The human genome has been sequenced from A to Z for the very first time

In 2003, research was changed forever by the very first sequencing of the human genome. A resounding scientific feat, and the culmination of a long series of founding works… or almost, because we now know that our genome still contained gray areas. But a team of researchers has just put a spotlight on these to produce what they describe as “the first truly complete sequencing of the human genome”.

In this work published in the prestigious journal Science, the researchers describe a process that allowed them to cover the entire genome from end to end, from the first to the last chromosome, and without leaving the slightest molecule to chance. “Since the first sequencing draft was done, determining the exact sequence of complex regions of the genome has been a big challenge.“, explains Evan Eichler, professor of medicine at the Washington School of Medicine.

It took until our time for sequencing techniques to advance sufficiently to achieve this; and they finally became complete and precise enough to spot a needle in this huge biochemical haystack. The efforts of researchers at the University of California have thus made it possible to identify 200 million base pairs A, T, G or C.

New information on 622 “medically relevant genes“

It is a small revolution in itself, since our knowledge of the human genome has direct implications in all aspects of medicine. This study also gives more precise information on 622 genes designated as “medically relevant” by the researchers. It is safe to say that this work is likely to improve our understanding of human evolution and health.

“Generating a truly complete sequencing of the human genome is an incredible scientific achievement,” says Eric Green, professor of genetics involved in the Human Genome Project. “This fundamental information will bolster the many efforts that attempt to understand all the functional nuances of the human genome, which in turn will fuel genetic studies of human diseases.“, he specifies.

“It’s like putting on a new pair of glasses”, adds Adam Philippy, a bioinformatician also affiliated with the research institute of the Human Genome Project. “Now that we can see everything in detail, we are closer and closer to understanding how it all works!”, he enthuses.

A new look at hard-to-reach objects

The other particularly interesting aspect is directly related to where they discovered that famous missing 8%. The majority of the material was located in two very specific regions of the chromosomes: the centromeres (the dense central region of the “cross” that a chromosome forms during cell division), and telomeres. We can very briefly liken them to caps that cover and protect the ends of the chromosomes, these balls of DNA cleverly folded to store our genome.

The fact of having been able to completely sequence these regions will probably change many things in the study of our genetic heritage. Indeed, there are many particularly important genetic and physiological phenomena whose keys are probably hidden in these parts of the chromosomes.

For example, numerous works suggest that several keys to the mechanisms of aging are hidden in the telomeres. One day, new elements could therefore contribute to producing treatments aimed at slowing down or even reversing aging, as Jeff Bezos wishes to do.

But the most interesting thing is that it may be an additional fresh start. By exploring the new genetic regions mapped in this way, researchers could well identify other fundamental mechanisms, essential in the mechanics of the genome. If necessary, this would once again make it possible to resume all this work with a new perspective, a bit like researchers did when genomics appeared, with potential new advances at stake.

“In the future, when someone has their genome sequenced, they will be able to identify all the variations in their DNA and use this information to take care of their health.“, concludes Adam Phillippy, one of the heads of the Human Genome Research Institute.