Proteomics analysis of bones from the Scladina site

Proteomics analysis of bones from the Scladina site

Abstract: Since many years, studies of ancient biomolecules have led to a better understanding of the evolution of several species. The old molecules such as proteins offer an opportunity to know the biological past. Proteomics has become attractive for fossil analysis and an alternative to DNA analysis which is limited by DNA amplification present in ancient samples and its contamination. The analysis of fossils is limited by the use of a low quantity of material in order to avoid damaging the samples. The extinction of the analysed species and the absence of their DNA sequencing make their identification a difficult task. The development of a proteomic workflow to answer the questions of the identification of taxa with extremely small quantities and the extinct species is a challenge. The proteomics approach used here shows that, for all samples and fractions, the majority of detected peptides match on collagen I alpha 1 and collagen I alpha 2. The average coverage of collagen I alpha 1 and collagen I alpha 2 is 64%. The identified genus taxa correspond to the anatomical analysis realized by paleontologists. Concerning four samples, the analysis has permitted to identify Panthera tigris altaica as specific species. Bioinformatics analysis allowed us to recognize amino acids substitutions on collagen 1 alpha 1 from Panthera tigris altaica in many positions. These results show that the amino acids substitutions are different in function of the geological position of the bones from the same species and a possible evolution of the collagen sequence. This methodology allows an analysis of fossil bones by providing informations on the collagen sequence, the modifications and the substitutions of the amino acids.