Straight line to more man-made life
The scientific world has a new machine at its disposal, with a novel tool to provide better designer organisms.
Biological engineers have unveiled a tool dubbed “the telomerator” – and they say it could redefine the limits of synthetic biology.
Researchers hope to use the telomerator to advance how successfully living things can be engineered or constructed in the laboratory based on an organism's genetic, chemical base-pair structure.
Synthetic biologists aim to use these ‘designer’ microorganisms to produce novel medicines, nutrients, and bio-fuels.
The telomerator was built by at New York University with the original goal of converting circular chromosomes into linear ones.
Research leader Dr Jef Boeke says this was because the straight line better resembles the natural structure of more complex organisms, including humans.
Comprising about 1,500 chemical base pairs linked together, the man-made piece of telomerator code can be inserted as a single unit at any position on circular DNA and almost anywhere among a chromosome's other genes, whose base pairs can number into the hundreds of thousands.
One of the greatest advances that the telomerator brings is in its precise capacity to add buffering chromosome endings, or telomeres, to newly linearised yeast chromosomes.
“Until now, we've relied on synthesising functional and stable yeast chromosomes in a circular format - with their telomeres cut off - so they can be uniformly reproduced for easy experimentation within bacteria, whose chromosomes are circular in shape,” Boeke says.
The key components of the telomerator are its telomere seed sequences, which are exposed when the telomerator “cassette” — its packaged components — is activated.
To test the device, the team inserted a telomerator cassette at 54 different locations on a circular synthetic yeast chromosome of about 90,000 base pairs.
They then tested whether the chromosome could be segmented and straightened at each position.
Researchers compared the process to a clock dial, in which they could insert the telomerator at any “hour” on the clock face to break the circle and yield 12 different timelines, but all of equal length.
Colonies grew for 51 of the linear yeast chromosomes, failing only in chromosomes where essential genes were placed too close to the telomere ends.
Additional testing confirmed that the modified yeast chromosomes were in a linear format and of the precise length predicted by researchers.