US scientists have stripped life back to its bare essentials — creating a synthetic microbe with the absolute minimum genetic information needed to grow and reproduce.

美国科学家将生命的多余部分剔除，只留下最基本的要素，由此创造出一种合成微生物，这种合成微生物拥有生长和繁殖所需的最低限度的基因信息。

The researchers, led by Craig Venter, the genomics pioneer, made Syn3.0, the “minimal synthetic bacterial cell”, as a follow-up to their much publicised creation in 2010 of Syn1.0, the first living cell with DNA (its genome) made from scratch using laboratory chemicals.

由基因学先驱克雷格•文特尔(Craig Venter)领导的研究人员创造了名为Syn3.0的“最小化合成细菌细胞”，这是他们在2010年创造的曾得到广泛宣传的Syn1.0的后续成果。Syn1.0是首个拥有用实验室化学品从零合成出的脱氧核糖核酸(DNA)的活细胞。

They hope Syn3.0 or its successors will provide a platform to which synthetic biologists can add genes for particular purposes, such as producing drugs or biofuels, though the more immediate aim is to understand better the fundamental biochemistry of life.

研究人员希望，Syn3.0或其后续样品能提供一个平台，供合成生物学家加入有特定用途的基因，比如生产药品或生物燃料的基因，尽管Syn3.0更直接的目标是更好地理解生命的基本生化机理。

The project, published in the journal Science, took four years longer than expected, Dr Venter said, and revealed “surprising” gaps in biological knowledge.

这个项目的研究成果发表在《科学》(Science)期刊上。文特尔博士表示，该项目持续的时间比预期长了四年，揭示出生物学知识中存在“令人吃惊的”空白。

The initial approach was to design a minimal bacterial genome using all the information available from the scientific literature, but that failed. The failure shows that “our current knowledge of biology is not sufficient to sit down and design a living organism and build it”, he said.

这个研究团队最初的思路是利用科学文献中提供的所有信息，设计一种最小化的细菌基因组，但这条路没有走通。文特尔博士说，这次失败证明“我们目前的生物学知识，不足以让我们坐下来设计一个活的有机体并将它造出来”。

Instead, the team went back to Syn3.0, which was based on Mycoplasma mycoides, the naturally occurring bacterium, and began the long process of discovering which of its 901 genes were essential for life by finding out what happened when each one was deleted.

后来，该团队调整了思路，转而研发基于丝状支原体的Syn3.0。该团队展开了漫长的探索，通过逐个剔除再观察结果的办法，观察丝状支原体的901个基因中有哪些是必不可少的。丝状支原体是一种天然的细菌。

One by one the unnecessary genes were eliminated until the team, working in California at the J Craig Venter Institute and Synthetic Genomics, its associated company, was left with 473 genes essential for replication and growth.

就这样，不必要的基因被一个接一个地剔除，最终得到了473个复制和生长所必需的基因。该团队的研究工作是在美国加州约翰•克雷格•文特尔研究所(J. Craig Venter Institute)及其附属公司合成基因组学(Synthetic Genomics)展开的。

The DNA encoding these 473 genes, amounting to 531,000 chemical “letters” of genetic code, was then synthesised in the lab and the resulting synthetic genome transplanted into the shell of M capriolum, another bacterium whose own DNA had been removed.

编码组成这473个基因的DNA，相当于53.1万个基因代码化学“字母”。这些DNA随后在实验室中被合成出来，合成出的基因组被植入另一种细菌山羊支原体(M capricolum)的壳中，该支原体自身的DNA已被移除。

The synthetic genome took over the biological machinery of the host cell, producing a healthy bacterium that reproduces rapidly in lab cultures and doubles its colony size every three hours.

该合成基因组接管了宿主细胞的生物学运作，产生了一种强健的细菌，该细菌经实验室培养可迅速繁殖，菌落规模每三小时翻一番。