2021年经济学人 昆虫阉割术,从根上消灭害虫(2)

Crucially, the genetic² tweak involved did not appear to hinder the modified mosquitoes in any other way. On every measure of healthiness they performed as well as their wild counterparts. And even though they were firing blanks, they were still able to mate with females in the laboratory.

至关重要的是，所涉及的基因变异似乎并没有以其他任何方式阻碍转基因蚊子。在每一项健康指标上它们都表现得和野生同类一样好。即便放的是空弹，但他们仍然能够在实验室里与雌性交配。

Although the details are not fully³ understood, says Dr Montell, once female mosquitoes have mated a few times, they become less receptive to doing so again. Mating with an infertile⁴ male is therefore not only fruitless in itself, but should also leave a female less interested in unmodified males in future. Sure enough, a series of experiments conducted in cages suggested that releasing between five and six genetically⁵ modified males for each wild male was enough to cut the number of reproducing females by half. Upping that ratio to 15:1 dropped it by 80%.

蒙特尔博士说，虽然细节还不完全清楚，但雌性蚊子一旦交配了几次，它们就不太愿意再次进行交配。因此，与不育的雄性交配不仅徒劳无功，而且还会在未来让雌性对未改动的雄性失去兴趣。果不其然，在笼子里进行的一系列实验表明，为每只野生雄性释放5到6只转基因雄性，就足以使繁殖中的雌性数量减少一半。将这一比率提高到15:1后，该比率下降了80%。

There is more work to do before field trials, says Dr Montell. But having established the principle, he is excited to see where the work might lead. That the target gene¹ is found in both fruit flies and Aedes suggests it is likely to exist in other disease-carrying mosquitoes, too. And that the engineered males leave no offspring means fewer worries about any unintended consequences which might arise from releasing millions of genetically modified organisms into the environment.

蒙特尔博士说，在实地试验之前还有更多的工作要做。但既然已经确立了原理，他很高兴看到这项工作的发展方向。在果蝇和伊蚊中都发现了目标基因，这表明它可能也存在于其他携带疾病的蚊子中。而且，经过基因改造的雄性不会留下任何后代，这意味着人们更少担心将数百万转基因生物释放到环境中可能产生的意外后果。

More speculatively⁶, the team is pondering whether it might be possible to create males which can outplay their un-engineered cousins at the mating game, despite being infertile. Improving on millions of years of evolution would usually be hard. Even if researchers could find an alteration⁷ that improved a male's attractiveness, it would probably reduce the animal's overall fitness. Such a genetic tweak would ordinarily be winnowed⁸ out by natural selection over subsequent generations. But because each generation of males is created anew in a laboratory, says Dr Montell, there is no long run to worry about. If the team can find the right mutation⁹, such genetically engineered hommes fatales could give mosquito-suppression efforts an even bigger boost.

进一步推测，研究小组正考虑是否有可能创造出尽管不能生育，但却能在交配中比它们的非工程近亲表现得更好的雄性。要改进数百万年的进化过程通常是很困难的。即使研究人员能找到一种方法来提高雄性的魅力，但也可能会降低动物的整体健康状况。这样的基因变异通常会在后代的自然选择中被淘汰掉。但是蒙特尔博士说，因为每一代雄性都是在实验室里新生的，所以不用担心什么。如果研究小组能找到正确的突变基因，这种基因改造的致命蚊子可能会给抑制蚊子的努力带来更大的推动。

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 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。

3 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。

4 infertile   

adj.不孕的；不肥沃的，贫瘠的

参考例句：

• Plants can't grow well in the infertile land.在贫瘠的土地上庄稼长不好。
• Nobody is willing to till this infertile land.这块薄田没有人愿意耕种。

5 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

6 speculatively   

adv.思考地，思索地；投机地

参考例句：

• He looked at her speculatively. 他若有所思的看着她。 来自《简明英汉词典》
• She eyed It'speculatively as a cruel smile appeared on her black lips. 她若有所思地审视它，黑色的嘴角浮起一丝残酷的微笑。 来自互联网

7 alteration   

n.变更，改变；蚀变

参考例句：

• The shirt needs alteration.这件衬衣需要改一改。
• He easily perceived there was an alteration in my countenance.他立刻看出我的脸色和往常有些不同。

8 winnowed   

adj.扬净的，风选的v.扬( winnow的过去式和过去分词 )；辨别；选择；除去

参考例句：

• Administration officials have winnowed the list of candidates to three. 行政官员将候选名单筛减至3人。 来自辞典例句
• I had winnowed the husk away when he came in. 他进来时，我已把糠筛去了。 来自辞典例句

9 mutation   

n.变化，变异，转变

参考例句：

• People who have this mutation need less sleep than others.有这种突变的人需要的睡眠比其他人少。
• So far the discussion has centered entirely around mutation in the strict sense.到目前为止，严格来讲，讨论完全集中于围绕突变问题上。