Quantitation of DNase I sensitivity in Xenopus chromatin containing active and inactive globin, albumin and vitellogenin genes.
The disappearance of defined restriction fragments of the beta 1-globin, an albumin and the A1 vitellogenin gene was quantitated after DNase I digestion and expressed by a sensitivity factor defined by a mathematical model. Analysis of naked DNA showed that the gene fragments have similar but not identical sensitivity factors. DNase I digestion of chromatin revealed for the same gene fragments sensitivity factors differing over a much wilder range. This is correlated to the activity of the genes analyzed: the beta 1-globin gene fragment is more sensitive to DNase I in chromatin of erythrocytes compared to hepatocytes whereas the albumin gene fragment is more sensitive to DNase I in chromatin of hepatocytes. The A1 vitellogenin gene has the same DNase I sensitivity in both cell types. Comparing the DNase I sensitivity of the three genes in their inactive state we suggest that different chromatin conformations may exist for inactive genes.
D000418:Albumins / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D002843:Chromatin / Q000032:analysis*; D004247:DNA / Q000235:genetics; D004262:DNA Restriction Enzymes; D003850:Deoxyribonuclease I; D003851:Deoxyribonucleases / Q000378:metabolism*; D004720:Endonucleases / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism; D005796:Genes; D005914:Globins / Q000235:genetics*; D008074:Lipoproteins / Q000235:genetics*; D008099:Liver / Q000378:metabolism; D008297:Male; D009693:Nucleic Acid Hybridization; D014819:Vitellogenins / Q000235:genetics*; D014981:Xenopus
D000418:Albumins; D002843:Chromatin; D008074:Lipoproteins; D014819:Vitellogenins; D005914:Globins; D004247:DNA; D003851:Deoxyribonucleases; D004720:Endonucleases; D004262:DNA Restriction Enzymes; D003850:Deoxyribonuclease I