MAR 04, 2020 12:33 PM PST

DNA Fragments and Cartilage Recovered From 75-Million-Year-Old Dinosaur Bones

WRITTEN BY: Carmen Leitch

An international team of researchers has analyzed cartilage from a baby duckbilled dinosaur, and they have identified bits of preserved proteins and what seems to be chromosomes inside of structures that resemble cells. Using microscopy tools, the scientists assessed skulls of embryos, eggs, hatchlings, and nestlings of a duckbilled dinosaur called Hypacrosaurus from the late Cretaceous period. Their work was reported in National Science Review.

The corresponding author of the study, paleontologist Alida Bailleul of the Chinese Academy of Sciences, found what looked like cartilage cells, called chondrocytes, and saw stuff that looked like chromosomes and nuclei inside of the presumed cells.

“The skull bones of baby dinosaurs are not fused when they hatch, but instead, some of them have cartilaginous plates that fuse later as bone forms in the spaces between them,” Bailleul said. “Seeing exquisitely preserved microscopic structures that resembled the specific cell types found only in cartilage, and which would have been present in the living organism in these tissues, led us to hypothesize that cellular preservation may have extended to the molecular level.”

Bailleul and colleagues set out to learn whether the molecules they observed were from 75 milloin years ago. They used various analytical techniques, and compared what they saw to the skull of an emu of a similar age.

“Bird skulls ossify, or harden, in the same pattern as this hadrosaur’s skull would have, and primitive birds (ratites) like emus are the closest relatives we have alive today to non-avian dinosaurs,” said study co-author Mary Schweitzer, a professor of biology at NC State with a joint appointment at the North Carolina Museum of Sciences.

The scientists saw that antibodies to a protein called collagen II reacted with the chondrocytes from the dinosaur skull, while the surrounding skull was non-reactive. Collagen I is the dominant form in bone, and collagen II is only found in cartilage.

“These tests show how specific the antibodies are to each type of protein, and support the presence of collagen II in these tissues,” Schweitzer explained. “Additionally, bacteria cannot produce collagen, which rules out contamination as the source of the molecules.”

The team also looked for chemicals linked to DNA by applying stains that attach to DNA fragments inside of cells. The stains appeared in the isolated cartilaginous cells, suggesting that fragments of DNA may remain inside (so this fragmented DNA won't be bringing extinct dinosaurs back anytime soon).

“We used two different kinds of intercalating stains, one of which will only attach to DNA fragments in dead cells, and the other which binds to any DNA,” Schweitzer noted. “The stains show point reactivity, meaning they are binding to specific molecules within the microstructure and not smeared across the entire ‘cell’ as would be expected if they arose from bacterial contamination.”

“Although bone cells have previously been isolated from dinosaur bone, this is the first time that cartilage-producing cells have been isolated from a fossil,” Bailleul added. “It’s an exciting find that adds to the growing body of evidence that these tissues, cells and nuclear material can persist for millions – even tens of millions – of years.”
 

Sources: NC State News, National Science Review
 

About the Author
BS
Experienced research scientist and technical expert with authorships on over 30 peer-reviewed publications, traveler to over 70 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
SEP 19, 2022
Genetics & Genomics
CGP: Simplifying the path from tumor to treatment
SEP 19, 2022
CGP: Simplifying the path from tumor to treatment
The promise of NGS in personalized cancer care For years, next-generation sequencing (NGS) has enabled oncologists to id ...
OCT 05, 2022
Cell & Molecular Biology
Researchers Discover Muscle Disease Starts Earlier Than Thought
OCT 05, 2022
Researchers Discover Muscle Disease Starts Earlier Than Thought
People with Duchenne muscular dystrophy (DMD) start to experience symptoms in early childhood. The disease is caused by ...
OCT 08, 2022
Coronavirus
Carriers of Certain APOE Variants are More Vulnerable to Severe COVID-19
OCT 08, 2022
Carriers of Certain APOE Variants are More Vulnerable to Severe COVID-19
Researchers have long known that certain things are risk factors for severe cases of COVID-19, such as old age or obesit ...
OCT 29, 2022
Coronavirus
Extreme Evolution - WHO Now Tracking Over 300 Omicron Subvariants
OCT 29, 2022
Extreme Evolution - WHO Now Tracking Over 300 Omicron Subvariants
As the pandemic has progressed, different variants of SARS-CoV-2 have arisen. Now Omicron subvariants are proliferating, ...
NOV 12, 2022
Earth & The Environment
45,000-Year-Old Human DNA Divulges Human Evolution Secrets
NOV 12, 2022
45,000-Year-Old Human DNA Divulges Human Evolution Secrets
In a recent study published in Nature Ecology & Evolution, an international team of researchers led by the Universit ...
NOV 20, 2022
Genetics & Genomics
Researchers Find Gene Expression Differences in ADHD Brains
NOV 20, 2022
Researchers Find Gene Expression Differences in ADHD Brains
ADHD is one of the most common mental health conditions, and it is estimated to impact 5 - 8% of boys, according to the ...
Loading Comments...