Like Elephants, Long-Lived Galapagos Tortoises Exhibit Duplication of Genes Related to Longevity and Cancer Suppression

Genes determine species longevity, though within a species, and particularly within our species, the estimated involvement of genetic variants in individual life expectancy is becoming ever smaller as ever more data accumulates. Nonetheless, researchers are very interested in the comparative biology of aging, the question of why long-lived species are long-lived in comparison to their closest relatives. Which of the many evolved differences tend to produce a longer life span? A longer species life span necessarily requires a lower incidence of cancer. Cancer is a numbers game: a larger body size means that there are more cells that can suffer mutation and become cancerous; a longer life allows more time for those cells to suffer mutation and become cancerous. Thus in larger and longer-lived species there must be mechanisms that either (a) lower the rate at which cancerous mutations can occur, or (b) increase the efficiency of cancer suppression mechanisms. These mechanisms are layered, ranging from those inside cells that provoke self-destruction when damage is identified, to the ability of the immune system to detect and destroy cancerous cells. Elephants are both large and long-lived, and yet have a lower risk of cancer than is the case for our species. In recent years, researchers identified that elephants have many duplicated copies of the TP53 cancer suppression gene. The protein p53 produced from this gene is involved in DNA repair, as well as induction of...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs