• Journal of KIISE
• /
• v.45 no.3
• /
• pp.200-210
• /
• 2018

Given a set of DNA read sequences, de novo sequence assembly reconstructs a target sequence without a reference sequence. For reconstruction, the assembly needs the overlap phase, which computes all overlaps between every pair of reads. Since the overlap phase is the most time-consuming part of the whole assembly, the performance of the assembly depends on that of the overlap phase. There have been extensive studies on the overlap phase in various fields. Among them, three state-of-the-art results for the overlap phase are Readjoiner, SOF, and Lim-Park algorithm. Recently, a rapid development of sequencing technology has made it possible to produce a large read dataset at a low cost, and many platforms for generating a DNA read dataset have been developed. Since the platforms produce datasets with different statistical characteristics, a performance evaluation for the overlap phase should consider datasets with these characteristics. In this paper, we compare and analyze the performances of the three algorithms with various large datasets.

• KIISE Transactions on Computing Practices
• /
• v.20 no.9
• /
• pp.513-518
• /
• 2014

It has become possible for small scale laboratories to interpret large scale genomic DNA, thanks to the reduction of the sequencing cost by the development of next generation sequencing (NGS). De novo assembly is a method which creates a putative original sequence by reconstructing reads without using a reference sequence. There have been various study results on de novo assembly, however, it is still difficult to get the desired results even by using the same assembly procedures and the analysis tools which were suggested in the studies reported. This is mainly because there are no specific guidelines for the assembly procedures or know-hows for the use of such analysis tools. In this study, to resolve these problems, we introduce steps to finding whole genome of an unknown DNA via NGS technology and de novo assembly, while providing the pros and cons of the various analysis tools used in each step. We used 350Mbp of Toxocara canis DNA as an application case for the detailed explanations of each stated step. We also extend our works for prediction of protein-coding genes and their functions from the draft genome sequence by comparing its homology with reference sequences of other nematodes.

• Proceedings of the Korean Information Science Society Conference
• /
• 2012.06c
• /
• pp.25-27
• /
• 2012

디노버 어셈블리는 레퍼런스 시퀀스 없이 리드의 염기 서열 정보를 이용하여 원래의 전체 시퀀스(original sequence)로 추정되는 시퀀스로 리드들을 재구성하는 방식이다. 최근의 NGS(Next Generation Sequencing) 기술은 대용량 리드를 훨씬 쉽게 저비용으로 생성할 수 있다는 장점이 있어, 이를 이용한 많은 연구가 이루어지고 있다. 그러나 NGS 리드 데이터를 이용한 디노버 어셈블리에 관한 연구는 국내외적으로 매우 미흡한 실정이다. 그 이유는 NGS 리드 데이터를 이용하여 디노버 어셈블리를 수행하는 경우 대용량 데이터, 복잡한 데이터 구조 및 처리 과정 등으로 인하여 매우 많은 시간과 공간이 소요될 뿐만 아니라 아직까지 다양한 분석 툴과 노하우 등이 충분히 개발되어 있지 않기 때문이다. 본 연구에서는 NGS 리드 데이터를 이용한 어셈블리의 실효성과 정확성을 검증한다. 또한 디노버 어셈블리의 처리 시간 및 공간 오버헤드를 해결하기 위하여 유사 종과의 리드 정렬을 활용하는 방안을 제안한다.