Thursday, December 11, 2008

Zebra Finches Show that Genes and Behavior is a Two-Way Street

A review published in the journal Science by three prominent biologists found that gene expression can change in response to environmental information in three species that they have studied. They believe that this points to a trend for most or all species. One of the scientists, Gene Robinson (an ironic first name) states: "there is a dynamic relationship between genes and behavior,"..."Behavior is not etched in the DNA."

One of the authors published a landmark paper in 1992 by David Clayton, therein he described how just after a zebra finch hears a song by another male of the species, the expression of a certain gene increases in the forebrain of the animal. The gene codes for a single protein which regulates the expression of many other genes. It is very likely that this regulation causes some large scale changes in the finch's brain which allows it to better respond to a potential threat in its environment.

Another example is in the hives of honey bees. Bees in the hive have different jobs to attend to and foragers tend to be the older members of the hive. It is well known that if you remove older foragers from a hive, younger bees will replace them and adopt foraging behavior. Robinson published a study in 2002 which found that foragers express a certain gene that is responsible for their behavior as well as a pheromone. When this pheromone is in low concentration, younger bees begin to express the foraging gene and begin releasing the pheromone. This feedback system keeps just the right number of foragers in the hive at all times.

More generally, the review stressed that behavior's influence on gene function is no longer new to neuroscience and is becoming a well-established idea. We will most likely discover similar patterns in most animal behavior and this is a remarkable step in our understanding of the brain. Clayton puts it figuratively: "Experience is constantly coming back in to the level of the DNA and twiddling the dials and the knobs."

Jimmy Sullivan

December 12, 2008 (week 12)


At 2:25 PM, Anonymous Anonymous said...

thats interesting that doing or seeing the behaviors has an effect on the genes. I didnt realize that it was older bees that foraged, is this beahvoir taught or do the bees just do it when new foragers are needed?

Erica Damon

At 2:53 PM, Anonymous Anonymous said...

Wow, how cool! Its a simple idea with a complex background. I think the way that bees work in general is neat, but the fact that they can sense what to do in the hive due to pheromones and genes is incredible. Thanks for posting such interesting material.

Michele Copeland

At 8:25 PM, Anonymous Anonymous said...

This is really interesting. The honey bees are extraordinary in the way the hive is set up. Did the article mention, or do you think, that these bees that become foragers at a younger age are at an disadvantage in finding food, or do you think it is all just instinct? I knew environment played a role in the expression of the phenotype, but I did not realize to what extent it could occur. Great article

Katie Cole

At 6:39 PM, Anonymous Allison Cornell said...

This article was neat because we've been learning how genes affect behavior, but this shows that it can work the other way around. The example with the bees was interesting because I actually had no idea that pheromones had other purposes other than to attract potential mates. Also, I've heard of lots of biological feedback systems within a single individual, but not within a social structure. Do other communal insects have similar feedback systems for their behaviors or duties?

~Allison Cornell (12)

At 6:36 PM, Anonymous Jen Kodela said...

Why do you think the gene in finches also allows it to better respond to threats. Can it be detrimental to the finch if it doesn't hear enough songs when it is young?

At 8:51 PM, Anonymous Anonymous said...

I can defiantly see how behavior affects their genetics. Would you agree that this can be seen in humans as well? For example, our behaviors (such as smoking) can change our genes by a physically altering the cell pathway. I'm not sure if your topic can be paralleled to this because the birds genes were being altered by a different stimulus. None the less, I'm sure they also done studies with humans where they stick someone under an MRI machine to see which part of the brain is active. Thanks for the post.

-Amanda Sceusa (12)

At 11:12 PM, Blogger Dan said...

I still find it fascinating that gene expression can change due to environmental factors. The example of the younger bees picking up foraging behaviors, do the young bees have to learn the behavior fresh? or is there observational learning as well?

~Dan Hong

At 8:14 AM, Anonymous Anonymous said...

This was a very interesting article. Its very cool what a simple trigger it takes to initiate or change gene expression. Are there other more common ways of causing gene expression? and does this change the current views on how it happens?

-Alex Jackson

At 1:07 PM, Anonymous Anonymous said...

I like your title. You said that when a zebra finch hears a song by another male zebra finch a certain gene increases in the forebrain. Does the gene multiply and become more common? Also is the expression of this gene dictated by age, season, or if they do or do not have a territory/ female, or is it expressed if any male calls?

Ada Marie Flores


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