Definition of 5‘ and 3‘ structural boundaries of the chromatin domain containing the ovalbumin multigene family.

This is the authors' abstract. We don't add key points for this paper.

Hen oviduct nuclei were subjected to pancreatic DNase I treatment under conditions known to preferentially degrade transcriptionally active genes (Weintraub, H., and Groudine, M. (1976) Science (Wash. D. C.) 93, 848-856). The ovalbumin gene, its structurally related genes, X and Y, and the spacer and flanking DNA were all found to exist in a DNase I-sensitive configuration. The DNase I-sensitive region was extended more than 20 kilobases beyond the 5' end of the X gene and approximately an equal distance beyond the 3' end of the ovalbumin gene before it became DNase I-resistant. The transition from a DNase I-sensitive to a -resistant conformation in oviduct chromatin occurred in a gradient fashion with 10 kilobases of DNA. Thus, ovalbumin and its related genes, X and Y, exist in a 100-kilobase DNase-sensitive domain in the oviduct tissue. In contrast, the entire domain was resistant to DNase I in spleen, liver, and erythrocyte nuclei. When the transcription of ovalbumin, X, and Y genes was eliminated by the withdrawal of hormone from estrogen-stimulated chicks, the entire domain remained in a DNase I-sensitive configuration. We conclude that DNase I-sensitive domains may provide the structural capability for gene expression and appear to be a result of the differentiation process since they are cell-specific and contain potentially expressible genes of that cell type. Repetitive sequences within this domain have been mapped and the possible relationship of these repetitive sequences to the DNase I-sensitive structure is discussed.