Although the current human genome is the most complete generated to date, it exhibits gaps in its DNA sequence and end-to-end (telomere to telomere) gaps, even after two decades of significant achievements .
To fill these gaps of ignorance, researchers at the University of California Santa Cruz resorted to a pioneering technique, developed by UC Santa Cruz itself, that allows "ultra-long readings" through so-called "nanopore sequencing."
Because a human genome is incredibly long and consists of approximately 6 billion bases, DNA sequencing machines cannot read all the bases at once. To avoid this, they cut the genome into smaller pieces, then analyze each piece to produce sequences of a few hundred bases at a time. Those shorter DNA sequences must be put back together .
Thanks to this new technique, then, we now have the complete DNA sequence of a human X chromosome, without interruptions or spaces between its telomeres and with an unprecedented level of precision , reveals a study published by the journal Nature .
This technique sequences DNA by detecting the change in the current flow of individual DNA molecules as they pass through the tiny hole (nanopore) in a membrane. The results show that it is now possible to generate a precise, base-by-base sequence of a human chromosome, and will allow researchers to produce a complete sequence of the human genome .
Of the 24 human chromosomes (including X and Y), the study authors chose to complete the X chromosome sequence first because they are most linked to many diseases, such as hemophilia.