VOA慢速英语--家畜很快会通过基因编辑获得新的品质

Farm Animals May Soon Get New Qualities With Gene¹-Editing

This may seem impossible, but an American company is seeking to change farm animals by cutting or adding to their genes².

By using a process called gene-editing, the company, Recombinetics, says it may be able to remove problem-causing genetic³ traits from some animals.

Recombinetics says it can produce cows born without horns — those sharp objects on top of their heads. By using the editing process, the company says it can also breed cows that survive in hot weather. With gene-cutting, it says, pigs could live and never fully⁴ grow up. Why would that be a good idea? When male pigs reach puberty, their meat can have an unpleasant smell.

The company must first persuade United States government officials that gene-edited animals are safe, and no different than ones bred the traditional way.

To date, no gene-edited animals are sold in the country. The U.S. Food and Drug Administration has approved a kind of salmon⁵ genetically⁶ engineered to grow fast, but those fish are not yet available.

There has been debate as to whether people would want to eat food that comes from gene-edited animals.

Last month, the FDA announced an action plan that described the steps it will take to support both plant and animal biotechnology, while safeguarding public health.

To make this technology more acceptable, Recombinetics is not yet changing animals’ genes to greatly increase their growth or productivity. That could make the animals seem too strange to people. Instead, the company says it is adding gene-edited traits to ease animals’ suffering.

“It’s a better story to tell,” Tammy Lee told the Associated Press. She is chief executive officer of the company, based in St. Paul, Minnesota.

Cow horns can hurt other cows, animals and people. Animal rights activists⁷ criticize the way farmers currently remove cow horns. They use hot irons or a caustic⁸, burning substance to remove the bone.

Gene-editing

This is how Recombinetics says gene-editing works: In a laboratory, workers use an instrument called a “molecular pencil” to “erase, or cut, re-write, remove, or add genes.” This newly edited gene then would be included when an animal is impregnated.

Recombinetics solves the cow horn problem by cutting out the gene for growing horns, ending the need for painful removals. Once the gene is taken out, all future generations after that first animal will also lack the gene -- and would not develop horns.

Last year, the company had a gene-edited male cow without horns. It fathered several cows. They were also all born hornless and are being raised on the grounds of the University of California, Davis. When the female offspring grow up and begin producing milk, the milk will be tested for any problems.

Recombinetics is also developing cows that are less likely to suffer in high temperatures, so they can live in hotter climates.

When it comes to raising pigs for their meat, Recombinetics is working with ones that will not go through puberty. When male pigs go through puberty, their meat can develop an unpleasant smell. Currently, farmers castrate the males, removing their sex organs. Animal rights activists say the treatment is painful because it is usually done without medicine to kill the pain. Editing genes to stop pigs from experiencing puberty would make castration unnecessary.

The company says that it is doing the work of traditional animal breeders, only much faster and with the exact science of cutting and editing genes.

Recombinetics’ Tammy Lee said she thinks if the public accepts gene-editing, farmers would be interested in traits that increase productivity in the animals. For example, she said, pigs would edited to have larger number of babies for each pregnancy⁹.

Change the animal or change the system?

Critics question whether using this technology is “playing God,” doing something that is not natural.

Paul Thompson is a professor of agriculture at Michigan State University. He told the Associated Press that gene-editing may serve as evidence of how modern food production already treats animals.

Thompson said there has been a debate for at least 20 years, “of whether you need to change the animal or change the system.”

Support for changing the genes may also depend on how the technology is used. For example, will it be used to help the animals, prevent disease, or increase productivity?

A Pew Research Center study last August found 43 percent of Americans supported genetically engineering animals for more nutritious¹⁰ meat.

The Humane¹¹ Society of the United States works for better treatment of animals. The society supports gene-editing to end castration of pigs and removing cows’ horns. But the group has yet to give the technology its complete approval.

I’m Anne Ball.

Words in This Story

trait - n. a quality that makes one person or thing different from another

bred - adj. to keep and take care of animals or plants in order to produce more animals or plants of a particular kind

puberty ?- n. ?the period of life when a person's sexual organs mature and he or she becomes able to have children

impregnate - v. to make (a woman or a female animal) pregnant

pencil ?- n. ?an instrument used for writing and drawing that has a hard outer part and a black or colored center part?

iron ?- n. ?a heavy type of metal that is very common, occurs naturally in blood, and is used to make steel and in many products

1 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

2 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪

3 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

4 fully   

adv.完全地，全部地，彻底地；充分地

参考例句：

• The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气，然后全部呼出。
• They soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。

5 salmon   

n.鲑，大马哈鱼，橙红色的

参考例句：

• We saw a salmon jumping in the waterfall there.我们看见一条大马哈鱼在那边瀑布中跳跃。
• Do you have any fresh salmon in at the moment?现在有新鲜大马哈鱼卖吗？

6 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

7 activists   

n.（政治活动的）积极分子，活动家( activist的名词复数 )

参考例句：

• His research work was attacked by animal rights activists . 他的研究受到了动物权益维护者的抨击。
• Party activists with lower middle class pedigrees are numerous. 党的激进分子中有很多出身于中产阶级下层。 来自《简明英汉词典》

8 caustic   

adj.刻薄的，腐蚀性的

参考例句：

• He opened his mouth to make a caustic retort.他张嘴开始进行刻薄的反击。
• He enjoys making caustic remarks about other people.他喜欢挖苦别人。

9 pregnancy   

n.怀孕，怀孕期

参考例句：

• Early pregnancy is often accompanied by nausea.怀孕早期常有恶心的现象。
• Smoking during pregnancy increases the risk of miscarriage.怀孕期吸烟会增加流产的危险。

10 nutritious   

adj.有营养的，营养价值高的

参考例句：

• Fresh vegetables are very nutritious.新鲜蔬菜富于营养。
• Hummingbirds have discovered that nectar and pollen are very nutritious.蜂鸟发现花蜜和花粉是很有营养的。

11 humane   

adj.人道的，富有同情心的

参考例句：

• Is it humane to kill animals for food?宰杀牲畜来吃合乎人道吗？
• Their aim is for a more just and humane society.他们的目标是建立一个更加公正、博爱的社会。