事件记录
面试官: 大发娱乐周围正在进行一场战争，而大发娱乐大多数人甚至都不知道. Dr. nel博士. Elde, assistant professor of human genetics is investigating the evolutionary arms race between viruses and ourselves. Dr. Dr. Elde you describe a so-called arms race between pathogens and humans, what do you mean by that?
Dr. Elde: One of the ways we think about this arms race is actually to do with a literary reference, 这就是所谓的红皇后假说. 这来自刘易斯·卡罗尔的书, 镜中奇遇记, 还有正在和爱丽丝说话的红皇后. And she says, "It takes all the running you can do to just stay in the same place.“大发娱乐在宿主-病原体进化中采用了这种想法. So the idea of an arms race at the molecular level is that we go in these back and forth counter adaptations where viruses and other bugs are having a negative impact on our health or fitness which leads to whether or not we're able to reproduce, 以及谁能繁衍后代? 另一方面, 当大发娱乐的人口能够打败一个虫子, 这是军备竞赛的另一回合. You can imagine this as just playing out again and again as evolution unfolds.
面试官: Every year we need a new vaccine for the different strains of flu that are circulating among us, 这是这个种族的一个例子吗?
Dr. Elde: 是的，采访者，这是军备竞赛的一个很好的例子. Every year we come up with a vaccine, that is hopefully beneficial for knocking out influenza. Then what happens is that its only useful for so long because in this arms race scenario the influenza virus return with genetic variation that can defeat that vaccine.
面试官: 是啊，那他们是怎么做到的? 有什么秘密吗？?
Dr. Elde: So these vaccines are designed to recognize certain shapes, basically, on the surface of 病毒. If we're able to effectively recognize those shapes it'll alert our immune system to come in and destroy 病毒es. So what 病毒es do is then through mutations and selection of their genes, change their shapes and then they become virtually invisible to our vaccines.
面试官: 那么如何在实验室中研究这些宿主-病原体的相互作用呢?
Dr. Elde: In particular, one of 病毒es we study is called vaccinio virus. 这是模型痘病毒. 天花病毒在医学上最著名的是天花. One of the ways it was eradicated was through vaccination using a highly related but much more safe virus called vaccinia. 所以 what we do is take this relatively safe virus into the laboratory, 用谜题或挑战呈现游戏. 例如，如果它不擅长复制，大发娱乐就给它细胞. 然后考虑到基因组序列技术的进步, what we can do is sequence the genomes of 病毒es before and after we present them with these immunity puzzles. 然后在最后问病毒有什么不同...
面试官: 哦,酷.
Dr. Elde: ...实验的结果.
面试官: 是的.
Dr. Elde: 是的，这是很有趣的实验. 当然，你必须小心，大发娱乐要对付的是病毒.
面试官: 是的.
Dr. Elde: 所以, one of the very cool findings from one of our initial studies of the vaccinio virus that really surprised us. 病毒适应的不仅仅是, 所谓的点突变, 只交换一个DNA字母, 可以这么说, 但是这些病毒变得, 基因组就在大发娱乐面前变得越来越大. 所以即使在几次感染的过程中, 病毒, 基因组的大小增加了10-20%. 这真的很惊人.
面试官: 基因组扩展意味着什么.
Dr. Elde: 我的意思是，如果大发娱乐只看基因组的大小, 例如, and for these pox viruses like vaccinia and smallpox there are about 200 kilo bases. 这是一排20万个DNA字母. 大发娱乐发现他们收到的信件越来越多. 他们从20万个字母增加到22万个字母. 这不仅仅是你在加, 20页的官样文章,000个字母, you were adding the same repetitive letters of about 300 in a row of a certain gene.
And it turns out this gene is actually an important inhibitor of one of our immune response genes. 大发娱乐看到的是，对于这个特定的基因, 它从一个拷贝开始, 多达20份, 非常迅速地. Having 20 copies meant that 病毒 was much more able to defeat our immune response versus if it only had one copy. What was really- a second surprise was that once this virus had 20 copies of this gene, it was actually 20 times more likely to come up with a new single letter change or a point mutation, 这本身就可以打败免疫系统.
面试官: So not only is it defending itself better but it is also driving it's own evolution.
Dr. Elde: 完全.
面试官: 太酷了.
Dr. Elde: 这是一赠二. 这很酷，但也有点吓人. 正确的?
面试官: 是的,正确的.
Dr. Elde: These things can really, and this is again sort of this idea of an arms race.
面试官: 是的.
Dr. Elde: And its sort of any mechanism that can aid 病毒 in its replication will 非常迅速地 be selected for. The imagery we've been using to name this hypothesis is called the accordion model of virus evolution. 他们的想法是病毒像手风琴一样扩张, 音乐家演奏音符的一部分, 然后在这个展开式中, 你对所有这些额外的副本进行取样以进行更改. If you hit on one that works then the accordion can contract the second part, 就像一个音乐家在做实验, 正确的?
面试官: 是的
Dr. Elde: But here 病毒 is playing evolutionary process and changing in ways that benefit its replication.
面试官: So, how can we use information like that to help combat these viruses?
Dr. Elde: We always want to look at what we see what we observe in the laboratory and ask, 这在野外也适用吗? There's this really interesting story with a pox virus that infects rabbits. 这是目的, 这种病毒被称为粘液瘤, it was purposefully released in Australia back in the 1950s as a biological control agent. The idea was that some of the settlers in Australia had brought rabbits from Europe. The rabbits had gone crazy and now billions of rabbits and you have a problem. One of the proposed solutions was to release a virus that could kill the rabbits. 这是黏液瘤病毒.
So, there's this really interesting historical record where people save 病毒 years after it was released in the rabbits. 大发娱乐的信仰, what we done is look at the genomic changes and we see hints of these gene duplication, 或者几乎像手风琴一样的动力. We think this could happen in the wild as viruses are exploring new hosts. What we're trying to do with this is trying to understand at a basic level, 这些病毒是如何运作的, 他们如何适应, 它们是如何进化的. 如果大发娱乐能在那之前得到信息的话, we might be in a much better spot to stop them before they get out of control as new epidemics or pandemics.
播音员: 有趣，内容丰富，而且都是为了更好的健康. 大发娱乐是Scope健康科学广播.