quinta-feira, 13 de dezembro de 2007

DNA NEANDERTAL (2006)

Sequencing and Analysis of
Neanderthal Genomic DNA
James P. Noonan,1,2 Graham Coop,3 Sridhar Kudaravalli,3 Doug Smith,1
Johannes Krause,4 Joe Alessi,1 Feng Chen,1 Darren Platt,1 Svante Pääbo,4
Jonathan K. Pritchard,3 Edward M. Rubin1,2*
.

Our knowledge of Neanderthals is based on a limited number of remains and artifacts from which we must make inferences about their biology, behavior, and relationship to ourselves. Here, we describe the characterization of these extinct hominids from a new perspective, based on the development of a Neanderthal metagenomic library and its high-throughput sequencing andanalysis. Several lines of evidence indicate that the 65,250 base pairs of hominid sequence so far identified in the library are of Neanderthal origin, the strongest being the ascertainment of
sequence identities between Neanderthal and chimpanzee at sites where the human genomic
sequence is different. These results enabled us to calculate the human-Neanderthal divergence
time based on multiple randomly distributed autosomal loci. Our analyses suggest that on average the Neanderthal genomic sequence we obtained and the reference human genome sequence share a most recent common ancestor ~706,000 years ago, and that the human and Neanderthal ancestral populations split ~370,000 years ago, before the emergence of anatomically modern humans. Our finding that the Neanderthal and human genomes are at least 99.5% identical led us to develop and successfully implement a targeted method for recovering specific ancient DNA sequences from metagenomic libraries. This initial analysis of the Neanderthal genome advances our understanding of the evolutionary relationship of Homo sapiens and Homo neanderthalensis and signifies the dawn of Neanderthal genomics.
1Mechanical and Aerospace Engineering, Cornell University,
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Ithaca, NY 14853, USA. 2Computing and Information
Science, Cornell University, Ithaca, NY 14853, USA.
*Present address: Department of Computer Science,
University of Vermont, Burlington, VT 05405, USA.
†To whom correspondence should be addressed. E-mail:
josh.bongard@uvm.edu
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