The peripheral chromosome scaffold, a novel structural component of mitotic chromosomes

Using an original high-salt extraction protocol, we observed a novel chromosome substructure, referred to as the peripheral chromosome scaffold. This chromosome domain contained the perichromosomal layer proteins pKi-67, B23/nucleophosmin and fibrillarin, but no DNA fragments (i.e., the loop domain bases were not associated with the peripheral scaffold). Modern models of chromosome organization do not predict the existence of a peripheral chromosome scaffold domain, and thus our observations have conceptual implications for understanding chromosome architecture.