Scientists at the University of Gothenburg have shown how sea squirts can activate the enzyme telomerase, which protects DNA. These organisms, and others that reproduce asexually by cloning have mechanisms that delay aging while providing exceptionally good health.
“Animals that clone themselves, in which part of an individual’s body is passes on to the next generations, have particularly interesting conditions related to remaining in good health to persist. This makes it useful to study these animals in order to understand mechanisms of aging in humans,” says Helen Nilsson Sköld of the Department of Marine Ecology, University of Gothenburg.
The lifespans of species on Earth range from a number of hours to thousands of years. There are some deep-sea corals that are tens of thousands of years old. Some plants and animals that reproduce asexually can surpass thousands of years and essentially achieve eternal life.
Helen Nilsson Sköld chose to study sea squirts and starfish because their genesare strikingly similar to those of humans.
“My research has shown that sea squirts rejuvenate themselves by activating the enzyme telomerase, and in this way extending their chromosomes and protecting their DNA,” explains Sköld. “They also have a special ability to discard ‘junk’ from their cells. Older parts of the animal are quite simply broken down, and are then partially recycled when new and healthy parts grow out from the adult bodies.”
Some starfish reproduce asexually by tearing apart their bodies, and some are only capable of reproducing sexually. Both types can regenerate lost body parts, but those that reproduce asexually have considerably better health.
The biggest problem with this method of reproduction is that there is very little genetic variation in the population. This makes them extremely vulnerable to environmental changes, disease and other problems. If climate change damages these plants and animals, we will lose an important source of knowledge about “the riddle of aging.”
Copyright © 2011 by Marine Science Today, a publication of OceanLines LLC