The Telomere to Telomere (T2T) consortium has unveiled the most complete reference human genome to date, T2T-CHM13, filling in some of the unresolved DNA sequences in previous attempts to sequence the genome of our species. This reference genome paves the way to study the origin of some diseases, describe which areas determine human traits and better understand what makes one individual different from another.
The genome that was considered complete 20 years ago was not
Twenty-one years ago, Celera Genomics and the Human Genome Project (HGP) published two initial versions of the complete sequence of the DNA found in the nucleus of our cells. This genome was the reference map on which to investigate genes, diseases and traits between humans, and in comparison with other species, or with our ancestors. However, it accumulated many errors, and although it was announced as complete at the time, in reality there were dark or unrevealed areas that could not be unraveled due to technological limitations.
Today those dark areas are illuminated and the most complete reference human genome is published, which not only reveals those sequences that had not been able to be distinguished, but also relates some of them to areas of the chromosomes that are of vital importance at the time to share the genetic material when a cell divides in two, duplicates and transfers the material to its two daughter cells. This process happens constantly as we grow, live and our tissues regenerate under normal or healthy conditions.
From the head of the first chromosome to the foot of the last
The reference genome, called T2T-CHM13, is the result of the work of several research teams from the Telomere to Telomere (T2T) consortium, which expresses "from the head of the first chromosome to the feet of the last" , and has just been published in Science .
“This new human reference is poised to have its own substantial impact on genome analysis and represents an important step toward models that represent all humans, which will better support personalized medicine, population genome analysis and editing. of the genome,” explains genomics researcher Deanna Church in Science .
Regions associated with neurodevelopmental disorders have been identified
The new reference genome presented has used DNA from human hydatidiform mole cells, a group of embryonic cells that do not reach term, characteristic of molar pregnancies. The use of these cells has made it possible to achieve a more complete genome than that previously sequenced using other cells, and lays the foundation for future research, but it has one limitation: it has not allowed the Y chromosome to be sequenced.
One of the most relevant parts of the T2T work is a type of complex and long regions related to neurodevelopmental disorders. For Church, despite having a complete assembly of the human genome as a reference that facilitates the analysis of important regions to investigate in biomedicine, “it is insufficient to represent the entire diversity of the human population […] but it establishes the framework to obtain more information on diversity at the population and individual level”, comments the researcher.
0 Comments