VOA慢速英语--佛罗里达州使用转基因蚊子对抗疾病

Officials in the Florida Keys plan to release genetically² modified mosquitoes next year in an effort to fight insect-borne diseases.

Genetically modified means an organism's genetic¹ structure has been changed through genetic engineering.

The test project in the Keys, a group of islands off Florida's southern coast, will involve the Aedes aegypti mosquito. The mosquito is not native to Florida. But it does transmit several diseases to humans, including dengue fever and the Zika virus.

In the Keys, nearly 50 cases of dengue have been reported so far this year.

The project is led by biotechnology company Oxitec. It is an American-owned company based in Britain. The plan calls for the release of millions of male, genetically modified mosquitoes to mate with females that bite humans.

The company says its male mosquitoes, which do not bite, are genetically engineered with a protein that makes any female offspring unable to survive. The process aims to lower the overall population of the insects to reduce the transmission of disease.

Kevin Gorman is an Oxitec scientist. He told The Associated Press the company completed similar projects in the Cayman Islands and Brazil that went "extremely well."

"We have released over a billion of our mosquitoes over the years," Gorman said. "There is no potential for risk to the environment or humans."

In a press release, Oxitec noted³ numerous studies by government agencies supporting the safety of the project. The Environmental Protection Agency and the U.S. Centers for Disease Control and Prevention approved the experimental project. Several government agencies in Florida approved it as well.

Some groups, however, worry that the use of genetically modified organisms could change the planet's natural balance. At a recent meeting of the Florida Keys mosquito control board, several people questioned the effects of the project.

"You have no idea what that will do," Barry Wray told the board. He is the director of the Florida Keys Environmental Coalition⁴.

Some experts have also questioned whether or not the modified mosquitoes can effectively crash the mosquito population in Florida as planned.

"The mosquitoes created in a lab have not gone through a natural selection process, in which only the fittest survive and mate," said Max Moreno, an expert in mosquito-borne diseases at Indiana University. He is not involved with the company or the test project.

Moreno asked, "Once they are released in the natural environment, will they be as fit as the naturally occurring males and able to outcompete them for mates?"

Another question is whether the mosquitoes could have unplanned effects on the environment. For example, if a spider, frog or bird eats the mosquito, will the modified protein have any effect on the predator⁵?

Moreno said an ecosystem⁶ is so complex and involves so many species that it would be nearly impossible to test all of them beforehand in a laboratory.

Still, Keys mosquito board members voted 4-1 in favor of the project. One of the supporters was Jill Cranny-Gage. She told the meeting that insecticides and other chemical methods have become less effective against the Aedes aegypti mosquito.

"The science is there," Cranny-Gage said. "We're trying everything in our power, and we're running out of options."

I'm Bryan Lynn.

Words in This Story

transmit – v. to cause a virus of disease to be given to others

offspring – n. the child of a person or animal

potential – n. qualities or abilities that may develop and permit someone or something to succeed

predator – n. animal that hunts and kills other animals for food

ecosystem – n. a biological community of interacting organisms and their physical environment

species – n. a group of animals or plants that are similar and can produce young animals or plants

beforehand – adv. before a particular time or event

option – n. a choice

1 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。

2 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

3 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。

4 coalition   

n.结合体，同盟，结合，联合

参考例句：

• The several parties formed a coalition.这几个政党组成了政治联盟。
• Coalition forces take great care to avoid civilian casualties.联盟军队竭尽全力避免造成平民伤亡。

5 predator   

n.捕食其它动物的动物；捕食者

参考例句：

• The final part of this chapter was devoted to a brief summary of predator species.本章最后部分简要总结了食肉动物。
• Komodo dragon is the largest living lizard and a fearsome predator.科摩多龙是目前存在的最大蜥蜴，它是一种令人恐惧的捕食性动物。

6 ecosystem   

n.生态系统

参考例句：

• This destroyed the ecosystem of the island.这样破坏了岛上的生态系统。
• We all have an interest in maintaining the integrity of the ecosystem.维持生态系统的完整是我们共同的利益。