Steve Baragona
June 10, 2014 12:08 PM
A new way to fight malaria aims to eliminate the female mosquitoes that spread the deadly disease.
對抗瘧疾有新方法,把傳播致命瘧疾的雌蚊徹底消除。
Scientists have developed mosquitoes that produce almost exclusively male offspring.
Females are the ones that bite. And they are the ones that produce more mosquitoes. The researchers say their technique could wipe out mosquito populations in a few months, without the use of insecticides.
科學家們培育出幾乎只能(exclusively)生出雄性後代(offspring)的蚊子。
會叮人和會製造更多蚊子的都是雌蚊。研究人員表示,他們研究的方法將能在不使用殺蟲劑(insecticide)的情況下,在幾個月就消滅掉(wipe out)蚊子族群。
World’s biggest killers
“Mosquitoes have been labeled as the most virulent animal in the world,” said Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine. “More people die of mosquito-transmitted infections than they do of almost any other type of illness.”
Spraying insecticides is one of the most effective ways to control them, but spraying comes with downsides. It can kill bees and other good insects, and cause environmental damage. And mosquitoes eventually develop resistance to the pesticide.
貝勒醫學院的熱帶病學(tropical medicine)學院的院長說,「一直以來蚊子都被認定是(…labeled as)世界上最具毒性的(virulent)動物,基本上可以說,死於(die of . . .)蚊子傳播的傳染病(infection)的人數高於任何其它疾病。」
噴灑(spray)殺蟲劑仍是控制蚊蟲的最有效的方式之一,但卻有其缺點(downside):不僅殺害了蜜蜂還有其它益蟲,對也造成環境破壞(environmental damage),且蚊子最後還可能對殺蟲劑產生抵抗力(resistance)。
So Imperial College London researcher Nikolai Windbichler and colleagues are trying a different approach. “We found an Achilles’ heel of these mosquitoes,” he said.
The insects have around 400 copies of a particular gene on the X chromosome. That’s the chromosome that carries the traits making the insects female.
倫敦帝國學院的研究人員試圖找出一個不同的方法(approach)。他說,「我們已經發現了蚊子的致命傷(Achilles’ heel)。」
蚊子的X染色體(chromosome)上大約有四百個一種一樣的基因,而正是帶有這個基因特徵(trait)的染色體會讓蚊子成為雌性。
Gene shredder
A creature called a slime mold produces a protein that cuts that gene in one specific place.
The Imperial College London team introduced that slime mold protein into mosquitoes using genetic engineering.
It is designed to turn on when the mosquitoes make sperm. When it does, it cuts the X chromosome in 400 places.
一種名為黏菌(slime mold)的生物能製造出一種可在特定處將基因切斷的蛋白。
倫敦帝國學院的團隊使用基因工程(genetic engineering)技術,將這樣的黏菌蛋白放入蚊子體內。
設計在蚊子製造精蟲(sperm)時開啟作用(turn on),在X染色體的四百處切斷基因。
“You can imagine, that’s pretty bad for a chromosome,” Windbichler said. “It gets destroyed. It cannot be passed on to the next generation.”
That leaves only male offspring. And those offspring also would only produce male offspring. Eventually the population would crash.
研究人員表示,「不難想像,這對染色體絕非好事。染色體被破壞了,也無法遺傳給(be passed on to . . .)下一代。」
只會剩下雄性的蚊子後代,而這些雄蚊再繁殖的也只有雄蚊,蚊子族群最後便會瓦解(crash)。
More Tests Needed
The research is published in Nature Communications.
They have more tests to do to make sure the method is safe and effective. But Windbichler says it beats the alternative.
“If you compare what we are doing to, for example, insecticides, which target any insect species out there, our method is very specific,” Windbichler said. “There may be hundreds of mosquito species in the environment, but our method really only would target that one.”
還需要有更多的測試來確保(make sure)這方式是安全而有效的(effective),但研究人員認為,這個方法的好處勝過(beat)其它的可能的選項(alternative)。
「與不分昆蟲種類都會一體攻擊的殺蟲劑相比,我們這個方法的目標是非常明確的(specific)。也許在某一個環境中會存有上百種的蚊子,但我們的方法可以鎖定某一種類為目標。」
Baylor’s Peter Hotez, who was not involved in the research, calls it an interesting and exciting finding. But, he added, “It’s still a very early stage.”
Meanwhile, he says, it will take more than just designer mosquitoes to beat malaria.
New drugs and vaccines will be needed, along with bed nets and clearing their breeding grounds with good, old-fashioned puddle-draining.
一位並無參與本研究的熱帶病學專家認為,這是個有趣而且令人振奮的發現,但仍只是初期階段。他認為就現階段要打敗瘧疾不能只靠這種特別改造的蚊子。除了新的藥物與疫苗之外,也還要(along with)蚊帳(bed net)與傳統上最有效的清理蚊子孳生地(breeding grounds)的方式,也就是放乾小水窪(puddle)的積水。
Language Notes
eliminate (v) 消除
wipe out (v phr) 消滅;徹底摧毀 xxxxxoffspring (n) 子孫;後代
virulent (a) 劇毒的;致命的 xxxxxxxxx dean (n) (大學的)教務長;學院院長
downside (n) 不利之處;可能的缺點 x resistance (n) 抵抗;抗藥性
Achilles’ heel (n phr) 致命的弱點XXXXX典故來自希臘神話。在神話中,阿基里斯的母親抓著剛出生的阿基里斯的腳踝,將其浸泡在斯提克斯冥河(River Styx)中以求能刀槍不入。但沒泡到水的腳踝,卻成了讓阿基里斯致命的弱點。 xxxxxxxxxxxxxx ix
trait (n) 特徵,特點xxxxxxxxxxxxxxxx shredder (n) 碎紙機 xxx
alternative (n) 替代方案xxxxxxxxxxxxxalong with (prep phr) 和…一起
Check your vocabulary!
Fill in the blanks with a word or phrase from the list above. Make necessary changes. After you finish, select the text below to reveal the hidden answers.
1. Much of the documentary evidence against her had been put through the shredder before she was arrested.
2. Whole villages were wiped out by the floods.
3. Vanity is his Achilles' heel.
4. Digital cell phones offer more security, but the downside is that they have less power.
5. The credit card eliminates the need for cash or cheques.
6. Jim's two most pleasing traits are generosity and energy.
Source:http://www.voanews.com/content/anti-malaria-plan-could-wipe-out-mosquitoes-without-insecticides/1933638.html
編譯:簡嘉呈