美国科学家在１３日出版的新一期《科学》杂志上报告说，他们从生活在６８００万年前的暴龙的化石中成功测定出了古老的胶原蛋白，这是化石分析领域的一大技术突破，同时蛋白分析结果也进一步佐证了鸟类起源于恐龙的进化理论。
这一暴龙化石是２００３年在美国蒙大拿州发现的。北卡罗来纳州立大学古生物学家玛丽·施魏策尔等人此前就曾在该暴龙的腿骨化石中发现了软组织存在。此次她与哈佛大学医学院等机构的研究合作者进一步发现，软组织中包含有古老的胶原蛋白，这是骨骼中的一种纤维状蛋白质。
施魏策尔说，对暴龙腿骨化石软组织进行的初步分子分析表明，其中很可能保存了暴龙原始蛋白质的片段。之后他们利用先进的质谱测定方法，成功测序出了组成骨胶原蛋白的氨基酸碱基序列，进一步证实了蛋白质的存在。他们认为，这一结果将改变人们对化石保存的看法。现代化石理论认为，蛋白质这样的原始有机物质不可能在如此长的时间跨度内保存下来。
另外，研究人员将暴龙胶原蛋白的氨基酸碱基序列与现代物种的氨基酸碱基序列对比后发现，暴龙的序列与鸡、青蛙和蝾螈的序列有类似之处。施魏策尔说，与鸡的序列类似进一步证明了现代鸟类与恐龙之间的进化关系。
部分英文原文：
Science 13 April 2007:
Vol. 316. no. 5822, pp. 280 - 285
DOI: 10.1126/science.1137614
Reports
Protein Sequences from Mastodon and Tyrannosaurus Rex Revealed by Mass Spectrometry
John M. Asara,1,2* Mary H. Schweitzer,3 Lisa M. Freimark,1 Matthew Phillips,1 Lewis C. Cantley1,4
Fossilized bones from extinct taxa harbor the potential for obtaining protein or DNA sequences that could reveal evolutionary links to extant species. We used mass spectrometry to obtain protein sequences from bones of a 160,000- to 600,000-year-old extinct mastodon (Mammut americanum) and a 68-million-year-old dinosaur (Tyrannosaurus rex). The presence of T. rex sequences indicates that their peptide bonds were remarkably stable. Mass spectrometry can thus be used to determine unique sequences from ancient organisms from peptide fragmentation patterns, a valuable tool to study the evolution and adaptation of ancient taxa from which genomic sequences are unlikely to be obtained.
1 Division of Signal Transduction, Beth Israel Deaconess Medical Center, Boston, MA 02115, USA.
2 Department of Pathology, Harvard Medical School, Boston, MA 02115, USA; North Carolina Museum of Natural Sciences, Raleigh, NC 27601, USA; and Museum of the Rockies, Montana State University, Bozeman, MT 59717, USA.
3 Department of Marine, Earth and Atmospheric Sciences, North Carolina State University, Raleigh, NC 27695, USA.
4 Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA.
* To whom correspondence should be addressed. E-mail: jasara@bidmc.harvard.edu
