New study is part of a broader genomic research program aimed at understanding what makes a polar bear a polar bear
A male polar bear. Credit: U.S. Geological Survey, Steven C. Amstrup
In the winter, brown and black bears go into hibernation to conserve energy and keep warm.
But things are different for their Arctic relative, the polar bear. Within this high-latitude species, only pregnant females den up for the colder months.
So how do the rest survive the extreme Arctic winters?
New research points to one potential answer: genetic adaptations related to the production of nitric oxide, a compound that cells use to help convert nutrients from food into energy or heat.
In a new study, a team led by the University at Buffalo reports that genes controlling nitric oxide production in the polar bear genome contain genetic differences from comparable genes in brown and black bears.
“With all the changes in the global climate, it becomes more relevant to look into what sorts of adaptations exist in organisms that live in these high-latitude environments,” said lead researcher Charlotte Lindqvist, PhD, UB assistant professor of biological sciences.
“This study provides one little window into some of these adaptations,” she said. “Gene functions that had to do with nitric oxide production seemed to be more enriched in the polar bear than in the brown bears and black bears. There were more unique variants in polar bear genes than in those of the other species.”
The paper, titled “Polar Bears Exhibit Genome-Wide Signatures of Bioenergetic Adaptation to Life in the Arctic Environment,” appeared Feb. 6 in the journal Genome Biology and Evolution.
Co-authors include scientists from UB, Penn State University, the U.S. Geological Survey Alaska Science Center, Durham University and the University of California, Santa Cruz.
The genetic adaptations the research team saw are important because of the crucial role that nitric oxide plays in energy metabolism.
Typically, cells transform nutrients into energy. However, there is a phenomenon called adaptive or non-shivering thermogenesis, where the cells will produce heat instead of energy in response to a particular diet or environmental conditions.
Levels of nitric oxide production may be a key switch triggering how much heat or energy is produced as cells metabolize nutrients, or how much of the nutrients is stored as fat, Lindqvist said.
“At high levels, nitric oxide may inhibit energy production,” said Durham University’s Andreanna Welch, PhD, first author and a former postdoctoral researcher at UB with Lindqvist. “At more moderate levels, however, it may be more of a tinkering, where nitric oxide is involved in determining whether — and when — energy or heat is produced.”
The research is part of a larger research program devoted to understanding how the polar bear has adapted to the harsh Arctic environment, Lindqvist said.
In 2012, she and colleagues reported sequencing the genomes of multiple brown bears, black bears and polar bears.
In a paper in the Proceedings of the National Academy of Sciences, the team said comparative studies between the DNA of the three species uncovered some distinctive polar bear traits, such as genetic differences that may affect the function of proteins involved in the metabolism of fat — a process that’s very important for insulation.
In the new study, the scientists looked at the mitochondrial and nuclear genomes of 23 polar bears, three brown bears and a black bear.
The research was funded by the University at Buffalo and the National Fish and Wildlife Foundation.
Media Contact InformationCharlotte Hsu
Charlotte Hsu | EurekAlert!
Severity of enzyme deficiency central to favism
26.07.2016 | Universität Zürich
From vision to hand action
26.07.2016 | Deutsches Primatenzentrum GmbH - Leibniz-Institut für Primatenforschung
Transparent electronics devices are present in today’s thin film displays, solar cells, and touchscreens. The future will bring flexible versions of such devices. Their production requires printable materials that are transparent and remain highly conductive even when deformed. Researchers at INM – Leibniz Institute for New Materials have combined a new self-assembling nano ink with an imprint process to create flexible conductive grids with a resolution below one micrometer.
To print the grids, an ink of gold nanowires is applied to a substrate. A structured stamp is pressed on the substrate and forces the ink into a pattern. “The...
A new Fraunhofer MEVIS method conveys medical interrelationships quickly and intuitively with innovative visualization technology
On the monitor, a brain spins slowly and can be examined from every angle. Suddenly, some sections start glowing, first on the side and then the entire back of...
Researchers at the U.S. Department of Energy's (DOE) Ames Laboratory have discovered an unusual property of purple bronze that may point to new ways to achieve high temperature superconductivity.
While studying purple bronze, a molybdenum oxide, researchers discovered an unconventional charge density wave on its surface.
Munich Physicists have developed a novel electron microscope that can visualize electromagnetic fields oscillating at frequencies of billions of cycles per second.
Temporally varying electromagnetic fields are the driving force behind the whole of electronics. Their polarities can change at mind-bogglingly fast rates, and...
Breakup of continents with two speed: Continents initially stretch very slowly along the future splitting zone, but then move apart very quickly before the onset of rupture. The final speed can be up to 20 times faster than in the first, slow extension phase.phases
Present-day continents were shaped hundreds of millions of years ago as the supercontinent Pangaea broke apart. Derived from Pangaea’s main fragments Gondwana...
15.07.2016 | Event News
15.07.2016 | Event News
11.07.2016 | Event News
26.07.2016 | Information Technology
26.07.2016 | Health and Medicine
26.07.2016 | Physics and Astronomy