A 28,000 Years Old Cro-Magnon mtDNA Sequence Differs from All Potentially Contaminating Modern Sequences
David Caramelli1, Lucio Milani1, Stefania Vai1,2, Alessandra Modi1, Elena Pecchioli3, Matteo Girardi3, Elena Pilli1, Martina Lari1, Barbara Lippi4, Annamaria Ronchitelli5, Francesco Mallegni4, Antonella Casoli6, Giorgio Bertorelle2, Guido Barbujani2*
1 Dipartimento di Biologia Evoluzionistica, Universitą di Firenze, Firenze, Italy2 Dipartimento di Biologia ed Evoluzione , Universitą di Ferrara, Ferrara, Italy3 Centro di Ecologia Alpina Fondazione Edmund Mach, Viote del Monte Bondone, Trento, Italy4 Dipartimento di Biologia, Universitą di Pisa, Pisa, Italy5 Dipartimento di Dipartimento di Scienze Ambientali , Universitą di Siena, Siena, Italy6 Dipartimento di Chimica Generale e Inorganica, Chimica Analitica, Chimica Fisica, Universitą di Parma, Parma, Italy
Abstract
Background
DNA sequences from ancient speciments may in fact result from undetected contamination of the ancient specimens by modern DNA, and the problem is particularly challenging in studies of human fossils. Doubts on the authenticity of the available sequences have so far hampered genetic comparisons between anatomically archaic (Neandertal) and early modern (Cro-Magnoid) Europeans.
Methodology/Principal Findings
We typed the mitochondrial DNA (mtDNA) hypervariable region I in a 28,000 years old Cro-Magnoid individual from the Paglicci cave, in Italy (Paglicci 23) and in all the people who had contact with the sample since its discovery in 2003. The Paglicci 23 sequence, determined through the analysis of 152 clones, is the Cambridge reference sequence, and cannot possibly reflect contamination because it differs from all potentially contaminating modern sequences.
Conclusions/Significance:
The Paglicci 23 individual carried a mtDNA sequence that is still common in Europe, and which radically differs from those of the almost contemporary Neandertals, demonstrating a genealogical continuity across 28,000 years, from Cro-Magnoid to modern Europeans. Because all potential sources of modern DNA contamination are known, the Paglicci 23 sample will offer a unique opportunity to get insight for the first time into the nuclear genes of early modern Europeans.
Citation: Caramelli D, Milani L, Vai S, Modi A, Pecchioli E, et al. (2008) A 28,000 Years Old Cro-Magnon mtDNA Sequence Differs from All Potentially Contaminating Modern Sequences. PLoS ONE 3(7): e2700. doi:10.1371/journal.pone.0002700
Editor: Henry Harpending, University of Utah, United States of America
Received: April 23, 2008; Accepted: June 17, 2008; Published: July 16, 2008
Copyright: © 2008 Caramelli et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: Study supported by funds of the Italian Ministery of the Universities (PRIN 2006). No sponsors had any role in any phase of the study, and the authors do not envisage any conflict of interests.
Competing interests: The authors have declared that no competing interests exist.
* E-mail:
g.barbujani@unife.ithttp://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0002700;jsessionid=077D0107E5A3BEEEDDA4FF0DBF5B0543