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Scientists have compiled the largest database of ancient DNA, based on the bones and teeth of around 5,000 humans who lived in parts of Western Europe and Central Asia from 34,000 years ago until the Middle Ages.
This uniquely detailed analysis of the pool of ancient genetic information shows that genes that may once have protected prehistoric hunter-gatherers and Bronze Age nomads from harmful pathogens now cause multiple sclerosis in Europeans. This suggests that it may increase the risk of neurodegenerative diseases such as Alzheimer’s disease.
The ambitious five-year project, involving a team of 175 international experts, will draw on previously known ancient genomes and new ones from hundreds of skeletal remains from museums and other institutions across Europe. The sequenced DNA was combined. Together, this data will form the world’s largest ancient gene bank, according to scientists involved in the project.
Researchers can use this database to chart the spread of genes and diseases over time as populations migrate and interbreed, allowing researchers to identify specific and dramatic changes such as the transition from hunter-gatherer to agricultural life. This study revealed how environmental changes caused specific genetic effects. Subspecies.
By comparing ancient DNA with modern samples, researchers have gained new biological understanding of modern debilitating diseases and physical characteristics. The project’s initial results were published in four papers in the scientific journal Nature on Wednesday.
“What’s remarkable about this dataset is that we can actually see what happened in the past, we can actually see what genetic variations have changed in frequency in the past due to natural selection. It gives us a very fine-grained picture,” Rasmus Nielsen, a geneticist and professor of integrative biology at the University of California, Berkeley, who helped spearhead the project, said at a press conference this week.
one of Key findings from the first batch of researchBased on over 1,600 genomes in our database, we have connected to. multiple sclerosis, MS, also known as MS, is a lifelong autoimmune disease of the nervous system that affects an estimated 2.5 million people worldwide. It is a complex condition formed by multiple environmental and genetic factors, with many potential symptoms, including problems with vision, arm and leg movement, sensation, and balance.
Research suggests that northern Europeans are among the most susceptible to the disease, but little is known about why.
Researchers used this database to investigate the genetic origins of multiple sclerosis. They found that the genetic risk of contracting the disease was correlated with the proportion of ancestry from an ancient group of pastoralists who introduced livestock to Europe about 5,000 years ago.
These cattle and sheep herders, known as the Yamnaya, hail from the Pontic Steppe, which stretches from southeastern Europe to Kazakhstan. They are thought to have been the first horsemen and are very maneuverable.
As they migrated west into Europe, they brought with them certain genetic mutations that researchers believe evolved to protect nomads from pathogens carried by livestock, the study found.
These genetic variations may have subsequently proven beneficial as European peoples transitioned from hunting and gathering to farming.
And because the Yamnaya migrated primarily to northern Europe, the researchers believe that an increasing proportion of pastoralist ancestry among modern-day northern Europeans may partly explain the high prevalence of the disease there. concluded that they may be involved.
“These results surprised us all. These studies represent a major step forward in our understanding of the evolution of MS and other autoimmune diseases,” said one of the authors of the paper, a postdoctoral fellow in the Department of Zoology at the University of Cambridge. co-author William Barry said in a statement. “Showing how our ancestors’ lifestyles influenced their risk of modern disease highlights how we are receptors of an ancient immune system in the modern world.”
Today, the protective effects of these genetic mutations are no longer as useful, says co-author Astrid Iversen, professor of virology and immunology at the University of Oxford.
“We now live very different lives than our ancestors in terms of hygiene, diet, and medical choices, and this, combined with our evolutionary history, makes us more susceptible to certain diseases than our ancestors, including autoimmune diseases such as MS. “That means it could be easier,” Iversen said in a statement.
The researchers also Alzheimer’s disease risk. One of four studies found that this gene is linked to early hunter-gatherer populations that once lived in prehistoric Europe.
“Hunter-gatherer DNA is prevalent in northeastern Europe, meaning there is a higher genetic risk of developing Alzheimer’s disease in this region,” Barry said.
Similarly, A repository of ancient genetic information Shedding light on the evolutionary history of traits such as height and lactose tolerance.
In a commentary accompanying the study, Samira Asghari, assistant professor of genetics and genomic sciences at the Icahn School of Medicine at Mount Sinai, New York, said, “To improve understanding, this type of research needs to be carried out beyond Europe.” It is important to expand to other regions.” We study how differences in population history contribute to the risk of autoimmune diseases such as multiple sclerosis. ”
“While human biology is shared, each population has a unique history, and focusing on a single population limits the opportunities for discoveries that yield insights that advance medicine.”4 writes Asghari, who was not involved in the study.
Tony Capra, associate professor of epidemiology and biostatistics at the Bakar Institute for Computational Health Sciences at the University of California, San Francisco, said the new database provides “the most comprehensive view yet of the genetic history of a region.” Ta.
“This allows the authors to fill in missing details in our understanding of both who lived where and when, and how natural selection has shaped the traits of modern individuals.” ” he said.
However, Professor Capra cautioned: “We are unlikely to find a simple answer to why some populations have genetic variation and others do not.”
“Our species’ evolutionary history has contributed much to our health and characteristics today,” Capra, who was not involved in the study, said in an email.
“But then and now, all of these genetic effects are modulated by the environment. And the genetic effects of most traits, including MS, are the result of multiple genetic variations,” he said. . “After all, we cannot say that MS came from Bronze Age populations, but the migration and environment of these populations contribute to differences in MS risk today.”