Packaging process for genes discovery

BMB Department’s B. Franklin Pugh, the Willaman Chair in Molecular Biology, led a team of scientists to develop a novel laboratory procedure to accomplish new research.  This group of scientists at Penn State University achieved a major milestone in the attempt to assemble, in a test tube, entire chromosomes from their component parts.

The achievement reveals the process a cell uses to package the basic building blocks of an organism's entire genetic code -- its genome. The evidence provided by early research with the new procedure overturns three previous theories of the genome-packaging process and opens the door to a new era of genome-wide biochemistry research. A paper describing the team's achievement was published in the journal Science in May 2011.

The team's research is designed to reveal the construction process for the chromosome -- the super-compressed marvel of molecular packaging that contains all an organism's DNA and associated proteins. "Our procedure starts with an entire genome of DNA from yeast cells that we propagate through bacteria, then purify, "Pugh said. "Next, we add equal parts of pure histones, the protein building blocks of chromosomes. Then we allow the assembly process to begin."

This work is significant because it now allows scientists to experimentally probe the structure and function of chromosomes and their component genes in ways that simply were off limits before. "The cell protects chromosomes from the outside environment, including probing scientists," Dr. Pugh explained. "We now have a way to study the components of the chromosome outside the protective confines of the cell." Because defects in chromatin organization lead to medical problems -- including certain cancers and developmental disorders -- more direct access to chromatin in its properly organized state is expected to help hasten the search for remedies to many human diseases.