454 Life Sciences, a centre of excellence of Roche Applied Science, has announced that researchers at Baylor College of Medicine and 454 have published the complete DNA sequence and analysis of an individual human diploid genome.
The genome was analyzed using the 454 Sequencing technology to 7.4 redundancy, facilitating a detailed comparison against the publicly available reference human sequence. The study, entitled “The complete genome of an individual by massively parallel DNA sequencing” appears in the journal Nature.
“This project sets a high standard for the key metrics from next-generation sequencing projects,” said Dr. Richard A. Gibbs, Co-senior author on the Nature study and The Wofford Cain Professor, Department of Molecular and Human Genetics and Director, Human Genome Sequencing Center, Baylor College of Medicine.
“The number of genetic variants that were detected and the completeness of how much of the genome was characterized both show the high quality of the data. It replaces the Sanger sequencing methods. The 454 technology has improved even more since the project, and we are looking forward to carrying out more whole human genome sequencing projects with even better performance,” Dr. Gibbs said.
The groundbreaking sequencing effort has been hailed for the reduction in time and cost by orders of magnitude over conventional Sanger sequencing technology. However, the key metrics of this project’s success are the quality of the mapped sequence data as well as establishing a more complete representation of the human genome from those first published in 2001 and in 2003.
Similar to the recent publication of a diploid human genome led by J. Craig Venter, Ph.D., and his team at the J. Craig Venter Institute, the data analysis revealed the presence of many single nucleotide polymorphisms (SNPs), 3.3 million including more than 600,000 previously uncharacterized SNPs compared to the reference sequence.
454 Life Sciences claims that their sequencing data was of such high quality that researchers were also able to detect over 200,000 insertion and deletion polymorphisms as well as copy number variations including the large scale gain and loss of chromosomal segments. Importantly, 454 Sequencing technology eliminates the major sources of bias seen in conventional Sanger sequencing due to bacterial cloning and consequently, the study reveals the identification of novel human sequence including several additional genes not previously identified.