Genome Technology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
Genome Res. 2010 Feb;20(2):249-56. doi: 10.1101/gr.097956.109.
We have developed a novel approach for using massively parallel short-read sequencing to generate fast and inexpensive de novo genomic assemblies comparable to those generated by capillary-based methods. The ultrashort (<100 base) sequences generated by this technology pose specific biological and computational challenges for de novo assembly of large genomes. To account for this, we devised a method for experimentally partitioning the genome using reduced representation (RR) libraries prior to assembly. We use two restriction enzymes independently to create a series of overlapping fragment libraries, each containing a tractable subset of the genome. Together, these libraries allow us to reassemble the entire genome without the need of a reference sequence. As proof of concept, we applied this approach to sequence and assembled the majority of the 125-Mb Drosophila melanogaster genome. We subsequently demonstrate the accuracy of our assembly method with meaningful comparisons against the current available D. melanogaster reference genome (dm3). The ease of assembly and accuracy for comparative genomics suggest that our approach will scale to future mammalian genome-sequencing efforts, saving both time and money without sacrificing quality.
我们开发了一种新的方法,利用大规模并行短读测序来生成快速且廉价的从头基因组组装,与基于毛细管的方法生成的组装结果相当。该技术产生的超短(<100 碱基)序列对大型基因组的从头组装提出了特定的生物学和计算挑战。为此,我们设计了一种在组装前使用简化代表性文库(RR libraries)对基因组进行实验分区的方法。我们使用两种独立的限制酶来创建一系列重叠片段文库,每个文库都包含基因组的一个可处理子集。这些文库共同允许我们在无需参考序列的情况下重新组装整个基因组。作为概念验证,我们将这种方法应用于测序和组装了 125Mb 的果蝇(Drosophila melanogaster)基因组的大部分。随后,我们通过与当前可用的果蝇参考基因组(dm3)进行有意义的比较,证明了我们的组装方法的准确性。组装的简便性和比较基因组学的准确性表明,我们的方法将适用于未来的哺乳动物基因组测序工作,在不牺牲质量的前提下节省时间和金钱。