Proteins And Remains Of Erythrocytes Are Preserved In The Bones Of The Hydrosaurus

Video: Proteins And Remains Of Erythrocytes Are Preserved In The Bones Of The Hydrosaurus

Video: Proteins And Remains Of Erythrocytes Are Preserved In The Bones Of The Hydrosaurus
Video: Erythrocyte Creation and Destruction 2024, March
Proteins And Remains Of Erythrocytes Are Preserved In The Bones Of The Hydrosaurus
Proteins And Remains Of Erythrocytes Are Preserved In The Bones Of The Hydrosaurus
Anonim
Image
Image
Image
Image

Scientists isolated individual cells from the fossilized bones of a hadrosaur that died 80 million years ago, and then restored the proteins that made up the ancient lizard.

The pursuit of the genome of fossil animals continues. For evolutionists, this is the most reliable way to draw the branches of the tree of life, for anthropologists - to explain the origin of man, and for most of us - to get acquainted with the result of reconstructions in the next popular science film. The problem is that DNA, in spite of any mosquitoes, tar, fossils and other artifacts of science fiction films, in the best case, lasts only a few tens of thousands of years. This is more or less suitable for reconstructing the genome of Neanderthals or mammoths, but will not help in the case of dinosaurs that disappeared tens of millions of years ago. In the absence of an original "source", paleobiologists have to be content with secondary production - proteins that can persist even when other substances are fossilized.

Some time ago, Chris Organ of Harvard University and his colleagues published data on the biochemical analysis of amino acid sequences isolated from the bones of a Tyrannosaurus rex, which died 68 million years ago. This work was then perceived ambiguously; None of their colleagues had doubts about the honesty of the specialists, but the very fact of the safety of the peptide chains has caused considerable controversy: maybe a misinterpretation? Could it be contamination with foreign proteins?

This time, Marie Schweizer of North Carolina University of the American State, along with Organ and 14 other colleagues from the UK and Israel, announced the successful analysis of the femur of the hadrosaurus Brachylophosaurus canadensis:

they managed to find several types of collagens, as well as elastin, proteins of the basement membrane of blood vessels and even individual cells in bone lacunae.

This became possible thanks to the careful selection of the material for analysis. The experience of paleontologists shows that the remains enclosed in sandstone undergo the least fossilization. It is for this reason that Schweizer and co-authors set out on excavations to the Judith River in Eastern Montana, armed with special equipment to maximize the safety of the material and isolate the protein for analysis.

It is not so easy for living organisms to maintain the constancy of the internal environment: the fact is that any biopolymers are constantly destroyed and the body spends a lot of energy on their restoration and restructuring. After the death of the organism, the situation, of course, only gets worse. If we are talking about fossil animals, then here petrification also comes into play, in which organic components are gradually replaced by inorganic ones.

Petrification, if it occurs, is usually completed in a million years. The ward of Marie Schweizer, who has lain in the sandstone for 80 million years, was no exception.

However, after demineralization, scientists were able to find well-preserved original structures - cells, blood vessels and even the intercellular substance of the bone.

Seven meters of sandstone saved them from destruction for millions of years.

Image
Image

As for laboratory analyzes, here scientists practically did not leave room for discussion: the presence of collagen and elastin was shown by various methods - from immunoblotting to mass spectrometry in several independent laboratories at once. They even managed to find the proteins of the basement membrane - a thin plate on which all the epithelial cells lining the vessels are located. The scientists compared these data with the collagen base for 21 living animals, as well as with the available results of analyzes of the remains of a mastodon and a tyrannosaurus.

This allowed B. canadensis to be placed on the same branch of the tree of life as T.rex, along with the modern chicken and ostrich, but far from lizards and alligators, which are more like second cousins than direct descendants.

It was not without a small "seed" for the future. Although Schweizer did not mention this in the scientific publication itself, traces of hemoglobin were found on mass spectrometry. Which will certainly become a topic for future research.

Recommended: