Researchers Create First-Ever 'Designer Chromosome' in Yeast [Video]

Researchers have created the world's first synthetic functional chromosome in yeast. The study could pave the way for designer bugs that act as tiny factories producing biofuels and even drug components.

The work on the synthesis of the eukaryotic (cells with membrane-bound nucleus) chromosome was carried out by researchers at NYU Langone Medical Center's Institute for Systems Genetics and colleagues.

The new chromosome is called as SynIII and has 273,871 base pairs of DNA compared to 316,667 base pairs present in biological yeast. Certain parts of the chromosome that were considered unnecessary such as repeating segments of the DNA, junk DNA and jumping genes were all removed during the synthesis of the chromosome, researchers said.

However, the pruning did not affect the functioning of the cell. The team transferred this artificial chromosome in a living yeast cell and found that it works just like a normal chromosome.

"This work represents the biggest step yet in an international effort to construct the full genome of synthetic yeast," said Jef Boeke, PhD, director of NYU Langone Medical Center's Institute for Systems Genetics,. "It is the most extensively altered chromosome ever built. But the milestone that really counts is integrating it into a living yeast cell. We have shown that yeast cells carrying this synthetic chromosome are remarkably normal. They behave almost identically to wild yeast cells, only they now possess new capabilities and can do things that wild yeast cannot."

The team chose to create Yeast chromosome III because it is the smallest of the 16 chromosomes found in a yeast cell. The construction of an entire chromosome, even a relatively small one, is no mean task. In the current research, an army of 60 undergraduate students worked on a "Build a Genome" project. The team had to assemble snippets of DNA into 750 to 1,000 base pairs or more. These pieces were then assembled into larger segments, which were then placed in a yeast cell instead of the natural ones, according to a news release.

Chromosomes have tightly-packed DNA wound around proteins called histones. Previously, researchers could only build bacterial chromosome and viral DNA.

Baker's yeast, called Saccharomyces cerevisiae, is a tiny, one-celled organism, which has been used extensively in genetic research. Other geneticists have created strains of yeast that accelerate ethanol production and even generate building blocks for anti-malarial drugs. This latest research, where scientists created a chromosome in the baker's yeast from scratch, is a crucial jump in genetics.

The next step in the research would be to synthesize larger chromosome and possibly even construct an artificial genome of an organism.

The designer chromosome has several applications. It can be used to improve production of alcohol, butanol, and biodiesel. In pharmaceutical industry, bugs with artificial chromosomes could produce drug components, according to the researchers.

The study is published in the journal Science.