Full version, published!

2022-09-16 0 By

Science and technology daily practice reporter Zhang Jiaxin is known as the “moon” life science of the human genome sequencing again: significant progress telomere to telomere alliance international science team (T2T) published the first complete, no clearance of the human genome sequence, for the first time reveals the highly repetitive genome section of the same area and its variation in the human genome.This is a “major upgrade” to the standard human reference genome, known as the Reference Genome Sequence (GRCh38), published in 2013.The achievement was reported in six papers published in the journal Science on Thursday (local time).The new results of the sequencing of the human genome were presented in a cover story and feature in Science magazine.On February 12, 2001, the International Human Genome Project (HGP), a collaboration of scientists from six countries, published its first map of the human genome and its preliminary analysis.On April 15, 2003, the draft human genome sequence was published.However, due to technical limitations, the original human genome project left a gap of about 8%.This part is difficult to sequence and consists of highly repetitive, complex chunks of DNA containing functional genes as well as centromeres and telomeres located in the middle and end of chromosomes.The new, no-gap version, called T2T-CHM13, consists of 3.055 billion base pairs and 19,969 protein-coding genes.Nearly 200 million base pairs of new DNA sequences were added, including 99 genes that might encode proteins and nearly 2,000 candidate genes that require further study.Most of these candidate genes are inactivated, but 115 of them may still be expressed.The team also found about 2 million additional variants in the human genome, 622 of which were present in medically relevant genes.In addition, the new sequence corrects thousands of structural errors in GRCh38.Specifically, the gaps filled in by the new sequences include the entire short arms of all five human chromosomes and cover some of the most complex regions of the genome.These include highly repetitive DNA sequences found in and around important chromosomal structures, such as telomeres at the ends of chromosomes and centromeres, which coordinate the separation of duplicating chromosomes during cell division.The new sequence also revealed previously undiscovered segmental repeats, long pieces of DNA that replicate throughout the genome and are known to play important roles in evolution and disease.A digital display shows the output of the DNA sequencer.The new sequence also provides important improvements in the identification and interpretation of genetic variations and reveals never-before-seen details about the region surrounding the centromeres.Variability in this region could provide new evidence of how our ancestors evolved.This complete, non-gap sequence is crucial for understanding the full spectrum of variations in the human genome and for understanding the genetic contribution of certain diseases, the researchers said.The researchers said the next phase of the study will sequence the genomes of different people to fully understand the diversity of human genes, their role and how we are related to our close relatives and other primates.The editors who highlight certain regions of the genome are essentially repeating themselves over and over again, including some of the most critical parts of cell division, as well as new genes that may help species adapt.In the past, all this repetition has prevented scientists from “assembling the pieces” in the right order — like a difficult jigsaw puzzle in which almost every piece is the same, leaving huge gaps in the genome map as people didn’t know which pieces went where.There is no longer anything hidden or unknown about the latest achievements, or rather, a whole new genetic treasure trove is opening up before humanity.