Genomics

基因组学

Dawn of an era

新时代的黎明

The Human Genome Project has transformed biology and medicine

人类基因组计划已经改变了生物学和医学

TWENTY YEARS ago, on June 26th 2000, those running the public Human Genome Project and its private-sector shadow, a firm called Celera Genomics, decided to declare victory. In a simultaneous breasting of the tape, each published a “working draft” of the genome. The broker, Bill Clinton, hosted the chief scientists at the White House. Hyperbolic comparisons were made to the Apollo project to land people on the Moon.

二十年前的2000年6月26日，受公共基金资助的人类基因组计划（Human Genome Project）以及它在私营部门的平行项目赛雷拉基因组公司（Celera Genomics）的负责人都决定要宣告胜利。两者同时冲过了终点线，都发表了基因组“工作草图”。居中斡旋的比尔·克林顿在白宫招待了两方的首席科学家。人们夸张地把该计划和阿波罗登月计划相提并论。

Unlike Apollo, though, this announcement marked a beginning rather than an end. Genomics is now so embedded in biology that it is hard to recall what things were like before it. Those first human sequences cost billions of dollars to obtain. Today, with the advent of new technologies, a full sequence costs about $200, and less detailed versions are cheaper still. It is as if, to use Apollo as the analogy, regular shuttles to the Moon had become available at prices an average family in the West could afford—and the more adventurous might now be considering a trip to Mars.

然而与阿波罗计划不同的是，这一宣告标志着一个开始，而不是结束。基因组学现在已深深根植于生物学，以至于很难回忆起在那之前是什么情形。当年获取第一批人类基因组序列要耗资数十亿美元。而今天，有了新技术之后，获得一个完整序列需要约200美元，较粗略的版本还要更便宜。若用阿波罗计划作类比，那就好像西方普通家庭现在已经能负担得起飞往月球的班机，而更有冒险精神的人现在可能都在盘算去火星旅行了。

Researchers with a hypothesis to test can, for instance, turn to biobanks containing details of tens or hundreds of thousands of people—their medical records, education, employment and, crucially, data about their genomes. Private companies will also sequence genomes to varying standards, for a suitable price. It is probably the case, and if not, it soon will be, that more than 1m human genomes have been sequenced by one method or another.

举例来说，如果想检验某个假设，研究人员可以求助于生物资料库，其中存有几万或几十万人的详细信息，包括病历、受教育和就业情况，还有最重要的——他们的基因组信息。私营公司也会按照多样的标准，以合适的价格提供测序。很可能已经有超过100万个人类基因组通过某种方法被测序——如果还没有，那也很快就会实现。

Genomics also helps non-medical biology. Many non-human species, including crops and domestic animals, have had their genomes sequenced. Though tinkering directly with the genes of organisms that end up on people’s plates still makes some a bit queasy, that is increasingly unnecessary. Genomic knowledge can now be used to speed up selective breeding, without the need for genetic engineering.

基因组学对非医学生物学也有助益。包括农作物和家畜在内的许多非人类物种的基因组已被测序。直接对那些最终会成为盘中餐的有机体的基因动手脚仍然让一些人略感不安，不过这种情绪已经越发没有必要了。这是因为现在可以运用基因组学的知识来加速选择性育种，而不需要用到基因工程。

At the other end of the scientific spectrum, what can be done for Homo sapiens can be done, using DNA from fossils, for other (now extinct) species of human being: the Neanderthals and Denisovans. There is a possible practical interest even here. Sequencing shows that these species once interbred with Homo sapiens . It also suggests that the traces of that interbreeding which remain may help the recipient to fight off infections, by combating viruses and boosting the immune system. ■

而在科学光谱的另一端，利用化石中的DNA，可以把对智人的基因测序也用于其他（现已灭绝的）人种：尼安德特人和丹尼索瓦人。即使是这类研究也可能有实际用途。测序显示这些人种曾经与智人杂交，同时还显示残留的杂交痕迹可能帮助了受体对抗病毒和增强免疫系统，从而抵抗感染。