Nature 344, 656 - 658 (12 April 1990); doi:10.1038/344656a0

Chloroplast DNA sequence from a Miocene Magnolia species

Edward M. Golenberg^*, David E. Giannasi^†, Michael T. Clegg^*, Charles J. Smiley^‡, Mary Durbin^*, David Henderson^* & Gerard Zurawski^§

^* Department of Botany and Plant Sciences, University of California, Riverside, California 92521, USA
^† Department of Botany, University of Georgia, Athens, Georgia 30602, USA
^‡ Department of Geology and Geological Engineering, University of Idaho, Moscow, Idaho 83843, USA
^§ DNAX Research Institute, Palo Alto, California 94304-1104, USA

DNA has been successfully extracted from several samples of preserved tissue, the oldest so far reported originating from a 13,000-year-old ground sloth¹.But severe damage to the preserved DNA, primarily due to oxidation of the pyrimidines¹, has prevented the acquisition of sequence data from ancient samples except in a few cases^2–4. We report here the extraction of DNA from fossil leaf samples from the Miocene Clarkia deposit (17-20 My r old), the amplification of an 820-base pair (bp) DNA fragment from the chloroplast gene rbcL from a fossil of the genus Magnolia, and its subsequent sequencing. The sequence was verified by comparison with published and unpublished rbcL sequences. These results extend our ability to analyse ancient DNA and may open new avenues into problems in palaeobotany, biogeography, and in the calibration of mutation rates.