A Designer Yeast Chromosome

Someday yeast biofactories will produce all manner of important molecules, from breakthrough pharmaceuticals to biofuels to food. Already, the antimalarial drug artemisinin is churned out in quantity by yeast modified with genes from the sweet wormwood plant.

While this vision is promising, creating yeast capable of such feats is not easy. Synthetic biologists like yeast because it has a large, complex genome—more like higher organisms than those of viruses and bacteria synthesized to date.

Now a Bloomberg School researcher and colleagues have described in a Science journal article the world’s first yeast chromosome built entirely in the lab. Renowned bioengineer J. Craig Venter and others are hailing it as a significant first step toward a future of streamlined and easily modifiable designer yeast.

“We created a single, efficient chromosome, taking out extraneous genetic information, destabilizing elements and redundancies,” said Srinivasan Chandrasegaran, PhD, a senior author of the paper and a professor in Environmental Health Sciences. The genetic “building blocks” used to construct the chromosome were created by Johns Hopkins undergraduates directed by co-author Jef D. Boeke, PhD, an NYU professor and former Johns Hopkins School of Medicine professor.

Although this discovery is significant, Chandrasegaran urged the long view. This lone chromosome, but one of 16 in yeast, took five years to complete.

“We’re now leading an international team whose goal is a completely synthetic yeast cell—an almost ideal cell—that will make yeast biofactories much, much easier. But it will take time to create a fully synthetic cell,” he says.