학술논문

Patterns of damage in genomic DNA sequences from a Neandertal
Document Type
Report
Source
Proceedings of the National Academy of Sciences of the United States. Sept 11, 2007, Vol. 104 Issue 37, p14616, 6 p.
Subject
United States
Language
English
ISSN
0027-8424
Abstract
High-throughput direct sequencing techniques have recently opened the possibility to sequence genomes from Pleistocene organisms. Here we analyze DNA sequences determined from a Neandertal, a mammoth, and a cave bear. We show that purines are overrepresented at positions adjacent to the breaks in the ancient DNA, suggesting that depurination has contributed to its degradation. We furthermore show that substitutions resulting from miscoding cytosine residues are vastly overrepresented in the DNA sequences and drastically clustered in the ends of the molecules, whereas other substitutions are rare. We present a model where the observed substitution patterns are used to estimate the rate of deamination of cytosine residues in single- and double-stranded portions of the DNA, the length of single-stranded ends, and the frequency of nicks. The results suggest that reliable genome sequences can be obtained from Pleistocene organisms. 454 | deamination | depurination | paleogenomics