The scientific news of the week has a protagonist close to Ecuador: George, the Solitaire. An international team of scientists has managed to sequence their entire genome from blood samples taken in 2010. The results, published in Nature Ecology and Evolution, open a valuable chest of genetic data that can explain why some animals reach advanced ages without suffering diseases such a scancer.
It is believed that tumors are very rare in turtles, highlights the work. The genome of this animal has 27,200 genes, significantly more than a human, with about22,000. 500 have been analyzed in search of those that play a role in the nine known aging factors. Among these, 12 genes have been detected that contribute to six of these factors.
The results reveal interesting connections between long-lived species that,however, are separated by millions of years of evolution. For example, the genome of George the Solitary shows a possible prominent role of the FGF19gene, the same one that also seems key in humans who have lived 100 years or more.
The ancestors of the Galapagos giant tortoises arrived in the islands from continental America about three million years ago. Compared with mammals, the George species (Chelonoidis abingdonii) developed additional copies of genesrelated to the immune system, including those that enhance the production of Tlymphocytes responsible for eliminating pathogens and cancer cells.
Theturtle’s genome also shows that other genes lost their ability to synthesizeproteins. Among them is the NLN, whose deactivation in mice increases glucoseabsorption and insulin sensitivity, a protection against diabetes, another of the most important ailments associated with age. Compared with other vertebrates, C abingdonii has also developed more copies of several genes that could protect against the appearance of tumors.
Even the giant turtle also seems to have reinforced the natural mechanisms of DNA repair, whose wear over time is a well-known marker of aging. These chelonians have developed additional copies of genes related to the protein NEIL1, which has been found in higher amounts in two other species: humans and the amazing bald mole rat, the longest rodent and one of the most cancer-resistant mammals.
At the moment this type of studies provide fundamental knowledge on the different adaptations in very diverse species to achieve greater longevity, but in the future could have a positive impact for people, says Pedro de Magalhães, aresearcher at the University of Liverpool and expert in the analysis of the genome of long-lived mammals.
If wediscover genetic adaptations that increase the longevity and resistance to cancerin these animals, it could be viable to transfer them to humans, for example with drugs that mimic the effects of these mutations or by applying genetherapy, “explains the researcher. (I)