Distribution of estrogen receptors in hen oviduct chromatin fractions in the course of DNAase II digestion.
Hen oviduct chromatin was digested with DNAase II and two fractions were isolated: MgCl2-insoluble chromatin and MgCl2-soluble chromatin. The former contained 14 and 50% of the total DNA after a digestion time of 3 and 30 min, respectively. The fraction was characterized in sucrose gradients by a peak sedimenting at 11S. In the course of DNAase digestion this fraction lost most of its estrogen receptors as assayed by [3H]estradiol exchange reaction. The specific radioactivity of chromatin was particularly low in the 11S region. The MgCl2-soluble chromatin contained at most 5.1% of the total DNA. In sucrose gradients the fraction displayed peaks at 4S and 14S. After a 30 min DNAase digestion the specific radioactivity of chromatin in this fraction exceeded that of the MgCl2-insoluble fraction 7.7 fold. Material sedimenting at 14 S and at larger S values was enriched in estrogen receptors. The results suggest that estrogen receptors are unevenly distributed on hen oviduct chromain.
D000818:Animals; D002645:Chickens; D002843:Chromatin / Q000378:metabolism*; D003851:Deoxyribonucleases; D004958:Estradiol / Q000378:metabolism; D005260:Female; D008274:Magnesium; D008970:Molecular Weight; D010057:Oviducts / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism*; D012995:Solubility
D002843:Chromatin; D011960:Receptors, Estrogen; D004958:Estradiol; D003851:Deoxyribonucleases; D008274:Magnesium