Comparing the DNA of great apes to treat incurable human illnesses

Barcelona (ACN).- The DNA sequencing of great apes by Catalan researcher Tomàs Marquès is taking place at Barcelona’s Biomedical Research Park. A large percentage of human, chimpanzee, gorilla and orangutan DNA is similar. The four species come from the same ancestor. However, their evolution paths diverged at some point in history. It is now precisely those differences that can help to find a cure for human illnesses deemed incurable. Marquès is leading the project. He works at the Department of Evolutionary Biology at CEXS. The project is funded by the European Union with 2 million euros provided by the programme ‘Starting Grant’. It has enabled Marquès to form a team of 6 people, working for 4 years on the ‘Primate CMV’ project.

The Starting Grant, from the European Research Council, is a “unique opportunity” for a young researcher, as nowhere in Catalonia nor in the rest of Spain is there “anything comparable” to encourage scientific research on an ambitious project, explains Marquès. His project has a four-year time frame, and in that period the team he leads will have to analyse between 20 and 30 individuals from each of the 4 species (humans, chimps, gorillas, and orangutans). “If we want to understand the human genome’s global architecture we have to understand those of chimpanzees and the other great apes”, Marquès told CNA. “We, human beings, think we are superior” but “having such a flexible genome has a cost: multiple illnesses we cannot solve because we do not know their causes”, says Marquès. Alzheimer’s is one of those with an unknown origin and with no cure. An extensive understanding of our genome could help find a cure.

The young Catalan researcher’s project consists of comparisons between the DNA chains of  the great apes “to understand what human beings were like 6, 8 or 14 million years ago” and to understand how “the genome’s architecture” evolved. “We are not as similar as we thought”, concludes Marquès, when he talks about comparing the four different species. For instance, “there is a difference of between 10% and 15% in humans and chimpanzees”. Previous genetic studies comparing both species had set the differences at only 1%, without taking into account the parts “that cannot be compared”.

Sequencing was in fact impossible before 2003. It is now possible to complete it in Barcelona’s lab in less than a day and in an entire week if we take into account the whole process of preparing and treating the samples. This is possible thanks to the collaboration between Marquès’ team and the National Centre of Genomic Analysis (CNAG), located in the same Barcelona Biomedical Research Park building, next to the Mediterranean Sea. Collaboration is vital for the project: “their computer capacity is much larger than mine”, explains Marquès. In addition to the sequencing process, the CNAG also stores all the data in its supercomputer, which can be remotely accessed.

Tomàs Marquès plans to sequence 100 different genomes in order to be able to work in depth for the next few months. In order to do so, he will have to solve “the DNA puzzle”, as “the machines offer us small pieces of the chain, made up of 100 chemical bases each”, he explains. A complete chain is formed by some 3 billion bases. The supercomputers have made it possible to solve it within a single week. After this step, the long comparison process begins.

“The investigation I’m carrying out is pioneer, but not unique”, explains Marquès. Recently, he collaborated in the sequencing of Orangutan and Neanderthal genomes, which was published in ‘Nature’. Different labs throughout the world have the same objective and this is why we need to be “efficient” and “competitive”, despite bureaucratic obstacles. “Colleagues from the time I spent in Seattle ask me how is it possible to do research in Europe”, explains Marquès referring to the time and red-tape researchers need to endure and deal with in order to get the necessary permits and funds.

However, the evolution of Science and Biomedics in Catalonia, thanks to the investments made in the last number of years, convinced him to quit Seattle. There he was pursuing his post-PhD studies at Washington University. He was finally convinced to go to Catalonia when the CNAG sequenced the entire genome of the albino gorilla ‘Snowflake’, a famous inhabitant of Barcelona zoo. “If 5 years ago someone had told me the DNA could have been entirely sequenced in Barcelona, I would not have believed it”, he concluded.