When she's turned on, some of her genes turn off

Dec 10, 2007

When a female is attracted to a male, entire suites of genes in her brain turn on and off, show biologists from The University of Texas at Austin studying swordtail fish.

Molly Cummings and Hans Hofmann found that some genes were turned on when females found a male attractive, but a larger number of genes were turned off.

“When females were most excited—when attractive males were around—we observed the greatest down regulation [turning off] of genes,” said Cummings, assistant professor of integrative biology. “It’s possible that this could lead to a release of inhibition, a transition to being receptive to mating.”

The same genes that turned on when the females were with attractive males turned off when they were with other females and vice versa.

This is one of few studies to link changes in the expression of genes with changes in an individual’s behavior in different social situations.

Cummings and Hofmann suggest that the gene sets they studied could be involved in orchestrating mating responses in all vertebrates.

Their research appeared online December 4 in Proceedings of the Royal Society of London B.

Female swordtails are attracted to males that are large and have ornaments on their bodies, such as long tails and striking coloration.

In experiments, females were placed in the center of a tank separated into three zones for 30 minutes. When an attractive male was in one of the adjacent zones, females showed typical behaviors indicating that they had chosen the male for mating. The females were also tested with other females, with unattractive smaller males, and in empty tanks.

The researchers immediately extracted RNA from the females and used gene array technology to identify genes that were being up regulated (turned on) and down regulated (turned off) in the females’ brains.

The researchers looked at more than 3,000 genes and found that 77 were involved in the females’ mate choice behavior.

“We’ve found a number of new genes that haven’t been implicated in mating behavior before,” said Hofmann, assistant professor of integrative biology.

The genes turned on or off very quickly during the 30-minute testing period.

“What we have not appreciated until now is how dynamic the genome is,” said Hofmann. “It is constantly changing and even in a very short period of time, 10 percent of the protein-coding genome can change its activity. We now have a genomic view of these dynamic processes within a social context.”

The biologists next seek to identify specific regions in the brain where the genes are expressed. They also aim to enhance or inhibit specific genes and observe the resulting behavioral change.

“We’d like to take a female who is a ‘high preference gal’ and make her a ‘low preference gal’ and vice versa,” said Cummings.

She said that gaining a better understanding of individual expression of behavior and its underlying genetic causes can shed light on how behavior drives and maintains the evolution and diversification of species.

Source: University of Texas at Austin

Explore further: Parasite provides clues to evolution of plant diseases

add to favorites email to friend print save as pdf

Related Stories

Male sexual despots rewrite history

Feb 04, 2015

"Heredity", opined the pioneering cultural anthropologist Alfred L. Kroeber in 1915, "cannot be allowed to have acted any part in history". I have yet to encounter a crisper expression of the view that biological explanations have no place in the study of society ...

Picking up on the smell of evolution

Jan 28, 2015

UA researchers have discovered some of the changes in genes, physiology and behavior that enable a species to drastically change its lifestyle in the course of evolution.

Men want commitment when women are scarce

Jan 13, 2015

The sexual stereotype, in line with evolutionary theory, is that women want commitment and men want lots of flings. But a study of the Makushi people in Guyana shows the truth is more complex, with men more ...

Recommended for you

Parasite provides clues to evolution of plant diseases

5 minutes ago

A new study into the generalist parasite Albugo candida (A. candida), cause of white rust of brassicas, has revealed key insights into the evolution of plant diseases to aid agriculture and global food security.

Conservation organizations need to keep up with nature

1 hour ago

Nature is on the move. As the impacts of climate change reveal themselves, species and ecosystems are moving in response. This poses a fundamental challenge to conservation organizations—how do you conserve ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.