April 25 is celebrated as DNA Day, commemorating the discovery the DNA structure by Watson and Crick in 1953. Furthermore, this date coincides with another important milestone in the DNA history, such as April 2003, when the “Human Genome Project” was completed. Both discoveries represented a true revolution and a breaking point in the investigation of the molecular bases of genetic inheritance.
These two ephemerides are celebrated worldwide with a large number of events in which public and private scientific institutions open their doors to disseminate this molecule and its implications in our daily lives to the general public.
What is the DNA?
DNA contains the genetic information of most organisms and is made up of four units called nucleotides: Adenine (A), Guanine (G), Cytosine (C) and Thymine (T). These 4 letters alternate with each other forming long DNA sequences as if it were a pearl necklace. This combination of letters is not produced randomly but in a precise way since living beings have encoded in these 4 letters the instructions (genes) to synthesize all their proteins, the molecules in charge of controlling and executing all the processes that take place in our organism.
This information is highly valuable and living beings pamper and preserve it by storing it in the nucleus of our cells. DNA does not leave the nucleus at any time and only copies (messenger RNA) are sent in the form of individual instructions. If this sequence of letters is altered (genetic mutations), it can give place to non-functional proteins that lead in many cases to the development of hereditary diseases. Hence, the great relevance of the sequencing of the human genome, as it has unveiled the complete instruction book that is our DNA, our genome, and has been the starting point of a great revolution in biomedicine.
Advances in the study of the human genome
Since 2003, a large number of projects have been launched to unravel many other questions and enigmas that our DNA contains:
- Number of genes (genetic instructions) that exist in humans and how they are organized (ENCODE Project)
- Total variants that can be found and what effect they have on cellular processes (1000 genomes project).
- How the expression of these genes is controlled (Epigenome Project).
DNA is in our everyday lives. Genetic analyses are requested more frequently by our doctors to find out the origin of our diseases and in some cases carry out tailored therapies based on our genetic profile (personalized medicine). This diagnostic work has been facilitated by a breakthrough in DNA analysis technologies:
- The array CGH techniques (Comparative Genomic Hybridization) allow us to check if there is any region of our genome in excess or defect as it happens in some neurological diseases (ex Autism).
- Massive Sequencing (NGS) techniques allow us to sequence all our DNA in record time and identify the mutations responsible for any disease.
- Prenatal diagnostic techniques (in foetus) and preimplantation (in embryos) make it possible to identify diseases before birth, and it will even be possible to correct them in an early stage (CRISPR / Cas9 technology).
Now, not only is possible to detect DNA in the nucleus of our cells, but also circulating through the bloodstream. This new source of DNA (liquid biopsies) is being very useful for the diagnosis of cancerous processes without the need for more aggressive methods such as the supposed tumor biopsies.
International DNA Day
We are living a new era in medicine with better and more effective therapies to cure diseases and based on new DNA technologies. Hopefully they are only applied for this purpose and not used for any other purpose such as eugenics. The scientific community will ensure we don’t fall into this temptation, as it has happened at other times in our recent history.
Instituto Bernabeu, at the forefront in the application of genetic techniques in reproductive medicine, wants to join the celebration of “DNA Day” and congratulate all the researchers who from Watson and Crick have worked to unravel the mysteries of life through the study of the DNA molecule.