Skip to content

Researchers state they have discovered the sixth DNA base in eukaryotes.

DNA (deoxyribonucleic acid) is the main component of human genetic material. It is formed by combining four parts known as Adenine (A), Cytosine (C), Guanine (G) and Thymine (T) respectively.  These ‘parts’ are called bases of DNA and they combine in thousands of possible sequences to provide genetic variability.  In the early 80s, a fifth base was added to the four classic bases of DNA.  This new fifth base, methyl-cytosine, is derived from cytosine and is recognized as the main cause of epigenetic mechanisms.

Not only is methyl-cytosine able to switch genes on or off depending on the physiological needs of each tissue, in recent years interest has increased in the is base, with methyl-cytosine mutations linked to the development of many human diseases, including cancer.

Now, researchers from the Institut d’Investigació Biomèdica de Bellvitge (IDIBELL) and the University of Barcelona describe the possibility of the existence of a sixth DNA base, methyl-adenine, which also helps to determine the epigenome and would therefore be key in the life of the cells.

The team explain that it has long been known that certain bacteria have methyl-adenine in their genome with a protective function against the insertion of genetic material from other organisms. But it was believed that this was a phenomenon of primitive cells and it was very static.

However, three new papers suggest that more complex cells called eukaryotes which make up the human body, also present the sixth DNA base. These studies suggest that algae, worms and flies possess methyl-adenine which acts to regulate the expression of certain genes, thus constituting a new epigenetic tag or mark.

Eukaryotic cells have an organized nucleus with a nuclear envelope, explain the team. They have a ‘brain’ for the cell. They have a discreet area where they keep their DNA. It is also said that they have a ‘true nucleus’.  Eukaryotic cells usually have organelles. They might have mitochondria, maybe a chloroplast, or some endoplasmic reticulum. They have parts that work to make the cell a self-sufficient organism.  All multicellular organisms are eukaryotes, including humans, animals, plants and fungi.

This team state that these results have been made possible thanks to the development of analytical methods with high sensitivity because levels of methyl-adenine in the mapped genomes are low. In addition, the data findings show that methyl-adenine also plays a specific role in stem cells and early stages of development.

The researchers plan to confirm this data and find out whether humans have this sixth DNA base, whilst mapping the exact role of methyl-adenine within the human genome.

Source:  Institut d’Investigació Biomèdica de Bellvitge

Discovered the sixth DNA base - healthinnovations

Healthinnovations View All

Michelle Petersen is the founder of Healthinnovations, having worked in the health and science industry for over 21 years, which includes tenure within the NHS and Oxford University. Healthinnovations is a publication that has reported on, influenced, and researched current and future innovations in health for the past decade.

Michelle has been picked up as an expert writer for Informa publisher’s Clinical Trials community, as well as being listed as a blog source by the world’s leading medical journals, including the acclaimed Nature-Springer journal series.

Healthinnovations is currently indexed by the trusted Altmetric and PlumX metrics systems, respectively, as a blog source for published research globally. Healthinnovations is also featured in the world-renowned BioPortfolio,, the life science, pharmaceutical and healthcare portal.

Most recently the Texas A&M University covered The Top 10 Healthinnovations series on their site with distinguished Professor Stephen Maren calling the inclusion of himself and his team on the list a reflection of “the hard work and dedication of my students and trainees”.

Michelle Petersen’s copy was used in the highly successful marketing campaign for the mega-hit film ‘Jumanji: The Next Level, starring Jack Black, Karen Gilian, Kevin Hart and Dwayne ‘The Rock’ Johnson. Michelle Petersen’s copywriting was part of the film’s coverage by the Republic TV network. Republic TV is the most-watched English language TV channel in India since its inception in 2017.

An avid campaigner in the fight against child sex abuse and trafficking, Michelle is a passionate humanist striving for a better quality of life for all humans by helping to provide traction for new technologies and techniques within healthcare.

Leave a Reply

Translate »