2021-09-26

Scientists found potential residues of primitive dinosaur DNA in well preserved dinosaur cells

By yqqlm yqqlm

Scientists found potential residues of primitive dinosaur DNA in well preserved dinosaur cells < / P > < p > this dinosaur is called Caudipteryx, a small peacock sized omnivore with long tail feathers. It wandered along the shallow lake of Rehe biota in Liaoning Province during the early Cretaceous</ p> < p > Li Zhiheng, associate professor of IVPP and co-author of this research paper, pointed out: “the geological data accumulated over the years show that the fossil preservation of Jehol biota is very special, because the small volcanic ash buried the body and preserved it to the cell level.” < / P > < p > scientists extracted a piece of distal articular cartilage from the right femur of this specimen and decalcified it, Different microscope and chemical methods were used to analyze it. They realized that all cells were silicified after the animal died. This silicification is probably the reason why these cells are well preserved</ p> < p > they also found two main cell types: healthy cells during fossilization and less healthy cells that become porous and fossilized during death. Alida bailleul, associate professor of IVPP and corresponding author of the study, pointed out: “it is possible that these cells are dying even before animals die.” < / P > < p > cell death is a natural process in the lives of all animals. But the ability to place a fossil cell at a specific location in the cell cycle is quite new in paleontology. This is one of the goals of IVPP scientists: to improve the image of cells in fossils</ p> < p > in addition, the team isolated some cells and stained them with a chemical used in biological laboratories around the world. This purple chemical, called hematoxylin, binds to the nucleus of a cell. After staining the dinosaur material, a dinosaur cell showed a purple nucleus with some deeper purple lines. This means that the nucleus of this 125 million year old dinosaur cell is well preserved, retaining some original biological macromolecules and chromatin lines</ p> < p > chromatin in cells of all organisms on earth is composed of closely arranged DNA molecules. Therefore, the results of this study provide preliminary data, suggesting that the remains of primitive dinosaur DNA may still be preserved. But to test this accurately, the team needs to do more work and use more sophisticated chemical methods than the staining methods they use here</ p> < p > “to be honest, we are obviously interested in the nucleus of fossils, because if the DNA is preserved, most of the DNA should be here,” Alida bailleul said. Last year she published another report on the preservation of special nuclear and biomolecules in dinosaur chondrocytes in Montana. “Therefore, we have good preliminary data and very exciting data, but we are just beginning to understand the cell biochemistry in very old fossils. We need to do more work on this.” < / P > < p > the research team thinks they need to do more analysis, Even new methods have been developed to understand the processes that may preserve biomolecules in dinosaur cells, because no one has ever successfully sequenced any dinosaur DNA. In the ancient DNA world, sequencing methods are used to confirm whether ancient DNA is preserved in fossils. So far, these methods have worked only on young fossils (no more than a million years), but never on dinosaur materials. Dinosaurs were considered too old to retain any DNA. However, chemical data collected by scientists from IVPP and STM show that this is not the case</ p> < p > even if more data must be collected, this study certainly shows that 125 million year old dinosaur cell fossils cannot be considered 100% rocks. They are not completely “petrified”. On the contrary, they still contain residues of organic molecules. Now, the key is to find out what these molecules are and whether they retain any biological information and DNA residues</ p>