首个完整人类基因组序列完成，或将解码生命奥秘？

The first human genome was mapped in 2001 as part of the Human Genome Project, but researchers knew it was neither complete nor completely accurate. Now, the new version has filled in gaps and corrected mistakes.

作为人类基因组计划的一部分，第一个人类基因组图谱于2001年绘制完成。但当时的基因组序列并不是完整和准确的。如今新版本的基因组填补了先前版本的空白并纠正了错误。

The sequence is the most complete reference genome for any mammal so far, and it should lead to a deeper understanding of human evolution and potentially reveal new targets for addressing a host of diseases.

该序列是迄今为止任所有哺乳动物里最完整的参考基因组，它将会对人类进化带来更深的了解，并可能为人类揭示解决一系列疾病的新途径。

The work is the result of the Telomere to Telomere consortium, which is supported by NHGRI and involves genetic and computational biology experts from dozens of institutes around the world. The group focused on filling in the 8% of the human genome that remained a genetic black hole from the first draft sequence. Since then, geneticists have been trying to add those missing portions bit by bit. The latest group of studies identifies about an entire chromosome’s worth of new sequences, representing 200 million more base pairs (the letters making up the genome) and 1,956 new genes.

这项工作是一个名为“端粒到端粒”联盟的成果，该联盟受到美国国家人类基因组研究所（NHGRI)的支持，涉及来自世界各地数十个研究所的遗传和计算生物学专家。该小组专注于填充在第一稿人类基因组图谱中缺失的8%的序列。其实，遗传学家一直在尝试一点一点地添加那些缺失的部分，直到这项最新的研究，在过去的基础上确定了大约 2 亿多个碱基对和 1956 个新基因，这相当于一条人类染色体包含的信息。

The newly sequenced regions include previously inaccessible sections such as the centromeres, the tightly wound central portions of chromosomes that keep the long double strands of DNA organized as the strands unwind, bit by bit, to copy themselves and separate into two cells as a single cell divides. These regions are critical for normal human development and also play a role in brain growth and neurodegenerative 

新测序的区域包括以前无法涉足的部分，例如着丝粒--染色体的紧密缠绕的中心部分，它组织着 DNA 的姐妹双链在展开时的运动，使复制的染色体在细胞分裂时均等地分配到子细胞中。这些区域对人类正常发育至关重要，并且在大脑生长和神经退行性疾病中发挥着作用。

Scientists were also able to sequence the long stretches of DNA that contained repeated sequences, which genetic experts originally thought were similar to copying errors and dismissed as so-called “junk DNA”. These repeated sequences, however, may play roles in certain human diseases.

科学家们还能够对包含重复序列的长段DNA进行测序，这些片段最初被认为与复制错误相似，并被视为所谓的“垃圾 DNA”。然而，研究表明这些重复序列可能在某些人类疾病中发挥重要作用。

Even with the more complete version of the human genome, scientists likely won't be clamoring to replace the old version, despite its gaps and errors. That's because the decades of work on human genetics has made that older version far more annotated than the new one.

即使有了更完整的人类基因组版本，科学家们也不会迫切地寻求替换旧版本，尽管旧版本不完整且存在错误。这是因为几十年来人类遗传学的研究使得基于旧版本的注释比新版本多得多。

All the clinical and research labs have built decades worth of data based on the old, gap-filled genome. To redo all of that work for any individual lab would be horrific.

之前所有的临床和研究实验室都基于旧基因组构建了价值数十年的数据，所以对任何单个实验室来说，重做这些研究将会是可怕的工作量。

 As with the original human genome, the new one is also posted on a public database for any scientist to use. 

即便如此，与原始人类基因组一样，新基因组也发布在公共数据库中，供任何科学家使用。

many labs may will gradually switch over to working with the new genome by comparing just smaller datasets first in a test run to see how much richer and more comprehensive the information they generate from the newer genome is. 

许多实验室或许会逐渐转向使用新基因组，他们首先在测试运行中比较 较小的数据集，观察他们从新基因组中生成的信息有多丰富和全面。

In coming years, researchers will also start to generate more of the complete genome, using both maternal and paternal DNA, to help scientists identify the best targets for new therapies and improve understanding of human development and evolution. 

未来几年，研究人员还将开始使用母系和父系 DNA 生成更多完整的基因组，以帮助科学家确定新疗法的最佳靶点，并提高对人类发展和进化的理解。

No one should see this as the end, but the beginning of a transformation not only in genomic research but in clinical medicine as well.”

这一最新研究并不是一个结束，而是在基因组研究和临床医学领域中转变的开始。