Hereditary ancestry: analysis of the genes of ancient Russian warriors will help strengthen the immune system

For the first time, Russian scientists conducted a genetic analysis of the remains of the defenders of ancient Yaroslavl, who died during the capture of the city by Batu's troops in 1238. The decoding of the warriors' genome revealed the presence of 65 mutations associated with various pathologies that can potentially be passed on to descendants. According to the researchers, studying the mechanisms of hereditary transmission of such changes can help in finding ways to correct them, as well as in understanding the aging processes of the immune system. At the same time, experts note that such studies are promising, but their results need practical confirmation.

Decoding the genome of ancient Russian warriors

Scientists from the Moscow Institute of Physics and Technology (MIPT), the Institute of Archaeology of the Russian Academy of Sciences and the St. Petersburg Polytechnic Institute conducted a genetic study of human remains found in the Yaroslavl Kremlin. All of them died during the capture of the city by Batu Khan's troops in 1238. Experts found traces of tetanus DNA and a number of dangerous dental infections in them.

Genome-wide sequencing made it possible to analyze in detail the hereditary characteristics of the five studied men and find mutations in them that increase the risk of a wide variety of diseases. As a result, after selecting for clinical significance, the researchers identified 65 genetic variants associated with various pathologies, as well as four mutations associated with bone dysplasia. In some cases, such changes could affect growth, bone health, or the functioning of the cardiovascular system, which is the same health parameters that are important for people today.

— Our study is the first step towards understanding how mutations accumulated and then affected modern humans. By understanding these processes, we will be able to make corrections to the genome in order to prolong a healthy human life. Many diseases leave their mark on the genome. Genetic traces lead to a weakening and decrease in immunity in the elderly," said Haris Mustafin, one of the authors of the work, head of the Laboratory of Historical Genetics, Radiocarbon Analysis and Applied Physics at MIPT.

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Scientists analyzed the microbiome of dental pulp and the genomes of 11 people from mass graves in Yaroslavsky Detinets, the oldest wooden fortress built at the beginning of the 11th century at the confluence of the Volga and Kotorosli rivers. This is the central, fortified part of the city, which served as protection for the prince and his retinue. The data obtained made it possible to determine which infections and hereditary ailments were characteristic of the population of this medieval city.

The fact that the material relates specifically to the devastation of Yaroslavl in 1238 was shown by comprehensive research by specialists from the Institute of Archaeology of the Russian Academy of Sciences, who conducted excavations here. Scientists from two institutes were responsible for the laboratory and analytical part: the MIPT took samples and isolated the DNA of 11 buried, and the Polytechnic University of St. Petersburg‑We analyzed the genome-wide sequencing data.

"The work carried out clearly shows how paleogenomics methods make it possible to reconstruct not only the origin of ancient populations, but also the everyday causes of mortality, which remain invisible to traditional archaeology," said Asya Engovatova, head of the excavation, Deputy director of the Institute of Archaeology of the Russian Academy of Sciences.

Another striking finding was the discovery of DNA from the bacterium Clostridium tetani, the causative agent of the deadly tetanus, in a 30-34-year-old woman from this burial.

Photo: RIA Novosti/Evgeny Biyatov

Tetanus is an anaerobic infection that leaves no traces on bone tissue and has so far been considered "invisible" to archaeologists. Therefore, the discovery of his DNA from a victim of the Mongol devastation of Yaroslavl actually opens a new page in the reconstruction of the diseases of medieval Russia. It can be assumed that the infection could have occurred through a soft tissue wound received during the defense of the city. This means that this woman could have lived for a few more days and then died — there was no way to help her in the 13th century," said Maria Mednikova, a leading researcher at IA RAS.

Microbiome analysis showed that the inhabitants of medieval Yaroslavl suffered massively from periodontal diseases, problems that are well known to modern dental patients.

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Practice will show

Also, among the identified mutations, changes were found related to a disease that can lead to congenital hearing loss and progressive blindness. Scientists have discovered genetic signs that increase the risk of sudden cardiac arrest and laryngeal edema with the risk of suffocation, immunodeficiency, and muscle weakness during exercise.

Photo: IZVESTIA/Andrey Erstrem

— Now research is really underway on how to ensure that the immune system does not lose its strength. However, there have been no significant successes related to the regulation of such genes so far. And it has not yet been possible to reverse the aging process of the immune system, which theoretically weakens the body's defenses and makes it more vulnerable to infection and cancer. These studies may be valuable from the point of view of evolutionary genetics, but it is difficult to say how useful they are from a practical point of view," said Andrey Prodeus, chief immunologist and allergist at the Ministry of Health of the Moscow Region.

Such research is promising and needs to be continued, says Dmitry Kwon, head of the scientific and methodological department at the GENEX Center.

According to immunologist Mikhail Bolkov, the genetic traces of diseases really accumulate with age and weaken the immune system. Such studies are promising, but their results need to be confirmed in practice.