史無前例 人造細菌問世

美國研究人員研發出第1個由合成基因組控制、可自行複製的細菌細胞，這項突破引發在試管再造生命的相關新議題。
研究主持人范特爾（Craig Venter）公布持續15年的研究，他說：「這是第1個人造的合成細胞。」

「我們稱之為合成，因為這個細胞完全由合成染色體發育而成，從電腦裡的訊息開始、以4瓶化學物質在化學合成器上製造出來。」

研究團隊表示，他們現在希望研發出的方法，「探索生命的基本機制，並打造出特地設計用以解決環境或能源問題的細菌。」
研究報告指出，這項方法可用來設計專門協助製造生質能源或清除環境危害物。

可能的應用包括製造出可以清除二氧化碳的藻類，或為煉油廠生產新的能源碳氫化合物。
研究員也希望開發可加快生產疫苗的技術，以及製造新食材與化學物質。

這項研究由范特爾（J. Craig Venter Institute）進行，成果刊載在「科學」（Science）期刊。

Scientists in the US have succeeded in developing the first living cell to be controlled entirely by synthetic DNA.
The researchers constructed a bacterium's "genetic software" and transplanted it into a host cell.

The resulting microbe then looked and behaved like the species "dictated" by the synthetic DNA.

The advance, published in Science, has been hailed as a scientific landmark, but critics say there are dangers posed by synthetic organisms.

Some also suggest that the potential benefits of the technology have been over-stated.

But the researchers hope eventually to design bacterial cells that will produce medicines and fuels and even absorb greenhouse gases.

The team was led by Dr Craig Venter of the J Craig Venter Institute (JCVI) in Maryland and California.

Craig Venter defends the synthetic living cell

He and his colleagues had previously made a synthetic bacterial genome, and transplanted the genome of one bacterium into another.

Now, the scientists have put both methods together, to create what they call a "synthetic cell", although only its genome is truly synthetic.

Dr Venter likened the advance to making new software for the cell.

The researchers copied an existing bacterial genome. They sequenced its genetic code and then used "synthesis machines" to chemically construct a copy.

"As soon as this new software goes into the cell, the cell reads [it] and converts into the species specified in that genetic code."Dr Venter told BBC News: "We've now been able to take our synthetic chromosome and transplant it into a recipient cell - a different organism.

"This is the first time any synthetic DNA has been in complete control of a cell," said Dr Venter.
The new bacteria replicated over a billion times, producing copies that contained and were controlled by the constructed, synthetic DNA.


How a synthetic cell is created?

The scientists "decoded" the chromosome of an existing bacterial cell - using a computer to read each of the letters of genetic code.



They copied this code and chemically constructed a new synthetic chromosome, piecing together blocks of DNA.



The team inserted this chromosome into a bacterial cell which replicated itself. Synthetic bacteria might be used to make new fuels and drugs.