Ferraro M, Prantera G
Dipartimento di Genetica e Biologia Molecolare, Università La Sapienza, Rome, Italy.
Cytogenet Cell Genet. 1988;47(1-2):58-61. doi: 10.1159/000132506.
Active human ribosomal gene clusters (NORs) are distinguishable from inactive ones by silver staining. By sequentially applying deoxyribonuclease I (DNase I)-directed in situ nick-translation and silver staining to fixed chromosome preparations, we found that active NORs are more sensitive to DNase I than inactive ones. Use of the two restriction isoschizomeres MspI and HpaII to modify the nick-translation technique showed that active NORs are significantly less methylated than inactive ones. Taken as a whole, our results indicate that ribosomal gene activity, DNase I sensitivity, and DNA methylation are closely interrelated.
