Upon further examination, he found that the switch between the genes was controlled by the state of their chromatin domains on each chromosome. Dr. Krawetz found that the domains could take on two conformations: one that closed off all but a few genes for expression, and another that opened up the genes, making them available for expression.
"There are multiple times that potentiation can occur during development, therefore there are multiple points of entry," he said. In other words, a cell's destiny is fine-tuned with each successive opening and closing of the gene-containing chromatin domains. In his resulting research paper, Dr. Krawetz concluded, "These results are key to understanding how differentiative pathways are controlled and cellular phenotypes determined."
By understanding the mechanism behind "natural" potentiation, Dr. Krawetz theorized, scientists might then be able to access any cell's genetic makeup and turn off or turn on specific genes. Shutting down tumor genes, or creating additional bone cells or brain cells would not be unthinkable, he noted. In summarizing the work on a more informal level, he remarked, "What is most exciting in terms of differentiation is that cells can change their destiny."