12874
DNA accessibility to restriction enzymes within the chromosomal copy of the vitellogenin gene B1 promoter shows that the estrogen responsive unit and the promoter proximal region are sensitive to digestion in uninduced and estrogen -induced hepatocytes but not in erythrocyte nuclei .
 ( DNA: vitellogenin gene B1 promoter, None) , ( cell type: hepatocytes, None) , ( cell type: estrogen -induced hepatocytes, None) , ( DNA: promoter proximal region, None) , ( protein: restriction enzymes, None) , ( DNA: estrogen responsive unit, None) 
Locate the role in the text that participated in the event based on the event type and return it in the event list. 
 Option: Event type: RNA,cell type,protein,cell line,DNA, Arguments type: . 
Text: {0} 
Answer:
 ( DNA: vitellogenin gene B1 promoter, None) , ( cell type: hepatocytes, None) , ( cell type: estrogen -induced hepatocytes, None) , ( DNA: promoter proximal region, None) , ( protein: restriction enzymes, None) , ( DNA: estrogen responsive unit, None) 