Scientists, in a world first, announced Wednesday they had added two letters to the genetic code that forms the chemical blueprint for life.
They said they had modified a bacterium so that it incorporated and replicated two DNA ingredients that are not found in nature.
The experiment, they said, was designed to show that the alphabet for DNA, which has existed for hundreds of millions of years, can be expanded through human intervention.
This is the first step on a longer road that could lead to revolutionary drugs and innovations in nanotechnology, they said.
DNA ― deoxyribonucleic acid ― is the set of hereditary instructions for making and sustaining life.
A long molecule in the heart of a cell, it comprises a double-stranded helix in the form of a twisted zipper. Its “teeth” are millions of so-called base pairs of letters, meaning chemicals that match up with each other.
Adenine teams up with thymine to creating the A-T base pair, while cytosine links up with guanine to make the C-G base pair.
The new work, reported in the scientific journal Nature, adds a third, manmade pair to the helix.
However, the inclusions only survive with external help and are removed from the genome once this support is removed.
“Life on Earth in all its diversity is encoded by only two pairs of DNA bases, A-T and C-G,” said Floyd Romesberg at Scripps Research Institute at La Jolla, California.
“What we’ve made is an organism that stably contains those two plus a third, unnatural pair of bases.” (AFP)
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