Scientists ‘on the brink’ of creating complex life form
Artificial organism based on baker’s yeast expected to come into being by the end of the year
Chinese scientists are taking part in an immense international project that is expected to create complex artificial life in the laboratory for the first time by the end of the year.
Researchers had previously produced simple life forms such as viruses and bacteria but this time the aim is to make an “eukaryotic organism”, one with cells containing a nucleus surrounded by a membrane and with DNA held together by proteins.
A research team with more than 200 scientists from countries including the United States and China will announce on Friday that Sc2.0, the world’s first artificially designed and built eukaryotic organism, is expected to “come alive” by the end of this year.
The new organism could lead to advances in genetic therapies that could help people live longer, the scientists said.
More than a third of the work was already complete, they said, with successful laboratory synthesis of six of the 16 chromosomes that held the organism’s DNA strands. Their methodology, research observations and technological developments were detailed in seven papers in the latest issue of Science.
Sc2.0 is designed to be a single-cell microorganism derived from Saccharomyces cerevisiae, also known as baker’s yeast. The artificial blueprint is intended to look “perfect” compared to nature’s raw design, or so the researchers hope. The design plan is to correct, streamline and remove the genetic flaws, transcription chaos and redundancy sequences prone to occur during the “selfish” evolution of natural yeast.
The reworked yeast is expected to be of use from brewing beer to the production of antibiotics.
A human genome redesigned and built from scratch could give rise to new genetic therapies to make people healthier and live longer, the scientists said.
“This work sets the stage for the completion of designer, synthetic genomes to address unmet needs in medicine and industry,” said Professor Jef Boeke, leader of the Sc2.0 project and director of NYU Langone’s Institute for Systems Genetics.
“Beyond any one application, the papers confirm that newly created systems and software can answer basic questions about the nature of genetic machinery by reprogramming chromosomes in living cells,” Boeke said.
Professor Yuan Yingjin, a Chinese researcher at Tianjin University who is part of the project, said creating yeast was not easy. Each chromosome contained a large number of chemical codes, and creating them from scratch was both labour intensive and time consuming. But advances in technology meant making life had in a way become similar to building a house, he said.
“We borrowed some ideas from civil engineers,” Yuan said. “Instead of putting up the chromosomes brick by brick, we developed a mass construction method, like house prefabrication, which sped up the progress.”
The DNA codes were “prefabbed” into base chunks, and then assembled into mini-chunks, then mega-chunks for final assembly.
The completed artificial chromosomes would be debugged carefully for errors, and inserted one by one into living yeast cells to replace the natural chromosomes for the creation of S2.0.
“This is playing God,” said Professor Li Jingsong, a Shanghai-based biologist who is not involved in the study.
“Up till now, the evolution of life on this planet has followed the rule of natural selection, which came up with meticulous designs through millions of years, but the new technology might allow humans to sidestep nature, and the result would be a completely new life form.
“Can we really do the job better than nature?” Li asked.
The Sc2.0 project came after two decades of effort, beginning in 1996 when about 12 million lines of genetic code from baker’s yeast were sequenced.
Though yeast is one of the most researched organisms, it was not until 2014 that the first chromosome was synthesised by a team led by Boeke, who later initiated the Synthetic Yeast Genome Project with participants from China, France and Scotland.
Of the six completed chromosomes, four were synthesised in China.
Professor Joe Bader, a participant of the project from the High Throughput Biology Centre at the Johns Hopkins University School of Medicine, said it had been a “real pleasure” to work with colleagues from China, who came from academic and industrial sectors including Tianjin University, Tsinghua University and BGI, a leading Chinese genome sequencing organisation.
“China has been impressive in promoting areas of science that are set for the biggest breakthroughs and greatest impacts over the coming years.The contributions made by Chinese institutions to Sc2.0 have been impressive and essential to the project, including accomplishments in chromosome synthesis,” and crucial innovations and scientific advances,”Bader said.
The researchers working on the project said their studies followed ethical guidelines, and the new organism would not pose a danger to the natural environment.
“Yeast is generally considered a safe organism. We have not introduced any alien genes into the Sc2.0, so it should behave just like a natural species. But we will keep it locked in our lab. We will not release it into nature,” Yuan said.
Bader said bioethicists had been full partners in Sc2.0 from the beginning.
“The changes we have designed will make it a valuable platform for contributing to society by making it easier to develop strains that generate valuable products.”