2017年CRI Scientists build DNA from scratch to alter life's blueprint

Scientists build DNA¹ from scratch to alter life's blueprint²

Yeast³ is a tiny ingredient of everyday life.

A baker⁴ carefully adds yeast to his dough⁵ before kneading and shaping it into the perfect sized loaf.

Without the yeast, the bread wouldn't rise in the oven - making it a vital ingredient.

That same yeast could soon also help scientists learn how to build redesigned human DNA from scratch.

New York University scientist Jef Boeke has teamed up with an international scientific group, including a team from Tsinghua University in China, to make yeast that works with chunks⁶ of man-made DNA.

In other words, they are working to redesign the organism's DNA and create it from scratch.

Boeke believes it's a good stepping stone towards tackling the bigger DNA codes of mammals, including people.

"You can think of the genome of the yeast as a book with many chapters, 16 to be exact, because yeast has 16 chromosomes⁷. And what we are doing is we could just rewrite the exact same book but that wouldn't be very interesting. So what we are doing is essentially⁸ coming out with a new edition of the book where we are making a major revision and we are enabling the book to do something it could never do before," Boeke said.

The process to redesign yeast DNA involves using a computer program to edit its natural sequence.

The new edited sequence is then used as a blueprint to build artificial DNA that is inserted into yeast cells for monitoring.

The deleted sequence can be used later on to deliver a different instruction to the cell than it did before.

Leslie Mitchell, a Post-Doctoral Fellow with the Boeke Lab explains:

"Rather than starting with what exists in nature and making changes to see what happens, we can do this bottom up approach where we design whole systems from scratch and see if they work as we predict."

Biologist June Medford is doing similar research with plant DNA and is watching the yeast project closely.

She is genetically⁹ engineering plant DNA to be able to detect pollution and explosives.

She says one day, bomb sniffing¹⁰ dogs could be replaced by bomb sniffing plants.

"We've basically encoded a computerized detection technology in the plant. So now if you want to detect something like a bomb in an airport we can make a plant do that. And our sensitivity is about down to that of a dog. So, it's very, very sensitive." Medford said.

While many scientists believe that the success of this project is a step forward to new possibilities, many moral and ethical¹¹ dilemmas¹² are also concerned as of reconstructing DNA world.

Leslie Mitchell says they are aware of the challenges in the study and believe maintaining an open dialogue is key.

"I think transparency and engaging all the interested parties and stake holders¹³ that are involved and that involves talking to ethicists, policy makers¹⁴, regulators, scientists, the general public. I want my mom to be ok with this. And I think a major component¹⁵ will need to be education," she noted¹⁶.

The project has so far reported building about one-third of the yeast genome. Boeke hopes the rest of the construction will be done by the end of the year.

1 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

2 blueprint   

n.蓝图，设计图，计划；vt.制成蓝图，计划

参考例句：

• All the machine parts on a blueprint must answer each other.设计图上所有的机器部件都应互相配合。
• The documents contain a blueprint for a nuclear device.文件内附有一张核装置的设计蓝图。

3 yeast   

n.酵母；酵母片；泡沫；v.发酵；起泡沫

参考例句：

• Yeast can be used in making beer and bread.酵母可用于酿啤酒和发面包。
• The yeast began to work.酵母开始发酵。

4 baker   

n.面包师

参考例句：

• The baker bakes his bread in the bakery.面包师在面包房内烤面包。
• The baker frosted the cake with a mixture of sugar and whites of eggs.面包师在蛋糕上撒了一层白糖和蛋清的混合料。

5 dough   

n.生面团；钱，现款

参考例句：

• She formed the dough into squares.她把生面团捏成四方块。
• The baker is kneading dough.那位面包师在揉面。

6 chunks   

厚厚的一块( chunk的名词复数 )； （某物）相当大的数量或部分

参考例句：

• a tin of pineapple chunks 一罐菠萝块
• Those chunks of meat are rather large—could you chop them up a bIt'smaller? 这些肉块相当大，还能再切小一点吗？

7 chromosomes   

n.染色体( chromosome的名词复数 )

参考例句：

• Chromosomes also determine the sex of animals. 染色体也决定动物的性别。 来自《简明英汉词典》
• Each of four chromosomes divide longitudinally. 四种染色体的每一种都沿着纵向分裂。 来自《现代汉英综合大词典》

8 essentially   

adv.本质上，实质上，基本上

参考例句：

• Really great men are essentially modest.真正的伟人大都很谦虚。
• She is an essentially selfish person.她本质上是个自私自利的人。

9 genetically   

adv.遗传上

参考例句：

• All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
• Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物

10 sniffing   

n.探查法v.以鼻吸气，嗅，闻( sniff的现在分词 )；抽鼻子（尤指哭泣、患感冒等时出声地用鼻子吸气）；抱怨，不以为然地说

参考例句：

• We all had colds and couldn't stop sniffing and sneezing. 我们都感冒了，一个劲地抽鼻子，打喷嚏。
• They all had colds and were sniffing and sneezing. 他们都伤风了，呼呼喘气而且打喷嚏。 来自《现代英汉综合大词典》

11 ethical   

adj.伦理的，道德的，合乎道德的

参考例句：

• It is necessary to get the youth to have a high ethical concept.必须使青年具有高度的道德观念。
• It was a debate which aroused fervent ethical arguments.那是一场引发强烈的伦理道德争论的辩论。

12 dilemmas   

n.左右为难( dilemma的名词复数 )；窘境，困境

参考例句：

• They dealt with their dilemmas by mixing perhaps unintentionally an explosive brew. 他们――也许是无意地――把爆炸性的佐料混合在一起，以此来应付困难处境。 来自辞典例句
• Ten years later we encountered the same dilemmas in Vietnam. 十年后，我们又在越南遇到了同样进退两难的局面。 来自辞典例句

13 holders   

支持物( holder的名词复数 )； 持有者； （支票等）持有人； 支托（或握持）…之物

参考例句：

• Slaves were mercilessly ground down by slave holders. 奴隶受奴隶主的残酷压迫。
• It is recognition of compassion's part that leads the up-holders of capital punishment to accuse the abolitionists of sentimentality in being more sorry for the murderer than for his victim. 正是对怜悯的作用有了认识，才使得死刑的提倡者指控主张废除死刑的人感情用事，同情谋杀犯胜过同情受害者。

14 makers   

n.制造者，制造商（maker的复数形式）

参考例句：

• The makers of the product assured us that there had been no sacrifice of quality. 这一产品的制造商向我们保证说他们没有牺牲质量。
• The makers are about to launch out a new product. 制造商们马上要生产一种新产品。 来自《简明英汉词典》

15 component   

n.组成部分，成分，元件；adj.组成的，合成的

参考例句：

• Each component is carefully checked before assembly.每个零件在装配前都经过仔细检查。
• Blade and handle are the component parts of a knife.刀身和刀柄是一把刀的组成部分。

16 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。