Scientists Move Closer to Inventing Artificial Life

It is reported that an international team has inserted a man-made chromosome into brewer's yeast, producing a life form that thrives and successfully passes the designer genes on to its off spring.


Chromosomes are the packages for genes. In plants, animals, and fungi like yeast, they are contained within a cell nucleus, which simpler microbes like bacteria do not have. People have 23 pairs of chromosomes, and yeasts have 16. Best known for their role in baking bread and brewing beer, yeasts share about a third of their genes with people.


(Pic 1 The budding yeast is just like roast photo with delicious sausage. 图为正在出芽的啤酒酵母,看起来像不像一个土豆盖着许多片烤香肠呢? 嘿嘿,是不是又饿了^_^)

Tolerant of genetic tinkering, yeast played a role in a previous synthetic biology breakthrough, when scientists led by J. Craig Venter assembled the first artificial bacterial genome inside yeast cells in 2009. And man-made DNA strips cooked up inside yeasts, so-called yeast artificial chromosomes (YACs), have been used to make gene maps for decades. Yeast was one of the first organisms to have its entire genome sequenced, in 1996.

由于对基因改造有很好的耐受性,酵母在以往合成生物学的重大突破中都扮演了很重要的角色。2009年,以J.Craig Venter为首的科学家们在酵母细胞中组建了第一个人工细菌基因。另外,酵母中的某些DNA被人工敲除(使酵母中原有的一些可以表达的基因沉默不能表达,从而抑制相关生物功能),改造成为酵母人造染色体(YAC),多年来都被用作构建基因图谱。1996年,酵母成为第一个被全部测序的有机体。

The new study's "synIII" artificial chromosome implanted into brewer's yeast builds on this legacy. It crowns a seven-year "Build a Genome" project that involved more than 60 biologists in its assembly. 这项将“synIII”人造染色体植入啤酒酵母中的研究全部建立在上述基础上。它被称为“7年构建一个基因组”项目,共有60多位生物学家参与它的构建。

Essentially, the study researchers created a stripped-down, but still functional, third chromosome of brewer's yeast, which contains about 2.5 percent of the organism's total genes.


“This is a major step towards being able to design completely novel organisms," says Todd Kuiken of the Woodrow Wilson International Center for Scholars in Washington, D.C. "The research team has created what some might call the first synthetic cell that was designed, built and reproduced without a host cell present," he says.

这是迈向设计出全新生物体的重要一步。“华盛顿特区Woodrow Wilson国际学者中心的Todd Kuiken说,“研究小组已经创造出第一个合成细胞,它能够不需要宿主细胞的存在而自主设计、构建和复制。”

Still awaiting scientists is the assembly of a complete artificial genome: man-made versions of all the chromosomes in a plant or animal.


Ideally, synthetic biology will produce microbes with specific genetic codes embedded to cheaply churn out renewable fuels or medicines such as the antimalarial drug artemisinin.