Question: what regulates the packing of dna into chromosomes
[{'answer': 'Methylation of histones', 'provenance': [{'wikipedia_id': '4440593', 'title': 'Histone methylation', 'start_paragraph_id': 1, 'start_character': 194, 'end_paragraph_id': 1, 'end_character': 217, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '4440593', 'title': 'Histone methylation', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 733, 'bleu_score': 0.982060959997838, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8275305434370747066}, 'section': 'Section::::Abstract.'}]}]