Placeholder Image

字幕列表 影片播放

自動翻譯
  • If this bat were a human, she'd be in deep trouble.

    如果這隻蝙蝠是人類,她就麻煩大了。

  • She's infected with several deadly viruses,

    她感染了幾種致命的病毒。

  • including ones that cause rabies, SARS, and Ebola.

    包括引起狂犬病、SARS和埃博拉病毒的。

  • But while her diagnosis would be lethal for other mammals,

    但雖然她的診斷對其他哺乳動物來說是致命的。

  • this winged wonder is totally unfazed.

    這個長著翅膀的奇蹟完全不為所動。

  • In fact, she may even spend the next 30 years living

    事實上,她甚至可能在接下來的30年裡

  • as if this were totally normalbecause for bats, it is.

    好像這很正常一樣 因為對蝙蝠來說,這很正常。

  • So what's protecting her from these dangerous infections?

    那麼,是什麼在保護她免受這些危險的感染呢?

  • To answer this question, we first need to understand

    要回答這個問題,我們首先要了解以下內容

  • the relationship between viruses and their hosts.

    病毒與其宿主之間的關係;

  • Every virus has evolved to infect specific species within a class of creatures.

    每一種病毒都是為了感染一類生物中的特定物種而進化的。

  • This is why humans are unlikely to be infected by plant viruses,

    這就是為什麼人類不太可能被植物病毒感染的原因。

  • and why bees don't catch the flu.

    以及為什麼蜜蜂不會感染流感。

  • However, viruses do sometimes jump across closely related species

    然而,病毒有時會跨越密切相關的物種進行跳躍性傳播

  • And because the new host has no established immune defenses,

    而且因為新的宿主沒有建立免疫防禦系統。

  • the unknown virus presents a potentially lethal challenge.

    不明病毒是一個潛在的致命挑戰。

  • This is actually bad news for the virus as well.

    這對病毒來說其實也是個壞消息。

  • Their ideal host provides a steady stream of resources

    他們的理想主機提供了穩定的資源流

  • and comes into contact with new parties to infect

    並與新的黨派接觸,以感染。

  • two criteria that are best met by living hosts.

    兩個標準,活著的宿主是最符合的。

  • All this to say that successful viruses

    所有這一切都說明,成功的病毒

  • don't typically evolve adaptations that kill their hosts

    通常不會進化出殺死宿主的適應性----。

  • including the viruses that have infected our flying friend.

    包括我們的飛行朋友所感染的病毒。

  • The deadly effects of these viruses aren't caused by the pathogens directly,

    這些病毒的致命影響並不是由病原體直接造成的。

  • but rather, by their host's uncontrolled immune response.

    而是由其宿主不受控制的免疫反應。

  • Infections like Ebola or certain types of flu have evolved

    像埃博拉或某些類型的流感這樣的傳染病已經進化到了。

  • to strain the immune system of their mammalian host

    使其哺乳動物宿主的免疫系統受到影響。

  • by sending it into overdrive.

    通過將其送入超速狀態。

  • The body sends hordes of white blood cells,

    身體會派出大批的白血球。

  • antibodies and inflammatory molecules to kill the foreign invader.

    抗體和發炎分子來殺死外來入侵者。

  • But if the infection has progressed to high enough levels,

    但如果感染已經發展到足夠高的程度。

  • an assault by the immune system can lead to serious tissue damage.

    免疫系統的攻擊會導致嚴重的組織損傷。

  • In particularly virulent cases, this damage can be lethal.

    在毒性特別強的情況下,這種損害可能是致命的。

  • And even when it's not,

    即使是沒有。

  • the site is left vulnerable to secondary infection.

    該部位容易發生繼發感染。

  • But unlike other mammals,

    但與其他哺乳動物不同。

  • bats have been in an evolutionary arms race with these viruses for millennia,

    蝙蝠與這些病毒進行了數千年的進化軍備競賽。

  • and they've adapted to limit this kind of self-damage.

    而他們已經適應了限制這種自我傷害。

  • Their immune system has a very low inflammatory response;

    他們的免疫系統的發炎反應很低。

  • an adaptation likely developed alongside the other trait

    適應症

  • that sets them apart from other mammals: self-powered flight.

    使它們與其他哺乳動物不同的是:自我驅動飛行。

  • This energy-intensive process can raise a bat's body temperature to over 40ºC.

