Scientists explore the mystery of the longevity of giant tortoises

genome sequencing has helped scientists understand the size and longevity of two giant tortoises, including Lonely George, according to two papers published in the New York Post. The paper was published online in Nature - Ecology and Evolution.
"Lonely George" is the last iconic member of the now extinct Pinta Island elephant turtle in the Galapagos Islands.
, Carlos Lopez-Otín of Yale University in the United States, Adalgisa Caccone and colleagues sequenced the genomes of Lonely George and an Aldabra tortoise. The Aldabra tortoise is the only remaining species of giant tortoise in the Indian Ocean. By comparing the genomes of other close-edge species, the researchers found positive selection markers and expansion markers in gene families associated with metabolic regulation and immune response. The researchers believe these markers may be linked to the turtle's large size and longevity.
Longevity organisms theoretically face a higher risk of cancer, but the researchers found that the turtle's tumor suppressor gene expanded compared to other vertebrates, and found giant tortoise-specific changes in two genes known to cause cancer from overexpression. While these findings suggest that there may be a giant tortoise-specific cancer, tumors are rare in turtles, so further research is needed to determine whether these genomic features are associated with tumor development.
researchers say the data will help understand the biology of giant tortoises and help protect other giant tortoises in the Galapagos Islands. (Source: Tang Erdu, China Science Daily)