Navigation Links
Researchers advance toward engineering 'wildly new genome'
Date:10/19/2013

In two parallel projects, researchers have created new genomes inside the bacterium E. coli in ways that test the limits of genetic reprogramming and open new possibilities for increasing flexibility, productivity and safety in biotechnology.

In one project, researchers created a novel genomethe first-ever entirely genomically recoded organismby replacing all 321 instances of a specific "genetic three-letter word," called a codon, throughout the organism's entire genome with a word of supposedly identical meaning. The researchers then reintroduced a reprogramed version of the original word (with a new meaning, a new amino acid) into the bacteria, expanding the bacterium's vocabulary and allowing it to produce proteins that do not normally occur in nature.

In the second project, the researchers removed every occurrence of 13 different codons across 42 separate E. coli genes, using a different organism for each gene, and replaced them with other codons of the same function. When they were done, 24 percent of the DNA across the 42 targeted genes had been changed, yet the proteins the genes produced remained identical to those produced by the original genes.

"The first project is saying that we can take one codon, completely remove it from the genome, then successfully reassign its function," said Marc Lajoie, a Harvard Medical School graduate student in the lab of George Church. "For the second project we asked, 'OK, we've changed this one codon, how many others can we change?'"

Of the 13 codons chosen for the project, all could be changed.

"That leaves open the possibility that we could potentially replace any or all of those 13 codons throughout the entire genome," Lajoie said.

The results of these two projects appear today in Science. The work was led by Church, Robert Winthrop Professor of Genetics at Harvard Medical School and founding core faculty member at the Wyss Institute for Biologically Inspired Engineering. Farren Isaacs, assistant professor of molecular, cellular, and developmental biology at Yale School of Medicine, is co-senior author on the first study.

Toward safer, more productive, more versatile biotech

Recoded genomes can confer protection against viruseswhich limit productivity in the biotech industryand help prevent the spread of potentially dangerous genetically engineered traits to wild organisms.

"In science we talk a lot about the 'what' and the 'how' of things, but in this case, the 'why' is very important," Church said, explaining how this project is part of an ongoing effort to improve the safety, productivity and flexibility of biotechnology.

"These results might also open a whole new chemical toolbox for biotech production," said Isaacs. "For example, adding durable polymers to a therapeutic molecule could allow it to function longer in the human bloodstream."

But to have such an impact, the researchers said, large swaths of the genome need to be changed all at once.

"If we make a few changes that make the microbe a little more resistant to a virus, the virus is going to compensate. It becomes a back and forth battle," Church said. "But if we take the microbe offline and make a whole bunch of changes, when we bring it back and show it to the virus, the virus is going to say 'I give up.' No amount of diversity in any reasonable natural virus population is going to be enough to compensate for this wildly new genome."

In the first study, with just a single codon removed, the genomically recoded organism showed increased resistance to viral infection. The same potential "wildly new genome" would make it impossible for engineered genes to escape into wild populations, Church said, because they would be incompatible with natural genomes. This could be of considerable benefit with strains engineered for drug or pesticide resistance, for example. What's more, incorporating rare, non-standard amino acids could ensure strains only survive in a laboratory environment.

Engineering and evolution

Since a single genetic flaw can spell death for an organism, the challenge of managing a series of hundreds of specific changes was daunting, the researchers said. In both projects, the researchers paid particular attention to developing a methodical approach to planning and implementing changes and troubleshooting the results.

"We wanted to develop the ability to efficiently build the desired genome and to very quickly identify any problemsfrom design flaws or from undesired mutations and develop workarounds," Lajoie said.

The team relied on number oftechnologies developed in the Church lab and the Wyss Institute and with partners in academia and industry, including next-generation sequencing tools, DNA synthesis on a chip, and MAGE and CAGE genome editing tools. But one of the most important tools they used was the power of natural selection, the researchers added.

"When an engineering team designs a new cellphone, it's a huge investment of time and money. They really want that cell phone to work," Church said. "With E. coli we can make a few billion prototypes with many different genomes, and let the best strain win. That's the awesome power of evolution."


'/>"/>

Contact: David Cameron
david_cameron@hms.harvard.edu
617-432-0441
Harvard Medical School
Source:Eurekalert

Related biology technology :

1. New England Biolabs Introduces Polbase, an Information Repository of Scientific Data for Polymerase Researchers
2. In new quantum-dot LED design, researchers turn troublesome molecules to their advantage
3. Multidisciplinary team of researchers develop world’s lightest material
4. Researchers shrink tumors and minimize side effects using tumor-homing peptide to deliver treatment
5. Innovative MetaMorph® NX Software Shatters Barriers Between Researchers and Image Analysis Goals with Exclusive Visual Workflow
6. UCLA researchers demonstrate fully printed carbon nanotube transistor circuits for displays
7. Penn and Brown researchers demonstrate earthquake friction effect at the nanoscale
8. Two Top Biological Imaging Centers Offer Powerful Free Online Tool to Researchers, Educators, and Public
9. Researchers develop one of the worlds smallest electronic circuits
10. MU researchers identify key plant immune response in fight against bacteria
11. Researchers realize high-power, narrowband terahertz source at room temperature
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/25/2016)... ... May 25, 2016 , ... The American Medical ... Office of the National Coordinator for Health IT (ONC) outlining a measurement approach ... data were available when and where it was needed. The organization of health ...
(Date:5/25/2016)... , ... May 25, 2016 , ... WEDI, the nation’s ... exchange, today announced that Charles W. Stellar has been named by the WEDI Board ... since January 2016. As an executive leader with more than 35 years of experience ...
(Date:5/25/2016)... Connecticut (PRWEB) , ... May 25, 2016 , ... ... the U.S. Food and Drug Administration (FDA) has granted the company’s orphan drug ... the company’s second orphan drug designation granted by the FDA. , Spinocerebellar ...
(Date:5/24/2016)... TEL AVIV, Israel , May 24, 2016   ... on providing physicians with artificial intelligence, real-time decision support tools ... selected to present at the 2016 Israeli Advanced Technology Industries ... part of Israel,s 15th National Life ... to 26th at the David Intercontinental Hotel in ...
Breaking Biology Technology:
(Date:4/19/2016)... UAE, April 20, 2016 The ... as a compact web-based "all-in-one" system solution for all ... fingerprint reader or the door interface with integration authorization ... access control systems. The minimal dimensions of the access ... into the building installations offer considerable freedom of design ...
(Date:4/13/2016)... , April 13, 2016  IMPOWER physicians supporting ... are setting a new clinical standard in telehealth thanks ... By leveraging the higi platform, IMPOWER patients can routinely ... pulse and body mass index, and, when they opt ... and convenient visit to a local retail location at ...
(Date:3/23/2016)... WAKEFIELD, Massachusetts , March 23, 2016 ... kombiniert im Interesse erhöhter Sicherheit Gesichts- und ... Xura, Inc. (NASDAQ: MESG ... heute bekannt, dass das Unternehmen mit SpeechPro ... insbesondere aus der Finanzdienstleistungsbranche, wird die Möglichkeit ...
Breaking Biology News(10 mins):