Twenty -two years after the completion of the human genome project, scientists have unveiled the most wide catalog of human genetic variations ever.
In two new articles published on Wednesday (July 23) in the journal Nature, scientists set up DNA of 1,084 people around the world. They Leverage Recent Technological Advancements To Analyze Long Stretches of Genetic Material From Each Person, Stitched Those Fragments Together And Compled the Resulting Genomes in Fine Detail.
The results deepen our understanding about “structural variations” within the human genome. Instead of affecting a single “letter” in the DNA code, such variations affect large parts of the code – they can be deleted or added from the genome, or can be extended to the places where the DNA has turned around or moved to a different place.
These studies revealed the “invisible” properties of the human genome that were technically difficult for the first study. Life -coreThe interim head European Molecular Biology Laboratory (EMBL) HeadburgBoth are co -authors of new papers. For example, large parts of the genome contain codes that repeat repeatedly, and they were thought to be non -verbs.
“Some 20 years ago, we thought about it as ‘Junk DNA’ – we gave it a very bad term,” Corble told the science directly. “More and more realizes that it is not wasteful,” and the new work has highlighted the layout of these long moral DNA.
In addition, all the data generated in new studies are open access, so others in this field can now “find the results, some tools we have developed and use them for their purposes to understand the genetic basis of the disease.” “I fully believe that a subset of the progress we are publishing in nature today will also make it to be diagnosed.”
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More than a thousand genome
When the first draft of a “complete” human genome was published in 2003, about 15 % of its setting was missing due to the technical limits of the time. In 2013, scientists succeeded in closing the vacuum to almost HALF half. And finally, in 2022, First “gaples” human genome Was published.
In 2023, researchers published The first draft of the human panjumWhich was primarily added to DNA from 47 people around the world, rather than being based on a person’s DNA. And the same year, the researchers published The first Y chromosome that was ever arranged from the end to the endBecause in the previous “gallus” genome, the man still lost sexual chromosome.
In the past few years, new technologies and most thanks to the new technologies and efforts to enhance DNA samples beyond the European breed. These progress started this week’s two papers published in nature.
In the first research, researchers Sorted to DNA of 1,019 persons Representing 26 population in five continents. To analyze the DNA, researchers collected “Long Reds”, consisting of tens of thousands of twenty -three pairs. A twenty pair is similar to a crack in the spiral staircase of DNA molecule.
The co -author of the study explained, “With a short reading of about 100 100 pairs, it is difficult to distinguish in genomic areas that look alike.” Jesus Emiliano Suitelo-FunicaDoctorate student at the Center for Genomic Regulation (CGR) in Barcelona, Spain. This is especially true in the repeated areas of the genome. “With Longer Reads, of Around 20K Base Pairs, Assigning Each Read To A Unique Position In The Genome Gets Much Easier,”
More than half of the new genomic variations exposed in the study were found in difficult repetition areas, including transporters, also known as jumping gene. Transposin can jump in various locations in the genome, copy and paste their code. Sometimes, where they come down, they can destabilize the genome, introduce harmful variations and contribute to diseases like cancer.
“Our studies suggest that some of these transplossys can hijack regulatory streams to enhance their activity, which helps to understand the biological methods behind their change,” or the ability to mobilize variations, co -author of the study, Bernardo Rodrig Z MartinAn independent colleague at the CGR and a former post post in Corbal’s EMBL lab, told Science directly in an email.
Jumping genes can essentially stop the ride with some regulatory molecules – long non -coding RNA – and using this trick to make more copies more than itself. “This is a very wonderful method for us,” said Corble.
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95 % to 99 %
Second research included very few genomes – only 65 in total – but These genomes were configured in a more comprehensive way than the first research. About 9595 % of each genome analyzed in the first research was occupied, while the second research created 99 % full genome.
“It may seem like a small difference, but this is in fact a bigger from the genome of the genome scientist,” said Corble. “To achieve the last few percent, this is a great success.”
This jump requires different techniques as well as a new analytical approach. “This project used modern software to collect genome and indicate genetic variation, most of which did not exist for a few years ago,” co -authored Charles LeeProfessor of the Jackson Laboratory for Genomic Medicine told Science directly in an email.
The techniques of continuity included something that created long reading with very few mistakes and one who created ultalong red who was slightly more mistaken. Rodriguez Martin said that at the expense of analyzing fewer genomes, this approach, however, enabled another study to get DNA lengths that had already been completely missed.
Were included in these “invisible” areas CentromerisMain structures in centers of Chromosomes Which are key for the cell division. When a cell prepares to distribute, fibers are connected to the cantomeris and then pull the chromosome into two. This study has found that about 7 % in Centeromarers, there are possibly two places where these fibers can be attached to just one.
“Does it mean that chromosomes are more volatile? Because if the spindle [fiber] He added that it may be confused, linked to two points.
Look
Problems with chromosome distribution can lead to variations. For example, “Chromosome is the result of chromosome separation errors during the cell division in the Dowan syndrome meuses,” when the cells are divided to make sperm and eggs, co -author Dr. Mary KonkelAssistant Professor of the Climson University Center for Human Genitics, told Science directly in an email.
Like the first study, the second research also featured an unprecedented look at jumping genes, which list more than 12,900. Beyond cancer, jumping genes can also be dynamic Different genetic diseases Kunkel noted that by the cause of the change, and how the genes is closed and turned off, they also get more subtle changes. A better understanding of jumping genes can help open their work in human health and illness.
Corball noted that by looking at both studies, scientists can now compare new setting genomes with other data, including both genome and health data. This will be the first step towards connecting health results with concrete results and adding new found structural changes to add these insight into medical exercises.
“Some medical studies won’t be able to ignore them [sequencing] Due to the techniques they will give them high sensitivity to identify the variations.
Lee added that more work is needed to improve genomic data, at the same time, Lee added. Further DNA can be added to the unmanned population, and the technique and software of setting up the process to make the process more efficient and accurate can be further improved. But in the meantime, the pair of new studies indicates an important technical achievement.
“These modern tools were recently designed to handle large quantities of long -reading data that we are now using for every genome,” said Lee. “A few years ago, a complete human chromosome collecting from the end to the end, especially, was practically incredible, because the software and the algorithm were not yet solid.”
