More complicated than you think
复杂程度超乎想象
A new, giant virus is confounding old certainties
新品种巨型病毒颠覆常规认知
Oct 28th 2010
BIODIVERSITY is not just a matter of tigers and whales, or butterflies and trees, or even coral reefs and tuna. It is also about myriad creatures too small to see that live in numbers too large to count in ways too numerous to imagine. It is easy to forget, especially at meetings like the one to discuss the Convention on Biological Diversity that has been taking place in Nagoya under the auspices of the United Nations, that most of biology is in fact microscopic. Indeed, the more microscopic biology gets, the more diverse it becomes.
"生物多样性"不仅仅关乎老虎和鲸、蝴蝶和树，乃至珊瑚礁和金枪鱼，还包括无数肉眼看不到的微生物。微生物数量之庞大无法统计，生存方式之多样也难以想见。微生物研究其实是生物学的一大分支――人们往往容易忘记这一点。相关的国际会议尤为容易忽略微生物的主题，即将讨论《生物多样性公约》的这次会议就是这样一个例子。（在联合国的促成下，此次大会已经在日本名古屋开幕。）实际上，体型越微小的生物，其种类越繁多。
In that context, the discovery by Curtis Suttle of the University of British Columbia and his colleagues of a critter they propose to call Cafeteria roenbergensis virus, or CroV, should not be surprising. But for those brought up on a textbook definition of what a virus is, it is still a bit of a shock. For CroV is not a very viruslike virus. It has 544 genes, compared with the dozen or so that most viruses sport. And it may be able to make its own proteins―a task that viruses usually delegate to the molecular machinery of the cells they infect.
这样说来，英属哥伦比亚大学的柯帝士・萨特尔(Curtis Suttle)及其同事发现新物种一事就不足为怪了。柯帝士・萨特尔等人提出将他们发现的生物命名为CroV病毒（Cafeteria roenbergensis virus）。CroV病毒是一种不怎么像病毒的病毒：常规病毒一般只有十来个基因，而CroV病毒却拥有544个基因。此外，病毒一般会将制造蛋白质的任务交由受感染细胞的分子机器完成，而CroV病毒却能自己制造蛋白质。因此，对于那些从小就从课本上习得"什么是病毒"的人们来说，这一发现仍然让他们有些吃惊。
CroV, as its full name suggests, is a parasite of Cafeteria roenbergensis, a single-celled planktonic organism that was itself discovered only in 1988. Despite the recentness of its discovery, C. roenbergensis is one of the commonest creatures on the planet. It is also reckoned by some, given that it hunts down and eats bacteria, to be the most abundant predator on Earth. It is found in every ocean. The samples of C. roenbergensis from which Dr Suttle and his team extracted their quarry were collected off the coast of Texas.
从CroV病毒的全称可以看出，它的宿主是海洋微型异养鞭毛虫（Cafeteria roenbergensis）――一种直到1988年才发现的单细胞浮游生物。尽管海洋微型异养鞭毛虫为世人所认识的时间很短，但也只是地球上众多最普通的生物之一。又由于其捕食细菌的习性，有人将其归为地球上数量最多的捕食性生物。海洋微型异养鞭毛虫普遍存在于各个海洋之中。萨特尔博士和他的团队提取CroV病毒所用的海洋微型异养鞭毛虫样本，就是在德克萨斯州海滨的水体中采集到的。
To see a world in a grain of sand
一沙一世界
That quarry's nature, reported this week in the Proceedings of the National Academy of Sciences, is not a complete surprise. A larger virus, called Mimivirus, which lives in freshwater amoebas, turned up in 2003 and a few other, similar, viruses have been found since then. But CroV is by far the biggest to come out of the sea.
本周，《美国国家科学院学报》的报告指出，CroV病毒的性质并不罕见。早在2003年，人们就发现过一种名为"巨病毒"（mimivirus）的体型更为庞大的病毒，它寄生在淡水中的阿米巴原虫体内。此后，又陆续发现了其他几种类似的病毒。然而，CroV病毒却是迄今为止从海水中发现的体型最大的病毒。
Those who like their categories cut and dried may wonder whether viruses are alive or not. Wise biologists do not struggle too much with such questions. Viruses have genes, can reproduce and are subject to the evolutionary pressures imposed by natural selection. That is enough for biology to claim them. As for CroV, those 544 genes (composed of 730,000 base pairs, the DNA letters in which the language of the genes is written) mean its genome is bigger than those of several bacteria―creatures which everyone agrees are alive.
拘泥于将事物归为既定类别的人们可能想知道，病毒是否有生命。有见地的生物学家不会过多地纠结于此类问题。病毒有基因，能繁殖，也服从于自然选择的进化压力的支配。这就足以将其认定为生物了。至于CroV病毒，它的544个基因（由73万组碱基对构成；碱基对为基因编码所用到的DNA字符）表明，其染色体组要比几种细菌的染色体组都大――毫无疑问，细菌是有生命的。
The problem with categorical thinking in biology is that evolution does not work like that. It actually works by whatever works working. If an organism can successfully subcontract part of the business of metabolism to another while retaining the rest itself, rather than offloading the whole lot as most viruses do, then there are no rules to stop it happening.
