Disruption of the typical chromatin structure in a 2500 base-pair region at the 5' end of the actively transcribed ovalbumin gene.

AUTOR(ES)

Bellard, M

RESUMO

We examined the chromatin organizations of approximately 3 kb of DNA in the 5'-end flanking region of the ovalbumin gene in chicken erythrocyte and oviduct cell nuclei. With specific DNA probes and an indirect end-labeling technique, we analysed the pattern of the DNA fragments obtained after micrococcal nuclease digestion and generated comparative maps of the nuclease cuts. This region of the chicken genome displays a "typical" chromatin arrangement in erythrocyte nuclei, with nucleosomes apparently positioned at random. In contrast, in oviduct nuclei, the same region has an "altered" chromatin structure, and lacks a typical nucleosomal array. The existence of specifically positioned proteins and of alterations in the DNA secondary structure in this region of the oviduct chromatin is suggested by comparison of the nuclease cleavage maps which reveals specific changes: disappearance of nuclease cuts present in "naked" and erythrocyte chromatin DNAs, and appearance of new cuts absent from these DNAs.

Documentos Relacionados

• The [poky] mutant of Neurospora contains a 4-base-pair deletion at the 5' end of the mitochondrial small rRNA.
• Do eukaryotic mRNA 5' noncoding sequences base-pair with the 18 S ribosomal RNA 3' terminus?
• Estrogen induces a demethylation at the 5' end region of the chicken vitellogenin gene.
• A structural snapshot of base-pair opening in DNA
• The 5'-limit of transposition and upstream barren region of a trypanosome VSG gene: tandem 76 base-pair repeats flanking (TAA)90.