10大神祕病毒(上)

Viruses challenge our definition of life. Neither dead nor alive, they are simply functional or not. Viruses do not possess the machinery to replicate themselves. Yet you can even argue that they are more evolved than us. With each discovery about viruses, we realize there is so much more to learn.

病毒挑戰了我們對生命的定義。它們沒有活着和死了的區別，只有是否還具有功能。病毒沒有自我複製的機制。不過你也可以說，這意味着它們在進化上比我們更先進。每個關於病毒的發現，都讓我們意識到自己知識的有限。

k Widow Virus

10.黑寡婦病毒

Scientists have recently discovered a virus containing the gene for black widow poison.

科學家新近發現了一種帶有黑寡婦毒蛛毒素的病毒。

The WO virus specifically targets Wolbachia bacteria in arthropods. Latrotoxin kills by poking holes in cell membranes. It is believed that the venom genes allow the WO virus to break through cells and evade the host’s immune system. This is the first time animal genes have been seen in bacteriophages—bacteria-targeting viruses.

WO病毒的宿主是感染節肢動物的沃爾巴克氏菌。黑寡婦毒蛛毒素致命的原理是戳破細胞膜。據稱，這種毒素的基因使WO病毒侵入細胞，並攻陷宿主的免疫系統。這是微生物界發現的第一種動物基因——攻擊細菌的病毒。

Experts hypothesize that the virus picked up the genetic material after breaking out of a Wolbachia bacterium into a black widow cell. However, it is possible the spider stole the gene from the WO virus.

專家推斷，WO病毒在裂解一個沃爾巴克氏菌後，將遺傳物質帶入了黑寡婦的細胞。不過，也可能是這種蜘蛛偷了WO病毒的基因。

rtility Virus

9.不孕病毒

A mysterious viral infection may be the cause of half of unexplained cases of infertility. In one-quarter of infertility cases—roughly one in 70 women under the age of 44—doctors cannot find a cause. An Italian research team discovered that a virus in the herpes family is to blame. It causes immune reactions that make the womb inhospitable for an embryo. Customized anti-viral treatment could offer help.

一種神祕的病毒感染，可能是半數不明原因不孕的原因。在四分之一的病例中，也就是70名44歲以下婦女中的一人，醫生找不到病因。一個意大利研究團隊發現，罪魁禍首是一種皰疹病毒。它會導致免疫反應，使子宮不適合胚胎存活。

The team studied 30 mothers and 30 women with unexplained infertility. 13 of the infertile women were infected with HHV-6A. None of the mothers had it. This herpes variety was discovered over 30 years ago but remains a mystery. HHV-6A infection releases estradiol hormone, which triggers ovulation and prepares a womb for fertilization.

該團隊研究了30名媽媽和30名不明原因不孕的婦女。13 名不孕婦女都感染了HHV-6A，但沒有媽媽感染。這種皰疹病毒變體30多年前就被發現，但一直是個迷。HHV-6A感染導致雌二醇釋放，刺激排卵並使子宮增厚。

ivor Virus

8.倖存者病毒

Scientists have recently unlocked the secrets to a virus that can survive boiling acid.

科學家近期破解了抗沸酸病毒的祕密。

The SIRV2 virus infects a microbe called Sulfolobus islandicus, which lives in acidic hot springs where temperatures top 80 degrees Celsius (175 °F). Using a Titan Krios electron microscope to examine the specimens in previously unimaginable detail, scientists have unlocked the basic mechanism of resistance to heat, desiccation, and ultra-violet radiation.

SIRV2感染一種叫冰島硫化葉菌的微生物。這種微生物生活在溫度可達80攝氏度的酸性熱泉中。通過Titan Krios電子顯微鏡，科學家觀察到了過去無法想像的病毒細節，解密了它耐熱、耐旱、還抗紫外線輻射的機制。

SIRV2 forces genetic material into a protective structural state called A-formation to survive extreme conditions. The mechanism is remarkably similar to the spores bacteria form to survive such environments. These spores are known to cause hard to combat diseases like anthrax. Scientists plan on using these survival mechanisms to design a DNA package for gene therapy.

SIRV2將遺傳物質轉化成一種叫A字陣式的保護性結構，從而在極端條件下存活。這種機制與細菌面對極端環境時產生的孢子非常像。炭疽熱之類的疾病難以治癒，就是因爲孢子。科學家準備通過這種生存機制，設計一種基因治療用的DNA包。

icomponent Virus

7.複合病毒

Normal viruses have all their genes in one viral particle. This viral ball attaches to a cell, opens, and injects its genetic material inside. The host cell begins replicating the virus. Once enough copies are made, they kill the cell, break free, and infect more.

通常，病毒的全部基因都儲存在一個病毒顆粒中。這個顆粒附在細胞上並打開它，把自己的遺傳物質注入其中。然後宿主細胞就開始複製病毒了。複製體足夠多後就裂解並離開宿主，感染更多細胞。

The Guaico Culex virus is different. To become infected, a cell needs to be exposed to four varieties of packages. A fifth appears optional.

Guaico Culex病毒則與此不同。4種變體一起，才能感染細胞。當然也可以再加上一種。

Named after the region in Trinidad it originated, Guaico Culex was discovered during a comprehensive study by the US Army Medical Team to isolate mosquito-borne viruses around the globe. While researchers do not believe Guaico Culex virus can infect mammals, they recently discovered a closely related variety in Uganda's red colobus monkeys.

美軍醫療隊在一個分離全球蚊媒病毒的綜合性研究中，發現了這種病毒。它的名字就來源於特立尼達拉島的發源地。雖然研究人員不認爲Guaico Culex可以感染哺乳動物，他們最近還是在烏干達的紅疣猴身上，發現了該病毒的近親。

n Endogenous Retrovirus

6.人內源性逆轉錄病毒HERV

Roughly 8 percent of the human genome comes from ancient viruses. Retroviruses reproduce by inserting their genetic material into a host and hijacking its replication machinery. Occasionally, these viruses infect sperm and egg cells. If these cells survive, they go on to create an organism containing the virus's DNA in every cell. These are referred to as endogenous retroviruses—in humans, HERVs. The vast majority are considered non-functional "fossils." However, a small portion are still intact and can make infectious particles.

人類基因組中，大約8%來自遠古病毒。逆轉錄病毒將自身遺傳物質注入宿主，從而劫持其複製系統，達到複製自身的目的。這些病毒偶爾會入侵精子和卵細胞。如果這些細胞存活了下來，就會產生每個細胞都含有這種病毒DNA的新個體。它們被稱作內源性逆轉錄病毒，在人體中就是HERV。它們中大部分似乎是沒有功能的“基因遺蹟”。不過也有一小部分保持着活性，能製造傳染性微粒。

Despite being millions of years old, the HERV-K group of viruses appears capable of replicating. Researchers recently discovered a variant that contains no mutations that would downgrade its function. It is believed that this HERV-K remained "alive" within humans until recently. Scientists are unsure whether the dormant virus could reemerge. There is speculation that HERV-K might have been selected for a survival advantage it offered.

HERV-K病毒家族雖然有幾百萬年曆史了，卻似乎仍有複製能力。研究人員近期發現了一種變體，不包含能降低其功能的變異。似乎直到最近，它都在人體內保持着活性。科學家不確定這種休眠的病毒是否會重出江湖。有人猜測，HERV-K能留下來，可能是因爲它帶來了進化優勢。