双语新闻：英国基因研究人员表示，古代DNA揭示北欧人比其他欧洲人患神经疾病的风险更高的原因

Genetic researchers at the University of Cambridge in Britain say ancient DNA shows why northern Europeans have a higher risk of getting a nerve disease than other Europeans.

英国剑桥大学的基因研究人员表示，古代DNA揭示了为什么北欧人比其他欧洲人患神经疾病的风险更高。

The disease is called multiple sclerosis or MS. The researchers said the risk lies in genes from horse-riding cattle herders who entered northern Europe about 5,000 years ago.

这种疾病被称为多发性硬化症(ms)。研究人员表示，这种风险存在于大约5000年前进入北欧的骑马牧牛牧民的基因中。

The findings come from a huge project to compare modern DNA with ancient genetic material taken from human remains including teeth and bones.

这一发现来自一个大型项目，该项目将现代DNA与从人类遗骸(包括牙齿和骨骼)中提取的古代遗传物质进行比较。

A study released last year said it identified the earliest evidence of horse riding in people called the Yamnaya. The scientists say they lived 4,500 to 5,000 years ago during the Bronze Age period of human history.

去年发布的一项研究称，它发现了Yamnaya人骑马的最早证据。科学家们说，他们生活在4500到5000年前的人类历史上的青铜时代。

The Yamnaya moved from the grasslands of what is now Ukraine and Russia into northwestern Europe. However, the researchers say those people carried gene versions that today are known to increase a person's risk of multiple sclerosis.

亚姆纳亚人从现在的乌克兰和俄罗斯的草原迁移到欧洲西北部。然而，研究人员表示，这些人携带的基因版本今天已知会增加一个人患多发性硬化症的风险。

The researchers added that they believe the same genes protected those herders from infections from their cattle and sheep.

研究人员补充说，他们认为相同的基因保护这些牧民免受牛羊的感染。

The research was published in Nature, a scientific publication.

这项研究发表在科学刊物《自然》上。

William Barrie is a genetic researcher at Cambridge. He helped write the study. He said everyone involved was surprised. "These variants were giving these people an advantage of some kind," he said.

威廉·巴里是剑桥大学的一名基因研究员。他帮助撰写了这项研究。他说，所有参与者都感到惊讶。“这些变异给了这些人某种优势，”他说。

The finding was made possible by a gene bank with thousands of examples of early humans in Europe and western Asia. That project is led by Eske Willerslev of Cambridge and the University of Copenhagen in Denmark.

这一发现是由一个基因库提供的，基因库中有数千个欧洲和西亚的早期人类样本。该项目由剑桥大学和丹麦哥本哈根大学的Eske Willerslev领导。

While MS can strike any population it is most common among white descendants of northern Europeans. Scientists have been unable to explain why.

虽然多发性硬化症可以侵袭任何人群，但在北欧人的白人后裔中最为常见。科学家一直无法解释其中的原因。

The cause of the disease is not known. However, one theory is that infections could cause it in people who have certain genetic qualities. Scientists say they have found 230 genetic variants that might increase the risk of MS.

这种疾病的病因尚不清楚。然而，有一种理论认为，感染可能会导致具有某些遗传品质的人患上这种疾病。科学家表示，他们已经发现了230种可能增加患多发性硬化症风险的基因变异。

The researchers studied DNA from about 1,600 ancient Eurasians. They used the information to develop of map of population movements in northern Europe. They said farmers from the Middle East began pushing out hunter-gatherers about 5,000 years ago. Then the Yamnaya moved in. They traveled with horses and wagons and herded cattle and sheep.

研究人员研究了大约1600名古代欧亚人的DNA。他们利用这些信息绘制了一幅北欧人口流动地图。他们说，大约5000年前，来自中东的农民开始驱逐狩猎采集者。然后亚姆纳亚人搬进来了。他们骑着马和马车旅行，放牧牛羊。

The research team compared the ancient DNA to the genetic information of 400,000 modern-day people stored in UK Biobank in Britain. They wanted to see if MS-linked genetic variations persisted in the north. That is the part of Europe where the Yamnaya moved, rather than southern Europe.

研究小组将古人的DNA与储存在英国生物银行的40万现代人的基因信息进行了比较。他们想看看与ms相关的基因变异是否在北方持续存在。那是扬纳亚人迁移的欧洲地区，而不是南欧。

In what is now Denmark, the Yamnaya replaced ancient farmers, making them the closest ancestors of modern Danes, Willerslev said.

威勒斯列夫说，在现在的丹麦，扬纳亚人取代了古代的农民，使他们成为现代丹麦人最近的祖先。

Rates of MS are especially high in the northern part of Europe known as Scandinavia.

在欧洲北部的斯堪的纳维亚半岛，多发性硬化症的发病率尤其高。

The findings raise additional questions and suggest a need for more research. One of the writers of the study, Astrid Iverson of Oxford University, questioned why a gene variant that seems to have strengthened immunity later plays a part in causing what is believed to be an autoimmune disease. Differences in how modern humans are exposed to animal germs might push the immune system out of balance, she said.

这些发现提出了更多的问题，并表明需要进行更多的研究。该研究的作者之一、牛津大学的阿斯特丽德·艾弗森质疑，为什么一种似乎增强了免疫力的基因变异，后来却在引发一种被认为是自身免疫性疾病的疾病中发挥了作用。她说，现代人接触动物细菌的方式不同，可能会使免疫系统失去平衡。