生物学上的绝对主义存在问题――他们对进化的定义不符合实际情况。实际上，不管白猫黑猫，抓得住老鼠就是好猫（不论何种形式，只要能通过该形式达到进化结果，就算实现了进化）。如果有一种有机体可以像大多数病毒那样，可以成功地借助另一生物完成部分代谢作用，又不完全依赖另一生物，而将其余代谢留给自己完成，那么该有机体的进化是必然的。
CroV seems to do just that. Besides the genes that relate to protein synthesis it has others which encode DNA repair mechanisms and still others which are involved with protein recycling and signalling within cells. This is not mere hijacking. It is tantamount to a complete personality transplant for the infected cell.
CroV病毒似乎就是这样进行代谢的。它包含三种基因：一种用于合成蛋白质，另一种可以对DNA修复机制进行编码，还有一种用于在细胞内进行蛋白质回收及其信号的发送。这就不光是对受感染细胞进行劫持，简直无异于从根本上改变受感染细胞的性质。
About a third of CroV's genes are similar to Mimivirus genes, suggesting they share a distant ancestor. On the other hand, two-thirds are not. A significant chunk of them seem to have been copied from bacteria. But the majority are unique, and previously unknown to science. A whole new chapter of life, in other words, has been opened.
CroV病毒约有三分之一的基因和"巨病毒"类似，这说明两种病毒在很久以前拥有共同的祖先。然而，它还有三分之二的基因和"巨病毒"不相似。这些基因中相当大一部分似乎是从细菌那里复制过来的。但其中大多数基因都很独特，是以往科学完全没有研究过的。也就是说，生命由此开启了新的篇章。
This discovery, then―and the earlier one of C. roenbergensis itself―speak volumes, albeit in a microscopic language, about biodiversity. Two centuries after Carl Linnaeus invented the system now used to describe it, and a century after Charles Darwin worked out what causes it, the ability of that diversity to surprise is still staggering.
因此，CroV病毒的发现，连同先前海洋微型异养鞭毛虫的发现本身，都通过微生物的方式充分体现了生物多样性。两百年前，卡尔・林奈（Carl Linnaeus）开创了对生物进行分类的方法。如今，人们使用他的方法来描述大千世界的各种生物。一百年前，达尔文发现了导致生物表现出多样性的原因。然而直到今天，生命形态的丰富多彩依然令人啧啧称奇。
复杂程度超乎想象
A new, giant virus is confounding old certainties
新品种巨型病毒颠覆常规认知
Oct 28th 2010
BIODIVERSITY is not just a matter of tigers and whales, or butterflies and trees, or even coral reefs and tuna. It is also about myriad creatures too small to see that live in numbers too large to count in ways too numerous to imagine. It is easy to forget, especially at meetings like the one to discuss the Convention on Biological Diversity that has been taking place in Nagoya under the auspices of the United Nations, that most of biology is in fact microscopic. Indeed, the more microscopic biology gets, the more diverse it becomes.
"生物多样性"不仅仅关乎老虎和鲸、蝴蝶和树，乃至珊瑚礁和金枪鱼，还包括无数肉眼看不到的微生物。微生物数量之庞大无法统计，生存方式之多样也难以想见。微生物研究其实是生物学的一大分支――人们往往容易忘记这一点。相关的国际会议尤为容易忽略微生物的主题，即将讨论《生物多样性公约》的这次会议就是这样一个例子。（在联合国的促成下，此次大会已经在日本名古屋开幕。）实际上，体型越微小的生物，其种类越繁多。
In that context, the discovery by Curtis Suttle of the University of British Columbia and his colleagues of a critter they propose to call Cafeteria roenbergensis virus, or CroV, should not be surprising. But for those brought up on a textbook definition of what a virus is, it is still a bit of a shock. For CroV is not a very viruslike virus. It has 544 genes, compared with the dozen or so that most viruses sport. And it may be able to make its own proteins―a task that viruses usually delegate to the molecular machinery of the cells they infect.
这样说来，英属哥伦比亚大学的柯帝士・萨特尔(Curtis Suttle)及其同事发现新物种一事就不足为怪了。柯帝士・萨特尔等人提出将他们发现的生物命名为CroV病毒（Cafeteria roenbergensis virus）。CroV病毒是一种不怎么像病毒的病毒：常规病毒一般只有十来个基因，而CroV病毒却拥有544个基因。此外，病毒一般会将制造蛋白质的任务交由受感染细胞的分子机器完成，而CroV病毒却能自己制造蛋白质。因此，对于那些从小就从课本上习得"什么是病毒"的人们来说，这一发现仍然让他们有些吃惊。
CroV, as its full name suggests, is a parasite of Cafeteria roenbergensis, a single-celled planktonic organism that was itself discovered only in 1988. Despite the recentness of its discovery, C. roenbergensis is one of the commonest creatures on the planet. It is also reckoned by some, given that it hunts down and eats bacteria, to be the most abundant predator on Earth. It is found in every ocean. The samples of C. roenbergensis from which Dr Suttle and his team extracted their quarry were collected off the coast of Texas.
