National Biodefense Analysis and Countermeasures Center, 110 Thomas Johnson Drive, Frederick, MD 21702, United States.
National Biodefense Analysis and Countermeasures Center, 110 Thomas Johnson Drive, Frederick, MD 21702, United States.
Curr Opin Microbiol. 2015 Feb;23:110-20. doi: 10.1016/j.mib.2014.11.014. Epub 2014 Dec 1.
Like a jigsaw puzzle with large pieces, a genome sequenced with long reads is easier to assemble. However, recent sequencing technologies have favored lowering per-base cost at the expense of read length. This has dramatically reduced sequencing cost, but resulted in fragmented assemblies, which negatively affect downstream analyses and hinder the creation of finished (gapless, high-quality) genomes. In contrast, emerging long-read sequencing technologies can now produce reads tens of kilobases in length, enabling the automated finishing of microbial genomes for under $1000. This promises to improve the quality of reference databases and facilitate new studies of chromosomal structure and variation. We present an overview of these new technologies and the methods used to assemble long reads into complete genomes.
就像大块拼图一样，使用长读长测序得到的基因组更容易组装。然而，最近的测序技术更倾向于降低每个碱基的成本，而牺牲了读长。这极大地降低了测序成本，但导致了片段化的组装，这对下游分析产生了负面影响，并阻碍了完成（无间隙、高质量）基因组的创建。相比之下，新兴的长读长测序技术现在可以产生长达数十千碱基的读长，使得在 1000 美元以下就能自动完成微生物基因组的测序。这有望提高参考数据库的质量，并促进对染色体结构和变异的新研究。我们介绍了这些新技术以及将长读长组装成完整基因组的方法。
