According to a report from NYU’s School of Medicine, an international team of scientists has synthesized the first functional chromosome in yeast. The discovery is an important step in the emergent field of synthetic biology, in which scientists are designing microorganisms to produce new medicines, raw materials for food and biofuels.
Over the preceding five years, scientists have constructed bacterial chromosomes and viral DNA, but this is the first report of an entire eukaryotic chromosome, which is the threadlike structure that carries genes in the nucleus of all plant and animal cells, built from scratch. The researchers, led by Jef Boeke, PhD, director of NYU’s Langone Medical Center’s Institute for Systems Genetics, say their team’s global effort also marks one of the most important advances in yeast genetics since 1996, when scientists originally mapped out yeast’s entire DNA code.
“Our research moves the needle in synthetic biology from theory to reality,” said Dr. Boeke, a pioneer in synthetic biology who recently joined NYU Langone from Johns Hopkins University. “This work represents the biggest step yet in an international effort to construct the full genome of synthetic yeast.”
The researchers reported their findings online March 27 in the journal Science and described how, using computer-aided design, they built a fully functioning chromosome, which they call synIII, and successfully incorporated it into brewer’s yeast, known scientifically as Saccharomyces cerevisiae.
The seven-year endeavor to construct synIII tied together some 273,871 base pairs of DNA, shorter than its native yeast counterpart, which has 316,667 base pairs. Dr. Boeke and his team completed more than 500 alterations to its genetic base, removing repeating sections of some 47,841 DNA base pairs, deemed unnecessary to chromosome reproduction and growth. Also removed was what is commonly termed “junk DNA,” including base pairs known not to encode for any particular proteins, and “jumping gene” segments known to randomly move around and introduce mutations. Other sets of base pairs were added or altered to enable researchers to tag DNA as synthetic or native, and to delete or move genes on synIII.
Student participation kicked off what has become an international effort, called Sc2.0 for short, in which several academic researchers have partnered to reconstruct the entire yeast genome, including collaborators at universities in China, Australia, Singapore, the United Kingdom, and elsewhere in the U.S.