从CroV病毒的全称可以看出，它的宿主是海洋微型异养鞭毛虫（Cafeteria roenbergensis）――一种直到1988年才发现的单细胞浮游生物。尽管海洋微型异养鞭毛虫为世人所认识的时间很短，但也只是地球上众多最普通的生物之一。又由于其捕食细菌的习性，有人将其归为地球上数量最多的捕食性生物。海洋微型异养鞭毛虫普遍存在于各个海洋之中。萨特尔博士和他的团队提取CroV病毒所用的海洋微型异养鞭毛虫样本，就是在德克萨斯州海滨的水体中采集到的。
To see a world in a grain of sand
一沙一世界
That quarry's nature, reported this week in the Proceedings of the National Academy of Sciences, is not a complete surprise. A larger virus, called Mimivirus, which lives in freshwater amoebas, turned up in 2003 and a few other, similar, viruses have been found since then. But CroV is by far the biggest to come out of the sea.
本周，《美国国家科学院学报》的报告指出，CroV病毒的性质并不罕见。早在2003年，人们就发现过一种名为"巨病毒"（mimivirus）的体型更为庞大的病毒，它寄生在淡水中的阿米巴原虫体内。此后，又陆续发现了其他几种类似的病毒。然而，CroV病毒却是迄今为止从海水中发现的体型最大的病毒。
Those who like their categories cut and dried may wonder whether viruses are alive or not. Wise biologists do not struggle too much with such questions. Viruses have genes, can reproduce and are subject to the evolutionary pressures imposed by natural selection. That is enough for biology to claim them. As for CroV, those 544 genes (composed of 730,000 base pairs, the DNA letters in which the language of the genes is written) mean its genome is bigger than those of several bacteria―creatures which everyone agrees are alive.
拘泥于将事物归为既定类别的人们可能想知道，病毒是否有生命。有见地的生物学家不会过多地纠结于此类问题。病毒有基因，能繁殖，也服从于自然选择的进化压力的支配。这就足以将其认定为生物了。至于CroV病毒，它的544个基因（由73万组碱基对构成；碱基对为基因编码所用到的DNA字符）表明，其染色体组要比几种细菌的染色体组都大――毫无疑问，细菌是有生命的。
The problem with categorical thinking in biology is that evolution does not work like that. It actually works by whatever works working. If an organism can successfully subcontract part of the business of metabolism to another while retaining the rest itself, rather than offloading the whole lot as most viruses do, then there are no rules to stop it happening.
生物学上的绝对主义存在问题――他们对进化的定义不符合实际情况。实际上，不管白猫黑猫，抓得住老鼠就是好猫（不论何种形式，只要能通过该形式达到进化结果，就算实现了进化）。如果有一种有机体可以像大多数病毒那样，可以成功地借助另一生物完成部分代谢作用，又不完全依赖另一生物，而将其余代谢留给自己完成，那么该有机体的进化是必然的。
CroV seems to do just that. Besides the genes that relate to protein synthesis it has others which encode DNA repair mechanisms and still others which are involved with protein recycling and signalling within cells. This is not mere hijacking. It is tantamount to a complete personality transplant for the infected cell.
CroV病毒似乎就是这样进行代谢的。它包含三种基因：一种用于合成蛋白质，另一种可以对DNA修复机制进行编码，还有一种用于在细胞内进行蛋白质回收及其信号的发送。这就不光是对受感染细胞进行劫持，简直无异于从根本上改变受感染细胞的性质。
About a third of CroV's genes are similar to Mimivirus genes, suggesting they share a distant ancestor. On the other hand, two-thirds are not. A significant chunk of them seem to have been copied from bacteria. But the majority are unique, and previously unknown to science. A whole new chapter of life, in other words, has been opened.
CroV病毒约有三分之一的基因和"巨病毒"类似，这说明两种病毒在很久以前拥有共同的祖先。然而，它还有三分之二的基因和"巨病毒"不相似。这些基因中相当大一部分似乎是从细菌那里复制过来的。但其中大多数基因都很独特，是以往科学完全没有研究过的。也就是说，生命由此开启了新的篇章。
This discovery, then―and the earlier one of C. roenbergensis itself―speak volumes, albeit in a microscopic language, about biodiversity. Two centuries after Carl Linnaeus invented the system now used to describe it, and a century after Charles Darwin worked out what causes it, the ability of that diversity to surprise is still staggering.
因此，CroV病毒的发现，连同先前海洋微型异养鞭毛虫的发现本身，都通过微生物的方式充分体现了生物多样性。两百年前，卡尔・林奈（Carl Linnaeus）开创了对生物进行分类的方法。如今，人们使用他的方法来描述大千世界的各种生物。一百年前，达尔文发现了导致生物表现出多样性的原因。然而直到今天，生命形态的丰富多彩依然令人啧啧称奇。
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