    這個耗能的過程可以將蝙蝠的體溫提高到40℃以上。

  • Such a high metabolic rate comes at a cost;

    如此高的新陳代謝率是有代價的。

  • flight produces waste molecules called Reactive Oxygen Species

    飛行會產生被稱為活性氧物種的廢物分子。

  • that damage and break off fragments of DNA.

    破壞和斷裂的DNA片段。

  • In other mammals, this loose DNA

    在其他哺乳動物中,這種鬆散的DNA

  • would be attacked by the immune system as a foreign invader.

    會作為外來入侵者被免疫系統攻擊。

  • But if bats produce these molecules as often as researchers believe,

    但如果蝙蝠像研究人員認為的那樣經常產生這些分子。

  • they may have evolved a dampened immune response

    他們可能已經進化出了一種減弱的免疫反應。

  • to their own damaged DNA.

    到自己受損的DNA。

  • In fact, certain genes associated with sensing broken DNA

    事實上,某些與感知斷裂DNA相關的基因。

  • and deploying inflammatory molecules are absent from the bat genome.

    和部署發炎分子的蝙蝠基因組中沒有。

  • The result is a controlled low-level inflammatory response

    其結果是一個可控的低水平發炎反應。

  • that allows bats to coexist with the viruses in their systems.

    使得蝙蝠能與系統中的病毒共存。

  • Even more impressive,

    更讓人印象深刻。

  • bats are able to host these viruses for decades

    蝙蝠能夠將這些病毒寄生幾十年

  • without any negative health consequences.

    而不會對健康造成任何不利影響。

  • According to a 2013 study, bats have evolved efficient repair genes

    根據2013年的一項研究,蝙蝠已經進化出高效的修復基因。

  • to counteract the frequent DNA damage they sustain.

    以抵消它們經常受到的DNA損傷。

  • These repair genes may also contribute to their long lives.

    這些修復基因可能也是它們長壽的原因。

  • Animal chromosomes end with a DNA sequence called a telomere.

    動物的染色體末端有一個DNA序列,稱為端粒。

  • These sequences shorten over time in a process

    在這個過程中,這些序列會隨著時間的推移而縮短。

  • that many believe contributes to cell aging.

    許多人認為會導致細胞老化。

  • But bat telomeres shorten much more slowly than their mammalian cousins

    但蝙蝠端粒的縮短比哺乳動物的表親要慢得多。

  • granting them lifespans as long as 41 years.

    賦予他們長達41年的壽命。

  • Of course, bats aren't totally invincible to disease,

    當然,蝙蝠也不是完全無敵於疾病的。

  • whether caused by bacteria, unfamiliar viruses, or even fungi.

    不管是由細菌、陌生病毒,甚至是真菌引起的。

  • Bat populations have been ravaged by a fungal infection

    蝙蝠的數量已經被一種真菌感染蹂躪了

  • called white-nose syndrome,

    稱為白鼻綜合症。

  • which can fatally disrupt hibernation and deteriorate wing tissue.

    它能致命地破壞冬眠,使翅膀組織惡化。

  • These conditions prevent bats from performing critical roles

    這些條件使蝙蝠無法發揮關鍵作用

  • in their ecosystems, like helping with pollination and seed dispersal,

    在它們的生態系統中,比如幫助授粉和種子散播。

  • and consuming pests and insects.

    並消耗害蟲和昆蟲。

  • To protect these animals from harm, and ourselves from infection,

    為了保護這些動物不受傷害,也為了保護我們自己不受感染。

  • humans need to stop encroaching on bat habitats and ecosystems.

    人類需要停止侵犯蝙蝠的棲息地和生態系統。

  • Hopefully, preserving these populations

    希望能保護這些種群

  • will allow scientists to better understand bats' unique antiviral defense systems.

    將使科學家更好地瞭解蝙蝠獨特的抗病毒防禦系統。

  • And maybe one day, this research will help our own viral immunity take flight.

    也許有一天,這項研究會幫助我們自己的病毒免疫力騰飛。

If this bat were a human, she'd be in deep trouble.

如果這隻蝙蝠是人類,她就麻煩大了。

字幕與單字
自動翻譯

影片操作 你可以在這邊進行「影片」的調整,以及「字幕」的顯示

B2 中高級 中文 TED-Ed 蝙蝠 病毒 宿主 哺乳動物 免疫

為什麼蝙蝠不會生病--阿林傑-巴納吉 (Why bats don't get sick - Arinjay Banerjee)

  • 11 2
    林宜悉 發佈於 2021 年 01 月 26 日
影片單字