Eureka! Scientists unveil giant leap towards synthetic life

Achievement akin to ‘climbing Mount Everest’ in its complexity

Science Editor

Scientists have made the first artificial chromosome which is both complete and functional in a milestone development in synthetic biology, which promises to revolutionise medical and industrial biotechnology in the coming century.

The researchers built the artificial chromosome from scratch by stitching synthetic strands of DNA together in a sequence based on the known genome of brewer’s yeast. They predict that a completely synthetic yeast genome comprised of its entire complement of 16 chromosomes could be made within four years.

“Our research moves the needle in synthetic biology from theory to reality. This work represents the biggest step yet in an international effort to construct the full genome of synthetic yeast,” said Jef Boeke of the New York University School of Medicine, a lead author of the study published in the journal Science.

“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,” Dr Boeke said.

“They behave almost identically to wild yeast cells, only they now possess new capabilities and can do things that wild yeast cannot [do],” he said.

“Not only can we make designer changes on a computer, but we can make hundreds of changes through a chromosome and we can put that chromosome into yeast and have a yeast that looks, smells and behaves like a regular yeast, but this yeast is endowed with special properties that normal yeasts don’t have,” he explained.

The synthetic yeast chromosome was based on chromosome number 3, but scientists deleted large parts of it that were considered redundant and introduced further subtle changes to its sequence – yet the chromosome still functioned normally and replicated itself in living yeast cells, they said.

“We took tiny snippets of synthetic DNA and fused them together in a complex series of steps to build an essentially computer-designed chromosome 3, one of the 16 chromosomes of yeast. We call it ‘synIII’ because it’s a completely synthetic derivative that has been engineered in a variety of interesting ways to make it different from the normal chromosome,” Dr Boeke said.

The achievement was compared to climbing Mount Everest in its labour-intensive complexity, as it involved stitching together 273,871 individual building blocks of DNA – the nucleotide bases of the yeast’s genes – in the right order, and removing about 50,000 repeating sequences of the chromosome that were considered redundant.

“When you change the genome you’re gambling. One wrong change can kill the cell. We have made over 50,000 changes to the DNA code in the chromosome and our yeast still lived. That is remarkable, it shows that our synthetic chromosome is hardy, and it endows the yeast with new properties,” Dr Boeke said.

Britain is one of several countries involved in the international effort to synthesise all 16 yeast chromosomes. Last year, the Government announced that it will spend £1 million on the yeast project out of a total budget of £60 million it has dedicated to synthetic biology.

Paul Freemont of Imperial College London said that the first complete and functional synthetic yeast chromosome is “a big deal” and significant step forward from the work by DNA scientist Craig Venter, who synthesised the much simpler genome of a bacterium in 2010.

“It opens up a whole new way of thinking about chromosome and genome engineering as it provides a proof of concept that complicated chromosomes can be redesigned, synthesised and made to work in a living cell,” Dr Freemont said.

Artificial chromosomes designed by computer will be vital for the synthetic life-forms that scientists hope to design for a range of applications, such as the breakdown of persistent pollutants in the environment or the industrial manufacture of new kinds of drugs and vaccines for human and animal medicine.

“It could have a lot of practical applications because yeast is used in the biotechnology industry to produce everything from alcohol, which has been produced for centuries, to biofuels and speciality chemicals to nutrients,” Dr Boeke said.

“Yeast is a really interesting microorganism to work on because it has an ancient industrial relationship with man. We’ve domesticated it since the days of the Fertile Crescent and we’ve had this fantastic collaboration to make wine, break and beer,” he said.

“That relationship persists today in a wide range of products that are made with yeast such as vaccines, fuels and specialty chemicals and it’s only going to be growing. Yeast is one of the few microbes that packages its genetic material in a nucleus just like human cells. So it serves as a better model for how human cells work in health and disease,” Dr Boeke added.

Synthetic microbes: Possible uses

Medicines

Being able to make synthetic chromosomes for yeast cells would allow scientists to speed up the rate of yeast evolution in order to produce strains specifically tailored for making certain difficult medicines.

