An international team of scientists claims to have reconstructed the entire human genome, closing the gap of missing sections left out when the first human genome was sequenced 20 years ago, according to a preprint study shared late in May.
In 2000, leaders from the Human Genome Project and Celera Genomics announced they had sequenced the first human genome from the White House lawn. But if this latest claim is confirmed as true, the remaining 8% of the human genome has officially been mapped, and we finally know, to the most basic genetic precision, what we're made of.
New DNA sequencing results are 'a technical tour de force'
Assuming this is for real, the gap in our grasp of human genes was filled with new technology, but the new tech has its own limitations. For example, the kind of cell line employed to hasten the mapping process. "You're just trying to dig into this final unknown of the human genome," said Karen Miga, a researcher at the University of California, Santa Cruz, who was one of the leaders of the international group working to sequence the entire human genome, in a Stat News report. "It's just never been done before and the reason it hasn't been done before is because it's hard." Miga stressed that she isn't going official with the paper until it receives peer-review and is published in a legitimate medical journal.
However, assuming the findings are correct, this is a substantial advancement in genetics, which was made possible via new DNA sequencing tech developed by two private firms: Oxford Nanopore, in Oxford Science Park, U.K., and Pacific Biosciences of Menlo Park, California. The two companies' technology possesses minute but crucial advantages over conventional tools of the last several decades. Deputy Director-General of the European Molecular Biology Laboratory said the results were "a technical tour de force," according to the Stat News report. The initial genome studies were cautious, since no single sequencing process worked through the entire DNA molecule, added Birney.
Closing even minor gaps in DNA can open the door to the regulation process of genes
"What this group has done is show that they can do it end-to-end," explained Birney. This opens the door to more research, because, (if confirmed) scientists have proof that the entire DNA molecule can successfully be sequenced. But while this could serve to incentivize genetic research, the question remains: Is this "missing link" of the genetic code really that important? The international group said it had increased the number of DNA bases to 3.05 billion, from 2.92 billion, a jump of 4.5%. By contrast, the new number of genes that code proteins grew to 19,969, a rise of only 0.4%. While this might be a let-down, it could also bring other scientists closer to further discoveries, including uncovering the regulation process of genes.
Notably, the DNA sequence used for the study wasn't taken from a person, but from a growth in a woman's uterus called a hydatidiform mole, which happens when sperm fertilize an egg that lacked a nucleus. This leaves the cell with two copies of the same 23 chromosomes, instead of two distinct sets (which is what typical human cells have). There's much to explore in this new technology, and the substantial progress we've seen in DNA sequencing technology in the last 20 years. And if this study checks out, we are living in one of the most exciting moments in the history of science (although, it's pretty clear that we already were).