Z-DNA in transcriptionally active chromosomes.
Due to the striking correlation between the distribution of transcriptionally active subdivisions of the polytene chromosomes and Z-DNA, we have addressed the question of whether the Z-DNA configuration exists in native, transcriptionally active chromosomes of Drosophila hydei prepared without interference by procedures known to induce the B to Z conformation. Our experiments indicate that Z-DNA forms are present in a specific set of sites on the native chromosomes. They occur on interbands and other subdivisions of dispersed DNA, but there is no correlation between the amount of Z-DNA detected and DNA compaction. The results suggest, moreover, that Z-DNA forms are restricted to specific genes, because various subdivisions induced to transcription in puffs show different patterns of Z-DNA. We show, in addition, that removal of chromosomal proteins by proteinase K has a strong influence on the level of anti-Z-DNA reactivity.
Lancillotti
F
F
Lopez
M C
MC
Arias
P
P
Alonso
C
C
D000818:Animals; D002868:Chromosomal Proteins, Non-Histone / Q000032:analysis; D002875:Chromosomes / Q000032:analysis*; D004247:DNA / Q000032:analysis* / Q000276:immunology; D000431:Ethanol / Q000494:pharmacology; D005453:Fluorescence; D009690:Nucleic Acid Conformation; D009693:Nucleic Acid Hybridization; D014158:Transcription, Genetic
D002868:Chromosomal Proteins, Non-Histone; D000431:Ethanol; D004247:DNA