease also cleaves at position-specific sites.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 797-806 |
| Number of pages | 10 |
| Journal | Cell |
| Volume | 16 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 1979 |
Funding
We thank Miriam Schweber for communicating her unpublished in situ hybridization data on the chromosomal location of the cloned DNA; John Wooley for discussions on higher order structure; Gerry Rubin for the use of his Drosophila embryo homogenizer; Mark Ptashne for the use of facilities for the development of autoradiographic film; and Susan Abmayr for assistance in the preparation of figures. This work was supported by grants from the NIH to S.C.R.E. C.W. is supported by a scholarship from the Harvard Faculty of Arts and Sciences and funds from an NIH grant. P.M.B. is supported by an NIH training grant; K.J.L. is supported by a scholarship from the Harvard Faculty of Arts and Sciences and formerly by an NSF predoctoral fellowship; R.H. is an NSF predoctoral fellow; S.C.R.E. is supported by an NIH Research Career Development Award.
ASJC Scopus subject areas
- General Biochemistry, Genetics and Molecular Biology