Researchers uncover genetic mutations that allow polar bear eating a high-fat diet without bearing the heart disease risk.
Scientists unveil the results of a thorough analysis of the genetics of polar bears on Thursday, May 8, 2014 and compare it to its closest cousin, the brown bear.
Polar bears could hold key to avoiding Heart disease. (Picture from: http://bit.ly/1mJrJDh) |
They found that since differentiate themselves from brown bears less than 500,000 years ago to be a new species, the polar bear through the remarkable genetic changes that allow them to consume high fat foods in the Arctic is very cold where they live.
Several genes related to cardiovascular function and metabolism of fatty acids has changed radically through mutations that allow them to consume high-fat menu without incurring a high risk of heart disease, the researchers said.
One important example is the change in apoB gene, which plays a role in removing cholesterol from the bloodstream and into the cells, which then lowers the risk of heart disease.
"For polar bears, being very fat is not a problem," said Eline Lorenzen, a molecular ecologist at the University of California, Berkeley, as reported by Reuters news agency.
"All of this makes sense in species that rely entirely on fat to survive," said Lorenzen. In the Arctic region where they lived, much-needed energy and polar bears have more fat tissue to produce it.
Up to half of his body fat and can be a source of fresh water they are metabolic water - water the rest of the body's breakdown of fat, Lorenzen said.
"They basically live in the polar desert," said Lorenzen. In a study published in the journal Cell, the researchers decipher the genome - the genetic blueprint - polar bears based on blood and tissue samples from 79 polar bears from Greenland. They also used a sample of 10 to study the genome of the brown bear species.
Rasmus Nielsen, evolutionary geneticist at the University of California, Berkeley, said the genetic data showed polar bears become more different from brown bears some 400,000 years ago probably, over the end of previous estimates.
Some recent estimates put the origin of the polar bear about five million years ago. "In this short time, the polar bear has adapted to the cold Arctic environment and a new diet. Adaptation we see traces of this in the genomes of polar bears," said Nielsen.
Polar bears are the largest terrestrial carnivore and most large compared to the other eight bear species. They occupy the highest point in the Arctic food chain and spent most of his life in the Arctic sea ice to hunt prey such as seals. Adult male polar bears can weigh up to about 770 kg.
Polar bears are now threatened with extinction, the total population is about 20,000 to 25,000. And climate change causes sea ice shrinkage into which they depend.
Their diet allows the formation of body fat while helping them become baffle float when swimming. But it comes with sacrifice - the level of LDL cholesterol or "bad" cholesterol and high triglycerides in the blood.
High cholesterol and triglyceride levels lead to cardiovascular disease in humans but changes in the genetic make the polar bear able to overcome that problem. *** [EKA | FROM VARIOUS SOURCES | SCIENCEDAILY]