為什么蚊子愛叮你？

It’s annoying enough when mosquitoes start buzzing around your ears， but it’s downright crazy-making when they start biting you and nobody else around you. Ever wondered why？ Well， James Logan at the London School of Hygiene and Tropical Medicine has， too.

James： We have， sort of， 1）anecdotal evidence from people that， you know， members of their family might get bitten more than others. And that led us to believe that there might be some sort of 2）hereditary component. So there might be a genetic link with how attractive you are to mosquitoes.

To try to find out， Logan and his colleagues brought 37 pairs of twins into the lab to do a series of experiments， to see if there was any difference between the identical twins， who have exactly the same genes， and nonidentical twins， who have different genes， in terms of being mosquito magnets or not.

James： The attractiveness of the identical twins was very similar to each other and much greater than when we looked at non-identical twins， which suggests that the genes are controlling， certainly， a significant proportion of how attractive you are to mosquitoes.

The next thing Logan wants to do is try to identify which genes exactly do this and how. He hopes that will lead to better ways to keep mosquitoes away.

James： What we might also be able to do， further down the line， is possibly develop a drug that you could take that would cause the body to 3）up-regulate the production of natural 4）repellents and therefore minimize the need for putting 5）topical repellents on the skin.

That would be a huge development and not just for backyard barbecues. Richard Pollack is a public health 6）entomologist at Harvard. He says mosquitoes spread lots of terrible diseases.

Richard： The mosquito tested here， 7）Aedes aegypti， the yellow fever mosquito， is the main transmitter of the yellow fever virus and the 8）dengue viruses and yet some other infectious agents. So the more we learn about what causes a mosquito to find a person， the better we’ll be able to design better strategies to protect people.

But Logan and Pollack agree that’s a ways off. So for now， we’re stuck 9）slathering on the 10）DEET， wearing longsleeved shirts and pants and running back inside when we just can’t take it anymore.

蚊子開始在你耳邊嗡嗡叫就已經夠讓人心煩了，但當它們誰也不叮只叮你時，那簡直能讓人徹底瘋掉。你有沒有想過這是為什么呢？倫敦衛生與熱帶醫學院的詹姆斯·洛根也想知道個中緣由。

詹姆斯：我們常常會聽到這樣的例子，你知道，很多人都說自己家里人比其他人更招蚊子，這讓我們相信其中可能存在某種遺傳因素。你對蚊子的吸引力可能與你的基因有關。

為了找到根由，洛根和他的同事將37對雙胞胎請進實驗室，進行了一系列實驗，從而觀察在吸引蚊子方面，同卵雙胞胎（基因完全相同）與異卵雙胞胎（擁有不同基因）之間是否存在差異。詹姆斯：同卵雙胞胎之間對于蚊子的吸引力十分相似，這種相似度遠遠大于異卵雙胞胎的情況。這說明了基因對你有多招蚊子肯定起著非常重要的作用。

接下來，洛根想找出到底是哪些基因在作怪，以及它們是如何產生作用的。他希望通過這項研究找到更好的防蚊方法。

詹姆斯：我們也許能更進一步，發明出一種藥，你吃下去就能讓身體產生更多天然驅蚊劑，從而盡可能地減少在皮膚上涂抹外用防蚊劑。

這將是一個巨大的科研進展，其意義可不僅僅是為了讓人享受后院燒烤。理查德·波拉克是哈佛大學的一位公共衛生昆蟲學家。他說，蚊子會傳播多種可怕的疾病。

理查德：這里所測試的蚊子是埃及伊蚊，又稱黃熱病蚊，是黃熱病毒、登革熱病毒以及其他傳染病的主要傳播者。因此，我們對蚊子叮人的問題有更多了解，就越能制定出更有效的防蚊對策來保護人類。……