Biofuels

Designing new kinds of yeast chromosomes could improve the efficiency of producing alcohol-based biofuels through fermentation.

Pollutants

Natural microbes already have an ability to degrade environmental toxins, but creating synthetic-biology versions could improve the speed at which they work.

Start your day with The Independent, sign up for daily news emails
PROMOTED VIDEO
ebooks
ebooksA special investigation by Andy McSmith
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Tradewind Recruitment: PMLD Teacher

Negotiable: Tradewind Recruitment: PMLD Teacher A specialist primary school i...

Recruitment Genius: Online Media Sales Trainee

£15000 - £30000 per annum: Recruitment Genius: Now our rapidly expanding and A...

Recruitment Genius: Public House Manager / Management Couples

£15000 - £20000 per annum: Recruitment Genius: Are you passionate about great ...

Recruitment Genius: Production Planner

£20000 - £30000 per annum: Recruitment Genius: This fast growing reinforcing s...

Day In a Page

As in 1942, Germany must show restraint over Greece

As in 1942, Germany must show restraint over Greece

Mussolini tried to warn his ally of the danger of bringing the country to its knees. So should we, says Patrick Cockburn
Britain's widening poverty gap should be causing outrage at the start of the election campaign

The short stroll that should be our walk of shame

Courting the global elite has failed to benefit Britain, as the vast disparity in wealth on display in the capital shows
Homeless Veterans appeal: The rise of the working poor: when having a job cannot prevent poverty

Homeless Veterans appeal

The rise of the working poor: when having a job cannot prevent poverty
Prince Charles the saviour of the nation? A new book highlights concerns about how political he will be when he eventually becomes king

Prince Charles the saviour of the nation?

A new book highlights concerns about how political he will be when he eventually becomes king
How books can defeat Isis: Patrick Cockburn was able to update his agenda-setting 'The Rise of Islamic State' while under attack in Baghdad

How books can defeat Isis

Patrick Cockburn was able to update his agenda-setting 'The Rise of Islamic State' while under attack in Baghdad
Judith Hackitt: The myths of elf 'n' safety

Judith Hackitt: The myths of elf 'n' safety

She may be in charge of minimising our risks of injury, but the chair of the Health and Safety Executive still wants children to be able to hurt themselves
The open loathing between Barack Obama and Benjamin Netanyahu just got worse

The open loathing between Obama and Netanyahu just got worse

The Israeli PM's relationship with the Obama has always been chilly, but going over the President's head on Iran will do him no favours, says Rupert Cornwell
French chefs get 'le huff' as nation slips down global cuisine rankings

French chefs get 'le huff' as nation slips down global cuisine rankings

Fury at British best restaurants survey sees French magazine produce a rival list
Star choreographer Matthew Bourne gives young carers a chance to perform at Sadler's Wells

Young carers to make dance debut

What happened when superstar choreographer Matthew Bourne encouraged 27 teenage carers to think about themselves for once?
Design Council's 70th anniversary: Four of the most intriguing prototypes from Ones to Watch

Design Council's 70th anniversary

Four of the most intriguing prototypes from Ones to Watch
Dame Harriet Walter: The actress on learning what it is to age, plastic surgery, and her unease at being honoured by the establishment

Dame Harriet Walter interview

The actress on learning what it is to age, plastic surgery, and her unease at being honoured by the establishment
Art should not be a slave to the ideas driving it

Art should not be a slave to the ideas driving it

Critics of Tom Stoppard's new play seem to agree that cerebral can never trump character, says DJ Taylor
Bill Granger recipes: Our chef's winter salads will make you feel energised through February

Bill Granger's winter salads

Salads aren't just a bit on the side, says our chef - their crunch, colour and natural goodness are perfect for a midwinter pick-me-up
England vs Wales: Cool head George Ford ready to put out dragon fire

George Ford: Cool head ready to put out dragon fire

No 10’s calmness under pressure will be key for England in Cardiff
Michael Calvin: Time for Old Firm to put aside bigotry and forge new links

Michael Calvin's Last Word

Time for Old Firm to put aside bigotry and forge new links