Ingrida Domarkienė research historic DNA, weaving collectively fragments of genetic materials from trendy people and our long-extinct human relations to retell their tales.
From a background in molecular biology and medical genetics, Domarkienė now spearheads Lithuania’s first historic DNA lab, headquartered on the Medical Science Centre at Vilnius College. Together with worldwide collaborators, the lab is learning the stays of individuals in medieval mass graves in Poland to find out about social practices that had been prevalent within the area on the time, in addition to the migrations of Iron Age people in Lithuania.
They’re additionally revealing insights into the aftermath of the 1986 catastrophe on the Chernobyl nuclear power plant. Wanting on the DNA of Lithuanian employees concerned within the cleanup after the catastrophe, the researchers recognized genes that help protect against the effects of radiation.
Stay Science spoke with Domarkienė, who can also be an affiliate professor at Vilnius, asking about her analysis, the distinctive challenges related to learning historic DNA, and the way delving into our genetic historical past can result in medical advances at present.
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Emily Cooke: What’s it about historic DNA that you just discover attention-grabbing?
Ingrida Domarkienė: It is fascinating, how one can reassemble tales from DNA items, you realize: You simply sequence DNA; it is type of the technological factor.
And for me, coming from molecular biology, it is so fascinating that you just learn the biochemical fragment, natural molecule, and then you definately evaluate it with different samples, and also you get an image of how individuals moved, the place they got here from, the place they went, how they lived. You may get “admixture alerts” — that signifies that individuals [from different populations] combined, and you will get an thought of who met whom and the way they went on and on, and you’ll retell [their] tales.
EC: What are the distinctive challenges related to learning historic DNA?
ID: Probably the most essential problem is that it’s a must to embrace uncertainty and failure right here. Why is that? Since you are by no means fairly certain if you’ll get the standard and amount of DNA to work on additional.
That is as a result of, when an organism dies, DNA begins to decay, and there is nothing there to restore the DNA as it’s in residing cells. So it begins to fragment, and modifications in composition. What’s extra, it blends with all different environmental DNA, which, when extracted, seems as contamination. So, on this case, I like an analogy of a confetti — or what’s left of it after an enormous celebration.
EC: Are you able to speak a bit about your analysis on Chernobyl survivors?
ID: Chernobyl survivors — cleanup employees or liquidators, they’re additionally known as.
It was our mission with colleagues on the Division of Human and Medical Genetics, and within the group, we had the thought to research the genomes of Chernobyl liquidators, and we invited them to take part within the examine. And once they began coming, we heard their tales, and we understood that — you realize, these individuals went by way of so much, however nonetheless, there have been so a lot of them who had been growing older fairly wholesome, with out cancers. You could possibly count on the worst outcomes after what they have been by way of, however they had been fairly OK.
After which we acquired this speculation: that perhaps there’s something within the genomes of these survivors that protects them from all that unhealthy that occurred, as an example — additionally, psychological stress, which was immense again then, once they had been taken from the place they had been in the meanwhile and delivered to Chernobyl with out saying a phrase. They had been telling tales of how they had been woken up, they usually had been simply there on a prepare going to God is aware of the place.
After which that was a tough time, in fact, there, they usually had not solely to work arduous by way of liquidation work, but additionally making an attempt to maintain sane in that type of place.
So, we began analyzing their genomes, and we discovered some potential alerts of protecting variation. After which we even have this new [as of yet unpublished] paper written by our scholar, which is on mitochondrial DNA. So, these Chernobyl liquidators may need protecting variants additionally within the mitochondrial genome and nuclear genome [DNA in the nucleus] that helps mitochondrial perform. So maybe that is the thought.
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EC: How can learning our genetic historical past assist us handle medical challenges at present?
ID: Finding out the previous by way of historic DNA is prime analysis and takes time to comprehend what the findings are and the way they are often applied in observe. Maybe a very powerful ingredient can be a robust interdisciplinary staff which you could belief, and you’ll’t do something alone, actually.
I discover Svante Pääbo‘s work as a benchmarking instance: How will you discuss historic DNA with out mentioning Svante’s title?
He and his staff developed the entire discipline of paleogenomics and generated the reference genome of Neanderthals. They began to offer us explanations of what the variations between human and Neanderthal sequences are and what they imply in a practical method. For instance, one in all Svante Pääbo’s group scientists, Dr. Hugo Zeberg, with colleagues, discovered that the Neanderthal variant within the progesterone receptor is related to preterm delivery, but additionally protective against miscarriage, and leads to extra dwell births. That information could be translated into actual assist for ladies to save lots of their pregnancies.
Or, one other love story: metagenomics [the study of genetic material from all organisms in an environment], which is [an] much more difficult discipline. However it will possibly assist with infectious ailments, as we simply witnessed one of many pandemics — and with the altering local weather, there might be even more. So whereas reconstructing genomes of pathogens and constructing phylogenetic timber [diagrams of evolutionary relationships between species], we are able to perceive the methods pathogens evolve and unfold.
With these analyses, we are able to even begin new narratives. For instance, a very long time in the past, it was thought that the Spaniards launched tuberculosis to the New World. However professor Johannes Krause‘s staff [at the Max Planck Institute for Evolutionary Anthropology] confirmed that the micro organism was there earlier than Columbus was, and apparently it was brought and transferred to humans by seals, which had been a nutritious meals for the individuals residing there in Peru.
So you’ll be able to see that, with this discipline, we can provide science and drugs much more.
EC: What do you assume the way forward for historic DNA analysis will appear like?
ID: From my standpoint, I believe that with the fast-evolving applied sciences, we can go deeper within the sequences, wider within the datasets, and extra divergent markers that we analyze.
As a result of now, we often analyze single nucleotide polymorphisms, or SNPs [pronounced “snips,” which are variations in single building blocks of DNA], as we name them. However my dream can be to reconstruct copy quantity variation, that are the massive chunks of [repeated] DNA, and it isn’t potential to try this now, however there are initiatives to try this.
We will additionally go for evaluation of epigenomic markers [changes to DNA across the genome that alter the activity of genes without affecting the underlying sequence], that are excellent markers for evaluation of how the genome is regulated — to know the way it was again then. These epigenomic markers additionally can be of nice worth.
And apart from evaluation of sociocultural buildings of historic websites, I might say analysis will certainly be directed in direction of understanding the practical that means of the DNA variation that we analyze.
And within the grand finale, we’d be integrating the entire knowledge of the holobiome. Meaning all genomic info from the surroundings — not solely people, but additionally micro organism, viruses, crops, animals, the whole lot who lives there. And integrating this knowledge not solely from the totally different disciplines, but additionally with totally different strategies now we have. As a result of the information comes utilizing totally different strategies, and that will be good to combine the whole lot. And perhaps then we may have the whole image.
Editor’s word: This interview has been condensed and edited for readability.
