Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UMass scientist identifies gene that governs obesity, physical activity, sex behaviors in mice

10.12.2002


Findings based on ’knock-out’ mice detailed in the journal Physiology and Behavior



A team led by University of Massachusetts Amherst researcher Deborah J. Good has identified a gene that appears to play a role in obesity, physical activity, and sex behaviors in mice. Good works with so-called "knock-out" mice, which have a specific gene deleted. Scientists then monitor the animals for changes in their physiology and behavior, in an effort to determine the gene’s role. Her findings are detailed in the current issue of the journal Physiology and Behavior. The project is funded with a four-year, $1 million grant from the National Institute of Diabetes and Digestive and Kidney Diseases, and a two-year, $70,000 grant from the National Institute of Child Health and Human Development, both of the National Institutes of Health.

Good is studying the mechanisms in the brain and nervous system that regulate appetite and body weight. Although more than 20 genes have been implicated in the regulation of body weight, the mechanisms through which these genes work remain unclear, she says. Recent evidence by Good suggests that a gene called Nhlh2 plays a key role in the regulation of genes controlling body weight, as well as physical activity levels and mating behavior.


"The knock-out mice can weigh up to 100 grams or more, while most normal mice weigh 25 to 30 grams. Thus, the knock-outs are the equivalent of a 450-pound person," Good says. Two issues contribute to their obesity: the all-too-familiar diet and exercise factors. The mice eat far past what should be the point of satiety, and show a marked disinterest in running on an exercise wheel. "Most mice love to run on a little exercise wheel when you put it in their cage," notes Good, "but not these guys. They run less than other mice before they become obese. Once they do put the extra weight on, their decreased physical activity contributes to their weight gain even more than their food intake."

But these mice can legitimately blame their weight on their genes – or rather, their lack of the Nhlh2 gene. "The gene is responsible for giving them the message, ’You’re full, so stop eating,’ or ’You need to increase your activity, so get some exercise.’" Without Nhlh2, the message is sent but can’t be received on a molecular level, so their body weight continues to increase, Good explains. "It’s as if someone is sending you e-mail, but you’re not reading the message. The message has been sent, but it’s not useful."

"There are humans who have this mutation," notes Good. "If we understand the molecular mechanisms that deal with obesity, perhaps we’ll be able to develop pharmaceuticals for people whose enzyme activity is offset." She also notes that humans can be coached to increase their exercise levels and lower their food intake.

In addition, the gene deletion appears to affect sex behaviors. The knock-out mice have a smaller genital size and lower sperm counts than typical mice. In addition, they show disinterest in mating when they share a cage with a receptive female. (They are able to produce offspring through in vitro methods.) Good cautions that the findings may not be analogous in human beings, in terms of infertility. "We don’t know what would happen in humans," Good says. "There might be fertility problems, but human sex behavior is greatly affected by sociological and cultural expectations that certainly aren’t a factor among mice."

In a related project, Good is studying the molecular control of male reproduction. Although more than 16 specialized proteins are implicated in controlling fertility, the molecular mechanisms of reproduction remain unclear, Good says. She and her team are working toward understanding the molecular control of reproduction and fertility by a specific gene known as Nhlh2.


Note: Deborah Good can be reached at 413/545-5560 or goodd@vasci.umass.edu

Elizabeth Luciano | EurekAlert!
Further information:
http://www.umass.edu/

More articles from Life Sciences:

nachricht Repairing damaged hearts with self-healing heart cells
22.08.2017 | National University Health System

nachricht Biochemical 'fingerprints' reveal diabetes progression
22.08.2017 | Umea University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

Cholesterol-lowering drugs may fight infectious disease

22.08.2017 | Health and Medicine

Meter-sized single-crystal graphene growth becomes possible

22.08.2017 | Materials Sciences

Repairing damaged hearts with self-healing heart cells

22.08.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>