In “Jurassic Park” (from Michael Crichton’s novel of the same name), thanks to the perfectly conserved genetic code in the still intact blood cells of an insect trapped in a piece of amber , scientists manage to clone a dinosaur . Could this be replicated in reality? Until now, real attempts to extract DNA from amber or similar substances have not been successful and, unlike what the movies tell us, fossil tree resin is not a very advisable option to preserve DNA, with its instructions. genetics for the development, functioning, growth and reproduction of all known organisms. For what reason? Being trapped in this substance, the soft tissues immediately break down and most of the DNA is lost.
Now, a team of scientists has succeeded in extracting DNA from insects trapped in amber; they have specifically obtained DNA fragments of beetles in tree resin (Hymenaea ) from the forests of Madagascar. Does this mean that we will be able to resurrect the dinosaurs? The intention of the study is rather to find out the limits of the conservation of DNA that we have already seen that it is tremendously fragile.
How long can DNA be preserved?
Controversial studies claim to have detected DNA in 75-million-year-old dinosaur fossils, but all too often, they turn out to be contaminated from much more recent samples.
In fact, the insects trapped in amber under study are not millions of years old, but 2014. They died just a few years ago.
“Instead of looking for DNA in amber 100 million years or more, to dream of the resurrection of dinosaurs, we should start by detecting it in insects trapped a few years ago in resin”, David Peris, from the Institute of Geosciences and Meteorology of the University of Bonn, and leader of the work that publishes the magazine PloS One.
it’s possible
“Our new results show that it is indeed possible to genetically study organisms that were embedded in resin, although we do not yet know the time limit,” adds the expert.
The chemical composition of today’s amber tree resin is very similar to fossilized amber. The samples were stored for 2 to 6 years and then processed. They found that it was possible that the DNA, although very fragile, could be preserved in the samples. Of course, only after carefully cleaning the samples and repeating the PCR (polymerase chain reaction) process several times, was enough DNA replicated to study the genomics of the embedded organism. This method allows scientists to multiply the amount of genetic material to a level where it can be identified, and is commonly used in forensics to compare DNA samples with suspects, or in testing for viruses such as SARS-CoV-2.
Now that the team has discovered that it is technically possible to extract DNA from the resin (without using chloroform or alcohol), and the next steps are to analyze gradually older samples, using more sensitive sequencing methods, to determine how long the DNA might last.
“Investigating the time limit of DNA preservation and many other related issues is the goal of future experiments,” concluded Kathrin Janssen, a co-author of the research.
Referencia: Peris et al. DNA from resin-embedded organisms: Past, present and future, PLOS ONE (2020). DOI: 10.1371/journal.pone.0239521
