Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How bees decide what to be

17.09.2012
Johns Hopkins researchers link reversible 'epigenetic' marks to behavior patterns

Johns Hopkins scientists report what is believed to be the first evidence that complex, reversible behavioral patterns in bees – and presumably other animals – are linked to reversible chemical tags on genes.

The scientists say what is most significant about the new study, described online September 16 in Nature Neuroscience, is that for the first time DNA methylation "tagging" has been linked to something at the behavioral level of a whole organism. On top of that, they say, the behavior in question, and its corresponding molecular changes, are reversible, which has important implications for human health.

According to Andy Feinberg, M.D., M.P.H., Gilman scholar, professor of molecular medicine and director of the Center for Epigenetics at Hopkins' Institute for Basic Biomedical Sciences, the addition of DNA methylation to genes has long been shown to play an important role in regulating gene activity in changing biological systems, like fate determination in stem cells or the creation of cancer cells. Curious about how epigenetics might contribute to behavior, he and his team studied a tried-and-true model of animal behavior: bees.

Working with bee expert Gro Amdam, Ph.D., associate professor of life sciences at Arizona State University and the Norwegian University of Life Sciences, Feinberg's epigenetics team found significant differences in DNA methylation patterns in bees that have identical genetic sequences but vastly different behavioral patterns.

Employing a method that allows the researchers to analyze the whole genome at once, dubbed CHARM (comprehensive high-throughput arrays for relative methylation), the team analyzed the location of DNA methylations in the brains of worker bees of two different "professions." All worker bees are female and, within a given hive, are all genetically identical sisters. However, they don't all do the same thing; some nurse and some forage.

Nurses are generally younger and remain in the hive to take care of the queen and her larvae. When nurses mature, they become foragers that leave the hive to gather pollen and other supplies for the hive. "Genes themselves weren't going to tell us what is responsible for the two types of behavior," Feinberg says. "But epigenetics – and how it controls genes – could."

Feinberg and Amdam started their experiment with new hives populated by bees of the same age. That removed the possibility that any differences they might find could be attributed to differences of age. "When young, age-matched bees enter a new hive, they divvy up their tasks so that the right proportion becomes nurses and foragers," explains Amdam. It is these two populations that were tested after painstakingly characterizing and marking each bee with its "professional," or behavioral, category.

Analyzing the patterns of DNA methylation in the brains of 21 nurses and 21 foragers, the team found 155 regions of DNA that had different tag patterns in the two types of bees. The genes associated with the methylation differences were mostly regulatory genes known to affect the status of other genes. "Gene sequences without these tags are like roads without stop lights – gridlock," says Feinberg.

Once they knew differences existed, they could take the next step to determine if they were permanent. "When there are too few nurses, the foragers can step in and take their places, reverting to their former practices," says Amdam. The researchers used this strategy to see whether foraging bees would maintain their foraging genetic tags when forced to start acting like nurses again. So they removed all of the nurses from their hives and waited several weeks for the hive to restore balance.

That done, the team again looked for differences in DNA methylation patterns, this time between foragers that remained foragers and those that became nurses. One hundred and seven DNA regions showed different tags between the foragers and the reverted nurses, suggesting that the epigenetic marks were not permanent but reversible and connected to the bees' behavior and the facts of life in the hive.

Dramatically, Feinberg noted, more than half of those regions had already been identified among the 155 regions that change when nurses mature into foragers. These 57 regions are likely at the heart of the different behaviors exhibited by nurses and foragers, says Amdam. "It's like one of those pictures that portray two different images depending on your angle of view," she says. "The bee genome contains images of both nurses and foragers. The tags on the DNA give the brain its coordinates so that it knows what kind of behavior to project."

The researchers say they hope their results may begin to shed light on complex behavioral issues in humans, such as learning, memory, stress response and mood disorders, which all involve interactions between genetic and epigenetic components similar to those in the study. A person's underlying genetic sequence is acted upon by epigenetic tags, which may be affected by external cues to change in ways that create stable – but reversible – behavioral patterns.

Authors on the paper include Brian Herb, Kasper Hansen, Martin Aryee, Ben Langmead, Rafael Irizarry and Andrew Feinberg from The Johns Hopkins University, and Florian Wolschin and Gro Amdam of the Norwegian University of Life Sciences and Arizona State University.

This work was funded through the NIH Director's Pioneer Award through the National Institute of Environmental Health Sciences (#DP1ES022579), the Research Council of Norway and the Pew Charitable Trust.

On the Web:

Nature Neuroscience: http://www.nature.com/neuro/index.html
Feinberg lab: http://epigenetics.jhu.edu/
Feinberg's profile: http://epigenetics.jhu.edu/?section=personnelPages&personID=2
Feinberg is awarded NIH Director's Pioneer Award: http://www.hopkinsmedicine.org/news/media/releases/nih_directors_awards
_go_to_three_johns_hopkins_scientists_for_work_that_challenges_the_status
_quo_and_speeds_translation_of_research
Amdam lab: http://amdamlab.asu.edu/

Cathy Kolf | EurekAlert!
Further information:
http://www.jhmi.edu

More articles from Life Sciences:

nachricht How molecules teeter in a laser field
18.01.2019 | Forschungsverbund Berlin

nachricht Discovery of enhanced bone growth could lead to new treatments for osteoporosis
18.01.2019 | University of California - Los Angeles

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Ten-year anniversary of the Neumayer Station III

The scientific and political community alike stress the importance of German Antarctic research

Joint Press Release from the BMBF and AWI

The Antarctic is a frigid continent south of the Antarctic Circle, where researchers are the only inhabitants. Despite the hostile conditions, here the Alfred...

Im Focus: Ultra ultrasound to transform new tech

World first experiments on sensor that may revolutionise everything from medical devices to unmanned vehicles

The new sensor - capable of detecting vibrations of living cells - may revolutionise everything from medical devices to unmanned vehicles.

Im Focus: Flying Optical Cats for Quantum Communication

Dead and alive at the same time? Researchers at the Max Planck Institute of Quantum Optics have implemented Erwin Schrödinger’s paradoxical gedanken experiment employing an entangled atom-light state.

In 1935 Erwin Schrödinger formulated a thought experiment designed to capture the paradoxical nature of quantum physics. The crucial element of this gedanken...

Im Focus: Nanocellulose for novel implants: Ears from the 3D-printer

Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.

It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:

Im Focus: Elucidating the Atomic Mechanism of Superlubricity

The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.

One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Our digital society in 2040

16.01.2019 | Event News

11th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Aachen, 3-4 April 2019

14.01.2019 | Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

 
Latest News

Additive manufacturing reflects fundamental metallurgical principles to create materials

18.01.2019 | Materials Sciences

How molecules teeter in a laser field

18.01.2019 | Life Sciences

The cytoskeleton of neurons has been found to be involved in Alzheimer's disease

18.01.2019 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>