Scientists have developed the first cell controlled by a synthetic¹（合成的，人造的） genome. They now hope to use this method to probe the basic machinery² of life and to engineer bacteria specially³ designed to solve environmental or energy problems. The study will be published online by the journal Science, at the Science Express website, on Thursday, 20 May. Science is published by AAAS, the nonprofit science society.

The research team, led by Craig Venter of the J. Craig Venter Institute, has already chemically synthesized a bacterial⁴ genome, and it has transplanted the genome of one bacterium⁵（细菌） to another. Now, the scientists have put both methods together, to create what they call a "synthetic cell," although only its genome is synthetic.

"This is the first synthetic cell that's been made, and we call it synthetic because the cell is totally derived⁶ from（来源于） a synthetic chromosome⁷, made with four bottles of chemicals on a chemical synthesizer, starting with information in a computer," said Venter.

"This becomes a very powerful tool for trying to design what we want biology to do. We have a wide range of applications [in mind]," he said.

For example, the researchers are planning to design algae⁸（海藻） that can capture carbon dioxide and make new hydrocarbons⁹（氢氧化合物） that could go into refineries¹⁰（精炼厂） . They are also working on ways to speed up vaccine¹¹ production. Making new chemicals or food ingredients（食品添加剂） and cleaning up water are other possible benefits, according to Venter.

In the Science study, the researchers synthesized the genome of the bacterium M. mycoides and added DNA¹² sequences that "watermark" the genome to distinguish it from a natural one.

Because current machines can only assemble relatively¹³ short strings¹⁴ of DNA letters at a time, the researchers inserted the shorter sequences into yeast¹⁵（酵母） , whose DNA-repair enzymes¹⁶ linked the strings together. They then transferred the medium-sized strings into E. coli and back into yeast. After three rounds of assembly, the researchers had produced a genome over a million base pairs long.

The scientists then transplanted the synthetic M. mycoides genome into another type of bacteria, Mycoplasm capricolum. The new genome "booted up" the recipient¹⁷ cells. Although fourteen genes¹⁸ were deleted or disrupted in the transplant bacteria, they still looked like normal M. mycoides bacteria and produced only M. mycoides proteins, the authors report.

"This is an important step we think, both scientifically and philosophically¹⁹. It's certainly changed my views of the definitions of life and how life works," Venter said.

Acknowledging the ethical²⁰ discussion about synthetic biology research, Venter explained that his team asked for a bioethical（生物伦理学的） review in the late 1990s and has participated in variety of discussions on the topic.

"I think this is the first incidence in science where the extensive bioethical review took place before the experiments were done. It's part of an ongoing²¹ process that we've been driving, trying to make sure that the science proceeds in an ethical fashion, that we're being thoughtful about what we do and looking forward to the implications to the future," he said.