A protein, a key component of bone and connective tissue called
collagen , from a 68-million-year-old
fossilized Tyrannosaurus rex bone has been sequenced by the palaeontologists. Now, this breaks the record for the oldest protein ever sequenced. Earlier, the oldest sequenced protein (also collagen) came from a mammoth fossil that was 100,000-300,000 years old. Collagen is very abundant and collagen fibres form a particularly tough, triple helix, with three strands of protein wound together like rope. The collagen samples that Schweitzer isolated from the T. rex fossil were buried deep within the fossil's large, dense bones, which probably provided a protective casing for the protein. The optimistic scientists opine that similar well-preserved fossils can be isolatedalong with their resident proteins for further sequencing. Scientists hope that if similar
molecular data can be recovered from other fossils, the information can be used to firm up the dinosaur family tree and to better understand their relationship with living animals. On analysing the limited amount of data available on collagen sequences, the researchers determined that T. rex's closest modern
relative is the chicken as chicken is the closest relative for which collagen sequence is available in public databases. Schweitzer, the scientist,is optimistic that the results will also encourage palaeontologists to open their collections to molecular investigation.