'Tanned' whales' sun response gives clues to human ageing

The way that whales react to sunlight can shed new light on the human ageing process, say researchers.

Some species react by getting darker with UV exposure in the same way as humans get a tan.

Others though, protect from themselves from sun burn by turning genes on and off.

The work, which is published in the journal Scientific Reports, could lead to new anti-ageing treatments in humans.

For several years now, marine biologists in Mexico have noticed an increasing number of whales in the region with blistered skin as a result of exposure to UV light.

“The sunburnt DNA we find in whales is the same sunburnt DNA we find in humans and that is definitely linked to ageing,” Prof Mark Birch-MachinNewcastle University

Over a three-year period researchers took skin samples from three different species of whales during their annual spring migration, when they move to the sunnier waters of the Gulf of California.

Warmer Blue

The scientists found the different species reacted differently to the increase in sunlight.

Blue whales are the biggest creatures ever to have lived on Earth, and they respond to the Sun by increasing the amount of pigment in their skin, just like humans.

"When blue whales go on their holidays to the Gulf of California they get a tan the same way we do," Prof Mark Birch-Machin from Newcastle University told BBC News.

"And that tan protects blue whales from sunburnt DNA."

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'Selfish' DNA in Animal Mitochondria Offers Possible Tool to Study Aging

ScienceDaily (Aug. 9, 2012) — Researchers at Oregon State University have discovered, for the first time in any animal species, a type of "selfish" mitochondrial DNA that is actually hurting the organism and lessening its chance to survive -- and bears a strong similarity to some damage done to human cells as they age.

The findings, just published in the journal PLoS One, are a biological oddity previously unknown in animals. But they may also provide an important new tool to study human aging, scientists said.

Such selfish mitochondrial DNA has been found before in plants, but not animals. In this case, the discovery was made almost by accident during some genetic research being done on a nematode, Caenorhabditis briggsae -- a type of small roundworm.

"We weren't even looking for this when we found it, at first we thought it must be a laboratory error," said Dee Denver, an OSU associate professor of zoology. "Selfish DNA is not supposed to be found in animals. But it could turn out to be fairly important as a new genetic model to study the type of mitochondrial decay that is associated with human aging."

DNA is the material that holds the basic genetic code for living organisms, and through complex biological processes guides beneficial cellular functions. Some of it is also found in the mitochondria, or energy-producing "powerhouse" of cells, which at one point in evolution was separate from the other DNA.

Continued:  http://www.sciencedaily.com/releases/2012/08/120810112917.htm