text: Until the early 1990s , histones were dismissed by most as inert packing material for eukaryotic nuclear DNA , based in part on the `` ball and stick '' models of Mark Ptashne and others who believed transcription was activated by protein-DNA and protein-protein interactions on largely naked DNA templates , as is the case in bacteria .
simplified: Until the early 1990s , histones were dismissed as merely packing material for nuclear DNA .