Polar Bears study may boost fight against obesity

An international study involving scientists in Ireland has found the genetic make-up of polar bears could help provide solutions to the global problem of obesity in humans.

The research, the most comprehensive genomic study of polar bears ever undertaken, also revealed that the species is considerably younger than previously thought. The research began with a team of scientists from Denmark taking samples from 79 polar bears in Greenland, northern Russia and Alaska and a further ten brown bears.

The samples were then used by scientists at the Beijing Genomics Institute in China to produce the genomes or genetic code of the bears.

That data was then analysed by researchers in California, NUI Maynooth and Dublin City University, who have an interest in the genetics of animals and organisms that live in extreme environments.

The results are published in the current edition of the leading international journal Cell.

The scientists were particularly interested in understanding how it was that polar bears could eat such a fat-laden diet, without suffering from cardiovascular problems like humans do.  Polar bears live on blubber and 50% of their bodies are made up of fat.  Their analysis found mutations in genes involved in fat metabolism that make them look radically different from similar genes in other species.

One consequence of their findings is that it could help scientists and doctors better understand how humans could manage fat levels in their bodies.

According to Professor James McInerney, co-director of the Bioinformatics and Molecular Evolution Unit at NUI Maynooth, if we can understand how polar bears stay healthy and protected from heart disease, despite such a high fat and cholesterol diet, we could get insights into developing protection in a human system.

Dr Mary O'Connell, principal investigator at the Department of Biotechnology at Dublin City University, said such in-depth analysis of the genomes of different extreme species could in future help us to answer questions about many topics, including diseases, longevity and ageing.  This is because the genetic make-up of different organisms can be compared to one another, to see what makes them look and behave differently.

The research will also assist in the overall understanding of the popular species in the face of the growing threat of climate change.  There are currently around 25,000 polar bears left, and the species is considered vulnerable to possible extinction in the future.

View full article here: Population Genomics Reveal Recent Speciation and Rapid Evolutionary Adaptation in Polar Bears

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Tiny motors controlled inside human cell

For the first time, scientists have placed tiny motors inside living human cells and steered them magnetically.

The advance represents another step towards molecular machines that can be used, for example, to release drugs into specific locations within the body.

There is interest in the approach because it could enhance the benefits of drugs while minimising side effects.

The rocket-shaped metal particles were propelled using ultrasound pulses.

Materials scientist Prof Tom Mallouk, from Penn State University, and colleagues have published their research in the journal Angewandte Chemie International Edition.

Up until now, nanomotors have been studied only "in vitro" - in laboratory apparatus - but not in living human cells.

At low ultrasonic power, the nanomotors had little effect on these cells. But when the power was increased, the nanomotors surged into action, zooming around and bumping into organelles - structures within the cell that perform specific functions.

The nanomotors could be used as "egg beaters" to essentially homogenise the cell's contents, or act as battering rams to puncture the cell membrane.

"We might be able to use nanomotors to treat cancer and other diseases by mechanically manipulating cells from the inside," said Prof Mallouk.

In addition, he said: "Nanomotors could perform intracellular surgery and deliver drugs non-invasively to living tissues."

View more information here

Are you a lark or an owl?

Whether you prefer being up at dawn or burning the midnight oil depends on your genes, experts have found.

Some of us leap out of bed each morning, raring to start the day. Others need at least one alarm clock - preferably one with a snooze button - to ensure they get to work on time.

And some of us happily stay up chatting until the wee small hours, while others prefer to be tucked up listening to 'Book at Bedtime' with the lights turned out.

We really are divided into larks and owls. And this is set by our genes, says neurogeneticist Dr Louis Ptacek of University of California.

He says: "Whether we like it or not our parents are telling us when to go to bed - based on the genes that they gave us."

Scientists have come to realise the importance of understanding a person's chronotype, the time of the day when they function the best.  Knowing how much of a lark or an owl we are should help us live more healthily in the modern 24/7 world.

The results have been published recently in the January 12 issue of Cell  -  click on title below:

Modeling of a Human Circadian Mutation Yields Insights into Clock Regulation by PER2

View article on BBC News/Health