Researchers at the J. Craig Venter Institute (JCVI) have replaced the whole genome of a bacterial cell with one from a closely related species.
“The successful completion of this research is important because it is one of the key proof of principles in synthetic genomics that will allow us to realize the ultimate goal of creating a synthetic organism,” notes J. Craig Venter, Ph.D., president and chairman, JCVI. “We are committed to this research as we believe that synthetic genomics holds great promise in helping to solve issues like climate change and in developing new sources of energy.”
Carole Lartigue, Ph.D., and colleagues have transplanted the genome—in the form of naked DNA, virtually free of protein—of Mycoplasma mycoides into cells of a closely related bacterium, Mycoplasma capricolum. The recipient cells then appeared identical to the donor cells, the authors report.
The JCVI team devised several key steps to enable the genome transplantation. First, an antibiotic selectable marker gene was added to the M. mycoides LC chromosome to allow for selection of living cells containing the transplanted chromosome. Then the team purified the DNA or chromosome from M. mycoides LC so that it was free from proteins. This M. mycoides LC chromosome was then transplanted into the M. capricolum cells.
After several rounds of cell division, the recipient M. capricolum chromosome disappeared having been replaced by the donor M. mycoides LC chromosome. The scientists observed that M. capricolum cells took on all the phenotypic characteristics of M. mycoides LC cells.
“While we are excited by the results of our research,” says Dr. Lartigue, “we are continuing to perfect and refine our techniques and methods as we move to the next phases and prepare to develop a fully synthetic chromosome.”
This paper was published online by Science on June 28.