VOA科学技术2023--Scientists Change Fruit Fly Genes to Help Farmers

Scientists Change Fruit Fly Genes² to Help Farmers

Paul Nelson runs a raspberry farm in the northern U.S. state of Minnesota.

Raspberries are a popular red fruit that people like to eat in the summer.

At the farm, Nelson and his team spend a lot of time worrying about fruit flies.

The insect pest that hurts their berries is known as the spotted³ wing drosophila. The flies are from Asia and first came to the U.S. about 15 years ago. The flies hurt blueberries in Maine, as well.

As winters get warmer and springtime comes earlier, farmers in states such as Maine and Minnesota are having more trouble with the flies. Warmer winters permit the fruit flies to survive and have more babies each year. They are also becoming resistant⁴ to some pesticides⁶, which are chemicals used to kill pests.

The flies cause damage by laying eggs in the fruit.

Nelson said the flies can ruin fruit farms if farmers are not willing to put the time in to fight them.

Farmers use chemicals to kill the flies or place covers over the fruit plants to protect them. It is a lot of work, and even with the hard work, they lose 20 to 30 percent of their crop each year.

Researchers at North Carolina State University are working to solve the problem. In the laboratory, they are changing the DNA⁷ of female flies to make sure that any babies they have are not able to reproduce.

The scientists published their work recently in a publication called the Proceedings⁸ of the National Academy of Sciences. They found that if they mated one of their flies with a normal fly, 99 percent of the offspring would be sterile⁹, or not be able to reproduce.

The scientists used computer models to make predictions and found that by releasing modified flies over time, they could reduce the population of fruit flies in an area like a farm in only five months.

It is not the first time scientists have considered modifying the DNA of an insect. Scientists are using genetically¹¹ modified mosquitoes to reduce the population of the insects that cause diseases such as yellow fever, dengue and Zika. The use of gene¹ modification¹² technology has not been used as often in agriculture because it is easier to use pesticides.

Max Scott is a professor who studies insects at North Carolina State. He worked on the study. He said past methods for releasing genetically modified insects would be costly¹³ for farmers if they were used. However, his group's study shows a new method could reduce the population of fruit flies so fast that it would not cost so much.

"We're really excited about this," Scott said. "The system is working really efficiently¹⁴."

Bill Hutchison is an insect professor at the University of Minnesota. He agreed that if the gene modification works, it will help farms in the northern U.S. that now have more flies because of climate change.

Until recently, farmers in Minnesota did not think they had to worry about seeing flies in their fruit that would be ready to pick in June. But Nelson said that is no longer true. While he has not seen the flies this year, he has seen them before.

Two professors who were not part of the study said the North Carolina State research looks promising¹⁵. Luciano Matzkin is at the University of Arizona. He said Scott's team's plan to center on producing sterile insects is better than past plans that attempted to modify another part of the flies' DNA.

Lyric¹⁶ Bartholomay is a professor at the University of Wisconsin. She said "increasingly tailored genetic¹⁰ approaches" will be required as insects gain more resistance to chemical treatments.

However, the work by the scientists in North Carolina is many years away from being used outside of a laboratory.

Scott said he and his team still need to do more work. They have to confirm their computer models and get permission from government officials to test their plan in nature. The scientists need to learn more about how changing the DNA of the fruit flies will affect other insects and whether the DNA changes will work on slightly different fruit flies.

Matzkin was happy to learn about the North Carolina team's research, saying that a "bio-control approach is always preferable" to chemicals. That is why other insect experts are working on similar projects.

Nelson, the farmer, worries that all the research may take too long to help his farm. He is concerned about his farm today.

He said farmers wonder if research will help the next generation. He currently works with his son, who is 24. He hopes they have an answer by the time he is older.

Today, he just wants to be able to sell enough berries to keep the farm going.

"If we lose our sales on our crops of berries, that's a very large deal for our farm," he said.

Words in This Story

pest –n. an animal such as an insect that causes problems on farms or in homes by damaging food or other things

pesticide⁵ –n. a chemical that is used to kill pests

efficiently –adj. done in a quick and effective way

tailor –v. to change something so that it fits the situation very well

approach –n. a way of solving a problem

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 spotted   

adj.有斑点的，斑纹的，弄污了的

参考例句：

• The milkman selected the spotted cows,from among a herd of two hundred.牛奶商从一群200头牛中选出有斑点的牛。
• Sam's shop stocks short spotted socks.山姆的商店屯积了有斑点的短袜。

4 resistant   

adj.(to)抵抗的，有抵抗力的

参考例句：

• Many pests are resistant to the insecticide.许多害虫对这种杀虫剂有抵抗力。
• They imposed their government by force on the resistant population.他们以武力把自己的统治强加在持反抗态度的人民头上。

5 pesticide   

n.杀虫剂，农药

参考例句：

• The pesticide was spread over the vegetable plot.菜田里撒上了农药。
• This pesticide is diluted with water and applied directly to the fields.这种杀虫剂用水稀释后直接施用在田里。

6 pesticides   

n.杀虫剂( pesticide的名词复数 )；除害药物

参考例句：

• vegetables grown without the use of pesticides 未用杀虫剂种植的蔬菜
• There is a lot of concern over the amount of herbicides and pesticides used in farming. 人们对农业上灭草剂和杀虫剂的用量非常担忧。 来自《简明英汉词典》

7 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。

8 proceedings   

n.进程，过程，议程；诉讼(程序)；公报

参考例句：

• He was released on bail pending committal proceedings. 他交保获释正在候审。
• to initiate legal proceedings against sb 对某人提起诉讼

9 sterile   

adj.不毛的，不孕的，无菌的，枯燥的，贫瘠的

参考例句：

• This top fits over the bottle and keeps the teat sterile.这个盖子严实地盖在奶瓶上，保持奶嘴无菌。
• The farmers turned the sterile land into high fields.农民们把不毛之地变成了高产田。

10 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。

11 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

12 modification   

n.修改，改进，缓和，减轻

参考例句：

• The law,in its present form,is unjust;it needs modification.现行的法律是不公正的，它需要修改。
• The design requires considerable modification.这个设计需要作大的修改。

13 costly   

adj.昂贵的，价值高的，豪华的

参考例句：

• It must be very costly to keep up a house like this.维修这么一幢房子一定很昂贵。
• This dictionary is very useful,only it is a bit costly.这本词典很有用，左不过贵了些。

14 efficiently   

adv.高效率地，有能力地

参考例句：

• The worker oils the machine to operate it more efficiently.工人给机器上油以使机器运转更有效。
• Local authorities have to learn to allocate resources efficiently.地方政府必须学会有效地分配资源。

15 promising   

adj.有希望的，有前途的

参考例句：

• The results of the experiments are very promising.实验的结果充满了希望。
• We're trying to bring along one or two promising young swimmers.我们正设法培养出一两名有前途的年轻游泳选手。

16 lyric   

n.抒情诗，歌词；adj.抒情的

参考例句：

• This is a good example of Shelley's lyric poetry.这首诗是雪莱抒情诗的范例。
• His earlier work announced a lyric talent of the first order.他的早期作品显露了一流的抒情才华。