title: Preferential DNase I sensitivity of insert-free ribosomal RNA repeats of Drosophila melanogaster.
abstract: The five predominant types of rDNA repeats in D. melanogaster were analyzed with respect to their DNase I sensitivity. Only the insert-free repeats showed a generalized DNase I sensitivity pattern whereas the major type I, both minor type I and type II repeats were not as extensively degraded by the nuclease. For XX and XY embryonic nuclei, where there is rapid cell division, the majority of the In- repeats were DNase I sensitive. This indicated that these In- repeats have the potential to be transcribed during this developmental stage. When compared to the In- repeats, the chromatin configuration of the In+ repeats is indicative of a higher order of chromatin folding. The paucity of In+ primary gene transcripts observed in vivo could result from In+ repeats being packaged into a more condensed form of chromatin.
authors.forename: R L
authors.initials: RL
authors.lastname: Wayne
authors.forename: Z D
authors.initials: ZD
authors.lastname: Sharp
authors.forename: J D
authors.initials: JD
authors.lastname: Procunier
mesh_terms: D000818:Animals; D004262:DNA Restriction Enzymes / Q000378:metabolism; D004251:DNA Transposable Elements; D004275:DNA, Ribosomal / Q000032:analysis; D015245:Deoxyribonuclease BamHI; D015246:Deoxyribonuclease EcoRI; D003850:Deoxyribonuclease I / Q000378:metabolism*; D004331:Drosophila melanogaster; D012335:RNA, Ribosomal / Q000378:metabolism*; D012091:Repetitive Sequences, Nucleic Acid
chemical_list: D004251:DNA Transposable Elements; D004275:DNA, Ribosomal; D012335:RNA, Ribosomal; D004262:DNA Restriction Enzymes; D015245:Deoxyribonuclease BamHI; D015246:Deoxyribonuclease EcoRI; D003850:Deoxyribonuclease I