A researcher with BGI-Shenzhen tests the yeast in the experiment at BGI Research in Shenzhen, south China's Guangdong Province. Xinhua/BGI Photo
Washington - In a significant advance toward creating the first “designer” complex cell, scientists say they are a third of the way to synthesising the complete genome of baker’s yeast.

In seven studies published on Thursday in the journal Science, the researchers describe how they built six of the 16 chromosomes required for the yeast Saccharomyces cerevisiae, editing out some genes and writing in new characteristics.

“A lot of synthetic biology is motivated by this idea that you only understand something when you can build it,” said Johns Hopkins computational biologist Dr Joel Bader. “We know enough about biological systems that we can design a chromosome on a computer, synthesise it, put it in the cell and it will work.”

In 2010, scientists at the J Craig Venter Institute in Maryland created a bacterial cell controlled by a synthesised genome by copying the DNA of one bacterium into another.

Last year they built the first “minimal cell”, an organism never found in nature that had the smallest number of genes required for life. Some months later, Harvard Medical School researchers re-engineered a small fraction of E coli’s genes.

Jef Boeke, director of New York University Langone’s Institute for Systems Genetics, and his colleagues first synthesised a chromosome in 2014.

The chromosomes generated this time represent the largest amount of genetic material to be synthesised and the new cells are different from their natural relatives.